From the aircraft thread "aircraft that did the most.......... tank guns.

[Schweik]

They used 155mm howitzers and long guns in direct fire mode against tanks during the Ardennes Offensive, though definitely in an act of desperation. The "Long Tom" shot an astonishing 127 lb projectile 13 miles, so presumably a direct hit even with HE would be uncomfortable for a tank crew, even in a King Tiger.

In games like Advanced Squad Leader back in the 80's AP or HEAT ammunition for artillery was something you had to roll for, it was usually unavailable. (IIRC you had to roll something like a 3 or less on two 6 sided dice). In computer games like Combat Mission Afrika Korps it was a little more realistic, each artillery piece would have a small number of rounds equivalent to whatever the TO&E said they were supposed to have, plus or minus a few. So for an artillery piece that had 80 HE rounds it might have 5 HEAT rounds. Or it might have none.

Similarly for the tanks, the fairly rare HVAP rounds were much more effective but in a typical scenario you might only have 3 or 4 of them per tank or TD, or none. Overall fairly realistic though what they didn't have is re-armament even for a long battle.

 

[Milosh]

Schweik, it is StuG III Ausf. G, not StuGG III.

 

[michael rauls]

Uh oh. I hope for my sake we're not taking away points for bad spelling.

 

[Shortround6]

If they do I need a few hundred just to reach barely passing

 

[GrauGeist]

Virtually all StuG III types were used in the AT role at one point or another, not just the Ausf.G variant.

 

[yulzari]

I think that (and open to him correcting my guess) Nicholas Moran is saying about the M4 is that it was the correct choice for winning the war. Not necessarily winning a tank duel. Not a great comfort to an M4 crew but the US Army task was to win the war not to win every battle. Also to do it thousands of miles away from it's supply source.

Re the tank machine gun number issue. The British put hull MMGs in when the hull was big enough or not when the hull was deliberately kept small to allow more armour for the same weight e.g. Matilda II or Valentine. When ammunition was getting bigger the space of a hull gunner was wanted for ammunition. Hence the Centurion went over to just the co-ax (initially in 20mm).

Putting in a hull gunner on a Centurion would have meant far more weight to both give hime a useful position and extra armour thickness as well as area to compensate for the reduced slope. One might point to the German position in the Panther but I have sat in that position and you could see bugger all, not to mention no direct sights so one would be spraying virtually blind with only the tracer and fall of shot to guide you.

What is not mentioned is the role of the extra crewman in the workload and efficiency of the crew. Remove him and the same maintenance, general duties and guard standing fall upon the reduced crew who are thus less rested and have less sleep. Whatever the comparable battle ability of a Lee or a later Valentine the Leehas to give the crew an easier time with more than twice the numbers to do the same daily tasks.

Re the turret free machine gun as an AA resource. The British response, based upon learning on the job, was to shut the hatches and wait till the horrid things went away. Bren AA mountings soon disappeared from their turrets and went inside to be taken out for guard piquets.

 

[Shortround6]

A couple of points on this, I was reading a book on British AT guns and ran across the chamber capacities. Space available behind the shot/shell for powder.
The 2pdr was 25 cu in.
The 6pdr was 100 cu in
The 17pdr was 300 cu in.
While not a direct correlation to storage needs it is probably not too far off.

In a lot of wars tank commanders suffered a disproportionate number of casualties compared to the rest of the crew. Most people attribute that to them being more exposed than the rest of the crew because they tended to ride with at least their head out of the hatch.
It was done, it made the tank more effective, but there was a price.
There were times that high volumes of machine gun fire could be an advantage but it was (in WWII anyway )in close in combat against troops with very short range weapons. Wither those tanks should have had better infantry support is another discussion. Tanks used for helping clearing towns certainly saved infantry lives so trading some large lumps of metal and a few crewmen might be preferable to loosing large numbers of infantry.

 

[Shortround6]

Some posts (slightly edited) from an old thread but bearing on mostly British tanks and guns.

Often large differences in effectiveness came with sort of "behind the scenes" changes. As the war went on the communications, even in an Infantry division changed considerably. A 1939/40 division had about 75 radios of which 51 were in the divisional artillery regiment and 42 of those were operated by artillery regiment operators. In late 1944 a division had about 1000 radios. At the beginning of the war other 'signalling' methods included runner/messengers, flags/signal lamps/ signal panels (for aircraft) and of course telephone/telegraph wire. These three categories dropped off as the radio use increase.
In late 1944 any forward observer could call for the fire of any and ALL guns/tubes within range of the target regardless of what units they belonged to. A flexibility enjoyed by no other army. The BEF would need about 10,000 more radios to bring it up to 1944 standard of equipment let alone the changes in doctrine/training. See this site for much more detail: Artillery Communications

In some cases using the Germans as a model may make sense but not everything the Germans did was the best or only way of doing something.

I would also note that while the British army was the first to be motorized/mechanized this merely meant there were no horses. An infantry company in the BEF in France had Four 15cwt trucks. (1680lb/764kg payload) and one 8cwt truck. All the Infantry walked.

Going back to the tanks, you have the circle of doctrine (tactics) dictating the weapons specified in future tanks and then you had the weapons fitted helping dictate the tactics (doctrine) used in the field.
The British in the 1930s believed in "firing on the move". That is that rapid and accurate firing while moving/advancing would suppress the enemy and give the British an advantage. Without mechanical stabilizers the British tried a scheme of using tank guns that were free in elevation. That is there was no mechanical elevation mechanism, ie hand-wheels/gears. Elevation was controlled by the gunners shoulder against a shoulder piece and his legs/body allowed for a much more rapid and accurate adjustment in elevation as the the tank crossed less than smooth ground. This may very well have been true at slow speeds in tests. However in the real world the ability of the gunners to control elevation in this way was actually pretty limited. It also made no allowance for changes in line (lateral movement) which
It also had the follow on effect of degrading the armaments long range ability. It didn't matter how good the gun/ammo performed at long range (800-1000yds and beyond) as each shot was essentially a "first" shot because the gun/s moved under recoil even if the gun was stationary. Correcting a 1st shot miss wasn't a matter of going up or down a 1/4 turn on a handle for instance but trying to either push the rear end of the gun up or relaxing the leg/body muscles and letting it drop a bit, hardly precise. The firing on the move could also consume a lot of ammo for each hit actually achieved.
Now combine this with the decision to NOT us HE ammo because the 40mm was considered too small in spite of the fact that just about every army that used a 37mm tank gun issued HE ammunition and the British are having a real problem dealing with targets of all types at long range. The MG was supposed to deal with ALL non-armored targets and here we run into another problem. The vast majority of the worlds AT guns and light field guns were partially armored. At least they had nominally bullet proof shields covering the forward arc.
Granted a number of these shields could be pierced at close range by rifle/mg ammo at close range even without using AP ammo but that didn't help at around 800yds and beyond. The gun shields could and did protect at least a few of the crew from long range mg fire.
What this means is that British tankers, when faced with long range AT gun or field gun fire had two or three choices. One, call for artillery support while popping smoke. Given mid/late 30s radio nets this was somewhat iffy even if the tanks were within range of the supporting artillery. It also means a halt/temporary retreat in the advance. Two is attempting to slug it out at long range which is the worst choice and three, advance as fast a possible (charge?) to get close enough for the MG to become effective against the towed guns. Close enough to penetrate the shield or advance to a point to take the guns from the flank and/or close enough to make getting a hit on gun a likely proposition with the main gun AP shot. The last two choices are not very good ones but given the radio communications of the day may be the ONLY options.

Different choices in the design process may have allowed different tactics, which in turn, may have allowed for different choices for future tanks. Throwing out the "firing on the move" tactic early on may lead to improved long range accuracy for both the main gun and the co-ax gun which extends the range the tanks can deal with non-armored targets. Better, more precise elevation control for quicker walking successive shots onto the target. Buying HE ammo from the start would also do wonders for this stand off capability. The 40mm Bofors shell held 65grams of HE. The German 37mm held 25 grams and the US 37mm AT and tank shells held about 38 grams. The 2pdr wouldn't take out field fortifications but it's ability to deal with towed guns (and their towing vehicles, one or two 40mm HE vs how many MG rounds?) would be much enhanced.
The 2pdr solid shot was also a bit lacking in long range performance due to it's shape.

From

as I want to give credit for the picture.
4th round is an APCBC projectile and extended the practical range of the 2pdr by several hundred yds at least.

 

[Schweik]

M4 sherman tank crews did fire on the move and did get hits doing so, I can't speak necessarily to how fast they were moving. But it's pretty well documented.

 

[Shortround6]

I am sure you can find reports/accounts of many countries tanks firing on the move (British certainly tried to set up a system for it) and I believe the germans noted the it was a popular Russian tactic even with BT-7s and T-26s. They may have actually gotten hits doing it

The big advantage seems to have been they could get off a faster shot once they stopped due to the gun being at least somewhere near the right height/elevation when the tank stopped, require less gross adjustment of the elevation.

distances involved also matter.

 

[Glider]

M4 sherman tank crews did fire on the move and did get hits doing so, I can't speak necessarily to how fast they were moving. But it's pretty well documented.

I must admit that I don't know where it's documented. The situation is of particular importance, slow speed on a tarmac road is one thing, cross country at any speed (even dead slow) is quite another.
It should be remembered that the first tank to regularly hit a target whilst moving at any speed cross country was the Centurion Mk 3, and it caused quite a stir at the time as it was such a difficult achievement.

 

[Schweik]

I believe one source where I read this was "Armored Thunderbolt" by Stephen Zaloga. At least some of the incidents he specified were inside of towns. I have that book and many others on of of my bookshelves if I can find it I'll try to find his source.

One other thing I was left wondering about from reading that book, was considering the systematic up-armoring of Sherman tanks and other Allied tanks from late 1944 onward, during which some units piled sandbags, extra wheels, and railroad ties on the front of the tank, some put poured concrete forms, and Patton specifically outlawed those methods but instead had armor cut out from other Shermans or in some cases from German tanks welded to the fronts of his tanks turrets and hull as applique armor. Sometimes as much as 2" or 3".

They seemed to have done this and not suffered any particular problems as a result. Which begs the question, why weren't Shermans manufactured from that point on with the extra armor?

Concrete armor

M4 / 76 with applique armor, and the tank it was removed from (inset)

Applique armor

Armor with side skirts

Of course the general consensus seems to be that anything (like sandbags etc.) except the added armor was useless and even that was a wasted effort, but an extra inch or two of steel plate could make the difference between life or death for an M4 against the ubiquitous KwK 40 75/L48, and I suspect the sandbags may have helped set off shaped charge warheads early, like spaced armor.

 

[Shortround6]

They seemed to have done this and not suffered any particular problems as a result. Which begs the question, why weren't Shermans manufactured from that point on with the extra armor

Well, the ordnance dept had fooled around with these.

and built about 250 by July of 1944 and they had a pretty good idea what they could and could and could not get away with. They also changed the final drive gear ratio of the tank which not only dropped the top speed to 22mph but would have dropped the speed in any gear by a proportionate amount.

 

[Schweik]

Yes the M4A3E2 "Jumbo's" were a known quantity, but these were really specialized assault tanks - the armor was extremely thick IIRC up to 7" on the turret front. They had their role.

But the 3rd Army field mods were basically about at the midway between the regular production M4A1 or M4A3 and the "Jumbo", without any modification to the transmission so far as I know and anecdotally, without any major effect on speed or performance.

 

[Milosh]

Adding several hundreds of pounds of extra weight would certainly effect performance and reliability.

"Crews did still feel the need to add more armor and sandbags were a common addition to the glacis and in a few cases concrete was used. The additional weight of 4"-6" (101-152 mm) of concrete right on the nose of the tank must have made it a very difficult proposition to drive. The front bogie was almost certainly beyond its maximum weight capacity by that point and a mechanical failure on the front bogies was most likely a case of when, not if."
M4A3E2 Jumbo Assault Tank

 

[Shortround6]

The problem was that nobody really knew what the effect/s were going to be and Patton probably wouldn't happy with a bunch of unexpected breakdowns.

It is also one thing to overload a vehicle somewhat evenly, and another to add even 1/2 that weight but concentrate on one end or the other.

Steel weighs about 40lbs per sq ft per inch of thickness, you can add a lot of armor to the gun mantlet that spread out over the whole front of the tank doesn't really amount to much.

 

[Schweik]

Adding several hundreds of pounds of extra weight would certainly effect performance and reliability.

"Crews did still feel the need to add more armor and sandbags were a common addition to the glacis and in a few cases concrete was used. The additional weight of 4"-6" (101-152 mm) of concrete right on the nose of the tank must have made it a very difficult proposition to drive. The front bogie was almost certainly beyond its maximum weight capacity by that point and a mechanical failure on the front bogies was most likely a case of when, not if."
M4A3E2 Jumbo Assault Tank

As I pointed out already, both the concrete and sandbag field modifications were perceived as adding too much additional weight for too little benefit, which is why Patton (among some other commanders) banned them from his command. However the applique armor - the steel armor plate that was welded on top of the existing armor, did not seem to cause these kinds of problems according to what I have read. And it seems to have helped a great deal in combat.

As for the M4A3E2 I already addressed that.

 

[Milosh]

"Testing
On the 8th June, tank 50326 was shipped to the Chrysler Tank Arsenal Proving Ground in Detroit for endurance trials. After some 400 miles which resulted in one broken spring it was however noted that the same "low milage failures had been experienced with standard weight vehicles". It was apparent though that the additional weight of the Jumbo was seriously taxing the standard vertical volute suspension of the M4."

 

[Schweik]

I think the armor on the Jumbo was about 40% thicker than the Applique armored tanks, and maybe 60% thicker than a standard Sherman. Maybe somebody can look up the exact figures as I am still not at home....

 

[Shortround6]

The concrete and/or sand bags may have added weight out of proportion to the increase in protection they offered.

it appears this crew may be more worried about Panzerfausts than a tank gun dual.