German artillery what-if: going all-in with gun-howitzers past 1935

[tomo pauk]

... ie. artillery pieces that have the barrel length of some 30-35 calibers. Granted, this is a bit longer barrel than on the pieces that can be called like that. like the Soviet ML20, or the British 25 pdr, but bear with me for the duration of this thread. Artillery 'niches' are of 88 mm, 105 mm, 127/128mm, 150mm, and 170mm, with MV of some 650-700 m/s maximum. Max elevation is still above 45 degrees.
The 'no free lunch' rule will be evident - for the same weight vs. the howitzers, shell weight is going to be lighter, but the range will be longer, and so will be the ability to hit the moving targets that come in close, talk to about 1000m. Lets stipulate that Heer has no problems in specifying the 88 gun-howitzer as the backbone of their artillery park instead of the 105 mm howitzer (this is the hardest part probably, since the 105m shell was at least 50% heavier, even if that howitzer was short - if not very short - ranged). Or, go with 105mm gun-how for the motorized or mechanized divisions, and 88mm for the non-motorized units?
The dedicated guns are still being made, like the AT guns, or the long-range guns. They look at piggy-backing on the KM and LW guns for the long-barreled pieces, in order to save time and coin.

Will the Heer artillery park will be better off, or worse off?

 

[Shortround6]

Germans had 4-6 different 10.5cm howitzers with longer barrels (or at least longer range) than the standard le FH 18.
I am not sure where the crossover point is. They got one to have a range of 15km.
But you have the 10.5cm K 18 cannon with a range of 19.075km.
Problem is that they started to gain weight fairly fast although not so bad as the 10.5cm K 18.
The Prototype 10.5cm le K 41 did range to the 15km but it weighed 2640kg instead of 1985kg for the 'standard' Howitzer. Granted this is about 1/2 the weight of the 10.5cm K 18.
Germans thought it was too much gun for the shell weight.
Germans got another 1.65km out of the standard howitzer by using a special shell, a special charge and a muzzle brake.

A lot of people's howitzers maxed out at about 45 degrees of elevation. The US was something of an exception (not the only one). The actual need to fire at higher elevations mostly solved by using more intermediate charges. A shell falling at 60 degrees may very well have been fired at 45 degrees or a bit less. And the poor gunners had been digging in the trails for higher elevation since the days of muzzle loaders. Yes, simply turning the elevation wheel is a lot easier but the resulting gun is often heavier, higher off the ground and costs more.


The British built a very good 88mm gun howitzer and then shot it one wheel, the trail and the elevation system with the crappy ammo.

There are real problems with trying to use large heavy artillery pieces as AT guns. The 10.5cm K 18 fired a 15.56kg AP shell at 827mps which is sufficient to take out just about anybody's tank. Problems include you now have your divisional (or Corp) artillery on the front line and can be taken out by machine gun fire or 81-82mm mortars.
They are useless for using as general support artillery because the first round fired revels the position to any enemy within several km.
With the weight of the barrels they tend to track moving targets both slowly and they tend to overrun the target when the target stops.

As a general rule of thumb for anti-tank work you get a point blank range equal to the Muzzle velocity + 10%.
Now special sights can help out with this (a lot) but now you are spending money on sights that hopefully will never be used on general field gun (if your artillery which is supposed to be 4-6km behind the lines are shooting at enemy tanks the general situation has fallen in the toilet).

High velocity also means high barrel wear but this can be solved by using lighter charges for the shorter ranges as was done by just about everybody's normal howitzers.

A lot of gun companies had offered 75mm/100-105 combos (same carriage and recoil system) between WW I and WW II. Sometimes they needed a little fiddling with the gas pressure in the recoil system but the idea was a cheaper total buy and fewer spare parts needed. They tried selling the idea of swapping the barrels in and out to suit the target/range but that was not really practical.

The Germans did use the same carriages for some different guns. Like the 10.5cm K 18 and the 15cm FH 18 (and others).
The British used the same carriage for the 4.5in gun and the 5.5in gun/howitzer.
The US used the same carriage for the 4.5in gun and the 155mm howitzer.
In all three cases the smaller caliber gun/s fell out of favor as while the extra range was useful, the much lower destructive power for the amount of effort needed to transport and emplace them outweighed the extra range.
British also solved part of the range problem with the 5.5 by finally getting their heads out of their bums and getting a decent shell. The 80lb shell offered almost 1900yds more max range (almost 1/2 the difference between the 4.5 and the 5.5) and the 80lb shell held more explosive than the 100lb shell.

With artillery the weapon is the shell. The gun is just the launcher. Much like bomber aircraft, the weapon is the bomb/s. The bomber aircraft is just the deliver system.

 

[ThomasP]

What Shortround6 said , particularly in relations to the shell being the weapon.

Plus, the consideration that ideally you want to be able to outrange the enemy for the most part.

A paper exercise would be to use something like the US artillery establishment, and use the guns below for both sides:

75mm howitzer
105mm howitzer
155mm howitzer
103mm howitzer

No advantage to either side.

Then give side A gun/howitzers and side A now outranges side B.

Advantage to side A, particularly if side A is on the offense?

As Shortround6 said the weapon is the shell, but if we use the bomber analogy then the bomber has to have enough range to reach the target, as does the artillery piece. If you can hit the enemy at significantly longer range there is (I think) a clear advantage, even with reduced rates of fire and/or individual shell effect.

However, if you are on the defense, the balance changes (maybe?) in favor of rate of fire and/or individual shell effect.

Conventional impact or time fuzed ammunition vs proximity fuzed ammunition is an extreme example of the individual shell effect, as well as the outranged effect - ie with everything else being equal - if you are outranged by the enemy the your proximity fuzed shells do not matter as much unless you are on the defense. If you have the same range then the proximity fuzed shells can be devastating. And if you outrange the enemy and also have proximity fuzed shells then you have clear artillery superiority.

Maybe?

 

[tomo pauk]

Germans had 4-6 different 10.5cm howitzers with longer barrels (or at least longer range) than the standard le FH 18.
I am not sure where the crossover point is. They got one to have a range of 15km.
But you have the 10.5cm K 18 cannon with a range of 19.075km.
Problem is that they started to gain weight fairly fast although not so bad as the 10.5cm K 18.
The Prototype 10.5cm le K 41 did range to the 15km but it weighed 2640kg instead of 1985kg for the 'standard' Howitzer. Granted this is about 1/2 the weight of the 10.5cm K 18.
Germans thought it was too much gun for the shell weight.
Germans got another 1.65km out of the standard howitzer by using a special shell, a special charge and a muzzle brake.

Note that I'm willing to sacrifice the LR weapons on the altar of gun-howitzers, so the 105mm cannon is looked with even lower enthusiasm.

There are real problems with trying to use large heavy artillery pieces as AT guns. The 10.5cm K 18 fired a 15.56kg AP shell at 827mps which is sufficient to take out just about anybody's tank. Problems include you now have your divisional (or Corp) artillery on the front line and can be taken out by machine gun fire or 81-82mm mortars.
They are useless for using as general support artillery because the first round fired revels the position to any enemy within several km.
With the weight of the barrels they tend to track moving targets both slowly and they tend to overrun the target when the target stops.

I'm loathe to use the 5-6 ton towed guns as AT guns, apart the need of self defense.
The 88mm gun-how firing the AP shot at close to 700 m/s will deal with anything, bar later Churchill, KV and IS tanks anyway. HVAP shots can help out from 1941 on. The 105mm gun-how should improve the game further, ditto for the 127-128mm gun-how.

With artillery the weapon is the shell. The gun is just the launcher. Much like bomber aircraft, the weapon is the bomb/s. The bomber aircraft is just the deliver system.

Agreed.
A lot depends on the launcher, or on the delivery system, though.

 

[Shortround6]

Note that I'm willing to sacrifice the LR weapons on the altar of gun-howitzers, so the 105mm cannon is looked with even lower enthusiasm.

The German 10.5 cannon used the same carriage as the 15cm how so they saved a bit of money there. It might have been a bit heavy but tailoring a specific carriage for it might have been a bit much.
The question/s are how much weight you can save going to a lower velocity gun and how much range you have to give up.
Or how much bigger a truck or tractor/halftrack you need to tow it.
The standard Howitzer could be handled with a single horse team although they cheated by using a second team/wagon to cart the ammo. Where the 10.5cm gun howitzer falls???
An opening for the 8.8cm?

I'm loathe to use the 5-6 ton towed guns as AT guns, apart the need of self defense.

Yes, once AT guns went beyond 2 tons things got more than a little weird. Germans had mixed feelings about the 1.5ton 7.5cm PAK 40. It did the job, but it was hard to move.

The 88mm gun-how firing the AP shot at close to 700 m/s will deal with anything, bar later Churchill, KV and IS tanks anyway

This comes to the point of the matter. The British 25pdr (88mm) used a 20lb AP shot (solid) at about 610m/s. The gun weighed just under 4000lbs (2 short tons) and it was a crappy AT gun.
It was too tall, (in order to get the elevation needed) and it had 4 degrees of traverse without using the "wheel" and even that slowed down large changes in traverse. They got 70m of penetration at 400yds at 0 degrees impact. They also needed a supercharge and a muzzle brake to keep the recoil in check. Changing to a split trail carriage might mean several hundred pounds. British did not use horse traction in WW II.

Trying to use a 10.5cm gun firing a 33lb (15kg) shell at 700m/s means a much, much larger gun than the standard 10.5cm howitzers in anybody's army.

HVAP shots can help out from 1941 on. The 105mm gun-how should improve the game further, ditto for the 127-128mm gun-how.

Germans are between a rock and a hard place. They ran out of the materials for HVAP shot part way through the war. In fact the Americans were running low. M4 75mm Shermans were very seldom issued HVAP ammo because they thought the Tungsten carbide cores would be better used in the 3in/76mm guns and for a lot of 1944 these longer barreled weapons often had 2-4 rounds at a time. The 75mm gun tanks rarely saw any.
600m/s is a sort of border area on using capped shot vs plain shot and it also depends on the armor target. Face hardened armor often does better against one than the other but homogenous armor often changes the result. This is impact velocity not muzzle velocity. The next big change is around 800m/s (impact?) were even capped shot has a much greater chance of shattering and the need for the TC penetrators becomes more important. Now if you can simply overwhelm the target (Soviet 122mm gun) it doesn't matter if the shot breaks up. You get a big hole and lots of ex armor pieces and pieces of shot flying around inside of the tank making it a really bad day for the crew.

Getting 700m/s velocity out of large guns pushes them a little too far to the "gun" side

French 1917 GPF (also US 1917-1918) 155mm at 735m/s, only 35 degrees elevation and 13,000kg.

British 6in howitzer of 1915.

430m/s. 45 degrees and 3700kg. and 3700kg is no joke if you don't have trucks/tractors.

Please note that they appear to be pulling the howitzer along a narrow gauge rail line so the ballasted area may help with the weapon not sinking into the mud.

 

[z42]

I don't know if more range is worth the cost? Today, in Ukraine, we see that artillery range does seem to be very desirable. But today, there's also satellites, drones, counter-battery radar, and FO teams with small yet powerful radios that can provide targeting information. But during WWII? If most of your artillery shooting is done by firing at targets basically on the front line, yes range can be useful in the sense you can have more batteries spread out over the place firing into any one target, but less so than today.

Then again, if you're happy with a bit shorter range, a very cheap alternative to howitzers are heavy mortars. Soviets used their 120mm heavy mortar extensively (including post-war). Germans had something roughly comparable in the Granatwerfer 42 - Wikipedia . A large number of heavy mortars for the majority of artillery work on the front lines, and then a bunch of somewhat longer-ranged gun-howitzers for 'special' situations demanding longer range could be a pretty potent combination?

Secondly, you have mobility to take into account. Instead of allocating steel to making longer gun barrels and sturdier carriages, maybe use that steel to produce, say, 6x6 trucks for towing those artillery pieces around instead of using horses? That of course gets into the issue of fuel supply, if the Germans magically transform the Wehrmacht into a motorized force, how do they keep it running? Build more (much more?) synthetic fuel plants?

As for AT capability, yes by all means provide a few AP shells for self defense in situations where the excrement has hit the fan, but this should not be particularly high on the list of priorities for designing an artillery system.

Finally, there's artillery doctrine and targeting. The US is generally lauded as having the most efficient targeting system during WWII, able to rapidly shoot with multiple batteries within range, including time of arrival shooting capability. The last one is pretty useful, as after the first shell hits everybody jumps into cover and the efficiency of subsequent shells is greatly diminished. No reason why the Germans couldn't develop a system like this, and crucially it doesn't require massive extra amounts of steel production either.

 

[z42]

Yes, once AT guns went beyond 2 tons things got more than a little weird. Germans had mixed feelings about the 1.5ton 7.5cm PAK 40. It did the job, but it was hard to move.

By the time you need to back up a truck/halftrack or a team of horses to the gun, under fire, to tow it away, you're realistically gonna lose a lot of those guns very fast. For the smaller guns where the crew can move the gun a bit back before hooking up the towing vehicle/horses this is much less of a problem.

The Germans also had a 12.8cm PAK gun late in the war. Imagine having to move that thing around, under fire..

 

[Shortround6]

But during WWII? If most of your artillery shooting is done by firing at targets basically on the front line,

They stopped that by 1915. May depend of definition of front line. By 1915 (and early 1915) the guns were out of sight of what they were shooting at. The guns were behind buildings, woods, ridges, or in deep pits. Sound location was being used and so was flash at night. The problem was communication. Signal flags did not cut it. telegraph/telephone was used. Carrier pigeons were used for back up when the wires were cut.

The US is generally lauded as having the most efficient targeting system during WWII, able to rapidly shoot with multiple batteries within range, including time of arrival shooting capability. The last one is pretty useful, as after the first shell hits everybody jumps into cover and the efficiency of subsequent shells is greatly diminished. No reason why the Germans couldn't develop a system like this, and crucially it doesn't require massive extra amounts of steel production either.

British may have come up this first? Or at least in parallel.
Problem with this system is while it does not require a lot of extra steel production it required vastly increased radio production. The size of the "network" of interconnected observers, gun batteries, headquarters units exceeded the ability of the signal corp to run wires, maintain wires and, at times, pick up wires for reuse. A British Infantry division of 1944 had over 10 times the number of radios that a 1940 division in France had.

Yes the problem of finding, identifying targets more than few miles behind the lines was more difficult in WW II. The increase in big prime movers and SP guns meant that the guns can move much quicker and evade return fire. And in the 1950s they had radar that could track incoming shells back the firing guns. I think they were doing that with mortars at the end of WW II, at least on a trial basis?

 

[z42]

They stopped that by 1915. May depend of definition of front line. By 1915 (and early 1915) the guns were out of sight of what they were shooting at. The guns were behind buildings, woods, ridges, or in deep pits.

I meant shooting at targets that were located on the front line, not that the guns themselves needed to be there.