"Main Gun Depression" Topic

Playing World of Tanks has got me thinking… (no really)

A number of times I've found the 'perfect' Hull Down position, then found that the only thing I can hit is the head of a Mecha because the gun doesn't go down that far. WoT doesn't have Mecha.

Likewise I found good positions overlooking the enemy, only to find my excitement of looking down at the thin deck armour is tempered by the fact that I can't actually draw LoS.

How to represent this on the tabletop?

I'm not sure the problem should translate to the table. I've found that the computer games I play don't allow for fall of shot unless firing artillery. So tanks in hull down positions on high ground don't benefit as they should on the machine.

IIRC, the boardgame "Arab Israeli Wars" accounted for Soviet tanks being less capable of depressing their main guns (a side effect of their low profile) by making them less capable from hull down positions.

US tanks can depress their guns better than the Soviets.

So, for every 1" in elevation, you need about 6" of range to the target to fire on it, for US tanks, assuming about a 10 degree depression angle, and that the vehicle is in a level attitude relative to the surface of the Earth.

Soviets need 12" of range, since they can only depress their guns about 5 degrees.

See the chart below, and use the Tangent values for the various degrees of depression of the guns, e.g. divide 1.00 by the Tangent value for the degrees of depression applicable to your vehicle(s), in order to determine the rise/run distance. The latter is the horizontal distance needed in inches (or other units, if desired) for each 1" rise in elevation of your vehicle.

link

Of course, this doesn't account for the ballistic fall of shot at longer ranges, but it works for laser beams, which is close enough for me. ;-)

This is a very depressing subject.

Mako11,
Often the vertical scale of a wargame table is several times that of the horizontal scale. So the angle should be multiplied by this factor. Or at least the ratio should increased.

I agree don, it's just getting me down…

Yes, my main gun situation has been quite depressing since about the time I turned 55.

I leave figuring out if the tank on the table can hit the other one to the guy in the tank and the dice. Too much other stuff to worry about.

MJKerner- Blank ammo or lack of time on the firing range? Poor reload times?

Ditto – Good to know I wasn't being silly. I think with Platoon-Stand games its less of a problem- it is 3-5 tanks on a 200m frontage, you're not meant to drive them all. However in a 1:1 game when someone goes 'That is Hull Down' some sort of 'shadow' must be there.

For WWII, you'd have to check actual depression stats, but I wouldn't think there would be a whole lot of difference from other countries'? The depression thing started happening, I think, with the IS-3 and the emphasis on very low silhouettes.

A quick look at some Ospreys reveals:

KV-1 Model 1941 -4/+25
T-34 Model 1942 -3/+30
T-34-85 Model 1945 -5/+25
IS-2 Model 1944 -3/+20
T-55 -4/+17
T-62 Model 1972 -5/+18

Steve Wilcox -the Federation Space co-designer?

Cheer them up a bit by starting out with a few coax shoots.

It shows that hulldown over even a 5-degree sloped hill the Soviets aren't going to be firing at anything at lower elevation.

Tim,

Yes, in BF:WW2 there is a die-roll made to see if you find a hull down position (6 or more on a D10). You can essentially go hull down anywhere, but that's modified by the type of terrain you're in, how good your troops are or how big your vehicle is:

+/- Discipline Rating (i.e. +1 if Veteran/Elite or -1 if Raw)
+1 if on rough, rocky or sloping ground
-1 if Large Vehicle
+1 if Small Vehicle

An optional variant is to apply -1 if the ground is unusually flat.

In the Modern variant I also give some vehicles a -1 or +1 on their cards, which reflects their design (most Soviet tanks get -1 due to the small turrets and consequential poor depression stats).

Of course, you can always identify to the players, locations where a vehicle might automatically find a hull-down position, such as along a low embankment or or in pre-prepared scrapes.

Heh, is bleeped out!

I should have said 'Woman in comfortable shoes'.

Took me 3 euphemisms to get the right one!

In PW:WW2 the hull down factor varies from 1 to 6. Giving from 10% to 60% protection to the lower hull. This is multiplied by either 50m for open topped vehicles, 100m for Allied and German tanks and 200m by Russian tanks for 3-degree or less slopes. This gives a dead zone below the slope that can't be hit.

On steeper slopes the distances are doubled, except Russian tanks dead zone extends forever (cannot depress) to lower elevations.

Now, to go hull down on a hill a tank must first get to a back slope position and randomly roll (D6) a hull down number. A veteran crew can adjust this to any desired number the turn after the first.

Here's a chart I once made for similar thread: link

I have no idea what sources I used (probably Wikipedia or something equally reliable), but the values are mostly the same as Steve's numbers.

There are many more experienced tankers here than me, but we were trained to find a hull down position (where only the commander can see) then when a traget came – you drove forward until the gunner could aquire it – fired and withdrew back to hull down.
if you could shoot from your position – you weren't "hull down" enough.

Steve Wilcox -the Federation Space co-designer?

Nope, I'm Stephen C. Wilcox, and he's Stephen G. Wilcox!

… we were trained to find a hull down position (where only the commander can see) then when a traget came – you drove forward until the gunner could aquire it – fired and withdrew back to hull down.

In my experience that is generally referred to as a turret-down position.

AIUI the "advance to firing position – fire – withdraw" sequence really only became popular after modern stabilization and laser rangefinders came into common use. If you do not have a stabilized sighting picture for the gunner he won't acquire the target as the tank advances to firing position, so won't know when to call halt. If he doesn't have a fast range-finder and a high first-round hit probability, you won't be doing effective fire until the enemy is within battle-sights distance.

Without stab, and without LR/IFC, you are far more effective sitting in a hull-down position for multiple shots, so that you can observe and correct for range, then withdrawing only when enemy counter-fire starts to get close.

Or so I understand. Never done it myself. Strictly a desk-jockey.

-Mark
(aka: Mk 1)

We dont, diffrentiate between tanks. We do make some allowance for dead ground. I proably don't have the calcs I did. We made hull down/turret down a die role against leadership if it was not pre surveyed/pre engineered. We then apply standard dead ground. i.e 60m per contour. This means tanks hull down cannot see everything. Neither can a man using a crest line as hard cover. This is as always an approximation but it gets somwhere near and is within our KISS requirement (Keep I Simple and Stupid). An adage used in all training aids. We also put an elevation limit which is a bit more arbitart but better than nothing. This was based on the anecdotal evidence that german tanks main gun in WWII could typicaly not elevate to hit Russians on the second/3rd floor. We bent it a bit but crude is better (in our opinion) than nothing. We are interested in basic tactics not in really fine detail on individual detail. One mind can only cope with so much in 3 hours ;-).

The problems we kind of have is that the horizontal scale is 7 times the vehicle scale. The ground scale is 1:2000 ad the model scale is 1:285. The vehicle scale and the vertical scale are the same. So any slope is really 7 times actual scale. A model terrain slope of 45 degrees represents a scale slope of a little more than 6 degrees. Model GHQ tanks with smooth track bottoms can't even hold onto hills of 45 degrees. (CnC model tanks with track teeth all around have a better chance.)