device, either a figure eight plate or repel rack, and stops the descent. This is also known as a bottom belay. Another example of a single line belay is a single line self belay. Here, protection against a fall is also provided by the same rope that supports the repeller. As in the double line self belay, there's a prusik or mechanical rope clamp attached to the rescuer's harness. But instead of a separate belay line, the belay device is connected to the repel line. When a rope clamp is used, the connection between the rescuer's harness and the rope clamp is made using an intervening short slinger prusik. This creates the necessary length to allow the rope clamp to be attached to the rope above the repel device. The repeller guides the belay device with one hand while the other hand manages the rope below the figure eight plate. Because a repel rack requires both hands to properly manage it during a repel, it's difficult to use a single line and double line self belay with this device. Single line belays are said to be conditional, meaning that they will only work if the repel line and its anchor remain intact. If the repel line breaks or the anchor fails, the belay fails. When these belay systems are managed by the person traveling on the rope, they are also conditional on that person's ability to manage the belay device throughout the descent. When the double line or single line self belay is used during a repel evolution, the possibility exists that the belay device could become loaded and set on the rope. If this occurs, it is necessary to unload the belay device so that it can be released. If you have an extra prusik or rope clamp and an atria or foot sling with you, they can be used to take your weight off the belay and free the belay device. If this extra equipment is not available, then the following procedure should be used to release the belay. First lock off the descender, bend one leg and wrap the repel rope around the foot on the bent leg. The girth hitch will work here also. Pull the tail end of the rope up and hold it together with the rope above the descender. Straighten the bent leg and stand up. This should transfer the weight from the belay device to your leg and will create slack in the belay. Release the prusik hitch or, if a rope clamp is used, release the cam. Once the device is repositioned, bend the leg again and transfer your weight to the harness, making sure that the belay is manageable. At this point, unlock the descender. Now you should be able to continue your descent. There is another type of belay that should be mentioned here. That's the climbers belay. When a rescuer is not repelling or traveling on a raising or lowering system, a belay can still be used. Sometimes the rescuer must climb up or traverse a cliff or some structure, such as a bridge or tower in order to reach the victim. Here the end of the belay line is attached to the climber. The belay line runs through a number of carabiners that are attached to points along the route of travel. These protection points are set by the rescuer as progress is made. A belayer manages the belay line through a friction or ratchet belay device secured to an anchor at the point at the start of the rescuer's route of travel. The belayer lets out slack on the belay line as the rescuer progresses toward the victim. If the rescuer falls, the belay line goes slack back to the last protection point where the fall is arrested by the belayer. Here I should discuss the important points related to the management of the belay line by the person who is stationed at its anchor point. As I mentioned before, the best and safest system is the one that incorporates a belay with a separate anchor point and a separate person to manage the belay line as it passes through the belay device. Time for another rule. Always use a belay. Whenever possible, use a belay incorporating a separate line, a separate anchor, and a separate person to manage the belay. The anchor point must be strong enough to support the whole load even with the added force created by having to stop a fall. A load releasing hitch must be placed between the anchor sling and a ratchet belay device. This gives the person managing the belay the ability to release the line if the belay device becomes set on the rope for some reason. A second load releasing hitch should be kept nearby so that the one in service has to be released. It can be replaced without having to stop and retire. The next component of the belay is the belay device itself. This is where the controversy lies. Several different kinds of belay devices are used to do the work of catching the load in the event of a fall. Some are better than others, some just don't work at all. These devices can be divided into two categories. First, there are friction type belay devices. These include figure 8 plates, stitch plates, brake bar racks, and other friction systems such as running the belay line through a series of carabiners at opposing anchor points to create enough friction to give the person managing the belay line the ability to catch the load when a fall occurs or the haul line fails. The second type of belay devices are ratchet belay devices. These include prosthics and mechanical rope clamps such as the Gibbs Ascender. These ratchet devices are auto belay devices because the person managing the belay doesn't have to arrest the fall by holding back on the line as with the friction devices. The belayer merely lets go of the device and it grabs the belay line by itself to stop the load. Drop tests on rope rescue belay systems have been conducted since 1982. To the best of my knowledge, the latest comprehensive tests were done in Denver in 1987 and in Sedona, Arizona in 1989 by a group of rope rescue experts from the U.S. and Canada. These tests were documented by John Dill in a series of articles in Response Magazine in the summer and fall issues in 1990. John is a SAR tech for the National Park Service in Yosemite, California. The articles titled Are You Really on Belay are available from the National Association for Search and Rescue in Expanded Form. These tests used parameters that were set by the British Columbia Council of Technical Rescue and seem to have been a reasonable place to start. According to the articles, the belay device in these tests was attached to a rigged overhead anchor. A test specimen of belay rope was rigged to the device and the end of the rope was tied to a test block weighing 200 kilograms, 440 pounds, to simulate the weight of a two-person load. The NFPA standard for a two-person load is 600 pounds. The test block was also connected with a quick release link to a cable winch that acted as the haul line. The block was winched to a position 3 meters, 9 feet 9 inches below the belay device and the rope between the block and the belay device was made snug enough that there was no obvious slack. But not so tight that the device gripped more than it normally would before a fall. As though a belayer were keeping the rope hand-tight. To create a fall with 1 meter, 3 feet 3 inches of slack in the line between the block and the belay device, the block was simply winched up that distance, the drop height and the release from the cable. The articles also described what the belay must accomplish. One, it must catch the falling load. Two, the belay rope and system must survive the event sufficiently undamaged to allow the rescue of those hanging on the rope. Three, the maximum arrest force must not cause injury to rescuer or victim, nor may it cause system failures such as pulling out an anchor or cutting the rope over an edge. Four, the stopping distance must be short to prevent the load from striking obstructions during the arrest. Five, the system must work in any environment you may encounter, wet, icy, etc. And it must work with the other equipment you use. Six, it must be user-friendly. That is, you must be able to operate it properly when you're cold, wet, bored and out of practice, since most accidents are due not to equipment failure but to improper rigging and handling. These tests were performed in several different ways on a number of belay devices and yielded some interesting results. First, the friction type belay devices were inadequate to hold a 200 kg load, let alone arrest a fall. Of course this may not be as simple as I just stated because if enough friction is created, the load can be easily held in place. But remember, for the belay line to remain slack enough not to support the load and allow the belayer to let out and take up the slack as the haul system does its work, an unreasonable amount of friction is prohibitive. So basically when used in the normal manner, friction devices were inadequate to belay a two-person load. However, they may still work reasonably well to catch the weight of a single person load. This leaves ratchet belay devices. The commonly seen ratchet devices are the Gibbs Ascender and the Prusik. During the drop tests I've described, the Gibbs Ascender and other mechanical rope clamps either stripped or caused the belay rope to part, an unacceptable result. A single Prusik on the other hand performed much better and was able to successfully catch a fall of one meter. When Prusiks were used in tandem, one behind the other, they consistently caught falls of one meter and greater. At this point I must caution you against assuming that Prusiks will work without a hitch, pardon upon. There are many things to consider when using Prusiks as belay devices. I'll just mention a few. First, the material that the Prusik loops are made from is important. Prusiks should be eight millimeter diameter nylon current mantle, low stretch accessory cord. The suppleness of Prusik cord is critical. Accessory cord used for Prusiks must pass a pinch test in which the cord is bent in two to form a bite. At the point of the bite, the distance between the cord should be no greater than a diameter of the cord. This suppleness is necessary so that when the Prusik hitch catches on the belay rope, it will set and not slip excessively. I know of three brands of accessory cord that meet this standard. They are Mammut and Edelrid, both of European manufacturer and New England Prusik cord. This is not to say that there are no other effective accessory cords available, but they must pass a pinch test. The length of tandem Prusiks is very important to their successful operation. They should be cut to four feet five inches and five feet five inches in length respectively. The cord should be tied into loops using a double overhand bend, leaving a two inch tail on each end. A three-wrapped Prusik hitch should be used to secure each loop to the belay rope. The longer loop goes towards the load on the belay rope and the shorter loop toward the anchor. There should be approximately four inches between the two Prusik hitches on the rope when under load. The loops are then clipped into a carabiner which is attached to the load-releasing hitch. During a raising belay, the person managing the Prusiks cradles the Prusik hitches in one hand and pulls the belay rope through the hitches with the other. The key here is to keep the Prusik hitches just loose enough on the belay rope so that they don't catch needlessly, but not so loose that they fail to catch the rope if the belayer lets go. The same process is used on a lowering belay, except the rope is pulled in the opposite direction. There's a second option on the raising belay. Here, a Prusik mining pulley is also attached to the same carabiner on the load-releasing hitch that the Prusik loops are attached to. The Prusik mining pulley manages the Prusik hitches while the belayer simply pulls the belay rope through the pulley. We have been successful in teaching firefighters to use a single Prusik to belay a single person load and then to move to the tandem Prusiks to belay a two-person load. This approach seems to be a natural progression. It lets the student get familiar with single Prusik management techniques before attempting the more complicated tandem Prusik belay. As a final comment on Prusiks's belay devices, I like to quote from John Dills' article. If you decide to belay with Prusiks, do not just tear out the recipe above thinking you have the problem licked. Learn Prusik belaying from someone with lots of field experience and a will to live.  Good advice. The tactical key to any rope rescue is to keep the rescuer's job as simple as possible. As an example, suppose you are rescuing a stranded window washer from the local high rise. Assuming you can go to the roof and perform the rescue from above, there are a number of choices to make as to the type of rope system to use. One, a rescuer can repel down to the victim, attach the victim to the rescuer's rigging, and continue the repel to the ground or a position of safety. Two, a rescuer can be lowered to the victim, attach the victim to the rescuer's rigging, and continue the lowering operation to the ground or position of safety. Three, a rescuer can be lowered to the victim, attach the victim to the rescuer's rigging, and then be raised back up to the roof. Here, the correct choice is to lower the rescuer to the victim and then lower the rescuer and victim to safety. The rescuer's job is difficult enough without having to manage both the repel operation and the victim. And of course, lowering is always easier than raising. So here's another rule. Always design the system to make the rescuer's job as simple and therefore as safe as possible. If this thought process is carried out during rope rescue operations with all factors included, the simplest, safest plan should become apparent. Remember the old adage that the two greatest reasons for rope system failure are improperly tied knots and rope abrasion. Always safety check the system prior to operation. Pay particular attention to knots and pad sharp edges that the rope may run over. Always have a designated safety officer. If enough personnel are available, safety should be the safety officer's only job. Don't do things you haven't practiced or don't feel comfortable with. Get training from experienced, qualified instructors. Test the systems you use to see what happens when they fail. It's not that difficult. Use the kiss principle. Keep it simple. Remember nothing's foolproof. Rich? This sounds like another case where you need to take individual responsibility for yourself and check every inch of that rope before you use it and make sure you know that it's ready to do the job for you. That's always required. Good. Thank you, Tim. We'll talk to you soon. Thank you. Thanks a lot. All right. Our next guest now is Captain Tim Gallagher of the Phoenix Fire Department. We're going to talk about water rescue, another massively challenging kind of event, and you've got some very innovative little techniques to show us. Appreciate having you here. Thank you. We appreciate that much. You know, of all types of technical rescues that we've been called upon to perform, arguably the most dangerous and certainly the most dynamic are water rescues, specifically swift water rescue. When I say dynamic, I'm referring to how quick things can happen and change in the course of a rescue. The speed in the force of the current necessitate quick and decisive action on the part of rescuers. A miscalculated or poorly timed decision can turn rescuer to victim in a moment without notice. Because most of the water rescue-related problems and deaths we've had in this country in the last few years have been associated with floods, we'll spend most of our time today discussing our operational objectives with regards to swift water rescues. As first responders and rescue professionals, we must understand and recognize the hydraulic effects associated with moving water. One of the characteristics of swift water is that it is very predictable. If we understand the hydraulic effects associated with moving water and are able to recognize them, we are better able to make intelligent decisions about our level of commitment to these hazardous situations. We must also be able to recognize and identify the hazards associated with these type of operations. We better know what we're getting ourselves into when we respond to the scene of a swift water rescue. Probably the most obvious hazard to talk about with regards to moving water is the current itself. Understand that water obeys the square law and that if you increase the speed of the moving water by two times, the forces associated with it are increased by four times. To give you an idea of what kind of forces we're talking about, with chest deep water moving approximately 20 feet per second, it imposes approximately 500 pounds of force or pressure against the body. The best trained and biggest strongest rescuer cannot withstand those kind of forces for more than a few seconds. In flooding situation, water moves down a path, basically wherever it wants to, and scours the earth taking with it any and everything in its path. We call these loads, top load, suspended loads and bottom loads. Top loads are those things that are floating on the surface. They are lighter than water and positively buoyant. Depending on the size and the shape, if we are struck by one of these objects, it could cause serious injury. Suspended loads are those things that are moving downstream with the current suspended in the water. They're not so heavy as to sink to the stream bed and not so light as to float to the surface. They are neutrally buoyant suspended in the water. Once again, depending on the size and the shape of those objects, if we find ourselves out in the water struck by one, it could cause serious injury. The real problem with suspended loads is that you don't see them coming. Bottom loads are those things that are heavier than water. They sink to the river bed. They're negatively buoyant. Depending on the size, the shape, and the weight of those objects, they could be rolling along with the current or stationary in the water. The problem with bottom loads is that anyone caught in the water is set up for what we call foot entrapment. If a rescuer or a victim gets his foot trapped in the upstream side of a bottom load, they're held stationary in the water. In a moment without notice, the rescuer can become a victim. Other hazards to identify and recognize are strainers.  Just like the name implies, it allows water to flow through the strainer, but traps anything suspended in the water or floating on the surface. The real problem with strainers is that the water hits the upstream side of the strainer. It is forced downward and causes a tremendous undertow beneath the strainer. For anyone caught on the upstream side of the strainer, it's only a matter of time before the victim is swept under the surface and drowns. Many times every year, when someone has been missing in flooding situations, after water is recede, we typically find the victims caught underneath the upstream side of the strainer. Other hazards to be aware of are holes. Holes are vertical reversals of water flow caused by water flowing over an obstacle. When water flows over an obstacle, a rock or a face of a dam, it flows downstream and boils back to the surface. At that point, part of the water moves downstream in what's called the outwash, and part of it moves back upstream in what's called the backwash, and gets recirculated back up to the face of the dam. The problem with holes is that as the victim gets recirculated time and again inside the hole, they lose all perspective as to which way is up, down, river right or river left. These hazards are commonly referred to as drowning machines. Another hazard to keep in mind is the potential for hypothermia. In Arizona, where I come from, hypothermia is not much of a concern, but understanding that water absorbs heat away from the body 25 times faster than air, it's only a matter of time before anyone in water less than body temperature becomes hypothermic, if they are not wearing the proper thermal protection. As water rescue professionals, it is absolutely imperative that we recognize the hazards present during water rescue operations. As part of our initial and ongoing size-up of the situation, we must account for the hazards present, including the speed and the force of the water, the temperature of the water and any other hazards that may pose a threat to victims and rescuers. Let's talk for a few minutes about the proper personal protective equipment necessary for conducting these type of operations. Probably the basic piece of equipment is the personal flotation device or PFD. A U.S. Coast Guard approved type III or type V personal flotation device, as shown here, would be the proper type of device when operating in or near the water. It should be a matter of procedure that anyone directly involved in the rescue operation shall be wearing an approved personal flotation device. Another piece of personal protective equipment necessary for conducting water rescue operations is a helmet. The standard wide brim fire department helmet used for structural firefighting would not be the helmet of choice for conducting water rescues. A helmet that provided high visibility, low profile and high impact resistance, such as the helmet shown here, would be the helmet of choice for conducting these type of operations. Because of the debris that litters the bank during flooding situations, we would not want to overlook the use of proper footwear. The wet sock, wetsuit, booty and low cut tennis shoes, as shown here, does not provide the proper level of protection during swift water rescue operations. The standard leather high top zip up boots that firefighters wear with their fatigue uniforms provides good ankle support, good puncture resistant sole support, and a minimum level of thermal protection for conducting these type of operations. Another important piece of personal protective equipment would be thermal protection. The ambient temperature and the temperature of the water should dictate the proper level of thermal protection. A good three millimeter to quarter inch neoprene wetsuit should provide enough thermal protection for rescuers operating out in the water. We must keep in mind that cold water is a hazard to anyone and we must protect ourselves accordingly. With any rescue operation, we must use the proper personal protective equipment to help ensure the safety of rescuers throughout the operation. Now that we've talked a little bit about hydrology and the hazards and equipment, other considerations when extricating the victim from agro... Got a little problem here? Let's talk about our operational objectives for conducting these type of operations. Probably the simplest operation would be to talk the victim into self-rescue. If that is not possible, we would want to consider our low-risk operations available to us. Reach, throw, row, go, and healer would be the proper order of rescue for conducting these type of operations. To reach for the victim, we would like to reach out something such as a broomstick, a pole, or in this case is shown here a pike pole to reach to the victim so that when the victim is able to grab on to the pike pole, we can pendulum belay them back to the bank or the shore. Tim, you know, an interesting thing, you were making some points there. There are several levels of risk involved in these kind of risk operations. You want to just go up the ladder one time? Let's talk about low-risk first. Well, when we talk about our low-risk type things, certainly we talk some of the low-risk injuries that are associated with these type of operations would be, for instance, I mentioned the proper footwear. That's a very common injury on the scene of some of these rescues because of rescuers not wearing the proper foot protection. That not only includes the sole support for puncture resistance, but also the ankle support for twisting your ankle on rocks, trees, things like that. And in the rescue itself, if you can talk the victim into taking care of themselves, you're better off asking a lot of people. Oh, absolutely. Any time. Tell us a little bit about that. Any time we can talk the victim into self-rescue, what we're doing for ourselves is not having to expose rescuers to the hazards. And if the victim is capable of moving over to the bank that we can reach, so that we can reach him, that's going to be absolutely the lowest risk option available to us. Yeah, now one of the things that I know we've done is you can have a tether line on your person and bring them into the shore without, again, sending a rescuer out too. Well, as we see here, we're going to have a tether line on the shore. And this would be an example of reaching for the victim, to reach out something to the victim that they could grab onto, and we could belay them or tow them over towards the bank. Now, in this case, though, you only have one chance at it. So wouldn't you need to have some people stationed as they go down in case you missed? Absolutely. Command must consider, we must consider having personnel in position downstream because of the speed of the moving water. Typically, we only get one chance to rescue the victim. And if we miss that opportunity, we must have personnel downstream so that they're going to be able to get to the victim before they're swept in. Now, let's take a look. This one fascinated me, and we'll run this video here in a minute. This is with a fire hose, something very, very simple that any department can do. Absolutely. It is considered to be a very low-risk option available to us that we could reach the victim with. In the case, what we've done in Phoenix is we've actually welded three and a half inch male fitting and three and a half inch female fitting together and put a couple of valves on there, and then we simply fill the inflated fire hose, or we fill the fire hose with air to about 30 to 40 pounds of pressure, and this allows the victim to grab on to that. Okay, now once he's on it, how does he work his way back, or is there an angle that you can? Well, what we can do is just let go. What we're going to do is just hang on to one end of that hose, and then the rest of the rescuers let go, and the current will naturally pendulum that hose over towards the bank, and then we can reach the victim. So you're going to want to let go on the shore, let go on the middle of midstream side, and let it swing itself back into shore. To the bank that the rescuers are standing on. Sort of like the way you dock a boat. Exactly. To some extent. Okay, now you can also send people downstream. Now this is the kind you see on Rescue 911 a lot, where you have a whole bunch of people downstream, and making various kinds of efforts. Is that a good way? Does that raise the level of risk? Well, anytime we have personnel operating near the water's edge, it's going to be a risk to those personnel, but if they're trained properly equipped, and we have an operational plan, we have an action plan in place, there should be no problem at all if rescuers are trained to know exactly what to do. Okay, what about throwing stuff to the victims? Well, let's talk about that. That's raising it up. Now, let's look at this. Tell us what we got here. Okay, what we're doing is we're setting up what we call a boat base operation. We've inflated the fire hose, and we're deploying that on the downstream side of the bridge, in an attempt to reach the victim as they're moving downstream. We set this up on the downstream side of the bridge, and in the case shown here, we'd have a spotter on the upstream side of the bridge spotting the victim, so that the rescuers on the downstream side are going to be able to move into position properly here. Is that what this guy's doing here? He's spotting from the upstream side, because typically the rescuers on the downstream side can't see the victim, they're going to spot him in position like the tape is showing right here. The victim grabs the line, grabs the hose, I should say, the rescuers let go of it, and he pendulum belays over. We would like to have another rescuer downstream with a throw bag that we can throw a rope to the victim to help pull them out of the water. Let's make a safety point here too. Now, obviously this guy is one of your crew. He came downstream feet first. We need to make a good point of that. We want to avoid going downstream heads up, right? Absolutely, and we'll talk for just a moment about the the proper swimming position here. Probably the next option available to us would be to throw to the victim, to take a throw rope bag and throw to the victim at approximately 45 degrees upstream to the victim. If we miss in our first attempt to throw the bag to the victim, we would like to keep our eye on the victim as we move downstream and then gather in as much rope as possible so that we have one more attempt to throw to the victim before they're swept two times. So once you throw it down then, you keep the bitter end in your hand and then take up slack and throw that end in holding the middle. Well, if we've deployed all the rope, we just take it up from the rope that we've already deployed so that we have enough rope that we can attempt to throw one more time to the victim. And then as the victim grabs it, we'll pendulum and belay them over towards the bank or we can tow them over to the bank, preferably a nice calm spot that we can pull them out of the water. But you've got to be pretty good at that. This is a real practice. It certainly takes training and proficiency on the part of the rescuers. Okay, let's move up to the little higher risk kinds of things now. What would be the kinds of things that you might want to deal with in a higher risk kind of situation? Okay, as we move through our from our low risk options to our high risk options, we're talking about, well, this is the case here, the video has shown our throwback techniques, like I was saying, 45 degrees upstream to the victim. If we miss our first attempt to the victim, we would gather in as much rope as possible in an attempt to throw it to the victim one more time, like I was saying. Then once the victim grabs the rope, we can pendulum and belay them or tow them over towards the bank. We must consider, though, that we don't want to tow them into any type of a hazard. Nice calm spot, then we can pull them out of the water. Now, you wouldn't use a boat in an area like yours, though, because of all the garbage in the water, because it's a flood water. We talk about when we talk about our low risk to high risk options, we talk about reach, throw, then row, our boat based operations. Now, most public safety agencies that have large waterways within their jurisdiction have motorized watercraft that they can use to go out and rescue victims. This, however, requires some specific training on boat handling techniques and other rescue type procedures. But in Arizona, Phoenix, Arizona, where most of our water rescue-related problems are brought on by flooding, because of the debris in the water, it really precludes the use of a motorized watercraft. So we can use what we call the IRB, the Inflatable Rescue Boat. I think we've got some shots of that, too. We'll run that over here. But tell me a little bit about that. Is that a specialized boat? Well, it's a special boat, inflatable rescue boat, we call it. We can fill it up very quickly using a standard SCBA bottle. And like in the case shown right here, we go ahead and fill that thing up and we can deploy that very quickly. Now, one of our options that we could use to get to the victim is we could deploy the boat into the water to move out to the victims, either stranded in the trees or on top of a vehicle. This provides a very low-risk option available to us as rescuers. What about the tethering system on this? Well, we could set up what's called a two-point tethered operation, basically a tension line across the river here. In this case, we're deploying the boat out into the water in an attempt to reach the victims in the water. All right, there you go. Now, you're getting this guy out, right? Okay, go ahead. What happens if you can't reach or throw a row to the victim? Okay, as we move forward then with our next low-risk option, which is pretty much the line, the break-off line for our high-risk option, is to go to actually get into the water and attempt to rescue the victim. Understand any time a rescuer has to place him or herself in the water, they are considered to be very high-risk operations, especially during flooding situations because of all the hazards present. We do not like to put rescuers in the water. We must rule out all the low-risk options available to us prior to placing rescuers in the water. But if the action plan calls for us to go to actually move out into the water, we'd like to do so in a very controlled manner. We'd like to move out into the water in what we call a shallow water crossing, as shown here with the single-person shallow water crossing, the rescuer moves out into the water facing upstream. Feet should be approximately shoulder width apart, and we should be leaning forward into the current aided by an object such as a pike pole in an attempt to withstand the forces of the current trying to push us over. This three-point stance provides a great deal of stability as we move out into the water. Moving only one point at a time, making sure we have good solid footing before we take the next step. If the current is so strong and forceful for one rescuer to withstand, we can also do what we refer to as a multi-person shallow water crossing. In this case, as shown here, a multi-person wedge is a very effective and stable way to move rescuers out into the water in an attempt to reach the victim. We would want to put the biggest strongest rescuer up front, and then our other rescuers at the right and left flank in an attempt to support the upstream rescuer from being pushed over by the forces of the current. Another option available to us is the multi-person line of stern shallow water crossing as shown here. Once again, we would put our biggest strongest rescuer up front, and then the other rescuers behind the lead rescuer supporting each other as we move out into the water. Once again, we reach the victim, we can place the victim in the downstream side of our shallow water crossing formation and move back to the bank or shore that we started from. If the current is so strong that it pushes us over, the first thing we must do is assume the proper swimming position.  As we move downstream, we would want to be reading the hydraulic effects of the river and making sure to stay away from any hazards that we are approaching. If we must move to the right or left, we can do so by setting a proper ferry angle. This allows us to work with the current instead of against the current. As shown here, the rescuer is moving downstream about to hit a stationary obstacle in the water. He sets a proper ferry angle which involves placing the body at 45 degree angle to the current. If the head is in the desired direction of travel, the current will push you to the right or to the left, depending on which ferry angle you've set up. In this situation, it's very important that we keep our feet up, so we do not get them trapped on bottom loads on the river bed. Let's talk for a moment about making contact with the victim out in the water. Understand that one of the most hazardous situations we could become involved with in a water rescue operation is actually making contact with the victim. Most of these victims in these situations are very panicky and must be approached very cautiously by the rescuer. As shown here, the rescuer approaches from the upstream side of the victim and gives the command to turn around and face downstream. Understand that the victim usually sees the rescuer as nothing more than an object they're going to be able to climb up on top of to get out of the water and get some air. So we must approach the victims very cautiously. We would tell the victim to turn around and face downstream, and then as shown here, we would move in from the upstream side of the victim and make contact with the victim. Once we get close enough to make contact with the victim, we would do so in a very deliberate fashion, taking control of the situation. In this case, the rescuer is placing an alternate cross-chest carry on the victim. Once the rescuer has made contact with the victim, they will continue to move downstream. The rescuer will keep the victim in front of him or her and move to the rider left by setting a proper ferry angle. Hopefully, command is considered downstream personnel and we'll have those personnel in position with throw bags so that we can throw to the rescuer in an attempt to belay or tow the rescuer and victim over towards the bank. Once again, making contact with the panicky victim out in the water is extremely hazardous to rescuers and should only be done by confident, well-trained rescuers. Okay, let's talk about the last option available to us. That would be the use of a helicopter. We have not been able to reach, throw, row, or go to the victim for whatever reason. And the only option left would be the use of a helicopter. The first thing we must consider before using the helicopter is whether or not the pilot is proficient enough and comfortable enough with the rescue to do the operation. If the pilot tells command that he or she can do the operation or the rescue, command must consider this as an option available to them. Once again, the risk-benefit analysis must be taken into consideration. Command has the ultimate responsibility for this operation. But once command is decided to use the helicopter, he must turn it over to the helicopter pilot to do what he or she thinks needs to be done to affect rescue. Command doesn't want to tell the pilot how to fly his aircraft. Most helicopter pilots consider these to be pretty low-risk operations, while most water rescue professionals consider these to be very high-risk operations. As shown here, there are many different techniques that a helicopter can be used to affect rescue on the victims. Because of the potential of loss of life of many rescuers and victims, helicopter operations should be considered only after all other low-risk options have been considered and ruled out. Recap in things now. As first responders and water rescue professionals, we must be able to recognize the hydraulic effects and hazards associated with moving water. We must also use our proper personal protective equipment and keep in mind our operational objectives for attempting to rescue the victim. When we arrive on the scene of a water rescue, we must quickly do a size-up, do a risk-benefit analysis, and decide whether we are operating in the rescue or recovery mode of operation. We will then move forward with our action plan, considering our low-risk options first and then moving forward with our higher-risk options if our lower risk options will not work. Water rescue operations are very hazardous, but if we, as rescue professionals, have learned all that we can about the water environment and the hazards of these operations and then stay proficient through regular training exercises, we can minimize the potential for serious injury and death during these water rescues. Use a very interesting word at the beginning, dynamic. When you go on one of these scenes, it may seem to be quote unquote low-risk at the beginning, but you've got to be prepared, don't you, for it to suddenly escalate to a point where you've got to do something pretty drastic in a hurry. Especially if we're dealing with flooding situations, the speed of the current just makes everything happen so quick. So you must have things in position, an action plan with a backup plan in case that one fails because things do move so quick. It is so dynamic out there on the scene of those rescues. And that's for training and preparation. Absolutely. Okay, we'll talk more about that as we move on. Thanks a lot, Tim. All right, now a lot of times you probably don't think of farms as being dangerous. I mean, we think of cows and sheep and kind of quiet and laid back. Well, that's not exactly true in here to tell us how wrong we can be as Billy Parker. Mr. Parker is an Associate Training Specialist for the Texas Engineering Extension Service at Texas A&M. Welcome to the program. And there are some challenges hidden out there on the farm that we don't really think about. That's correct, Rich, and thanks for having me here. Yes, sir. Every year agriculture accidents cause approximately 120,000 injuries and 13,000 deaths in the United States alone. Having properly trained equipment emergency response personnel is vital to minimizing injuries and fatalities. There's a variety of different agriculture accidents that occur which may involve, excuse me, involve overturned tractors, prior takeoff equipment, hydraulic operating equipment, auger wagons and self-unloading wagons, augers and elevators, electrocutions, harvest equipment such as balers, combines and corn pickers, flowing grain entrapments, silos, manure storage, exposure anhydrous ammonia, agricultural chemical fires, pesticide accidents and spills, and other hazardous materials. It is essential for rescue personnel to adequately train and prepare to respond to agricultural accidents. In order to be effective, the rescue must know how to help himself without putting himself in extreme danger. Rescuers should receive training in the following areas in order to significantly increase their ability to save others while protecting themselves. These include agricultural equipment operations to include the shutdown procedures and associated hazards. Confined space entry and rescue procedures as well as rope rescue techniques and last, rescue equipment and tools, limitations, capabilities and availability. Other ways in which emergency personnel can better prepare and include developing a resource list of tools and equipment not commonly carried or available on the emergency vehicles in the area. Developing a resource list of groups or individuals with specialized expertise such as farm implement dealers. Physicians who can respond directly to the scene, poison control centers, as well as air helicopter ambulances. Rescuers can also use the resources available from dispatch communication personnel initializing the evaluation, sizing up the accident. By obtaining information from the reporting party, the responding personnel can begin to formulate rescue plans and determine if additional resources will be needed. If it is determined that responding units are inadequate, additional resources should be dispatched as soon as possible. The instant command system must be used in all operations in order to enhance the coordination of information, manpower and equipment resources. The instant command system also provides a means for monitoring and therefore better protecting the patient, rescuers, spectators and family members on the scene. When arriving on the scene, rescuers must establish a hazard zone. The instant commander should be looking for hazards that are particular to the type of agricultural equipment involved. These may include pinch points, wrapping points, shear points, crushing points or pull-in points. There are some other hazards that may be included. They may be fire, toxic or flammable gases, grain entrapment or further collapse of equipment or product. Establishing a hazard zone provides rescuers with more freedom to work while minimizing the number of personnel in the area. Rescuers in the hazard zone must wear and use appropriate protective equipment. When extricating from agricultural vehicles is necessary, stabilize the equipment prior to extrication by stopping the engines, blocking or chalking the wheels, safety locking or blocking the hydraulic systems, lockout, tagging out any mechanical or electrical equipment and cribbing and use of lifting devices such as airbags or hydraulic equipment. Cribbing must be used in conjunction with lifting devices in order to prevent the equipment from slipping or losing stability. Do not rely just on the lifting devices to hold or secure its load. It is recommended that cribbing be used to placed under the high side of the equipment, then lift the low side to position it. The cribbing. Once this equipment is stabilized, the rescue operation can proceed. The method of extrication used really depends on two things. One, the patient's condition and two, the type of equipment involved. The patient's condition is probably the most important consideration. The instant command will decide whether as best to disassemble or cut away the equipment. If the patient is stable or deceased, the rescue operation should focus on disassembling the equipment. This is a very time-consuming procedure and should be accomplished by personnel very knowledgeable in the particular type of equipment involved. If you experience personnel attempt to disable or disassemble the equipment, complications and further injuries to patient and rescue is likely. If the patient is not stable, rapid extrication is necessary. Then the rescue operation should focus on cutting away the equipment from the patient. Before proceeding, protect the patient with turnout coat, salvage covers, or blankets, or whatever is directly available. Before cutting away the equipment, realize that equipment rollovers and turnovers are common, so have adequate fire protection available. Shut off the engine whether it's running or not since the rear wheels can start some of the equipment. Bind the rear wheels that the chainer come along to prevent them from turning. Understand the hydraulic systems. They operated high pressure, can exceed 2,000 pounds per square inch and can cause serious accidents if they should fail. Loss of hydraulic pressure can cause the equipment to suddenly fail and severely crush or trap an individual. It's also flammable, so avoid open flames or sparks. Hydraulic control should only be used by someone experienced with a particular type of equipment to lift the machinery off the victim in order to prevent more injury. If no one is available who knows the hydraulic systems, it's best to lift and block the mechanism by other means to remove the victim. One possibility is to stabilize equipment and dig the patient out. If the pressure in the hydraulic system needs to be released, secure the equipment and release the pressure by using the controls, disconnecting the hydraulic lines or as a last resort cutting the hydraulic lines. Use proper protection when cutting the lines. Remember, releasing pressure may cause collapse and or change in the position of the equipment. Other considerations when extricating a victim from agricultural equipment should include watching out for overhead power lines when portable augers are raised, never using power from the tractor to attempt extrication, using padding between airbags and sharp edges and placing them carefully since they do tend to slip on around surfaces. I understand that since most agricultural equipment is built tougher than automobiles, variations may be needed when extricating. Using care with extrication tools and equipment and not forcing them beyond their limitations is a major consideration. When rescue from manure storage, facilities, or grain silos be especially cautious of the possibility of grain entramments and hazardous atmospheric conditions. Confined space entry and rescue procedures should be used. Generally, there is little danger from stored grain. Flowing grain, however, presents a potential suffocation entrapment hazards. Grain bends, bends which appear to be relatively safe have been seen as hundreds of deaths and entrapments. For rescuers requiring entry into confined spaces, lower the rescue rather than aligning the repelling into the area. If rescue requires vertical rescues systems, use systems that are safe, easy to use and reliable. Keep it simple, as Sam said. If emergency removal of grain is necessary, rescuers must not stand on the top of the grain during the rapid removal. Observations can be made from the bend hatch or if necessary rescue workers can be supported above the grain with a safety harness. Use caution when rescuing victims in and around silos. Assume there is deficient oxygen and use breathing apparatus inside any seal silo regardless of the time of year or the type of rescue. Lifeline should be used by emergency personnel entering any silo. This is a brief presentation on agricultural rescue for more information on this topic. Contact the Fire Protection Training Division Texas Injury and Extension Service Texas A&M University System College Station Texas 77843-8000 Telephone number to call is aircode<PHONE_NUMBER> or fax aircode<PHONE_NUMBER> Rich? Well it's interesting because I think in almost every state even those we think of as being big industrial states there are rural areas and I don't think we pay enough attention to that and let's talk a little more about that as we get on in the show too. Absolutely. You know the Midwest is pretty generically looked at as being the agricultural area of the country but agriculture incidents can happen anywhere in the United States. Another potential application for rescue techniques using that we're talking about here is machinery rescues in textile mills or printing presses. All these techniques are very similar in nature. Okay we'll be back in a minute we'll talk about that and we'll hear from you too it's your turn to ask us questions your last chance to get on the phone and get on the air stay with us. Hi I'm Barbara Barton with the United States Fire Administration I'm here on the campus of the National Emergency Training Center to talk to you about an upcoming E-Net show. On September the 15th the broadcast show will be implementing public education and volunteer fire departments. At that time we hope to discuss and give you some new ideas on targeting your audiences knowing your resources and knowing how to use them. So join us on September the 15th between the hours of 11 a.m. and 3 30 p.m. Eastern daylight time for the E-Net show entitled implementing public education and volunteer fire departments. Safety considerations for special rescue situations it's your turn to talk with us on the air right now and let me reintroduce our guests who have some very special expertise. We want to share with you here's our phone numbers first though let me give you the numbers and then we'll let the guys have a little break here 1-800-368-5781 1-800-368-5782 if you're calling from Alaska or from right around Washington DC the number is 202-463-370 or 463-3171 now here are our experts and they are experts so use this chance to call them Captain Sam Turner with the Ventura County California Fire Department who gave you that excellent presentation on rope rescue Billy Parker from the Texas A&M Technical Extension Service Billy talked about agricultural accidents and we want to spend some time talking about that as we go on and also Tim Gallagher Captain Tim Gallagher of the Phoenix Fire Department who gave us our presentation on water rescue another very challenging rescue so let's hear from you now we've got several minutes here to take your calls and we want to get as many on as possible so call in please if we get you on the air stay right on the phone I'll ask you to go on the air when it's time but don't put the phone down or give it to somebody else we want to hear from you now gentlemen let me start out with sort of a general question every one of these incidents that you've talked about in these rescues requires some pretty serious expertise what does a small department without a lot of resources and mainly volunteers maybe that doesn't have a lot of time to train how do they get this expertise what do you do well one of the things I think that the smaller departments need to do is go out and pre-plan their area and take a look and see what type of specific rescue problems that they may have and then they're going to have to get ready prepared with training and the proper equipment to do these also be able to identify any of the resources both equipment and personnel in the area that might be able to help them out in these situations what do you think I think of individuals that are interested in these specific aspects of rescue will kind of grab the ball and run with it a lot can be gained with some application in a lot of cases in rural areas you're already dealing with a smaller department is there a higher level awareness of the risks that are there do you think I think so I think most people do generally tend to look at the areas that they have to respond kind of determine what specialized training they need and for the most part they try to go out and get it if it's readily available let me while I've got you let me raise point I had the privilege a couple of years ago of working with some gentlemen in rural area of Virginia who sought out their equipment dealer and gave him a pager and they said look it may only go off two or three times a year but when it does will you give it to your number one mechanic let him take the truck with all the equipment and bring it to the scene or we'll have a deputy take him to the scene so that he can actually work this equipment we might want to make the point that a lot of this equipment has ratchets in it what goes in can't come out you can't back things off so you need these expertise is this a good way to work with your people absolutely if there's somebody in your area especially in farm implements that works on these on a data base they're the best people in the world to have there on the scene because if you've never taken one of these things apart it'll take you forever and having that type of expertise is extremely important and I would recommend it to anybody that's in the farm community to have those people available you have probably a little more difficult EMS situations too because the nature of this entrapment is often traumatic and the patient is sometimes involved for a lengthy period of time before you get the patient out yes most the accidents occur in very remote areas and it takes a long time to get transportation back out but also the patient may be physically involved in the machinery for longer than we would think in a car wreck so that has some pretty serious EMS implications very very much yeah okay hey we have a call let's get one this is from texas too butch lavel from brian texas butch are you with us you'll be up with us shortly hopefully all right hang on butch we'll get you on the line let me ask you a question tim you showed in there what i thought was a neat innovation was putting the caps on the hose any department can do this is there a limit though to where the average department should start doing water rescue before they really go ahead on and get some training i mean a lot of guys can swim and you can throw ropes and all but at what point do you really have to start thinking about i'd better get myself trained in some of these real techniques well if we have some real specific problems such as flooding ice things like that flooding situations and ice i mean those take some some rather advanced techniques and some specific training for dealing with those type of problems basic water rescue is pretty simple the american red crosses had a program out even long before our time on basic water rescue techniques but with these other complicated problem it does take some more advanced specific training for these type of techniques to maintain the safety of the rescuers probably even wouldn't you think more important that maybe knowing the rescue technique is knowing your water oh absolutely that's why i made mention there we we must learn to recognize the hydraulic effects and all the hazards associated with these type of operations because if we do recognize that then we really understand what we're getting ourselves into and we can make those intelligent decisions about our level of commitment we talked about the dynamics of things how quick things happen yeah and when you make a decision if you've made a an improper decision getting into a water for instance in a swift water setting things happen so quick if you made the wrong decision good luck yeah okay let's see if we can get butch level from Byron Texas on the line butch are you with us now yes sir all right sir go ahead with your question thanks for waiting well what i was going to ask uh mr parker there i understand that you know when you're trying to get into a school then it takes a name it is awful hard because there's so many firemen trying to get into the school and uh it makes it kind of hard on some of us because there's times that we cannot find schools to go to especially about the phoenix about the water rescue and the industrial and i was wondering if there's any like besides Texas saying name being a part training school is there any other smaller schools or training communities that we can go to that we may have access to because like right now we're efficient to a rescues team school out there the farmers training school for Texas World Speedway which i have been involved with back in the early 70s and it's you know i'd just like to try to maybe get something from you guys to let us know what we can get the access to the training that we need if we cannot go to a facility as Texas A&M with just within our organization alone we run approximately about 65 area schools scattered throughout the state and a lot of them are very specialized take for instance in the agricultural accidents we have a one day school going over in flow data in august 21st make contact with my office and we'll provide you with other alternative ways to get get this training to you because we realize it's very difficult for departments to send a lot of people and get into some of our week long schools but give us a call thank you miss parker and the rest of you and the gentlemen all right sir thank you very much for calling hope we've helped you out all right here is another call this one's from west wego louisiana i hope they have that right willy geel go ahead sir you're on the air yeah i'm handicapped but i was wondering what kind of uh knowledge y'all have about rescuing handicapped people with uh as far as water uh has it go you know that's uh that's an interesting point uh go ahead why don't you pick that up too well i think as as water rescue professionals certainly we must keep in mind that we want to keep ourselves safe we don't want to bring more victims to the scene there so we're going to do all the things that we would normally do about maintaining our own personal safety during these type of operations but once we get to the victim i think probably the biggest concern is that we just want to get the victim out of the water so whatever it's going to take whatever type of maneuver it's actually going to take to remove the victim from the water and then we can start dealing with some of the specific needs some of the handicapped type issues there but the biggest thing is keeping ourselves safe and then getting the victim out of the water mr. gill are you still with us yeah let me ask you a question from your perspective um i think tim makes a good point if you're up to your neck and water and it's rising fast it probably doesn't make any difference what's your physical condition is you need to be gotten out but is there anything perhaps maybe communication wise would be the only thing I can think of that you might be able to impart to us that might help us understand better the kind of special things we might want to do in a case like that well um I live between the Mississippi River and the Gulf Gulf of Mexico and the water around here it gets pretty bad sometimes especially when they got storm surges and all and uh you know I got a life jacket right here I got a boat and uh as far as I can see I can't think of nothing offhand that could really help y'all that is why I was calling to see if y'all have any information that y'all can relate to me I may be more aware of something that y'all may have knowledge of that I don't well Mr. Gia it sounds to me like you've done two things that I can hear right now that are probably the best things you could do number one you're totally aware of the fact that where you live may put you in risk and number two you've got the good common sense to get yourself a personal flotation piece of equipment that you could put on when you see that you're going to be in trouble and you've probably gone about as far as an individual citizen can go what do you think gentlemen in helping yourself I think it's an outstanding thing that may be the best message that you've offered there that perhaps people who do have difficulty in mobility ought to prepare themselves as well as you did and we appreciate you calling in with that what do you think guys thanks willy that's a good point to keep in mind that's a real good message there for and for our friends in texas let's put up on the screen for just a second the address again of the texas a n m agricultural training operation this is the training division texas a n m you see it right there we'll just leave it up for a second and billy you say you do what you did about 65 courses are they available just to texas before the criteria for getting in a course the area area schools that we conduct mainly on the weekends are pretty much open enrollment to anybody we don't we don't have any limitations whatsoever on of any kind on any of our classes unless they book full then we have to we have problems like that Sam let me raise a point as we're moving into the on on rope rescue again almost like swimming you know people think well I've gone out I've you know I've bought myself a nice little hat doll boy I'm a I'm a rock climber and I've seen situations where you'll come on the scene to do a rescue and two or three guys think that they know how to do rescue and they flung ropes over the side and they're swinging around on pretty soon you've got three or four people out there you have to rescue just being a recreational rock climber does not make you a rope rescue professional doesn't that's right rich actually a recreational or recreational rock climbing is a whole different discipline from rope rescue the techniques and the equipment are for the most part completely different and individuals who are not experienced in rescue techniques should not be attempting to rescue other climbers says I think you see that I mean the natural response if there's climbers around is to go do something certainly we see that in all aspects of rescue trench rescue


By winter 1942, one year after Pearl Harbor, our army fighting forces were building up fast and being deployed around the world. Fighting beside Australian troops in New Guinea, on Guadalcanal, where they had taken over from the long embattled Marines. Large-scale amphibious landings had been made successfully in North Africa. Joining up with the British and the fighting French. Other army units were arriving in overseas staging areas in North Ireland, England and Australia. As our combat and support forces began to encircle the globe, our lengthening supply lines were stretched to the utmost. An army cannot fight without food, clothing, weapons, ammunition, medical supplies and services, transportation, armor and aircraft that must be constantly supplied with fuel and as constantly serviced, repaired or replaced. During the fighting of the vast stretches of arid desert lands in North Africa, German General von Ravenstein, commander of the 21st Panzer Division, remarked that North Africa is a tactician's paradise and a quartermaster's hell. An American or Allied commander could very well have made the same statement. On the other side of the world, in the Southwest Pacific, support for the combat troops was even more difficult in an entirely different kind of warfare. Supply is spoken of as logistics. More specifically, it is the transportation, supply and quartering of troops, the procurement of all required military equipment and materiel, shipping and distributing cargo to the right place to arrive at the right time. In World War II, our military planners successfully solved the most stupendous problems of logistics the world has ever known. Our lines of supply fanned off like a network around the world, extending northward to Alaska and the Aleutians, to the Panama Canal, westward across the Pacific to a chain of islands, on to China by way of India, to Burma, to Australia, eastward across the Atlantic to North Africa, the length of the Mediterranean, the Middle East and the southern route through the Persian Gulf to Russia, to Great Britain, Iceland, and to Russia by way of Murmansk in the far north, and ultimately the entire continent of Europe. Under land lease to our allies alone, the services of supply shipped approximately $25 billion worth of war materiel. These included approximately 850,000 pieces of heavy equipment, tanks, trucks, free French forces in North Africa were supplied enough arms and materiel to equip 12 combat divisions. Millions of dollars worth of supplies went to China, flown there from India. To Russia alone, over the submarine manist route to Murmansk, almost a half million pieces of heavy equipment, railroad rolling stock and clothing, vast stores of munitions and equipment went to England and Commonwealth. All of this while we were supplying our own widely deployed forces and building up mountains of supplies for the massive invasion of Europe yet to come. The miracle of supply achieved by the United States Army in World War II was historic. It represented the outpouring of a great nation's energies and resources, not for conquest, but to win freedom for men who would be free everywhere. Mighty America had come fully alive. A revitalized agriculture reached the largest food production goals in the history of mankind. Food not only for ourselves and our allies, but for the hungry populations of the countries our armies would liberate and occupy. Industrial output staggered the imagination, brought renewed hope to our hard-pressed allies, dismay and consternation to the aggressors. It amazed even ourselves. At long last the United States had come of age, had found a vitality, a strength and a will to do that was phenomenal in all the annals of men and nations. Great convoys of ships stretched out as far as the eye could see, carrying the millions of tons of cargo we kept pouring overseas. Of this in support of G.I. Joe. And who was G.I. Joe? He was the off-times grimy, unshaven, heart and soul, blood and guts of America, the citizen soldier, the immortal image of the American fighting man whose forefathers had starved and frozen at Valley Forge to fight on and triumph at Yorktown and again a few years later at the Battle of New Orleans. He had been a raw recruit at Bull Run, but emerged the victor at Gettysburg and the winner of a great and tragic civil war at Appomattox. He was the man who drove the enemy to defeat at Chateau Thierry, at San Miguel and the Muse Argonne. He was and is the American soldier, personified. And who were his leaders? Marshall. Eisenhower. MacArthur. McNair. Bradley. Devers. Patton. Clark. Hodges. Kruger. Eichelberger. Men like Macaulay. Men who possessed the indomitable spirit and genius of Washington. Wenfield Scott. Andrew Jackson. Grant. Sheridan. George G. Mead. Robert E. Lee. John J. Pershing. This was the heritage of American military leadership in World War II. A heritage they could not and would not fail. Their one and only goal, victory. From buck privates to four star generals, these were the priceless outpouring of America's greatest resource. The product of more than a century and a half of freedom and democracy in action. Of a great dream that their forefathers had fought for and made a reality and which these, their sons, were fighting to preserve. But even amidst the tensions of war, there were precious hours of respite in which battle weary men found rest and relaxation and brief moments of humor. But when they fought, they fought to win. There's was a sublime dedication. This was a glory the world would not soon forget. While the fighting was continuing in North Africa, President Roosevelt and Prime Minister Churchill met at Casablanca to determine further strategical moves. They agreed on four major points. Invade Sicily and Italy at the first opportunity. Intensify counterattacks against Hitler's submarines and launch a combined bomber offensive on Germany. Begin preparing for a major offensive in the Pacific. Except nothing short of unconditional surrender as a basis for ending the war. This was the kind of positive, top-level determination the free world had long awaited. There was swift response on all fighting fronts. Tripoli fell to the British 8th Army. In bitter fighting, Nazi tanks hurled back allied forces to the Algerian border. But then combined American, British and French units stopped the German-Italian drive at Casserine and to Tunisia. In the Pacific, on bloody Guadalcanal, fighting an entirely different kind of warfare, United States troops overcame the last fanatical Japanese resistance and won complete control of the island and its airfield. In the Battle of the Bismarck Sea, Allied bombers sank eight transports and four destroyers of a Japanese convoy of 16 ships. 181 days after the allied landings in North Africa, Tunis and Bizerte fell before the drive of American, British and French forces. The drive reached its full fury with lightning speed in the air and on the ground. The enemy was hit harder and harder, crushed in a vice from which there was no escape. In five days, all German resistance in Tunisia collapsed. The Axis forces surrendered. The myth of Hitler's super race was beginning to crack. In the faraway Aleutian islands, American troops had landed on Attu. Still farther away in New Guinea, American and Australian troops drove back the stubborn and fanatical enemy in close fighting in malaria-infested jungles. Among the battle casualties we had suffered while fighting in the Boona area were three of our general officers, shot in action within less than a hundred yards of the Japanese lines. From victories on the deserts of North Africa, the fog-bound Aleutians to the tropical island of Guadalcanal and the New Guinea jungles where our troops were driving forward against desperate Japanese resistance, we had indeed spread our forces around the world. Who was it that once said, the United States was incapable of fighting a two-front war? Within less than 16 months, the United States Navy had performed a miracle of salvage. Of all the ships sunk or damaged on December 7th, 1941, at Pearl Harbor, all but three were back in service and in fighting trim by May 1943. An achievement on a scale unequaled in naval history. In Russia, the Germans had taken virtually all of Stalingrad by late 1942. Their conquest was short-lived. Early in 1943, the Russians launched a massive counter-attack.  It had started to turn in Russia. In June of 1943, hundreds of Royal Air Force planes engaged in a non-stop aerial offensive over occupied Europe that continued unremittingly for 10 days. While the tide was turning in the air over Hitler's fortress Europe, American Army, Navy and Air Forces, along with those of Australia and New Zealand, launched a concerted offensive to drive the Japanese out of New Guinea and the northern Solomon Islands. Three forces on Rendova Island were wiped out. Our troops drove for the Munda airfield on New Georgia Island. With all of North Africa in allied hands, preparations for Operation Husky were begun immediately to attack the soft underbelly of Europe. The immediate target, Sicily. Little time was lost. Only 60 days after the surrender, only 60 days after the surrender of Axis forces in North Africa, Patton's 7th Army invaded Sicily simultaneously with British and Canadian troops under Montgomery. Some 3,000 craft were employed to land an initial force of 160,000 troops. Almost 14,000 vehicles, about 600 tanks, nearly 2,000 guns. But Sicily was held by more than 200,000 Italian and German troops, strongly entrenched on rugged terrain. It was to be a tough, hard-fought campaign. We invaded Sicily just 18 months after Pearl Harbor. Actually an incredibly short period of time for a peaceful and unprepared nation to have accomplished so much, to have come so far. It was a brilliant reflection of our military planning and the energy and enterprise that implemented that planning. It was America at its dynamic best. The forces of agriculture, industry, labor and management, finance and manufacturing, and management, finance and manpower coordinated with the military. What the United States alone did in those first 18 months will live long in history. Yes, we had come a long way, but we still had far to go in Europe, still farther in the Pacific. It would be 11 months after the invasion of Sicily before we could build up and coordinate massive ground, air and sea forces for the invasion of Normandy. 11 months of bitter fighting in Italy and the vast island chain in the Pacific.


Hello and welcome to this presentation of the STM32 digital filter for Sigma Delta Modulator's interface. The features of this interface, which behaves like ADC with external analog part and configurable speed versus resolution ratio, will be described. The DF-STM peripheral is a new digital peripheral inside the STM32 products. Its behavior is finally like standard ADC with the analog part outside the microcontroller. The main benefit is to move the analog part outside the microcontroller and to propose an internal digital part with a wide range of features. The DF-STM represents the digital part which is connected to the analog part by fast serial interface. The external analog part is usually a Sigma Delta Modulator offered by a wide range of vendors. This feature offers the possibility to choose a specific analog part according to the user's needs. Like galvanic isolation for motor control or metering applications, a low noise and high precision analog part for sensor data acquisition applications, or a cheap analog part for price sensitive applications. Finally, the analog part provides digitized data for DF-STM. The digital part, represented by the DF-STM peripheral, performs a digital signal processing from external data. Therefore, it offers a scalable ratio solution between speed and resolution, but also an additional functionality integrated in standard built-in ADC like analog watchdogs, injected and regular conversions, flexible triggering system, break signal generation, and extreme detector. Digital MEMS microphones providing a PDM output data format can be directly connected to DF-STM, which can directly process the audio signal. The DF-STM is able to process the external serial data and also the internal parallel 16-bit data transfer provided by the CPU or DMA from memory. The DF-STM was developed due to a need for a Sigma Delta ADC with scalable speed versus resolution. More than 16-bit accuracy inside a microcontroller is a problem because of noise from the digital part. The solution is to move the analog part outside the microcontroller. The speed versus resolution ratio setting is a task for the internal digital part, which is the digital filter in the hardware. Although it behaves like a complete analog to digital converter with an external analog front end, the DF-STM is purely digital with its analog part outside the microcontroller. The DF-STM integrated inside STM32 products provides the digital part of the complete Sigma Delta ADC with an external analog part, which is the Sigma Delta modulator. Both parts are connected through the serial interface, which provides a one-bit Sigma Delta STREAM. The average value of this STREAM represents the analog value on input. Applications can benefit from the easy connection. Just one or two wires are needed. Thanks to the analog being located outside the microcontroller, there is less noise caused by the microcontroller. The balance between speed and resolution according to application needs can be set by configuring the digital filter. Transceivers provide the serial connection to the external Sigma Delta modulator. They support serial connections with configurable protocols, SPI or Manchester, and configurable parameters. Their functions will be explained later in detail. Transceivers also have support for internal 16-bit parallel data inputs, which will be written to the DF-STM input data registers by the CPU or DMA, and optionally by the internal ADCs. For STM32, L45X, 46X, 49X, 4AX devices only. Filters are the core of the DF-STM function. They perform 1-bit stream filtering to provide higher output resolution at lower speeds. There is an additional integrator behind the digital filter, which provides additional data averaging. Applications can be designed with various types of Sigma Delta modulators from various vendors. The parallel data input feature can perform post-processing of any internal data, for example internal ADC streams, audio data filtering, etc. There is a list of additional functions, which will be explained later in detail. The entire digital filter for Sigma Delta modulators interface consists of 8 serial transceivers, 4 sync filter parts and integrators, 4 output data units, 4 analog watch dogs, 8 short circuit detectors, 4 extreme detectors, and 8 parallel data input registers. For STM32, L45X, 46X devices, the configuration is only one-half, 4 transceivers and 2 filters and integrators. The STM32, L45X, 46X, 49X, 4AX devices feature parallel inputs from internal ADC. Serial transceivers provide the connection to the external Sigma Delta modulator. SPI mode works up to 20 MHz or the DFSDM clock divided by 4. There are configurable options, including sampling edge selection, data rate measurement, and clock presence monitoring. One-wire Manchester-coded mode, where clock is recovered from the data, works up to 10 MHz or DFSDM clock divided by 6. A synchronization detection feature is also available in Manchester mode. Manchester mode also offers the lowest system cost in case of optical isolation of the Sigma Delta modulator. Then only one single isolator per input channel is necessary. The DFSDM clock features a clock output signal to drive the Sigma Delta modulator. It can be used as a source for the SPI clock input by internal interconnection in order to save external pins. The clock output has an adjustable division factor and can be driven either from the system clock or from the fine-tuned audio PLL clock. Parallel transceivers provide parallel inputs from internal data sources, for example from memory buffers. Parallel inputs are usually used for fast hardware filtering of internal data from the ADC or any data collected from a communication peripheral. Data can be written to the DFSDM parallel input registers by the CPU or DMA configured in memory-to-memory transfer mode. For STM32L45X46X49X4AX devices, the internal analog-to-digital converters provide parallel data directly to the DFSDM parallel input registers. The digital filter averages the 1-bit input data stream from the Sigma Delta modulator into a higher resolution, but with a slower data output. The digital filter is sync-X type with an order from 1 to 5. A fast sync type filter is also available for selection. The oversampling ratio means how many samples will be averaged in a single filter run. The oversampling ratio can be selected in a wide range from 1 to 1024. Not all combinations of filter order and oversampling ratios are available because in higher filter orders, the oversampling ratio must be reduced to not overflow the 31-bit data width, which is the internal filter resolution. The integrator unit performs additional simple averaging of data provided by the digital filter. It provides just a simple summing of the data coming from the digital filter. The number of samples to be summed can be set from 1 to 256. The correct configuration must take care that the final data length fits into the 31-bit width, which is the resolution of the internal integrator. The width of the data coming from the digital filter must also be taken into account. The output data unit adjusts the final data before they are written to the final data register. An offset value that will be automatically subtracted from the data result for each channel can be defined in the offset register. The correct offset values are determined using the calibration procedure. This calibration procedure should be programmed in user firmware and depends on the type of Sigma Delta modulator connected and application needs. The maximum resolution of the final output data register is 24-bits, but the internal resolution can go up to 31-bits. But certain applications have their own constraints. For example, 8, 12, 16, or 24-bit data resolution. Therefore, there is an option to perform a right-bit shift of the data to provide the final data result with the required width and not overflow the 24-bit width of the final data register. Right-bit shift is configurable from 0 to 31-bits. The final resolution then depends on the digital filter and integrator settings as well as the right-bit shift option. The analog watchdog monitors sampled analog data to see if it remains within the selected high and low threshold values. The input to the analog watchdog function can come from the result of the final converted data or directly from the input serial channels through a configurable filter. If data exceeds the allowed boundaries, an interrupt can be invoked or a break signal generated. If an interrupt is invoked, the software decides about the next actions. If a break signal is generated, this break signal can perform a safety function directly by hardware. For example, stop a timer which controls the motor. There are separate high and low threshold levels and separate flags for each threshold to know if a threshold has been reached. The analog watchdog can monitor two types of data. The first type is standard output data as with a standard ADC. The second type of data can come from serial transceivers through configurable dedicated filters. This second option allows you to select faster signal monitoring when the required speed and resolution is set by the filter parameters. Each serial channel watchdog filter is configurable from 1 to 3 and its oversampling ratio in range from 1 to 32. The data from these watchdog filters can also be read by user firmware. The short circuit detector monitors input serial channels for a saturation state. When an input signal is saturated, it means that it is outside the allowed measurement range and therefore there is an overflow or underflow of the signal. When measuring current, this event usually detects an overcurrent or short circuit or an overvoltage when measuring the voltage. Detection of input signal saturation is based on monitoring the input serial data stream coming from the Sigma Delta converter and watching if there is a consecutive set of ones or zeros for a relatively long time. This maximum saturated time can be set in the range from 1 to 256 of sampled input data which will have the same value, zero samples or one samples. Monitoring is performed independently from the main conversion. The main conversion can perform conversion from another channel or can also be stopped. All input channels can be monitored in parallel with their own saturated time setting. When a saturation event is detected, an interrupt can be invoked or a break signal generated. Then just as with the analog watchdog, the software decides the following actions or the hardware break signal can perform a safety function without any software latency. For example, it can stop the timer which controls the motor in the event a short circuit is detected. The extremes detector monitors output results and stores the extreme values into minimum and maximum registers as well as the associated channel number. Monitoring of data for extremes is only performed on selected channels to ensure that channels do not mix different input levels. Stored extreme values are refreshed each time the values are read in the register. Regular conversions have less priority and can be interrupted by an injected conversion. If the regular conversion was interrupted by an injected conversion, it is restarted once the injected conversion is finished and this interruption is indicated as a flag for this delayed regular conversion. Regular conversions can be launched only by software and there is no scan mode available. Regular conversions can run in continuous mode in which there is no channel switching and they can be performed in fast mode without filter refill. Regular conversions are used for measurements for which timing is not critical, for example when measuring temperatures or slow signals. Regular conversions are also typically used for continuous conversions from one channel only, for example audio or energy measurement applications. Injected conversions have high priority. They can interrupt regular conversions immediately and start just after being triggered. Any of the input channels can be assigned into an injected channels group. There are two modes of conversion behavior, scan mode and single mode. In scan injected mode, all channels from the injected channels group are converted starting from the lowest to the highest channel number in a group when a trigger occurs. In single injected mode, only one channel from the injected channel group is converted and the next channel from the injected group is selected for the next conversion. The next trigger will start this next channel conversion and another higher channel from the group is selected. Injected conversions can be launched by software or by hardware, from timers or an external pin. Injected conversions cannot run in continuous mode, but this mode can be emulated using a periodic timer trigger. Those modes make it possible to choose the correct conversion mode according to application requirements. The MEMS microphone provides a pulse density modulated or PDM data signal whose format is theoretically like the Sigma Delta bit stream from the Sigma Delta modulator. The MEMS microphone has stereo support if two microphones are connected in parallel with common data and clock signals. Rising clock edge samples left audio data. Falling clock edge samples right audio data. Implementation into DF-SDM transceivers requires this configuration. Channel 0 uses redirection input from channel 1. Channel 1 uses direct input. Channel data left versus right are separated inside by selecting either the rising or falling edge in the SPI configuration of channels. The clock signal is provided by the DF-SDM clock output because the MEMS microphones are slaves and need an external clock for data sampling and communication. A set of interrupts related to DF-SDM events has been implemented to increase CPU performance. This table lists all of the DF-SDM interrupt sources, end of conversion events with separate flags for regular and injected conversions, data overrun events with separate flags for regular and injected conversions, analog watchdog events, short circuit detector events, and channel clock absence event. To decrease the CPU intervention, conversions can be transferred into memory using a DMA transfer. DMA transfers for injected and regular conversions can be enabled separately. The direct memory access controller, or DMA, can also be used as a method for fast data transfers into parallel data registers. In this case, the parallel data are transferred from the memory buffer into the parallel data register by using the DMA. The DMA should therefore be configured in memory-to-memory transfer mode where the target address is the address of the parallel input data register. The DF-SDM peripheral can be active only in run and sleep modes. In all other low-power modes, including stop, standby, and shutdown modes, the DF-SDM must be disabled. DF-SDM performance depends on the maximum allowed input data rate because each input data sample causes the next digital filter operation. DF-SDM allows operation at a maximum input data rate of 20 MHz in SPI mode or 10 MHz in Manchester mode. Parallel data inputs have the same performance, so parallel data can be put into DF-SDM at full 20 MHz speed using either the CPU or DMA. Applications benefit from DF-SDM high-speed processing, which now supports all existing sigma-delta modulator speeds. The STM32L4 evaluation board can be used to run two simple application examples to help you explore the digital filter for sigma-delta modulator's interface. The first example is a demonstration of the MEMS microphone directly connected to the DF-SDM peripheral. Data from the microphone are processed by DF-SDM with correct filter settings and then collected into a memory buffer using regular continuous conversions and the DMA. Recorded data from the microphone are then immediately sent by the DMA from this buffer to the I2S peripheral and played by headphones. The second example is a PT-100 thermometer which uses an external STPMS2 sigma-delta modulator which monitors two channels. One channel senses the voltage and the second one senses the current on the PT-100 sensor. Both channels are sampled using timer-triggered injected conversions in scan mode. Software then computes the PT-100 resistance from collected data and finally the temperature. This schematic shows an example of the PT-100 thermometer. Here you can see how the STPMS2 device senses the voltage and current over the PT-100 sensor. Sensed data are sent from the STPMS2 device to the DF-SDM peripheral through the serial interface. This example shows a typical one-phase electricity meter design using an STPMS2 device and STM32 microcontroller. The STPMS2 is a dual-channel sigma-delta modulator designed for electricity meter applications. It has voltage and current channel inputs. The current channel features a programmable gain amplifier to cover a wide range of measured currents. Sampled one-bit data are sent by the serial interface to the host device which here is the DF-SDM interface. Both voltage and current one-bit data samples are sent on the same data wire but the voltage is sampled on the rising clock edge while the current is sampled on the falling clock edge. The clock is provided by the DF-SDM and can run up to 4 MHz. The DF-SDM then processes the voltage and current channel one-bit data streams into output data with a higher resolution and slower data rate. Finally, the firmware uses FFT analysis to calculate the electric power and energy from the current and voltage sample. This example shows a three-phase electricity meter design using shunt resistors for sensing current. There is no need to use expensive current transformers. Voltages are sent by three resistor dividers and external sigma-delta modulators. Currents are sent by three shunt resistors. Each shunt resistor voltage is sensed by one sigma-delta modulator. Because each sigma-delta modulator operates at a high-phase voltage, galvanic isolation is used for data transfers into the DF-SDM. If the sigma-delta modulator uses the Manchester-coded serial protocol format and has an internal clock source, only one isolator per phase is necessary. If the sigma-delta modulator uses the SPI serial format, two isolators per phase are necessary. Each sigma-delta modulator is powered from a separate DC supply voltage. This example is related to a three-phase industrial high voltage, high current motor drive, where floating shunts and galvanic isolation are standard. A single reading channel is represented here while in the application, two or three channels are used for the current in addition to two or three channels for the voltage. The currents are usually measured simultaneously by three DF-SDM channels while the voltage can be measured sequentially with the same DS-FDM channel. The same bit stream is processed three times. First, for high accuracy measurements, the main filter is used over a relatively long time. This measurement is done synchronously with a PWM period to avoid switching noise and have regular samples. Second, the watchdog channel uses the same bit stream with its own lower-order filter, continuously monitors the signals and invokes an interrupt in case of overload with medium reaction time. And third, the short circuit detector is used to detect very rapidly a modulator saturation, continuous series of zeros or ones with a programmable length and automatically disables the PWM generator through a dedicated DF-SDM to the timer interconnection by a break signal. The peripherals listed here influence DF-SDM behavior. Please refer to the corresponding peripheral training for complete information. This slide presents the key differences between product devices.