Help support TMP

"scale question...am I getting this right?" Topic

14 Posts


For more information, see the TMP FAQ.

Back to the WWII Naval Gallery Message Board


Back to the Naval Gaming 1898-1929 Message Board

1,132 hits since 29 Dec 2011
©1994-2017 Bill Armintrout
Comments or corrections?

HesseCassel Inactive Member29 Dec 2011 7:26 p.m. PST

Figuring the scale of GQ3 and some other naval rules. This math assumes that a nautical mile is 2000yards even, altho Answers.com says that it is 1,852yards (due to it being 1 minute of arc on the Earth's ocean surface).


1 Knot ship speed = 1cm on table = 3 minutes game time = 100yards game distance & 1 yard on table = 10,000 yards game distance.

So the "true scale" of GQ3 is 1/10,000.

If I wanted to keep the game convenience of 1 Knot = 1cm but convert the game to 1/2400, I'd have to divide the time and other factors by about 4, so I'd have:

1 Knot = 1cm = 44 sec = 24 yards/cm and 1yard on table = 2400 yards in game.

Math isn't a strong point of mine – did I do this correctly?

Personal logo taskforce58 Supporting Member of TMP29 Dec 2011 8:13 p.m. PST

1 nautical mile is 1852 meters (not yards). This equates to about 6076 feet, and commonly simplified as 2000 yards for most applications.

Given that 1 knot is 100 yards (300 feet, or 3600 inches) per 3 minute game turn, just divide that by 2400 gives 1.5 inch per turn, or about 3.81 cm.

If you want to keep to 1 knot = 1cm at 1/2400 scale, divide the turn length (3 minute, or 180 seconds) by 3.81 giving 47 sec.

But I don't understand why you want to change the time scale also.

Trierarch30 Dec 2011 12:42 p.m. PST

GQ 3 scale is nearly the same as GQ 1 & 2 scale
GQ 3 – 10cm = 1000 yards (not metres)
GQ 1 & 2 – 4 inches – 1000 yards
(4 inches is 10.16 cm) so close enough for government work.

4" = 1000 yds is 1" = 250 yds or 1" = 9000"
ie GQ scale is 1/9000

Give that the time scale (1 turn = 3 minutes) is centrl to the gunnery system, to keep the odds about right you would need to use a d45 or restrict shooting to 1 turn in (about) 4.

You would also need quite a big table (floor).


HesseCassel Inactive Member30 Dec 2011 7:26 p.m. PST

TF58: The time scale would have to change if one kept the 1 knot speed = 1 cm on table movement. If you change the scale a cm represents, then you need to adjust time b/c the values of knots, meters, NM etc are fixed.

David – we're mainly doing night actions around Guadalcanal. You don't need much range in 1942, even the BBs were at point blank range.

Lion in the Stars30 Dec 2011 7:48 p.m. PST

Actually, I think you'd need to 1/4 the effectiveness of the small guns and allow the big guns to fire every fourth turn.

You're really better off keeping the same timescale.

Charlie 1231 Dec 2011 9:01 a.m. PST

Changing the scale of a game is a fairly simple exercise (in this case, just multiple by 4 to get from 1/9000 to 1/2400. !00yds = 4cm or 1 knot). Changing the turn scale is a lot more dicey. Most games are designed with a specific turn length; actions and effects within the game are keyed to that time block. Changing the turn length may be asking for a lot of unintended consequences. Personally, without having a deep knowledge of the game's systems, I wouldn't even try.

Additionally, 1/2400 means 10k yds works out to some 12' on the table. Adding room to move, you're going to need at least twice that. And that is a heck of a big space.

Lion in the Stars31 Dec 2011 10:41 p.m. PST


When we played Seapower, we all used plotting-table scale (1"=1000yds is 1/36,000 scale) with massively-oversized minis (1/2400).

I was working on a submarine mod for Full Thrust, and ended up with 1 MU=500 yards for my preferred groundscale.

HesseCassel Inactive Member01 Jan 2012 6:59 a.m. PST

distances in night actions are pretty much well under 10K yards. Throw in a few squalls, and you are suddenly fighting at arms length.

While a lot of gunnery and ship design theory gave big ships big guns with outrageous ranges, the fact of the matter is that the vast majority of historical naval actions in WWII (I understand) happened at 10,000y or less, due to visibility issues of various kinds.

To my knowledge, there was no large naval action where the big BBs fought at 20,000-30,000 yards against each other with the smaller ships as bystanders, which was what the Battleship Theorists said was going to happen.

So the question is, shouldn't we be gaming the history, not the theory? Or at least design the rules for the history and if some Battleship Fan wants to throw down big ships and fight at immense ranges, make that the same exception as the guys who like to have Eastern Front tank battles between Ferdinands/Tigers/Panthers and Soviet Heavies?

Personally, I'd like to game history, not theory, 90% of the time or more.

Charlie 1201 Jan 2012 8:38 a.m. PST


It wasn't theory, it was reality. Many daylight actions in the Med were fought at just this range. Even CAs could engage at long range (Komandorski Islands: IJN opened fire at 20k yds after sighting the USN force at 27k yds. Casablanca: Fire opened by French shore batteries at 24k yds and returned by USN. Second Casablanca: Augusta chased off by 29k yds shots from Jean Bart). Even night actions generally begin with targets detected (if not fired on) well in excess of 10k yds. So the capability was there (and not just for the BBs). If any game is going to be historically accurate, it must reflect this very real capability.

That there were no grand Jutland style battles in WWII has more to do with the rise of other technologies (aircraft), the success of the interwar treaty process (there just weren't that many BBs around compared to WWI) and difference in operational and strategic outlook (the great 'Decisive Battle' idea was no longer valid).

HesseCassel Inactive Member02 Jan 2012 8:20 p.m. PST

And no doubt there were days when the Ferdinands and Elefants plugged away from concealed positions and knocked out battalions of T-34s and uber-ranges. But this wasn't as common as people think, and it doesn't make for a good game.

Anyway, my understand is that the VAST majority of WWII actions were fought at around 10,000 yards or less. Not what the dominant naval thinking planned for. Sure, there are lots of reasons for it, from airpower to oil shortages. Hara says that the Yamato used as much oil as 30 DDs when moving.

Anyway, with plenty – the majority – of actions at short ranges, a 12 x 6' table available, and 1/2400 models our preferred scale, I am trying to figure out how to lessen the scale distortion from 1/10,000, but might not eliminate it. Also, a friend is working on some Russo-IJN rules while I'm working on some Spanish-American rules, so scale issues are being considered.

Hope that answers "Why" and thanks for the answers.

Lion in the Stars03 Jan 2012 3:12 a.m. PST

Honestly, a ~4x model:groundscale distortion isn't that bad, even for ground warfare. As I mentioned, my gaming group went with a 1/36,000 groundscale. This let us have maneuvering outside of gunnery range happen on the table, but we needed to measure ranges from the mainmast.

Ok, 1/10,000 groundscale means that you are going to be trading shots at about 36" apart. Why is that distance a problem?

HesseCassel Inactive Member04 Jan 2012 10:07 p.m. PST

it's not a terrible problem – we've a 12x6' board. But when you want the extra maneuver room, it's nice to have some space.

I've usually managed without using a map or something for the pre-game maneuvering, or just giving players a choice of routes and such until they detect one another, but it's interesting to try and put it to true scale, also.

John D Salt Inactive Member05 Jan 2012 2:25 a.m. PST

If you use sensible British cables of 200 yards (or 100 fathoms if you prefer), instead of that weird American thing, things get nice and easy to reason about. There are ten cables to the mile, so in a six-minute turn (one-tenth of an hour) a ship will move one cable per knot of speed. If you really must have a three-minute turn, then it's half a cable, or 100 yards, per turn per knot. 1cm representing 100 yards would be a scale of 1/9144, which seems too big for big-gun actions to me unless you have a ballroom. Lion in the Stars' suggestion seems much more sensible.

I see no good reason to change the time scale when changing the model or ground scales, and I have never heard of anyone doing it before.

I really wouldn't worry about the model scale compared to the ground scale -- a table full of ships looks a lot better than a table full of sea.

All the best,


hindsTMP Supporting Member of TMP05 Jan 2012 2:51 p.m. PST

Per JDS, you ***want*** a compressed ground scale.

Even if you own a gymnasium, a 20th century naval playing area at true ground scale would look way too empty. How many photos of modern naval surface actions have you seen with both sides in the same picture? Not many.

Same thing goes for WWII land games, in my opinion, unless you just want to see terrain. Recall the aerial photos of Western Desert or Normandy. All you see is terrain, with a few dots here and there if you're lucky.

So, in this case, financial necessity aligns with aesthetics.


Sorry - only verified members can post on the forums.