Can you believe it? That this channel has been going for six whole years. I can't either, but well thank you for keeping coming back every year. So this is the usual annual omnibus of pretty much every video from October last year to October this year. I can't believe how long this one actually is and it's uh well at the time of recording this voiceover part it's currently at 18 hours although I reckon it's actually going to be longer by the time I finish rendering it. Anyway thank you for six years and let's hope for a couple more years or maybe six more. I hope you enjoy this massively long amount of me talking. It is the 4th of January 1986 and 26 year old James Harrison is working at the Sequoia Fuels Corporation site in a scrubber building. He begins coughing little does he know that he has inhaled a deadly cocktail of hydrofluoric acid. An alarm is heard and he escapes the building but the chemicals he had ingested will prove to be fatal. The building he was working in was 15 meters away from a ruptured tank which held uranium hexafluoride a compound used in the enrichment of uranium for the nuclear industry. The event would release 29,500 pounds of material into the atmosphere and would expose and hospitalize many workers. It would not be the first time but Operator Kermige would be entangled in a nuclear controversy with the Karen Silkwood scandal in the late 1970s and it would not be the last. As like many similar events the release would be the result of improper management, multiple shift changeovers and product handling issues. Sadly the working-class employees would pay the price. As such I'm going to rate this disaster here five on my disaster scale but only three on my legacy scale due to the event being quickly forgotten because of another bigger disaster in 1986. The road to 1986 started back in 1968 with Kermige breaking ground on a new uranium processing plant. The site is near the town of Gore, Vian and Webber Falls in eastern Oklahoma not far from Interstate 40. The site was intended to be used to convert yellow cake into gaseous uranium hexafluoride and was licensed as a fuel cycle facility regulated by the Nuclear Regulatory Commission operated under Kermige Nuclear Corporation. Production started on site in April 1970 with a conversion capacity of 4550 metric tons of uranium per year working 24 hours a day with a four shift pattern. This subsidiary split into two companies in the early 1980s in which one of them, Sequoia Fuels Corporation, would be responsible for owning and operating the site. The process in its most basic explanation is yellow cake in uranium hexafluoride out but we will want to have a look in a little more detail. Uranium concentrate is weighed, sampled and indigested using nitric acid to produce uranium nitrate which then undergoes a solvent extraction process where impurities are removed from the product. The impure uranium nitrate solution enters at one end of the solvent extraction circuit while a mixture of organic solvents that have the ability to absorb uranium enters at the other. Passing encounter currents past each other the two solutions enter six stages of mixing and setting where the uranium is extracted from the solution and the impurities remain in the acid. The baron acid solution is neutralized and is further processed to remove radioactive uranium daughter products such as radium which are then stored on site as a sludge. The process raffinate which is virtually free of radioactivity is then stored on site in holding ponds to be reduced by evaporation. The solvent extraction solution containing the purified uranium is re-extracted into water in a countercurrent pulse column and enters an evaporation and boil down process. Evaporation concentrates the weak uranium nitrate solution into molten uranium nitrate hexahydrate or UNH. This intermediate form of uranium is then converted by thermal decomposition to uranium trioxide in a denitration process. Burnesses heat the denitrator troughs which are equipped with agitator arms that constantly stir the UNH. The U03 drawn from the denitrator troughs is shaped into orange colored pellets measuring about a millimeter in diameter. Grinding pulverizes these pellets into a fine powder. The powder is reacted with hydrogen in a two-stage counterflow fluid bed reactor to produce U02 as a powder. This powder is then put into a two-stage stir bed reactor also with a countercurrent flow. Hydrogen fluoride is added and the U02 is converted into uranium tetrafluoride. The uranium tetrafluoride is then transferred to a tower reactor where reaction with elemental fluoride creates the final product. To solidify the UF6 it is sent to coal traps. It is then heated again to turn into a liquid for pumping into storage tanks. Once inside the UF6 solidifies as it cools down to room temperature. These tanks are rolled around on carts running on tracks. The cart and tank before filling are rolled onto a set of scales. It will be kept here throughout the filling process to measure the net weight. Stopping the filling of the cylinders on site is done manually by operators and there is no automatic cutoff. During filling via a flexible pigtail line UF6 is kept at a temperature of around 210 degrees Fahrenheit. It can take several eight-hour shifts to fully fill a tank and all of this is dependent on the production rate on site. After filling the tank's valve is closed and the hose is removed and the product is moved via forklift to a steam chest which is used to keep the UF6 in liquid form. Cylinder number E2047 a model 48Y tank passed a 20-point inspection in October 1985. This was intended to find any damage to the valve or welds on the unit and is conducted by an experienced and licensed engineer.  The body is approximately 117 inches long with an inside diameter of 48 inches. In total the empty weight of such a container is 5,200 pounds and is not allowed to exceed a net weight of 27,500 pounds. The same inspection is undertaken by shift manager before any filling takes place which is exactly what happened on the 3rd of January 1986 at 10 a.m. Filling would initially take place at two different traps providing 1230 and 10,000 pounds of UF6 during the morning shift. During the evening shift a further 12,200 pounds are added bringing up the net weight to 23,430 pounds. Next came the midnight shift. As part of the handover the operator was informed that he would be continuing to fill the tank. The operator is to fill the tank to the target weight of 27,500 pounds. But he notices something strange when the scales won't go above 26,400 pounds. After investigation the operator notices that one of the cylinder's cart wheels aren't completely on the scales. This is a problem as the weight is not being properly measured. After several attempts to move the cart eventually he manages to get a new reading on the scales which can only show a maximum of 30,000 pounds. The operator is shocked to find that he is reading 29,500 pounds in effect bottoming out. Worried the operator consults his supervisor who suggests using vacuum from the previously emptied coal traps to remove the excess weight. The evacuation begins at 6.15 a.m. and initially around 150 pounds are removed in a space of 10 minutes. At the end of his shift he reports to the relieving operator of the overfill due to the cart being off the scales. As the day shift went on the operator who ironically was the one who initiated the filling the day before noted that no more product was being evacuated. As we saw before once the uf6 reaches room temperature it begins to solidify. The assistant supervisor and the operator then decided to move the tank into a steam chest. The placing of an overfilled tank into a steam chest is a direct violation of company policy. At around 11.30 a.m the tank ruptured after 2015 minutes of heating. The force of the explosion damaged the top of the steam chest. The uf6 vaporized and combined with moisture in the steam chest released a highly acidic gas. This deadly chemical made its way into the facility ventilation system. It was here that James Harrison inhaled the acidic gas. The plume left the plant had traveled 29 kilometers due to a strong wind heading south past the I-40 and over several sparsely populated residential areas. The vapor entered the ventilation intake vents of the process building injuring the employees within. Most of the approximately 40 workers on site at the time were in the lunchroom. Upon realizing the danger many escaped but had to pass through the cloud. The evacuation alarm was sent and the ventilation system was switched off. The rendezvous point for the site workers was luckily upwind where they observed the release for a further 40 minutes. The company didn't really have an emergency plan but the Gore Police Department was called and they notified the Sequoia County Sheriff's Department and Oklahoma Highway Patrol to close down the I-40 and Highway 10. Harrison was driven 13 kilometers to a nursing home for a canister of oxygen before he was taken to Sequoia Memorial Hospital. However upon reaching the hospital it was discovered that he was ill-equipped for treating Harrison and sent him to the larger Sparks Regional Medical Center in Fort Smith, Arkansas another 34 kilometers away. He would die at 3 p.m soon after arriving at the emergency room. The fatality was a result of the company not having an adequate emergency plan arrangement with local hospitals. In total 100 people were sent to hospital with 21 severely injured. Most of the contamination was within the boundary site. In total around three curries of radiation was released. In comparison Three Mile Island released over four times that at 13 curries. During the investigation it was found that the cylinder was not defective but instead succumbed to the extreme pressure caused by an overfilled container being heated and the UF6 expanding past the point of no return. The site after cleanup would continue to operate until 1993 but it would see another release in 1992. This coupled with storage ponds leaking into the ground meant that the site would need a long time to be fully decommissioned The incident didn't stir much in the media as you would have thought but luckily for Kermah Guy but just a few months later Chernobyl would happen. This video is a plain difficult production. All videos on the channel were Creative Commons Attribution Share like licensed. Plain Difficult Videos are produced by me, John, in a sunny south-eastern corner of London, UK. Help the channel grow by liking, commenting and subscribing. Check out my Twitter for all sorts of photos and odds and sods as well as hints on future videos. I've got Patreon and YouTube membership as well so if you fancy check them out to support the channel financially. And all that's left to say is thank you for watching. Approaching a terminus platform is one of the most important parts of a train driver's duties. This is because usually at the end of the line there is a wall, buffer stops or sand drag. Even at low speed a collision with a solid object can be pretty catastrophic. The reason is pretty simple. A big heavy object like a train stopping, hitting something, transfers all the momentum to the vehicle's occupants and even a collision at a few miles an hour can result in damage and injuries. An accident in 1975 would make London Underground completely rethink how it protects trains approaching terminus platforms. Resulting in an addition to the signalling system which would take the name of the tragedy Moorgate. Before the days of transmission based train control was implemented on the northern line, drivers were taught during manual handling Moorgate more break. But today's video isn't about the northern line platforms that you can visit today but instead platforms 9 and 10 which form parts of the route called the north city line. This short route between Moorgate and Drayton Park has had a number of operators since its 1904 opening and was under the control of London Transport up until 1976. The line when opened by the great northern and city railway ran from Moorgate to Thinsbury Park low level and was pretty much isolated from the rest of the rail network. It was built using a similar construction method to the city in south London line. This gave the tunnels a similar look to the deep level tube lines like the Bakaloo, Central, Piccadilly, Northern and Waterloo city lines but with one exception. That was the tunnel diameter. On your standard deep level line the tunnel loading gauge is around 12 feet but the new northern city line was built to accommodate mainline stock and as such it was built to a larger 16 feet loading gauge. During construction the route was originally planned to run beyond Moorgate to proposed Loughbury station. These plans were abandoned but a small runoff tunnel had been constructed which would house a sand drag. The line was never very profitable which led to being taken over by the Metropolitan Railway, the pre-runner to the Metropolitan line in 1913. After the formation of the London passenger transport board in 1933 the Metropolitan was lumped in with the other underground railways and the line was rebranded as the northern city line. In 1934 it was then re-rebranded as part of the Edgeware Morden line which was in itself renamed the northern line in 1937. Eventually in 1939 operations were transferred from the Metropolitan to the northern. The inclusion into the northern line formed part of the failed northern heights project. I'm not going to cover this here but I do know someone who has done a video on the subject. In 1964 the northern city line was cut back from Thinsbury park to Drayton park with its former platforms becoming part of the Piccadilly and the then new Victoria line to allow cross platform interchange. And this would form the final chapter of the line's London underground operation and you guessed it this came hand in hand with another rebranding to the northern line Highbury branch. This meant that passengers wanting to travel from Thinsbury park to Moorgate would have to travel on the Victoria line to Highbury in Islington and then change to the northern city line. Moorgate Platform 9 had a sand drag heaped up to about two feet above the rail level. Beyond this was a defunct hydraulic buffer stop then a brick wall. Entry to platforms 9 and 10 were accessible from a crossover which was protected by signal November Delta 9-10. And at the end of each platform was a fixer red light which denoted the limit of movement authority for trains in the station. In the early 1970s the route was once again pegged for change as a link was constructed from Drayton park back to Thinsbury park albeit this time on the high level to allow it to be connected to the main line. As part of these plans a line would then come under control of British rail and be operated on the national network albeit with local instructions very similar to the LUL rulebook. But this change over wasn't to happen until August 1976 and our disaster happened in February 1975 but first let's talk about the trains and their safety systems. The rolling stock used on the line were 1938 tube stock comprised of two three car units coupled together totaling 316 feet six inches in length weighing in at around 151 tons. The cars were body on frame construction with the body shell consisting of steel sheets welded and riveted together. This was placed onto a steel frame. The seating layout was standard for the time with a mixture of longitudinal and transverse similar but not identical to the 1972 stock on the Bakelulime. The door arrangement was again standard for the time with single leaf doors at each end with two double leaf doors in the middle. On the driving motor cars the cab took the place that would have been occupied by the single leaf door on one end. The trains were operated as part of the two person crew one motorman and one guard. Manual driven London Underground lines have a form of train protection called the train stop tripcock system and it's part of the two main safety systems employed on the network. It in its most basic form is a mechanical way to apply the emergency brakes on a unit in situations where the driver has passed a signal at danger or entered certain sections of track too fast. You see without this type of protection there'll be nothing to stop a train from going past a conflict point or into the rear of another train apart from the actions of the driver or shutting off traction current. The other safety system is called the dead man's device. This is fitted to the master controller. The controller is used to control the traction motors by actuating resistors. If the handle is released then the train pipe is vented to atmosphere putting the emergency brakes on. The 1938 tube stock made use of several intertwined systems all of which had to work to allow the unit to take power. One such was the control governor. This would cut out traction motors if there was insufficient air to operate the brakes. The train had two types of braking systems both operated the same physical brakes but provided air in different ways. The first let's look at the Westinghouse system which the brakes are based off. The system uses a reduction in air pressure in the train line to indirectly apply the brakes. It uses a triple valve which allows air into a tank ready to be used. It applies the brakes and it releases them. The braking system is a combination of the Westinghouse automatic brake and a self-lapping electroneumatic brake. The EP brake allows for multiple brake applications and releases and uses its own mainline air pipe whereas Westinghouse requires a little more thought. The Westinghouse brake isn't self-lapping meaning when you apply the brake you have to move the brake controller into lap to hold the required air in the brake cylinders and uses the train line air pipe. This system traces its heritage all the way back to the days of steam. This doesn't allow much room for error as you can only add brake pressure thus increasing braking force. If you do overdo it then you need to release the brakes and this is not something you'd want to do when approaching a platform. LUL uses a two aspect signalling system which only has unsurprisingly two aspects red for stop and green for go. Unlike national rail trains LUL rolling stock doesn't have a warning system like AWS. It's said relying on the driver's liner site to the next signal. If the signal visibility is obstructed say by the curvature of the track then a repeating signal is provided and can give two indications yellow meaning the signal it is repeating is at danger red and green meaning the signal ahead is clear. Each stop signal is provided with a train stop a metal bar that is next to the right hand running rail which is electroneumatically operated that rises three inches high when the associated signal is at danger. This makes contact with a trip cock that is mounted to the right hand shoe beam of the train when this is tripped vents all the air out and applies the emergency brake. If you wanted to be a driver on london underground way back when you had to follow a pretty sick career path the traditional route to motorman at the time was to work your way through the ranks starting as a guard after which you could then go for your motors which would promote you to a guard motorman until a position of motorman came up. This was the same career progression route for 50 year old motorman L.B. Neusen who had started with the company in 1969 as a guard working out of barking depot. He qualified as a guard motorman in 1974 racking up only six days of 1938 tube stock driving experience. He'd also gained around 31 days of experience driving the C69 stock on the Hammersmith and City service. In January 1975 he transferred to the hybrid branch line based out of Drayton Park depot aged 56. His training took place on the 22nd of January 1975. His instructor noted that Neusen was cautious but competent as a driver. For the next few weeks the newly qualified driver Neusen set about the usual duties of a motorman on the hybrid branch line. Between the 23rd of January and the 28th of February 1975 Neusen had driven to Moorgate several hundred times. This leads us on to the morning of the 28th of February 1975 and motorman Neusen booking on the number two duty at 624 driving 272. Unsurprisingly the shift would involve multiple trips to and from Moorgate including bringing the train into service at the start of the working. Neusen was already at work at 6.10 am with plenty of time to make a cup of tea and ready himself for the shift ahead. A fellow driver asked Neusen for some sugar which he obliged saying be careful with it as I'd like to have another cup after my shift. In his work bag he had his tea milk sugar rulebook and a notebook and in his coat he had 270 pounds to buy used car for his daughter in the afternoon. The day started off with Neusen's usual guard Mr Robert Harris running late and due to this another driver volunteered to work as the guard until Harris met the train en route. When Harris met the train at Moorgate the two set on their usual routine and nothing unusual was noted by Harris. It was well known by many of the drivers at Drayton Park that Neusen approached platforms slower than others showing a more cautious driving style. The remaining journeys went as they had done hundreds of times before with Neusen driving as he normally did. When 272 set off from Drayton Park at 08 38 am around a minute late little did anyone know that the busy rush hour train would be taking its last trip. Due to the exit stairway being at the end of the platforms at Moorgate the majority of the train's passengers occupied the front three carriages. As explained by guard Harris later all seemed well with Neusen testing the Westinghouse brake at the penultimate station as per the instructions for the 1938 tube stock. Harris walked around the rear carriage where the guard's panel was located in search for a newspaper but as soon as the train approached Moorgate and the station lights came into view Neusen seemed to be driving much more aggressively. A signalman on platform 9 at Moorgate saw train 272 approach the platform at a speed estimated at between 35 and 40 miles an hour, speeding down the platform and seeing the first couple of cars disappearing into the overrun tunnel. A second later the front cab then impacted the sand drag eventually going straight into the buffers beyond. This was quickly followed by car number two and three crushing into one another. The complete 52 foot length of the first car was crushed into 20 feet of tunnel. The second car had pushed under the first significantly damaging the body but not severely deforming the frame. The third car was much less damaged but did show signs of the impact. The thin steel body crumpled trapping passengers within. The platform became engulfed with a thick cloud of dust and debris from the impact and the sound rang about the tunnels of Moorgate station. The first emergency call was sent out at 848. The response was quick with the London Ambulance Service personnel reaching the station at 854. At around the same time the City of London Police informed nearby St Barts Hospital of a train collision at Moorgate but the severity of the incident was yet to be known. At 857 the first of the London Fire Brigade reached the scene and after an initial inspection the event was raised to major accident level. A doctor who had gone to the scene from nearby offices seeing the carnage requested all the morphine from a nearby boots pharmacy and by 9 a.m all from the third much less damaged carriage evacuated. By 9 30 a.m many of the surrounding roads had been closed off to allow space for the constant stream of ambulances taking casualties to hospitals. Byman cut holes in parts of the train structure including the floors and ceilings through which it was possible to crawl about the wreckage to retrieve casualties. By now a triage and makeshift operating theatre was set up on the platform tackling the severity of some of the injuries. Due to being underground radios were ineffective meaning runners had to be used to request assistance and extra medical supplies and again due to the location everything from plasters to machinery had to be moved by hand down to platform 9. By 12 noon only five live casualties were still stuck in the train and by 3.15 only two were left who were trapped together in the first carriage. Because services had ceased the air in the station began to stagnate as no trains were pushing in fresh air. This also had a horrible side effect of drastically increasing the temperature on the platform. The final two were removed at 8.55 p.m and 10 p.m respectively with the first needing to have her foot amputated. To clear the wreckage flame cutting equipment was used. On the first of March the third carriage began to be winched back down the track and a true damage was revealed to the rescue workers. During the first and second of March the wreckage of the second carriage was cut away in sections and it wouldn't be until the fourth that Newson's body could be retrieved. At 3.20 p.m on the same day the last passenger body was removed. The driver's cab normally three feet deep had been crushed to six inches. The investigators ascertained that Newson was at his controls although his head had been forced through the front window. Newson's body was removed at 8.05 p.m on the 4th of March. Remained with the wreckage was cleared by 5 p.m on the 5th of March and the control of the platform was handed back to London Underground. Now as always with incidents and with a death toll of 43 and over 70 people injured the question remains how did the accident happen? Well after investigators checked the service history of the train and inspections of the equipment it was deemed that the units were sound working condition. They also discovered that no braking effort was made as the handle positions were in off leaving one outcome the human element. This is where we'll never actually know what the cause was as the autopsy showed no signs of any physical conditions such as a stroke or heart attack. Initial tests showed no drugs or alcohol in Newson's blood stream and there was no evidence of liver damage from heavy drinking. An analysis of Newson's kidneys by toxicologist Dr. Ann Robinson showed his blood alcohol level at the time of the post mortem was 80mg per 100ml. However this can be caused as part of the decomposition process. Newson's demeanour on the day seemed to be the same as any other working day according to his colleagues and even the guard working with him. Suicide would seem unlikely as Newson did have plans after his shift and if he was showing signs of distress someone might have picked up on it with the regular changing ends on such a short route. Leaving a mystery as to why Newson didn't react to the situation. I.K.A. McNaughton was tasked with setting up an inquiry and on the 4th of March 1976 his report was published concluding. I must conclude therefore that the cause of this accident lay entirely in the behaviour of Motorman Newson during the final minute before the accident occurred. Whether his behaviour was deliberate or whether it was a result of a suddenly arising physical condition not revealed as a result of the post mortem examination there is not sufficient evidence to examine. But I am satisfied that no part of the responsibility for the accident rests with any other person and that there was no fault or condition of the train, track or signalling that in any way contributed to it. There are many theories linked to Newson's lack of reaction but one of the most likely is possibly due to daydreaming or distraction as cuts on his hands indicated that he had raised his arms before the point of impact. Leading up to the crash, Newson had had two platform overshoots in the week previously which may have hinted to a concentration issue but we will never know for sure. The disaster did have a positive effect on London Underground and its train protection system. A type of protection named after the crash came into effect. This Morgate system used multiple time controlled train stops on approach to buffers at terminal stations. These would lower the train stop once the train was doing a particular speed checking the train down to a safer velocity to reduce the damage of any potential impact. If the train violated the speed the train stop would hit the tripcock putting the train's emergency brakes on. This coupled with a resistor on the current rails set to reduce the amount of power a train can draw when approaching a terminus means that an accident like Morgate shouldn't happen again. Well at least not on London Underground. As more lines go to automatic operation the risks of human-related collisions go down drastically as most ATO lines limit manual operation when not protected by the signalling system to below 10 miles an hour. On the main line the implementation of TPWS on routes and stock should put accidents like Morgate firmly kept in the past. This video is a plainly difficult production. All videos on the channel are creative commons attribution share alike licensed. Plainly we've got videos are produced by me John in a sunny south-eastern corner of London UK. Help the channel grow by liking commenting and subscribing. Check out my Twitter for all sorts of photos and odds and sods as well as hints on future videos. I've got a Patreon YouTube membership as well so you can check that out if you fancy supporting the channel financially. All that's left to say is thank you for watching. It is the 29th of June 1995 and a luxury six-year-old department store will be the center of one of the world's most deadly structural failures not involving a terrorist attack. The event will serve as a stark warning against quick urbanization of cities and the importance of proper building use consideration. The collapse of the Sampoong department store in Seoul would be the largest peacetime disaster in South Korean history killing 502 people and injuring 937. As such I'm going to rate it here seven on my plainly difficult disaster scale but here eight on my legacy scale as the perpetrators of the event would actually be made to pay for their negligence. It is the 1980s and South Korea is enjoying an economic boom. Although the country politically is under the control of military strongman Chul-do Won it will towards the end of the decade move towards democracy. The country is experiencing great expansion of heavy industries, electronics and steel industries with the backing of the government. This is part of the miracle on the Han River where the country hurtled itself to be the 11th largest economy in the world. Towards the end of the decade Seoul hosts the 1988 Summer Olympics and the success of this on the international stage makes the city even more of a world destination. As such the nation's capital develops at a lightning pace stretching the country's construction companies to breaking point. This is further exasperated by bans against international contractors signing contracts for projects in Seoul. In 1987 riding on the wave of success in Seoul leading up to the Olympics ground was broken for a new building. The construction project is based in Seoul Chul district an area in the southern part of the city. The building is to be built across land that used to be used as landfill but it is now prime real estate ideal for a modern apartment block. The building will be a relatively straightforward four-story apartment block to be built by Woosung Construction. However this original plan wouldn't last long as the lead of Sampong Group's Construction Division Lee Joon decided that a change of use would make the project more profitable. This would involve turning the building into a department store. The change necessitated significant amendments to the plan to the building to accommodate a central escalator system but instead of recalculating the loads on each floor Joon's team made some adjustments to the blueprints. The building was designed without a steel skeleton instead each concrete floor would be supported by the columns without the use of horizontal beams. This method is known as flat slab construction. The use of this style of construction aids in speed of completion ease of installing sprinklers and utilities and other piping as well as cost but with the ease comes some serious downsides and that is the construction of large spans is more difficult and the size of the support column is vital. Throughout the central portion of the building each floor was to be supported in the original plans by multiple concrete columns 80 centimetres in diameter with 16 22 millimeter diameter reinforcing steel bars within but in order to accommodate the escalators and maximize retail space eight columns were reduced in size to 60 centimetres with only 8 22 millimeter reinforced bars. This was not liked by Woosong Construction which led to the company being dropped and Sampung completing its project in-house. The original 80 centimeter diameter columns meant that their spacing was set at 11 meters apart widening that gap with smaller pillars would push the building beyond its limits but that would not be the end to the modifications from Sampung. To further optimize the plot of land for a new department store a fifth floor was envisioned for a roller skating rink a relatively lightweight tradition to the already strained building but yet again the plan was changed. Gone was the lightweight use of the top floor but instead a food court was posed. The equipment needed for such a plan would greatly push the limits to the building past breaking point but the construction continued. Not only that but the Korean style of underfloor heating known as Ondol was specified for the fifth floor. This would include a concrete floor with heavy heating pipes running within. Original plans for level five had a calculated predicted load of 1040 kilograms per square meter but a new configuration had 1530 square meters nearly a 50 increase in weight strain on the already minimized supporting columns. The supporting columns didn't line up throughout the building leading to the load having to be transferred along the concrete floor slabs. To add even more load on the already stressed design three 15 ton air conditioning units were installed on the roof creating a 45 ton load that was four times originally envisioned. This was another side effect of the change of use for the building as originally the design wasn't intended to have such large air conditioning units. Not only the weight caused the stress on the building but the vibrations themselves generated from the units. Nevertheless the Trouble Project was completed in late 1989 seeing its first guests on the 7th of July 1990. Around 40,000 people per day would visit the bustling shopping mall attracting lunchtime customers from the nearby business district earning its business owners around four million US dollars per week. Around 1,000 people were employed in its day-to-day running and business is booming. Cooling towels on the building were installed on the side next to an apartment building. Shortly after opening, complaints started to come in to the department store's management. Instead of hiring a crane to move this heavy cooling structure, rollers were used and the 45 ton towel was dragged across the roof. This yielded some results, a cheaper and easier move but also caused significant damage to the roof as the weight rolled across. Along came 1995 and some worrying signs started to appear around the 5th floor at the Sampoong department store. Rack started to appear during April in the ceiling of the south wing. What should have been a major red flag was only met with a minor reaction from management in which staff were told to move the merchandise and stores from the top floor to the basement. The cracking around the south wing would continue to increase accelerated by vibrations of the air con tower. It is the 29th of June 1995 and the department store opens as usual. Hundreds visit the building but above their heads in the 5th floor ceiling the cracking continues to worsen. In the morning, cracks in the area had increased dramatically, prompting managers to close parts of the top floor. No evacuation was ordered and customers, although inconvenienced by the closure, carried on shopping as normal. However, executives for the company did evacuate as a precaution but to avoid a loss of a day's revenue management carried on as usual. This would still be the case when engineers were called up to investigate the cracking. After only a short check, it was revealed that the building was at risk of collapse and yet the building stayed open. Around lunchtime, loud bangs and cracks could be heard from the 5th floor as the concrete separated from the columns. By now, customers were complaining about severe vibrations throughout the building. To alleviate the concerns, management switched off the air con but the damage had already been done. A 10cm wide crack had appeared on the 5th floor with collapse all but guaranteed an emergency board meeting was held. Many argued for the closing and the evacuation of the building but Lee June insisted the store stayed open however Lee himself left the building. At around 5pm, the 5th floor was completely closed off as the roof began to sink but the rest stayed open. The decision to completely evacuate was taken at 5.50pm but this was too late. At 5.52pm, the Sampoong department store collapsed. The weakened roof gave way, sending the air conditioning units crashing through the overstressed 5th floor. The south wing pancakes crushing each subsequent floor below it, trapping over 1,500 people within the rubble. Rescue crews were on scene within minutes, frantically trying to rescue anyone trapped within. Heavy lifting equipment would arrive the next day but rescue efforts would be called off from fears of further collapsing in the area. To alleviate the fears of further damage from the structure, the remains of the store were steadied by guide cables. A week after the collapse, focus changed to clearing the structure but survivors were discovered as late as 17 days post disaster. A survivor who was pulled free 9 days after collapse described to rescuers that many had died drowning in the water sprayed on the structure for fire suppression. In total, 502 people lost their lives at the department store collapse. The event shocked the nation, even prompting President Kim Jung Sam to visit the wreckage site. As such, an investigation panel was set up to find out how the Sampoong department store collapsed and who was to blame. Professor Lang Chung from Dancook University's engineering school was chosen to head up the investigation. Initially, a gas explosion was thought to be the culprit, even more worrying was the culprit of a terrorist attack. Although the pancaking collapse with little debris ejected suggested the failure was more due to structural issues. After investigating plans and drawings of the building, a number of key issues were discovered with the design. The flat slab construction was highly criticised as it didn't have reinforcing beams, instead relying on the column to hold the slab in place. Too small of a column would result in it punching through the flat slab and this problem is exasperated if the weight the columns need to support is increased, just like level five at the Sampoong department store. The investigation summarised the cause of the collapse in four points. The changes in design and increase in load upon change design was the key cause of the disaster. The building was constructed poorly using improper concrete mixing and poorly reinforced ceilings and walls. An adequate building and structural planning using a flat slab construction was a factor that caused the progressive collapse. Slabs on the fifth floor and the roof floor in the vicinity of the 5E pillar and 5F pillar experienced sheer failure, eventually along the circumference of the pillars. This is believed to lead to destruction of adjacent slabs, which is a progressive collapse, ending up with the destruction of the entire building, potentially caused by the movement of the air conditioning units. What sets this event aside from many I've covered is that the driving force behind the disaster did actually meet some kind of justice. On the 27th December 1995, after some incriminating statements made during the collapse investigation, Lee June was found guilty of criminal negligence and received a prison sentence of 10.5 years, later reduced to 7.5. Lee June's son, who was also the store CEO Lee Han Sang, received 7 years for accidental homicide and corruption. Others would also be sentenced for crimes relating to bribery and building regulations violations and would include local government officials as well as company executives. The Samppoon Group, two months post-disaster, agreed to sign all of its money and assets over to the victims for compensation, which would result in a total of around US$300 million being paid out to 3,293 cases. Ironically, the land was cleared and in the early 2000s turned into luxury apartments. It is the 7th December 1993 and the first of several congressional hearings is waiting to begin. The room is full with people with an empty table near the front, one side has a TV screen and an easel. Senator John Lieberman holding a light gun begins to speak. He explains that video games are increasingly becoming a more violent and dangerous influence on children. The TV is switched on and a video of mortal combat springs to life. As the senator continues to speak, he describes the basis for the game. As the committee meeting goes on, a number of industry and educational experts speak. This hearing will become to be known as the 1993 Congressional hearings on video games and it was the culmination of a moral panic, the thinking being that violence shown in media will be emulated by children. The ultimate result of the hearings is a more unified age rating system for home media. Although not explicitly stated, this idea is an evolution of fears tracing its way back before home video games to a long-standing theory, the social learning theory. This line of thinking became part of the social zeitgeist from a number of studies, starting with BF Skinner's operant conditioning and culminating in a controversial but fascinating study called the Bobo Dole experiment, overseen by Albert Bandura.  The experiments would in retrospect be seen as a controversial and ethically questionable chapter in the discipline of psychology. Many criticisms to the experiments would be brought forward including accusations that the children were manipulated to gain the desired results and selection bias, but the results would influence general thinking on children copying actions observed, which would ultimately be the scientific justification of media censorship and age-related restrictions. Welcome to the dark side of science. Our story starts in a small town in Alberta, Canada, named Mundare, on the 4th of December 1925 with the birth of Albert Bandura. He was born to Polish and Ukrainian parents. Growing up in a small town, educational opportunities are fairly limited, but under the guidance of his family, he became self-motivated. It was encouraged by his parents to seek out experience of life beyond Mundare. After high school, he took a job in the Yukon. It would be here that his interest in science would be sparked in an unlikely turn of events. While studying at British Columbia University, he took a psychology course in order to pass the time in his empty early morning schedule, becoming passionate about the subject. In 1949, he would graduate with a BA. To further his newly discovered passion, he moved to the University of Iowa. From there, he gained an MA in 1951 and a PhD in 1952. Post doctorate in 1953, he took a teaching position at Stanford University. Throughout the 1950s, Bandura became fascinated in a new theory, originally posed by B. F. Skinner in his series of lectures in the 1940s on social learning. Skinner mentioned a thing called echoic response. In its most basic form is the copying of a parent's speech by child. Barely straightforward and obvious when observing a child copy a parent talking. But Skinner stated that all verbal behaviour was underpinned by operant conditioning. Around the same time, a book, Social Learning Theory was published in 1941 by Clark Lewis Hull, which suggested that personality traits were learned by copying parents' actions. In 1959, Noam Chomsky published his review of B. F. Skinner's verbal behaviour theories and criticised his 1957 book called Verbal Behaviour. Chomsky said that operant conditioning alone could not explain our ability to learn language, and instead there is something more. As if Skinner's theory was right, then to learn a new response would require multiple attempts and positive reinforcement, much like how you train a dog to sit. In the same vein, Bandura set out to find if learned behaviours were from operant conditioning, i.e. from reward or punishment, or from imitation, i.e. watching another do something and copy it. One particular thing that fascinated Bandura was aggression. In Social Learning Theory, three models of observational learning are posited. Live models, where a person is demonstrating the desired behaviour to a participant. Verbal instruction, in which an individual describes the desired behaviour in detail and instructs the participant in how to engage in the behaviour. And symbolic, in which modelling occurs by means of the media, including movies, television, literature and radio. Stimuli can either be from real or fictional characters. Working with one of his first doctorate students, Bandura set out to prove his theory. This resulted in a 1959 book, Adolescent Aggression. The research for the book involved looking into the origins of antisocial behaviour of 26 adolescent boys. Each boy and a matched control were given an intensive interview and a TAT-like projective test. The parents were also interviewed to determine their attitudes about and how they actually handled problems relating to dependency, aggression and sex as they arose from day to day. Bandura's next study would be the culmination of his research and that would be to put the theory into practice and see if a child would copy a model doing a certain kind of behaviour. And this involved a strange item, a large blarp clown doll. This is Bobo, a blarp clown doll. Although a kind of creepy looking toy, he is a bop bag and is intended to be used as a safe way for a child to practice boxing, bouncing around and generally playing with. Well, that's what my daughter does with it. An unlikely tool for a psychological study, but it would become a vital part of a classic series of experiments. The Bobo Dull experiment would start in 1961, but first let's look at the method that Bandura set out. The study involved 36 boys and 36 girls who had been enrolled in the Stanford University Nursery School. They ranged from the age of 37 to 69 months, with a mean age of 52 months. Two adults, a male and a female served in the role of model, and one female experimenter conducted the study for all 72 children. The children were split up into eight experimental groups of six, with a control group of 24. Half the experimental subjects would be exposed to aggressive models and half were exposed to models that were subdued and non-aggressive in their behaviour. These groups were further divided into male and female. Half the subjects that experienced the aggressive and non-aggressive models had same sex models, whereas the others had an opposite sex model. Each subject would be exposed to the scenario individually. This was to prevent the children from copying one another. The child and model would be brought into a playroom where they would be confronted by the Bobo clown doll. The child was seated in one corner filled with things such as stickers and stamps. The adult model sat in another corner with a toy set, a toy mallet, and the inflatable Bobo doll. Before leaving the room, the experimenter explained to the child that the toys in the adult corner were only for the adult to play with. In the aggressive scenario, the model would initially start playing with the Bobo doll. After a short while, the adult model would start to verbally and physically assault the doll. They would also use the mallet. After a period of 10 minutes, the experimenter came back into the room, dismissed the adult model and took the child into another playroom. In the non-aggressive scenario, the Bobo doll was completely ignored and the model simply played with the other toys in the room for the 10 minutes. Before being dismissed and the child, like in a previous scenario, was taken to another playroom. The next part of the experiment involved the child being allowed to play in the second playroom with some toys. To create frustration, after around two minutes, the experimenter would tell the child they would have to put the toys down because they were reserved for other children. They were told they could instead play with the toys in the experimental room. In the first room with the Bobo doll, the child was allowed to play for 20 minutes, while an experimenter evaluated the child's play. The experimenter would record each time the child would initiate aggression in four ways. The first measure was based on physical acts such as punching, kicking, sitting on the Bobo doll, hitting it with a mallet, or tossing it around the room. The second measure was any verbal aggression towards the doll, especially if it mimicked the model. The third measure was the number of times the mallet was used to display forms of aggression other than hitting the doll. And the fourth measure was each time aggression was shown that was not a direct imitation of the role model's behaviour. Landau's results were not particularly surprising. The children who experienced the aggressive scenarios were way more aggressive in the playing with the Bobo doll. The results also showed that if the model was of the same gender as the child, then they would be even more aggressive. The most aggressive were boys who had a male model who had shown aggression towards the Bobo doll. When compared between the two genders, males exhibited 270 aggressive instances compared to 128 instances exhibited by females. After the experiment, Bandura wanted to dive deeper, but it would take another two years before he upped the ante. For a second experiment, Bandura set out to see if the results would change if the children saw the aggressive scenario in the form of a cartoon or a film in comparison to a live model. Bandura also thought that maybe the children would experience a cathartic effect by seeing the aggression from the medium of media or would watching the aggression on TV create the same response as a live model. This time the number of subjects was increased from 72 to 96, but like before they were from the Stanford University nursery and were divided into three groups. A live aggressive group, a pre-recorded model aggressive group and a cartoon of a cat being aggressive to the Bobo doll group. There was also a 24-child control group, like before they were subdivided again to gender. The original results from the 1961 study were used as a control for the experiment and like before, each subject experienced the aggressive scenario individually. Like before, after the exposure the subject was placed in a mildly frustrating situation before being left alone with the Bobo doll. The results were similar to before with the live model, but what was interesting was that the children did actually show aggression after exposure to the pre-recorded model and the cartoon. A third experiment in 1965 sought out to find if classic conditioning could affect the results. This time 66 children, 33 boys and 33 girls were used for the study. Again three groups were used, which were again subdivided into gender. The first group would witness a model display aggression towards the Bobo doll, followed by a researcher praising the model, rewarding them with candy. The second group would witness the same scripted scenario of aggression behaviours, but instead the model received a rep command and was hit with a rolled wooden golf club. The third group served as the control and the model had no reward or punishment for the display behaviour. The children like before would watch individually. The child would then be placed in a room with the doll and any aggressive behaviours would be noted. The results showed no real difference compared to the previous studies, at least in regards to the reward and control group. However, the group that witnessed the model being punished showed an interesting reduction in aggression. The Bobo doll experiments helped further Bandura's social learning theory and carve a new way of thinking. This is mainly due to children observing the punished model and subsequently understanding this to modify their own response to the Bobo doll without being punished themselves. But let's look at the study's criticisms. Although not as controversial as other studies involving children, the Bobo doll experiments did have some shortcomings. Firstly, there was a question of whether the children did actually show aggression, or were they just mimicking the model. You see children are very well known for copying adults, with little thought to the consequences, meaning finding out the motivation behind the subject's actions can be difficult and open to interpretation. An overtly aggressive act to an adult observer might be perceived by the child as a simple action, with no weight placed on the actual meaning behind it. A later study which copied Bandura's method for the experiment found that subjects acted much less aggressively when observing an aggressive model if they had a neutral exposure to the Bobo doll in a previous experience. This means that the novelty of the doll in the study could have encouraged a more exaggerated response from the children. The study could also be considered as unreliable, as most of the subjects were from the same racial and economical background, being that in the early 1960s the majority of attendees were wealthy and Caucasian, due to having parents that were students of Stanford University. The main concern for the study, however, is its ethical implications. This is due to the children being almost trained into being aggressive by placing them in a frustrating situation before observing them with the Bobo doll. There is also a question of consent, as a child isn't able to make an informed decision as to whether they want to take part in a study. Needless to say, from all three studies the subjects did not agree nor disagree to take part, which leaves a potential ethical grey area. The children also didn't have a long enough cooldown period between experience exposure and observation. This means that there can be no proper conclusion as to the long term effects of exposure to aggressive acts, which brings us back to the media and whether it actually in the long term makes children more likely to be violent in real life. Personally I think age restrictions on media is a good thing, as a parent myself I would not want my child to be exposed to age inappropriate material, such as swearing. As I know, she would just start copying and say it to everyone she speaks to. I think the Bobo doll study is a very fascinating experiment, although not particularly dark, I still really enjoyed looking into the subject. The study is a very important cornerstone of modern day psychology, and this is reflected in Albert being the fourth most cited psychologist of all time. And as such I'm going to rate it a three on my ethical scale, which is mainly due to the lack of informed consent from the children. But more importantly, where would you rate this subject on my scale?  Let me know in the comments below. This is the Plain Difficult Production. All videos on the channel are creative commons attribution share alike licensed. Plain Difficult videos are produced by me, John, in a currently late night and dark southeastern corner of London, UK. Help the channel grow by liking, commenting and subscribing. Check out my Twitter for all sorts of videos and odds and sods, as well as hints on future videos. I've got Patreon and YouTube membership as well, so check them out if you fancy supporting the channel financially. And all that's left to say is thank you for watching. Radioactive sources are needless to say very dangerous in the wrong hands. It seems that lost source incidents are far more regular than you would like. After its disillusion, the countries that formed part of the former USSR were forced to maintain, protect and dispose of radioactive sources. An industry that was centrally controlled by an established government infrastructure was almost overnight dissolved, resulting in highly dangerous materials falling to the responsibility of new fledgling governments, dealing with the complex aftermath of communism. The change in the economies of such countries resulted in financial hardship, where government support was once there, no longer existed, leaving people to try and carve out a living by any method possible, and one such way was through scrap metal. A waste repository in Tamiku Estonia became a prime target of free opportunistic scrap thieves. This is due to the relatively isolated and unguarded state of the site, but this would be a very grave mistake. Today we're looking at the radiological accident in Tamiku, and as such I'm going to rate this incident here 5 on my Patented Plain Default Disaster Scale, and here 3 on the Legacy Scale. In September 1991, the Estonian Parliament declared independence from the USSR. After this was recognised by Moscow, the parliament approved a new constitution and was headed by a president. As part of this, much of the support from the USSR began to be cut off, and new departments in the country were set up to handle various elements of governance, and this included the management and disposal of nuclear waste. Estonia was neither a nuclear energy user, or even a research reactor operator, but a need for nuclear waste disposal was still present from uses relating to research, industrial and medicinal. In 1963, the Tamiku facility was set up 12km south of Tallinn, which is around here on the map. The site was intended for management of low and intermediate-level reactive wastes. The facility became the central storage disposal area for Estonia's nuclear industry. Much of the site's design came from the criteria developed in Moscow in the 1950s. The Tamiku site was situated in a remote forested area. It was surrounded by an outer barbed wire fence at a 500m radial distance, with a gate and guardhouse, and an inner fence around the liquid waste storage tank and solid waste storage vaults. The main disposal facility consisted of a 15x5x3m providing to disposal capacity for solid radioactive waste. The storage of liquid waste is an underground cylindrical concrete tank with a stainless steel lining, both for buried underground and are accessible via a locked roof cover. The site was updated in the 1980s, but the project was only partially completed due to lack of resources. None of the waste stored at Tamiku was planned to be treated, and after around 30 years of use, 1028 batches of waste had been disposed of at the facility, totaling approximately 97 tonnes, with a total activity of 200 terebecuels. The prominent radionuclides were strontium 90 and cesium 137. By the early 90s, the activity of the site had reduced to 76 terebecuels. The facility was also around the same time looking a bit worse for wear and no round-the-clock security personnel. Much of the timeline for this video is based off of the IAEA report into the event, and as always, the link is in the description if you fancy further reading. This brings us onto the 21st October 1994, and three brothers breaking into the Tamiku facility in order to gain access by climbed offences, broke into the repository, and climbed down into the pit, in doing so bypassing the electric alarm system. The three men cut off the padlock to one of the storage areas, pulled open the steel door and one of the brothers stepped inside. Once inside the underground vault, the brother found a metal container, and passed it up to his siblings. While he was doing this, a metal cylinder, 18cm long and 1.5cm in diameter, fell out of the open tube of the container. This was thrown back inside the storage area. A shorter cylinder, with the same diameter, had also come out of the metal container, but instead of throwing it back, one of the brothers placed the strange item inside his coat pocket. The three also broke into the liquid waste storage area, where they stole some aluminium drums. The hazardous contents were emptied onto the ground, the drums, and the metal container were then carried off site to be transported by car to a scrap metal dealer in Tallinn. During removal of the drums, one fell against one of the brothers' legs, the same one who had pocketed the strange item, causing minor injury. On route two of the men started to feel ill. The brother with his injured leg returned to his house in Kesar, where he lived with his stepson, the boy's mother, and the boy's great-grandmother. Upon entering, he hung up his coat which had the stolen item in it. Later on in the day, it was moved into a drawer in the kitchen. Throughout the later part of the day, the man started to vomit and experience extreme nausea. On the 25th of October, the brother went to the local medical centre to seek out care for his injured leg. Obviously he didn't mention how or where the accident happened, and the doctors diagnosed him with a crush injury. However, within a week, on the 2nd of November, he would be dead with an official cause of kidney failure. But this was because the medical practitioners weren't aware of what or where the brother had been and taken home with him from the woods. The theft at the Tamaku Storage Facility wasn't discovered until the 8th of November, when more waste was disposed of on site by operators. The workers noticed that the securing padlocks at the waste vaults had been cut and replaced them. What was even more suspicious was that the dose rate on site had drastically decreased since the last disposed-along site in September. The operators didn't think to report this all the damage to the locks to management. The days the item taken from the site sat in the kitchen drawer being close proximity to the inhabitants within, including the dead brother's stepson and the family dog. The next victim was said dog who had been showing signs of acute radiation sickness, which was not a considered cause of illness of a family pet. The Canis Familiaris passed away on the 16th of November. The stepson had discovered a strange item in the drawer after searching for tools to fix his bike and during this time he had touched the object. Finally on the 17th of November 1994 the 13 year old stepson was admitted to hospital with severe burns to his hands. These were diagnosed as radiation induced and the police were notified. This worrying case of the burns sparked a region-wide search for a possible multiple orphaned sources. Needless to say the item stolen from Tamaku was a deadly radioactive isotope source. The police in term notified the Estonian Rescue Board, which immediately sent staff to KISA who arrived at 23.30 on the 17th of November 1994. Initial dose rate surveys were undertaken of the household of the dead brother. Members of the rescue board briefly entered the house to try and locate the source. The measured dose rate of 1.2 grey per hour was recorded close to the surface of the drawer in the kitchen. The measured dose rates in other rooms were around 15mg an hour. This resulted in all houses within a 200m range being evacuated totaling 15 families. For the recovery efforts staff wore lead aprons and thin rubber gloves but did not have any proper handling tongs to place the source into a hastily obtained 3.5cm thick lead walled shielded box. Two limited time entries were planned to identify and recover the source by recovery staff. During the first entry lasting 2 minutes and 35 seconds the drawer of the kitchen cupboard was emptied onto the floor allowing operators to correctly identify the source. The dose rate was at 5-7cm from the unshielded source measured to be 1.5-1.8g an hour. The second entry unsurprisingly was to safely regain ownership of the source. This took 2 minutes and 15 seconds and necessitated carrying in the lead shield container and manipulating the source into it with the operator's hands. The contact exposure lasted 2-3 seconds. The dose rate close to the surface of the lead box was measured to be 100mg an hour. Once recovered the source inside its new container was placed in the back of a van but the transportation back to the Tamaku Repository. The recovery operation was completed by 2.30pm on the 18th November 1994. Neighbours were then permitted to return to their homes. The item that was thrown back by the brothers into the vault turned out to be a spacer hinting that the item stolen for scrap was actually a source carrier of some sort. Strangely it was uncertain at the time what radioactive element made up the lost source. As a recovery team lacked any portable gamma spectrometry equipment in Tallinn making it very difficult to determine the precise nature of the radioactive source. It was most likely either cesium-137 or cobalt-60 but eventually it was discovered to be cesium-137 when a portable gamma spectrometer provided by the IAEA was used at the Tamaku facility in December 1994. The source was estimated to be between 150GB 2.7.4TB of radioactivity, clearly enough to prove to be fatal if exposed near for too long. Even more worrying was that in January 1995 a second unaccounted 4 source was discovered alongside the road between Tallinn and Narva. A Swedish led recovery team helped in safely returning this 1.7TB source back to Tamaku. Due to the discovery of the sources the death of the brother was re-evaluated and it was estimated that the 25 year old had received a dose of between 2000 and 3000g an hour. One of the other brothers later showed signs of burns on his hands from a possible handling of the source as well. After the incident the surviving brothers were interviewed by the police and even though admitting to breaking into the Tamaku facility were adamant that they did not know the risks posed by the materials kept on site, instead only wanting scrap metal. The lessons from the incident are pretty obvious and were easiest to take on for the Estonian authorities. This included more robust reporting of suspicious activity and more importantly 24 hour guarding of dangerous material sites. Plus it seems a rather inefficient way to dispose such materials and the IAEA set out better guidance for Estonia moving forward which included better grading of high and low level waste as to make use of the limited storage facilities more effectively. The response to the discovery of a patient with ARS was quick however the team were ill-equipped for the situation necessitating manual handling of the deadly radioactive source which is a crazy way to deal with such an item. It's crazy to think that such a dangerous item could have been so easily stolen but sadly in a country that had only recently gained its independence some things would take higher priority than others to sort out and it seemed nuclear waste was not the most important thing to manage but a fledgling government and the radiological accident in Tamaku was the result. Thank you for watching this video is a plain difficult production all videos are produced by me John in a sunny southeastern corner of London UK all videos on the channel are creative commons attribution share like licensed if you'd like to support the channel financially you can on youtube membership and patreon and also if you fancy you can check out my twitter page for all sorts of hints and photographs to do with future videos and all there's left to say is thank you for watching. Scientists have tried to conquer the mind through many different ways for many different reasons one such is in the treatment of mental disorders experimental science has in some of its most controversial studies shed a light into how the brain works we've seen this in this very series with the monkey mother baby albert and milgram experiments but how about the treatment of mental disorders in a world before modern day medicinal drug based therapy around the mid 20th century a form of invasive surgical procedure would gain praise for being able to tackle the problem of overcrowded mental hospitals and treat the previously untreatable it would eventually be known as the lobotomy the surgery would go down in the annals of time as a barbaric and cruel procedure which would leave behind thousands of patients in its wake with devastating side effects including confusion incontinence seizures and in some cases even death one of the main characters in the story of this surgical procedure would describe the operation as surgically induced childhood eventually the surgery will become synonymous with the mishandling of mental health and the running rough shot over patients rights as such i'm going to rate this dark page in scientific history a nine on my plain difficult ethical scale welcome to the dark side of science it is the turn of the 20th century mental health institutions throughout europe and the usa have become dangerously overcrowded during the 19th century where scientific discovery took leaps and bounds many attempts to treat the mentally ill had failed leading to a large population of incurable patients this was due to many industrialized countries having national systems of regulated asylums these institutions sought out care for patients that had been disposed of in the system by their families poor houses and the criminal justice system with no proper ways of treating inhabitants of the asylums many different forms of medical procedure were tested on the unfortunate patients there are many gruesome types of treatment on offer in the early 20th century in 1917 malaria therapy was introduced where a patient would be deliberately infected with a zoonotic disease to induce fever to fight neurociphalous in 1920 the barbiturate induced deep sleep therapy for premature dementia aka precocious madness or in its modern name form schizophrenia this treatment used drugs to keep patients unconscious for days or even weeks in 1927 you might have been given insulin shock treatment which used the peptide hormone to introduce daily comas in 1934 patients could be prescribed with the first type of seizure therapy where a patient would be deliberately induced into convulsions by the use of pts this therapy would be superseded by the more familiar electroshock therapy although these treatments could cause long-term lasting psychological and physical trauma the patient had not undergone a surgical procedure to eradicate the disorder but in 1935 in Portugal a doctor named Antonio Moniz would change this when he performed the first leucotomy on a patient the leucotomy in its most basic form was the deliberate damage of brain tissue in order to treat mental illness the name would later be changed to a more recognizable name when a procedure spread across the Atlantic Ocean but that will come later on in our story the thinking that inspired Moniz was that mental illnesses originated from abnormal neural connections in the frontal lobe Moniz had seen the aft effects of soldiers who had received injuries to the front lobe in which the vectorines would show a calm and quiet disposition the brain is made up of two types of matter gray and white gray matter is the brain's neurons and associated blood vessels and extensions the white matter is the nerve fibers that connected to the areas of gray matter and carry messages between them through electrical impulses Moniz theorized that by severing the white matter fibers from the frontal lobe would improve the patient's mental illness although in theory this might make sense the connections within the brain in reality are far more complex than what was fought at the time the grim procedure in its first form would involve drilling holes in the skull either side of the prefrontal cortex and injecting the connecting fibers with alcohol to destroy them Moniz found this method to not yield very good results due to the solution damaging much more than the white matter a tool was developed called a leukotome which looked like a long stick with a retractable wire loop inside it allowed the operator to insert a metal loop into the brain which was used to sever the white matter by extending and then retracting said loop the process cut six cores in the white matter of each hemisphere using the new tool because the procedure involved cutting through the skull the patient had to be operated on in a proper operating theater under general anesthetic to test the theory Moniz enlisted neurosurgeon Almedia Lima to conduct a surgery on 20 test subjects of these initial 20 patients who were suffering from depression schizophrenia and anxiety Moniz claimed seven cures seven improvements and six unchanged cases although the results were open to interpretation Moniz claimed that the risk of some behavioral and personality deterioration outweighed the debilitating effects of severe psychiatric illness which is understandable when taking mental health care at the time as a contextual background a second set of patients were operated on due to the success of the first trial these 18 patients all suffered from schizophrenia and three were considered as almost cured and another two had also become improved Moniz did conclude that patients that had deteriorated considerably from their condition pre-procedure did not benefit much from the operation in a well-known quote from Moniz he described his radical new surgery prefrontal leukotomy is a simple operation always safe which may prove to be an effective surgical treatment in certain cases of mental disorder the procedure would eventually earn Moniz a Nobel Prize in 1949 but initially Moniz's new way of treating the thought to be untreatable was widely derided by the medical community in 1936 Moniz published his results through articles in the medical press and a monograph but to little attention on the 26th of July 1936 one of his assistants gave a presentation at the Parisian meeting of the society medico-psychologic on the results of the second test subjects the 18 people suffering from schizophrenia leukotomized by Lima this meeting wouldn't go down well as the lead doctor at the institute in Lisbon who had supplied the first set of patients to Moniz was also in attendance and widely denounced the after effects of the surgery saying that patients who had returned to his institute post operation were diminished and had suffered a degradation of personality further adding that the initial results of calmness and improvement were more likely attributed to the severe shock of the surgery and ultimately from the horrible brain trauma that the procedure induced on its victims many other physicians denounced the procedure but bizarrely this isn't the end as several individual clinicians thought Moniz's leukotomy could be useful on an experimental basis on severe patients and as such the surgery was spread throughout Europe and even to the US during the mid to late 1930s and this leads us down an even darker path it is here that we are introduced to American doctors Walter Freeman and James W Watts inspired by Moniz's new surgical procedure in 1936 the duo performed their own leukotomy Walter had learned of the procedure after a chance meeting of Moniz at the London hosted second international congress of neurology in 1935 the American was fascinated by the surgical technique upon returning to the US Freeman started communicating with the Portuguese doctor Moniz during the correspondence promised to send a monograph on leukotomy and urged him to purchase a leukotone of his own upon receiving the paper on the procedure Freeman reviewed it and set about with his colleague Watts on experimenting with the surgery which led to September 1936 seeing flaws in the surgery Watson Freeman developed their own variation which renamed the procedure the standard prefrontal lobotomy to differentiate it from the Moniz method this version severed more of the white matter and would be the de facto method moving forward for lobotomies performed in operating theatres Walter thought that the lobotomy could be streamlined even further still the new standard procedure had the same shortcoming of the Moniz method and that was access to the brain you see cutting through the patient's skull required the operation to be conducted in an operating theatre with all the trappings anesthesiologist qualified surgeon hygiene and so on and so forth Walter had heard of an Italian doctor Amorello Firenberti who had performed the leukotomy by accessing the prefrontal lobe through the eye socket in 1937 Firenberti's method was to puncture the thin layer of orbital bone at the top of the eye socket and then much like Moniz's early experiments inject alcohol into the white matter or in later surgeries cutting the white matter with a hypodermic needle Walter took this process and modified it using probably one of the most unlikely of tools this is a surgical tool or is this a surgical tool it's hard to tell as one was used in psychosurgery and the other is an ice pick well the similarity is not a coincidence as Freeman's improvements on Amorello Firenberti's transorbital lobotomy replaced a needle with a nice pick in development of this new method Freeman took an ice pick from his own kitchen and started practicing on a watermelon he would eventually graduate to using cadavers the thinking was that if the lobotomy could be performed without exposing the brain then it could be performed by psychiatrists in psychiatric hospitals allowing more people to be operated on these are the tools used to the Freeman transorbital lobotomy a new tool called the orbiter class essentially an ice pick with markings along the side and a hammer the method would involve the patient being either under anesthetic or electroconvulsive therapy used to render the subject unconscious then the orbiter class sharp end is placed under the eyelid and against the top of the eye socket the hammer is then used to penetrate the surgical instrument through the thin layer of bone and into the brain along the line of the bridge of the nose eventually going five centimeters deep the orbiter class was then pivoted 40 degrees at the orbital perforation so the tip cut towards the opposite side of the head after this the tool was then hammered in a further two centimeters into the brain again the orbiter class was pivoted around 28 degrees each side to cut outwards and again inwards once this was complete it was removed and the process was repeated on the other eye socket the first patient to receive the procedure was in 1946 but once Freeman's partner Watts had heard about this new method he left their practice disgusted at the transorbital lobotomy but like every other chapter in this story this would not hamper the procedure's prevalence the lobotomy had now been transformed from a serious surgical procedure of last resort to a 10-minute doctor's office job along with this came a severe lack of follow-up care and monitoring which led to high relapse rates because of this towards the end of the 1940s nearly 20,000 people in the US have received the procedure but not only that the transorbital lobotomy would spread across the world and even back to the leucotomy's home grounds of Europe spreading further still to the Soviet Union and Japan to get a lobotomy in its late 1940s peak you really didn't need to have much of a mental health condition with the treatment touted for all kinds of ailments the list of treatable illnesses with a lobotomy included but was certainly not limited to ADD, OCD, anxiety, PTSD, postnatal depression, chronic pain, Alzheimer's, criminality, and violent outbursts. Freeman Everett Showman was responsible for a patient's death in 1951 when pausing a lobotomy to pose for a photo in doing so causing severe brain hemorrhaging he was even known to lobotomize two patients at the same time one with each hand the doctor even performed the operational minors including children as young as four in total around 15% of patients who received the lobotomy died but many more would change for life a shell of what they once were for those who survived the ordeal relapse would often follow but like its first unveiling to the world in Paris in 1936 the procedure didn't go uncriticized in the late 1940s as Moniz was set to receive his Nobel Prize multiple voices in the medical community spoke out on the barbaric procedure but it wouldn't be the criticism for the December banning of the procedure in the USSR but the synthesization of chlorpromazine the first anti-psychotic. As a side note Soviet psychologist Dr. Nikolai Orozetsky was quoted saying that lobotomies violate the principles of humanity and that was from an official from 1950s USSR. The procedure gradually fell out of vogue but Freeman would continue to perform the lobotomy all the way until 1967 when after their third lobotomy one of Walter's patients died of a hemorrhage this final procedure would get him banned from performing it ever again the USSR wouldn't be the last to ban lobotomies as even Moniz's Portugal would disallow the procedure from use. With further developments in drugs such as SSRIs, anti-psychotics and types of therapy like CBT the need for surgical intervention slowly faded away and by the 1980s lobotomy became a thing of the past. Now how would you rate the lobotomy on my ethical scale one being good and nine being pure cruelty let me know in the comments. This is the Plain and Difficult Production all videos on the channel are creative commons attribution share like license. Plain and equal videos are produced by me John in a sunny southeastern corner of London UK help the channel grow by liking commenting and subscribing check out my twitter for all sorts of photos and odds and sods as well as hints on future videos I've got patreon and youtube membership as well so if you fancy check them out to support the channel financially and all that's left to say is thank you for watching. When investigating the causation of disasters the Swiss cheese model was often brought up I know it sounds like a strange comparison to bring up cheese but bear with me imagine a block of holy cheese sliced some holes only go part of the way through it imagine an event say you tripping up on a child's toy this could have been prevented in a number of ways say telling your two-year-old to put their toys away after playing with him or looking where you're going in the Swiss cheese model either of these potential blockers for your painful fall would have averted disaster but say all of those failures or holes line up like how you can line up the holes in slices of Swiss cheese to see all the way through then disaster is inevitable here is a more official sounding explanation the Swiss cheese model likens human systems to multiple slices of cheese stacked side by side in which the risk of threat becoming a reality is mitigated by the differing layers and the types of defences which are layered behind each other this means that one failure wouldn't result in disaster however more multiple lapses in safety procedures and human factors line up those holes resulting in a bigger failure of the system's place to prevent disaster now I've got you thinking about tasty cheese you might be asking what has this got to do with anything well one such incident in tenerife in 1977 would be the perfect example of how this model works today we're looking at the collision of klm flight 4805 and pan am flight 1736 as such i'm going to rate it here seven on my patented plain default disaster scale but here nine on my legacy scale this is the result of an impatient pilot multiple communications failings by using non-standard phrases radio interference a lost plane on a runway a terrorist attack at another airport and poor visibility due to low clouds each individual situation may have not led to disaster but when added together the collision of klm flight 4805 and pan am 1736 almost became inevitable it is the 27th of march 1977 and members of the canary islands independence movement detonate a bomb in a flora shop in grand canary airport near las palmas grand canaria injuring eight as security forces scrabble to investigate a second bomb threat is called in not wanting to be responsible for a massacre the police are forced to shut down all traffic to grand canary airport whilst they search for the hidden device with multiple planes in the air the decision by air traffic control is to divert many aircraft to nearby los roddeus airport in tenerife now called tenerife north airport some 75 kilometers away los roddeus by the early afternoon was a wash with aircraft far more than usually experienced at the airport the airport had only one runway and one main taxiway running parallel to it with four short taxiways for connecting the two so much was the congestion on the ground that planes were blocking the taxiway forcing aircraft to taxi on the runway before positioning themselves for takeoff a procedure known as back taxing at the beginning of the shutdown pan am flight 1736's crew would have much preferred to stay in the air in a holding pattern as at 1315 they had around two hours worth of fuel however the flight was ordered to land in tenerife much to the disappointment of her crew and passengers much better for the passengers comfort to be ready to land when the all clear was given especially due to the long distance the flight had covered from los angeles with an intermediate stop at new york the crew on board consisted of captain victor grubbs age 56 first officer robert bragg age 39 flight engineer george warns 46 and 13 flight attendants along with 380 passengers mostly of retirement age the flight crew had over 30 000 hours of experience although not all covered on the Boeing 747 the crew were confident in the plane the pan am plane was quite a historically important specimen for the 747's legacy it had operated the inaugural 747 commercial flight on the 22nd of january 1970 not only that but the plane had the honor on the 2nd of august 1970 to become the first 747 to be hijacked another plane caught out during the disruption of services to grand canary airport was KLM 4805 which much like pan am 1736 had found itself diverted to tenerife the KLM aircraft was also a 747 and was chartered by the holland international travel group and had departed from Amsterdam airport shreephole neverlands the crew were also experienced but was captained by somewhat of a KLM celebrity jacob the hoosen van zanten aged 50 van zanten was KLM star pilot and head 747 training instructor so much was his value to the company that his face was even on advertising material for the airline his flying career started in 1947 when he gained his private pilot's license and by 1950 he had achieved his commercial certification and began working for KLM the same year by 1977 he had amassed over 11,000 hours of flying time 1500 of which were on the 747 accompanying van zanten on the crew of the KLM were first officer and flight engineer William Schrader again like the pan am flight the team combined had several tens of thousands of hours of experience by late afternoon grand canary airport slowly opened up to traffic again this meant that the much delayed and diverted aircraft could complete their journeys not wanting to be delayed further at its destination and not wanting to break the laws on duty crew working time van zanten took the opportunity to refuel the KLM where they were however this would block in other aircraft including 1736 for over half an hour much to the annoyance of the pan am which still had enough fuel on board for the final leg of its journey the captain and first officer left the plane to measure the gap between the KLM and the active runway but the distance was lower than the safe minimum they were obliged to wait the added delay was further compounded by a dutch family not going back to the KLM on time finally at 1656 van zanten's KLM radioed the control tower for clearance to taxi tennery airport is at 633 meters above sea level this has an unusual side effect clouds at 600 meters above ground level at the nearby coast are at runway level at Los Rodeos with clouds being blown in from the sea this creates variable visibilities where clear visuals one minute can almost instantly drop below minimums the next and the 27th of march was just such a day after three minutes of confused conversation at 1659 the instructions to proceed down the main runway and to backtrack for takeoff were received and understood by the flight crew these instructions meant that the KLM would turn 180 degrees once at the end of the runway in preparation for takeoff at 1702 the pan am called the tower for clearance to taxi this was granted but with the additional instructions to turn onto the third left taxiway pretty straightforward you might think but when you look at the diagram of the airport those instructions make little sense only two taxiways on site look viable for a 747 to make the desired turn to reach the end of the runway the taxiways were unmarked and by now visibility on the runway was concerningly low the pan am called up the tower to confirm that it was not indeed taxiway one instead of the requested three the atc replied abruptly third one sir one two three third third one the aircraft proceeded to taxi up the main runway marking off the taxiways to their left as they passed number one and two were successfully identified but lost in a thick fog the crew failed to identify number three a confused conversation broke out in the cockpit hinting that they were now lost meanwhile the KLM plane contacted atc to confirm that they had passed a fourth exit the tower replied okay make 180 and report ready for clearance almost immediately after the plane was in a position for takeoff van zanten pulled back the throttles and the plane started to move first officer mers advised van zanten that atc clearance had not been given and captain replied no i know that go ahead ask in doing so bringing the engines back to idle at 1705 the KLM confirmed it was ready for takeoff and awaiting atc soon after atc informed the KLM what their route was to follow after takeoff but no authorization for takeoff was actually given the KLM replied and confirmed the information given but added we are at takeoff which is a non-standard message atc replied okay stand by for takeoff i will call you back during this message the KLM experienced radio interference muffling the instructions van zanten interrupted the co-pilot's readback with the comment we're going taking atc's non-standard use of okay as authority to proceed the KLM released its brakes took power and started to move down the runway with atc not being able to see the two planes in the thick fog they thought all movements were still under control the tower then contacted the panam flight saying papa alpha report when runway clear to which panam replied okay we'll report when runway clear unbeknownst to the panam and the tower that whilst this final conversation took place the KLM had started on a head-on collision course hearing the communications between the tower and the panam the KLM engineer said is he not clear that pan american van zanten replied oh yes but still continued with the takeoff the KLM loomed off in the fog as it hurtled towards the panam captain victor grubb shouted there he is the panam was now near exit number four grubbs yelled god damn that son of a bitch is coming captain brag applied the throttles and tried to turn on to the grass off the runway in an effort to avert disaster shortly after the KLM crew saw the panam on the ground by now it's traveling too fast to abort the takeoff they rotated the aircraft and attempted to clear the panam by getting airborne causing a tail strike at a speed of 160 miles per hour and at a distance of 100 meters from the panam the KLM's nose gear cleared the aircraft off the ground but the left side engines lower fuselage and mainlanding gear struck the upper part of the panam's fuselage the result was ripping apart the center part of the panam almost directly above the wing the right side engines crashed through the panam's upper deck behind the cockpit the momentum of the takeoff speed of the KLM led to a brief time in the air but it had received critical damage and subsequently the plane stalled took a sharp roll and impacted the ground 150 meters down from the panam after impact the freshly fueled aircraft burst into an uncontrollable fireball engulfing all within seeing the inferno rescue workers made a beeline to the site of the KLM completely ignoring the panam in a miraculous turn of luck the captain first officer and flight engineer of the panam 1736 had survived this would come to haunt them for the rest of their lives the only survivors of the disaster was 61 members of crew and passengers aboard the panam many escaped through and now opened central part of the fuselage onto the still intact wings jumping to the relative safety of the runway all aboard the KLM perished most likely from the impact and fire when the aircraft hit the ground although not severely deformed the escape doors on the plane's fuselage were not operated the 61 survivors were promptly transported to Santa Cruz hospitals needless to say Los Rodeos airport the only operating airport on Tenerife at the time was closed to all fixed wing traffic this closure would last for two days to allow some clear up efforts with 583 dead 61 injured and two multi-million-dollar aircraft written off the only questions available are how and why initially KLM upon hearing about a collision involving one of their fleet set about assembling an investigation team the logical person for this task would be the head of pilot training captain jacob third hueson van zanten but the company would be shocked to find out at the helm of the disaster was their most experienced 747 pilot the investigation into the event would gain international attention in part due to it being a collision between a dutch and american airlines on spanish soil but also due to the entirely preventable nature of the crash both planes were sound mechanically and both crews had more than enough experience for operating in such conditions however van zanten did take off disregarding all the apparent warning signs for example his first officer not gaining clearance for takeoff and the atc giving no explicit instructions to allow him to which should have pointed him to stay on the ground in the back of the captain's mind was a recently imposed law on limits of time a crew can operate when the rule came into force it was relatively easy for a captain to work out how much time his crew had to work but after december 1976 the process to work out the amount of operating time left became too complicated this meant that crews could not work without fully knowing the remaining time and as such aired on the side of caution as a violation could result in not just punishment from the company but also dutch law this would have played on van zanten's mind and even on that of the crews were exceeding the limit with result in the plane being grounded at los palmas and could have cost the company money and affected plans back at home the theory of being stuck far away from home would have had an effect on the crew called fixation an almost tunnel vision like mental state where the goal is the most important thing and all potential hazards are ignored in the spanish investigation into the crash it was thought that this phenomenon along with communication areas led van zanten to believe that he had the authority to take off let's look at the communication areas that could have caused this the dutch investigation pointed out that during communications between the tower and both planes background noise could be heard from a football game being listened to this could have contributed to some confusion or distraction amongst communications also the tower had to deal with a higher than normal workload on top of that poor visibility due to low clouds no one could see where the other was also the instructions to the panam to use taxiway 3 would have resulted in a difficult maneuver for the crew to do leading to confusion and eventual loss of position of the plane during the vital clearance request stage once the KLM had lined up a misunderstanding led the crew to believe they had clearance the statement by the first officer we are ready for takeoff and we are awaiting atc clearance was responded to from the tower with your clear to papa alpha beacon which was the atc clearance the intention of the atc was to inform them of their route after takeoff that this was understood as you are clear to go the second part of the control towers message was to stand by for takeoff clearance which was continued by okay followed on with a two second gap ending with the message I will call you back captain van Zanten took power halfway through the reback of the first officer in the assumption that the authority had been given which was further reinforced by hearing the word okay his crew on board could have questioned the assumption that his seniority and experience led them to accept his decision the main cause the accident was the confusion in communication where the KLM thought it had clearance for takeoff or simultaneously the tower fought the plane was stationary the final potential diversion from disaster was thwarted by pure bad luck as the panam heard the word okay from the tower they feared the KLM could misunderstand this in desperation they radioed saying that they were still on the runway but this was blocked out by the towers two second gap between the words okay and I will call you back this created a squeal sound in the KLM cockpit and the warning sign was missed multiple failures lined up at tenor if which each individual one wouldn't have resulted in the crash but when each hole was matched the outcome was inevitable the Dutch government initially refused to accept that van Zanten was responsible for the accident but with red lent and KLM paid the victims family's compensation ranging between fifty eight thousand and six hundred thousand dollars the event shook the airline industry and helped push forward the understanding of human factors most importantly completion bias and fixation these issues still remain in all industries today but the greater of one's ability to recognize these can help prevent future disasters las rodeas has now been relegated to domestic and smaller airplane flights the airport has subsequently been renamed to tenor if north a newer more modern airport opened in 1978 and has taken the load of international flights named tenor if south which by 2018 would handle over 12 million passenger journeys per year this is a plain difficult production all videos on the channel are creative commons attribution share alike license plain difficult videos are produced by me john in a sunny southeastern corner of london uk help the channel grow by liking commenting and subscribing check out my twitter for all sorts of photos and odds and sods as well as hints on future videos i've got patreon and youtube membership as well so if you fancy check them out and all that's left to say is thank you for watching it is the 5th of october 1999 at around 8 a.m a newly qualified driver michael hodder prepares his class 165 train on platform nine at paddington for its next working to bedwin in wiltshire the station is bustling with travelers consisting of commuters and holidaymakers trains serve paddington from all over the southwest of england and south of wales and this includes packed local trains and fast intercity services the departure time is 806 a.m and the initial part of the train's journey was to travel over a very complex section of track which allows trains to enter and exit london paddington station part of this complex journey involves observing and obeying a signal known to be troublesome especially during times of the day when the sun is at its lowest but at just three minutes after departing as the train heads towards ladbrook grove disaster strikes and the free carriage train travels head on to an intercity train killing 31 and injuring 417 the disaster will highlight many shortcomings in the british railway industry spanning driver training signal training and will boost a growing need for infrastructure changes and a more modern train protection system as such i'm going to rate this disaster here six on my scale but here eight on my legacy scale as if you've travelled on a train in the uk but the aftermath of this event has pretty much ensured your safe travel the disaster at lab at grove was a long time coming with multiple failures within the industry but before we get into the accident we need to look at the development of the railway signaling systems safety on the railways has always been a difficult task as you're relying on humans to be faultless which as we know is not the case this is why we do things to mitigate this take the gear shifter in my car as an example to stop you from accidentally rolling forward you can't go into drive without your foot on the brake pedal trains benefit from high efficiency of movement due to the reduced friction surface between wheel and rail but this has a major drawback and that is in stopping distances and conflicting movements ever since trains have achieved speeds that can mean it can't stop within the line of sight the railway has tried to keep trains safely apart which is what signaling is for a conflicting movement is where one line joins another which needless to say is where collisions can occur railway signaling in its most basic form is to allow one train in one section at one time and the history of this goes all the way back to the early days of the network originally a timetable system was relied upon to ensure each train was kept at a safe distance but needless to say that this method of working breaks down very quickly if a train goes too slowly or stops unexpectedly next came block signaling which was controlled by the signaler for each block as a train passed through and passed the signal box the state of the line will be telegraphed to the previous and next signaler a natural progression of this was for the state of the line to be communicated to the signaler automatically via a track circuit the visitor work the sections or blocks of track are electronically insulated from one another via a thing called an insulated block joint which is made from a non-conductive material as the steel wheel and axle enters the block it completes a circuit which can revert a signal to danger and once the last set of wheels have left the block the signal can change to green showing the section is clear this is a good system but if a train passes a signal protecting an occupied block then a collision can happen and as such it can be made safe for steel by the use of a thing called an overlap the overlap in its most simplest explanation is a safety margin and is roughly 180 meters beyond the signal i do cover the overlap in a little more detail in my clap and junction video so shameless plugs out of the way let's look at how this system can be improved upon further steel this is where multiple aspect signaling comes into play where a red signal is communicated to the driver via the signals on the approach to it in four aspect signaling this comes with two types of cautionary aspect preliminary caution or double yellow and caution single yellow the next signal after caution is danger or red the signals and the driver's knowledge of the route allow them to drive accordingly within the permissible speed for the line so if you're going past a single yellow then you've got to be slowing down for that red ahead we can make this system even more safer with the addition of extra warning of the signals what if we can give the driver of the train advanced information on the signal aspect before the signal well that's where a thing called aws comes into play aws or automatic warning system gives an audible and visual indication of the signal ahead to the driver the way this works is via two magnets between the running rails on the approach to a signal at around 180 meters one the magnets is permanent and the other magnet is an electromagnet when a signal is at caution preliminary caution or danger the second magnet is de-energized this is picked up by a sensor underneath the train and sends a signal to a device called the driver's visual reminder or DVR which displays this sign and then this sound is heard the driver has around 1.9 seconds to cancel the horn using the aws acknowledge button if the driver fails to do this then the emergency brakes come on and bring the train to a stand for 60 seconds if the signal is green then the electromagnet is energized the sensor picks up on this as the train passes over the magnet and the DVR will display this sign and a bell sound will be heard the driver in this case doesn't have to do anything this system was introduced in the 1950s and helped improve safety on the railway but it has one major flaw did you notice it well aws's major problem is that both a danger and a caution signal create the same warning for the driver if it is acknowledged then the train can still sail past a red signal this is also a major problem in poor visibility as if the driver doesn't react appropriately then a signal pass at danger can happen which is why in today's railway if your aws is cut out then you can only travel at a maximum speed of 40 miles per hour in situations of bad visibility this is a big problem and throughout the 1980s the rail industry tried to find a solution but we'll look more into this later on but first let's look at junctions in colour light track circuit signalling junctions are protected by signals much like ones used on normal running lines but instead of being controlled by the passage of trains they are controlled by the signal and as such are known as controlled signals diverging and converging points are when a train changes from one line to another and these are navigated at various speeds depending on the layout of the track and the condition of the track clearly when a train is passing through a junction you'd want to stop all other conflicting movements this necessitates bringing a train to a stand at a red signal if a train is to be signalled from one line to another a driver could receive one of two indications a junction or route indicator both do pretty much the same thing junction indicators can only convey seven routes whereas a route indicator usually consisting of a fiber optic display county and theory display an unlimited number of routes well that was my brief introduction to rssb signalling rules let's return to october 1999 and the 806 to bedwin the class 165 diesel multiple unit was operated by a post privatisation company called tems trains the company had been working the franchise since 1996 and boasted a fleet of 57 trains 53 year old driver brian cooper was working his hst which made up of the 603 first great western he had been driving for just over two hours and was making good progress the hst dating from the late 1970s was made up of two power cars and eight mark three slam door carriages driver cooper was on the final part of his journey to paddington as part of this he needed to navigate the upper mainline there in total six bi-directional lines on the approach to london paddington with trains moving in both directions as traffic flow increases in the morning it is a regular occurrence for trains to be held at signals to allow intercity services to terminate and this morning is no different driver cooper is receiving clear aspects although single and double yellows but the closer he gets to paddington he starts to see greens driver hodder upon receiving a clear signal at paddington departs at around 806 on time he departs on a green and a route indicator for line four his next signal is also green by now he has taken power up to around 44 miles per hour he receives a horn and a caution indication from the aws and he acknowledges it this prompts him to slow down to below 40 miles per hour expecting the next signal to be single yellow again the aws shows a warning on the approach to signal sierra november 87 he is given a junction indicator to the left he is now heading for line three he should be slowing right down and looking for his next signal which should be red but he just coasts along at near 37 miles per hour by now the sun is low and is bleaching the next signal sierra november 109 the light bounces off the lens making it look yellow the aws goes off exhibiting a warning and like before he cancels it but he is now fallen into the trap of the limitations of the system the signal is actually red thinking that the line is clear he takes power to just below 50 miles per hour the train continues across the points onto the down main driver cooper of the hst on the approach to signal sierra november 120 at green notices something a driver does not want to see his signal turns back to red in front of him the train is traveling at 81 miles an hour and cooper slams on the brakes meanwhile driver hodder sees the hst in the distance and slams on his breaks the two trains collide on a combined speed in the region of 130 miles per hour the hst and the turbo were offset due to the angle of both trains resulting in a glancing blow of the turbo train due to the hst being an older design crumple zones were not built in which resulted in the tems train taking the brunt of the collision both drivers of the trains were killed instantly with the hst driver brian cooper being thrown from the wreckage the power car of the hst rose up and fell towards the right multiple carriages of the hst were derailed and during the impact fuel tanks and the tems train were ruptured sending the wreckage into a fireball an emergency call was made at 8 10 a.m and fire crews from north kensington fire station arrived a minutes later they were confronted with a fireball and a cloud of smoke as more fire crews police and london underground emergency response units arrived rescue operations began the derailed carriages were secured enabling passengers to be recovered from the intact parts of the trains but many were trapped in the mangled wreckage first responders bravely fought the fire and helped find survivors in the wreckage much like what we saw at the moor gate and at clappham rescue workers went well above and beyond what was expected of them in total 31 people died in the crash 24 were on the tems train and seven were on the hst nearly all of the deaths were related to the initial and subsequent impacts but one of the victims died later in hospital due to the effects of the fire in total 417 were injured in the accident with many experiencing severe burns after recovery of the bodies clearing works could begin which involved a crane starting on the 9th of october the last carriages of the wreckage were removed on the 13th of october with such a tragic disaster investigators looked into the cause that could lead to such an event the obvious cause being the signal past the danger but the actual cause ran much deeper and would point the finger directly at the railway industry the course of the accident might seem straightforward but it can be divided into two parts what the driver could have done to prevent the spad and what could have been done to mitigate the after effects of the spad signal seara november 109 was notorious for drivers that worked trains in and out of paddington before october 1999 there had been eight known incidents where a train had passed its movement authority at the location since its re-signalling in 1993 because of this seara november 109 was classed as a multi spad signal meaning it had been passed multiple times when at danger the number of incidents at the signal put it in the top 22 most past signals in the country leading it to be described as a black spot multi spad signals are not a unique thing on the railway and can be caused by a combination of infrastructure and human factors that make them high risk places train operating companies have certain processes to make drivers aware incidents through the use of notice boards and incident folders where staff become for duty but ultimately it is down to the driver to know the risks of the route over which they drive one such way to prevent incidents is in the use of defensive driving which is where a driver reduces their speed when driving under restrictive aspects this strategy was known by tem's trains and information had been passed out to drivers although little extra training had been given needless to say if you're new to the job then there's a higher risk of not knowing instant hotspots and thus a higher risk of contributing to the spad statistics but this is usually mitigated through training driver hotter of the tem's train had only been qualified for two weeks before the collision which brings the question as to whether his training was adequate during the investigation it was found that driver hotter's training was far from acceptable you see privatization of the british railway operations was still relatively new and as part of the dismantling of the national network into multiple small private train operating companies the standard of training varied as companies sought out to streamline their syllabus back in the br days a more unified experience for driver training was used where a similar standard was set irrespective of depot and driving location this was due to a driver essentially having to learn both passenger and freight services the situation at tem's trains was pretty dire leading up to the disaster and this was mainly linked to training and management the company had twice the industry standard number for signal pastor danger six of the eight spads at seo and november 109 were attributed to tem's trains although having a terrible record the company hadn't made any serious improvements to its root learning training root maps were never provided and during root training instructors didn't see it as part of their job to teach characteristics of the lines driven this led to a serious gap in driver hotter's knowledge of the paddington to elaborate grove area but the buck doesn't stop at the driver's mistake as humans make errors it is also down to the railways industry as a whole to mitigate the danger resulting from an accident the hsc investigation led by law cullen highlighted multiple infrastructure issues you see seo november 109 had a very dangerous layout of its signal heads in an unusual un non-standard reverse l shape when compared side by side you can see how this setup could lead to confusion the style of the signal head also can create a high risk of misreading as they are susceptible to a thing called bleaching where sunlight reflects off the lens washing out the color displayed in the modern day railway rulebook a bleach signal should be reported to the signaler using the rt3185 form which would have also given the signaler a chance to inform driver hotter what the actual aspect on display was after resignalling in the area multiple complaints came in from drivers about the sighting and risk of read across for gantry 8 which housed seo november 109 as part of the modernization and electrification of the uk railways the paddington area have received overhead line equipment in 1995 this required the installation of stanchions the infrastructure installation further added to the cluttered visibility of gantry 8 the addition of banner repeaters was put forward which would have given an advanced visual indication of the signal ahead but these were not installed due to cost implications and the fact that the line speed would be restricted it was also found that during the re-signalling of the area a type of anti-collision system could have been implemented and that is called flank protection when a signal was held at danger at a junction the points can be set so that if a spat occurs the train can be directed towards the route least likely to cause a collision although in theory a simple addition it would have required the routing computer to work out the least dangerous route to be set which could have operational issues as it adds another level of complexity the other reason that the system was not implemented was the belief that a type of automatic train protection was just around the corner and this leads us to the final thing that could have prevented disaster automatic train protection during the final years of british rail and in the aftermath of the Clapham rail disaster a form of train protection was in the making you see underground lines the Wattford DC and a number of other routes had a type of protection called tripcock train stop as I mentioned in the Moorgate Crash video is a form of stopping the train after a spad by means of mechanically activating trains brakes the system is reliable and has shown great results in preventing collisions from conflicting movements and spads but it did have a number of drawbacks one such thing is that it is not very reliable at high speeds due to the tripcock potentially being damaged if struck too hard it also added a certain level of complexity and that is of the lowering of the train stop because of it being a mechanical item either electricity or as employed on the underground air is needed to lower the train stop this resulted in british rail looking for another form of protection and the system they sought to trial was called ATP this employed beacons in the track that would stop a train if passed a signal at danger without authority the system was installed in the 1990s on the Paddington to Bristol route which ran right through signal Sierra November 109 and was active on the day of the crash but installing the train mounted system was time-consuming and expensive many trains had ATP fitted including the HST involved in the crash although it was defective on that particular train tems trains had employed engineering firm ws atkins to perform a cost of benefit analysis for fitting their trains and track with the ATP system it was found that the cost of benefit was not significant enough to employ ATP and as such tems trains rolling stock was not retrofitted part of this analysis also took into account the cheapest system called train protection and warning system which was also being trialled elsewhere and was looking to be the preferred system thus leaving ATP obsolete ws atkins came under criticism by overestimating the cost of installation of equipment by costing the installation of line side equipment which in most cases would have been paid for by rail track the company in charge of uk railway infrastructure at the time all of which factored into tems trains decision to not install ATP all of the factors from driver error to lack of safety system led to the disaster which changed the railway industry forever tpws has been installed on most main lines in the uk now and greater emphasis on training and personal protection strategies have increased safety on the railway but sadly accidents still happen we saw this recently with the chow font and latimer near miss where tripcock brake demand was reset resulting in two trains nearly having a head on collision another improvement that can be seen rolling out across the network today is the use of led type signal heads these are less susceptible to bleaching from the sun and although not perfect they are a step in the right direction and even more advanced step in train protection than tpws is etcs a type of in cab train control and signaling which ironically is being rolled out on some parts of the great western mainline this system has other benefits in achieving automatic train operation like what can be seen on the tems in core where train is fully controlled by signaling the disaster has changed the uk railway industry for the better but even still those tragic deaths on that day in october 1999 will still leave a mark on the industry this video is a plain difficult production all videos on the channel are creative commons attribution share alike licensed many different videos are produced by me john in a currently very wet and gloomy corner of southeast london uk help channel grow by liking commenting and subscribing check out my twitter for all sorts of photos and odds and sods as well as hints on future videos i've got patreon and youtube membership as well so check that out if you fancy supporting the channel financially and all that's left to say is thank you for watching throughout history mankind has sought to answer what happens after death after all the end of life is part of the human condition in an effort to alleviate our fears of demise many theologians religious scholars and scientists have sought to discover proof of the soul and to a greater extent where it goes post death one such scientist was set out to find if the very center of our being has a physical weight although an impossible task you might think a theory was conceived that concluded that a soul weighs around 21 grams derided as a case of selective reporting the theory would see widespread rejection within the scientific community despite this many see the results as a hopeful glimmer of life after death in order to prove this the study would go down a dark path welcome to the dark side of science it is 1907 and a new theory of proof of the soul is leaked in the new york times the headline exclaims the soul has a weight position from hava hill massachusetts duncan mcdougal thinks but our story starts all the way back in glasgo in 1866 with the birth of duncan mcdougal he emigrated to hava hill massachusetts in the united states at around the age of 20 shortly after emigrating he attends the boston university school of medicine receiving his medical degree he would return to hava hill where he would meet mary and have a son in the mid 1890s like many people of this era mcdougal was fascinated with death and the human condition as such he devised a way to prove the existence of the soul he surmised that if we have a soul that it must hold a physical space and therefore can be weighed once death is complete then in theory as consciousness is extinguished when the soul leaves the body then the weight of the deceased will change in his 1907 hypothesis published in the journal of the american society the psychical research he said since therefore it is necessary to the continuance of conscious life and personal identity after death that they must have a basis that which is space occupying or substance the question arises has this substance weight to prove the theory mcdougal needed access to people near the point of death but not only that but also incapable of being able to move as this would make conducting the weighing easier and more accurate as said by mcdougal himself it seemed to me the best to select a patient dying with a disease that produces great exhaustion the death occurring with little or no muscular movement because in such a case the beam could be kept more perfectly at balance and any loss occurring readily noted needless to say this task is easier said than done as very few people in their last moments of life would be willing to take part in a study but a disease that killed roughly 25 percent of the adult population would create a ready supply of bed ridden subjects and this was named consumption or better known today as tb the disease takes a relatively easily predictable progression allowing sufferers time to make arrangements for their affairs post death this prediction of the time of death was assisted with the discovery of the x-ray in 1895 by Wilhelm Röntgen as the disease was spreadable by kissing coughing breathing or sneezing many sufferers were sent to homes for treatment and to stop the spread one of these was Dr. Cullis's consumptives home between the 1860s and 1890s the institution based in Roxbury Massachusetts had taken care of over 2000 critically ill patients Dr. Cullis believed in cure by faith in which prayer would help heal the sick although not the most scientific method the home offered comfort and care for its patients back doogle had been refused by many homes for his morbid study into the point of death but Cullis's home offered an opportunity for McDougal the faith based institution who agreed to allow the scientific experiment thought that proving that the cell was real could have both spiritual and medical importance in total six dying people would volunteer for the experiments the process set out for the experiment involved taking the patient as their last moments approached and placing them into a cot suspended from a fair bank scale sensitive to two tenths of an ounce due to the progression of the disease the patients were so ill they did not move allowing the measurements to be accurate McDougal and two physicians carefully observed the patient noting the weight on the scale as the moment arrived they recorded the exact time of death and looked for any change of weight at that moment the experiments would start on the 10th of April 1901 when the first volunteer was wheeled into a room which housed the cotton scales the man continued to breathe for three hours and 40 minutes before death suddenly coincident with death the beam end dropped with an audible stroke hitting against the lower limiting bar and remaining there with no rebound the loss was ascertained to be three fourths of an ounce or roughly 21 grams the second subject a man also suffering from TB was observed for four hours and 15 minutes before his death at which time the weight dropped half an ounce all more patients will be observed by McDougal patients three and five were observed losing a small amount of weight but four was discounted due to scale failure and six was disallowed due to the patient dying was entering the cot in McDougal's thinking animals didn't have souls so as a control of sorts he conducted the study on 15 dogs he would later state surrounded by every precaution to obtain accuracy and the results were uniformly negative no loss of weight at death although not explicitly stated it is likely that the dogs were poisoned in order to measure the moment of death the tests on the d