Heer, from january 1936 on?

[Shortround6]

Thanks for the engines overview. We will need to start with the 125 HP engine, switching on more powerful ones as they became available.

That sounds good but the low powered engines may not give you the speed/mobility you want. Spending time and money on chassis that will only become acceptable performers several years down the road (without spending even more money on development) doesn't sound like a good use of resources.

On May 1st 1938, there is 2300 x 20mm, 670 x 37mm and 2000 x 88mm in Wermacht hands. By Sept 1939, it is 6700 of the 20 and 37mm (mostly 20mm, single mounts) and 2628 of 88mm (mostly) and 105mm, increased to 9817 and 3095 in June 1940 - that's 14000 Flak. The German Flak gunners sure have had on what to learn their trade, and then some (got to extract the Westerman's tables somewhere...)

Thank you, The Heer seems to have had enough guns, at least for the first 3 years of the war.

The MK 101 was lighter than the MK 103: 139 kg vs. 145 kg - bare gun; 180 kg is for the MK 101 with a full 30-rd drum.
The HE shell was 440g vs. 120g for the 2cm; there was also the M-shell of 330g available, while it seems that HE shell was not used on the MK 103? Granted, the drum is necessary, until we receive the MK 103. Quirk might be that we need about same manpower for the single 2cm as we need for the single 3cm, that has maybe 3 times the practical 'throw weight' at a maybe 50% greater distance and altitude.

It appears you are correct on the weights of the guns but using "throw" weight gets a bit deceptive. A British 3in 20cwt AA gun has the same "throw" weight as the MK 101 using 440 grams shells if the 3in fires 15-16 rounds a minute. Problem is hitting the target (unless you can scare them away with tracer). The low rate of fire with the MK 101 means that a 300mph aircraft can move almost 33 meters between each shot fired. The 2cm Flak 38 cuts that to about 19 meters traveled.
Once you can get the high cycle rate MK 103s the 30mm gun has just about all the advantages. But using the MK 101 is a bit iffy.

German Army never used a twin 20mm mount during the war, Perhaps a opportunity there?

I'll admit that the Germans were on the forefront when it comes down to self propelled AAA. Until the LW was bested, or at least equaled in the air, there was no much need for the AAA for the 'tactical' ground forces.

There was a need, it's just that it seems to have been pretty well filled by existing equipment/scale of issue.

 

[tomo pauk]

That sounds good but the low powered engines may not give you the speed/mobility you want. Spending time and money on chassis that will only become acceptable performers several years down the road (without spending even more money on development) doesn't sound like a good use of resources.

The Pz 38(t) will become quickly obsolete, even more so within the limits of this thread. The body (powerplant, suspension etc) is a decent one, so using it for a bigger gun might be good use. The max speed on 9,5 ton was 42 km/h with 125 PS The 'Waffentrager' withe the L/71 gun was supposed to weight 11,2 (per German Wikipedia) while using 100 PS engine??
The L/56 version should weight 10-10,5t?

It appears you are correct on the weights of the guns but using "throw" weight gets a bit deceptive. A British 3in 20cwt AA gun has the same "throw" weight as the MK 101 using 440 grams shells if the 3in fires 15-16 rounds a minute. Problem is hitting the target (unless you can scare them away with tracer). The low rate of fire with the MK 101 means that a 300mph aircraft can move almost 33 meters between each shot fired. The 2cm Flak 38 cuts that to about 19 meters traveled.
Once you can get the high cycle rate MK 103s the 30mm gun has just about all the advantages. But using the MK 101 is a bit iffy.

We can recall that all 2cm Flak guns weren't of the Flak 38 variety, but the Flak 30 was in majority in the early ww2. RoF was 280 rpm vs. 230-260 rpm for the MK 101.

The targeted aircraft were almost always 'followed' when within sights, ideally the angular velocity of the barrel matching (when looking from gunner's standpoint) the angular velocity of the target. It was a thing where, say, one of 20 bursts hits an aircraft (not all the shells from a burst, of course). Not when one or two shells from each burst hits. The high rate of fire was not a cure for an ill-trained gunner, but it can help.
Barrage fire (we all fire in a portion of the sky where the aircraft will roughly appear) was sometimes used, but the ammo consumption vs. aircraft hit was out of proportions.

German Army never used a twin 20mm mount during the war, Perhaps a opportunity there?

Indeed. Introduction of 60-rd drum would also boost the weapon's efficiency.

 

[parsifal]

There are darn few heavy tanks before 1942.

maybe 6 of these or a few more including prototypes?

I forgot your concept of a heavy tank is quite unique, In my vernacular, as well as everybody else in 1936, a mkIV is a heavy tank. thats certainly how the Heer described them. Dropping everything for MKIV option means basically that the Heer fights Poland and France with no more than 250 tanks....in other words it loses the war before it starts. Sure, move to develop the mKIV after June 1940, but thats raises the issue of "who knew they were going to win with such style"

4X2 trucks work for crap unless you have really good roads. Not a guarantee in Western Europe let alone eastern Europe (and that is before you hit the Russian border.)
So you need 4X4s or 6X6s. 4x6 often don't make it. And to really last they have to be over-built.

Its an often quoted piece of misinformation that Half Tracks and 4x4s in Russia were more reliable and than the lighter 2x4s. Not significantly true (at least for vehicles with a military origin). ive read that a Half Track cost as much as 5x the cost of a basic 2x4, yet its life expectancy in Russia was not 5x, it wasnt even 2x. I expect the same was true for the 4x4s.

Russians used American trucks 43-5 and expended nearly 350000 of them to wastage. Despite their "over engineering", they dont put up with the abuse much better either. There was really only one way to overcome the wastage and that was to build more, doesnt matter what type, though the German later war tracked artillery tractors are a notable exception (RSOs. These are the exceptions to the rule. They were as cheap as chips, had a simple track system based on an existing chassis of a type already in service. It doesnt get better than that. The track system was able to cope with Russian mud and snow because of its wide tracks and no return rollers, it had exceptional reliability, ease of maintenance, and all terrain capability to boot. The US equivalent, the M4 would not be able to fulfil the same role because it used a too complicated...and therefore far too expensive to build in quantity... track system.....the Soviet STZ-5 was better, but still used a return roller system that at least had wider clearances. The RSOs four road wheels per side, all in a single line as part of a "slack-track" system with no return rollers, comprised a much simpler...and therefore much cheaper.... suspension system that was cheap to build and easy to maintain, much more able to handle the rasputitsa mud season and Russian winter conditions, without mud or snow freezing between the wheels of the complex overlapping/interleaved Schachtellaufwerk suspension systems that German half-track vehicles like the SdKfz 7 possessed.... ) are an exception to this statement. They were excellent and the stand out in the crowd.

Numbers gives you the ability to maintain and lessens the wastage rates due to breakdowns. A broken down axis truck is usually an effective loss....you have to burn it due to partisans usually...doesnt matter if its got chrome plated grease nipples, or is a US type (see below)

The American 2 1/2 ton truck was rated at 2 1/2 tons payload cross country or "off highway". On Highway it was rated at a 10,000lb payload. It was also rated to pull a 7,500lb trailer/load on highway and 4,500lbs off highway.
An International Harvester K7 (commercial) 1941 2 1/2 ton 4X2 was rated at 5,000lbs on high way and 7,000lb off highway. A big difference was the IH had a 5 speed gear box while the standard military 2 1/2 tonner had not only the 5 speed but a 2 speed transfer case. Net weight for the 6X6 was about 2,000lbs heavier (over 10,000lbs)

Russians used these and other US types. It would be wrong to say they were not very successful , but there is no significant difference, long term to the wastage rates of these vehicles, to well designed lighter types. If youve got the luxury of having the worlds largest motor vehicle industry, you will have both the numbers and the quality, but if you have to make a choice, numbers is the way to go....

You need a certain amount of half-tracks as gun tractors or a certain amount of full tracked gun tractors. You probably don't need the variety of different models of 1/2 tracks the Germans had though.

For a nation with problems like germany, Id put tracked capability as "nice to have" rather than "essntial", except if such capability was at little or no cost to numbers. . Having the all terrain capability is nice to have, but having the numbers, in a rationalised fleet is a far more important imperative. German Halftracks and artillery prime movers found they could not operate in the winter conditions of Russia. They were just too over engineered to put up with the primitive conditions. If there were more trucks, on the days that movement was possible (some days in Russia during midwinter, you would be down to your shirt sleeves according to my father) you made hay whilst the sun shone. if you have more light vehicles, as opposed to less tracked vehicles, you are going to be relatively better off by far because of numbers.

But then a lot of European countries tried to make up in "fripperies" what the Americans did with big engines.The standard American 1/2 tracks using engines of the size and power that the Germans used in their 5 and 8 ton 1/2 tracks.

American equipment was better quality and more plentiful, hence it had a lower attrition rate, because it could be maintained more effectively. Retain the numbers, and you have a better chance at keeping your motor pool in better order. Something worth considering for the east...a better sand more reliable sized motor pool would have given the germans some spare capacity to repair and extend the road and rail networks and thereby reduce the wastage still further, so that their lighter types would have been less of a problem still. Germans started with good numbers, but rapidly fell away because many were not of a military standard and they just didnt really have numbers given the size of their force structure. and it was not possible to maintain the park properly. It became a vicious circle. A poor standard of MT, too many types, too much reliance on non military types, not enough capacity to even keep up with basic logisitic needs, no capacity for infrastructure recovery...it just fed off itself.... They needed fewer types and designed to a military standard...forget the US centric all terrain capability...the US Army has never been tested like the heer was in Russia. and more secure rear areas. When not given that situation, US equipment was no better (or not significantly so) than any other form of MT. In the snow it got just as stuck as any other nationality.

The only exceptions that really were dogs to this are the French and German commercial vehicles that were press ganged into service after the war broke out. These really werent comparable, but then there would have been less need of them if the military production was better organised. less types, better supply, and then you arent relying on crappy French Trucks in the depths of a Russian winter.

 

[tomo pauk]

Again about the AAA, this time the heavy guns. In retrospect, was it better bet to rely on a 'hit to kill', or to employ the time fuses?

 

[Shortround6]

Again about the AAA, this time the heavy guns. In retrospect, was it better bet to rely on a 'hit to kill', or to employ the time fuses?

Hard to say without doing a very detailed mathematical analysis of the situation. Near the end of the war the the 'hit to kill' method was shown to be better but in the early years the bombers flew lower. The problems with the time fuses were the errors in setting the fuse correctly to begin with and then the error in the fuse itself. A fuse might be accurate to 2% or less of the time it was set for (expected flight time) and the shorter flight times to the lower altitudes meant the error was the same percentage of a much shorter flight time. The shells slowing down considerable with altitude.
I have no idea were the cross-over point is/was.
The time fuse (in theory) increase the lateral lethal distance but because of the fuse problems introduced an error along the line of flight (usually bursting too early, a late burst might result in the shell hitting the target plane). The longer the time of flight the greater this "axial" error became.
Of course not having to set fuses might speed up the rate of fire a bit.

We are back to are you planning for 1939-41 in 1936/37 or are you planning for 1943-45?

 

[tomo pauk]

For pre-1943 time. Was thinkering about an AA gun that is similar to the Panther's gun, obviously on a AA carriage and with neccesarry extras.
Or, the bread butter 88 L-56, firing the HE shell 'core' wrapped in a carriage to make up to 88mm, looking sorta APCR. So instead of the 9 kg HE, firing the 5-6 kg 'HE-SV' round. The barrel wear should be increased with greater MV, though.
The Gerlich system (tappered bore) does offer a 1200 m/s speed, but barrel life was only 1000 rds for the 7,5cm pak 41, vs. 6000 rds for the 7,5cm pak 40, for example.

 

[Shortround6]

I forgot your concept of a heavy tank is quite unique, In my vernacular, as well as everybody else in 1936, a mkIV is a heavy tank. thats certainly how the Heer described them. Dropping everything for MKIV option means basically that the Heer fights Poland and France with no more than 250 tanks....in other words it loses the war before it starts. Sure, move to develop the mKIV after June 1940, but thats raises the issue of "who knew they were going to win with such style"

I don't think that my "concept" of a "heavy" tank was that far out of line with what many armies thought in 1936 (or the mid 30s). 18-20 ton tanks were NOT considered "heavy" tanks in many armies. The Russians were working on the 20+ ton T-28 tanks, the 40+ ton T-35s and as 1940 approached the even heavier multi turret tanks and the prototype KVs. The French had the 10 old 2C tanks and were building the CHAR B series and the Somua 35 was a 19 ton cavalry tank not a heavy. The British got up to about 17-18 tons with one prototype "medium" tank. Cost often governed what was bought, not tactical ideas. The fact that the MK IV mounted a 75mm piece of ordnance shouldn't be seen as a dividing line either as the Russians mounted 76mm ordnance on BT-5/7 and the French mounted 75mm ordnance on left over (or late built) FT-17s which are by no stretch of the imagination heavy tanks.

Russians used American trucks 43-5 and expended nearly 350000 of them to wastage. Despite their "over engineering", they dont put up with the abuse much better either.

I guess that is why the Russians wasted as little time as possible once the war was over to copy a couple of the a
American designs of all-wheel drive trucks(of course their war time trucks were either copies or licence built american trucks)


The advantage of all wheel drive trucks (and they can certainly use simple live axles) is that they can keep moving in marginal conditions. Nothing moves it really bad conditions. WHere is the dividing line? They can also substitute as gun tractors when conditions are decent.
A "proper" 4X2 might work but very few countries had "proper" 4X2 design in production or even in prototype form. which is one reason the Germans used all those crap commercial/civilian trucks. If you are driving on paved roads the higher empty weight of a "military" standard truck cuts into payload or performance. Commercial operators had little interest in buying "military" trucks if they had to pay full price for them. In some cases governments offered subsidies to commercial operators to use trucks suitable for military use should they be needed for mobilization. Of course then your civil/commercial transport system goes to crap if too many of the trucks are mobilized.

 

[Shortround6]

For pre-1943 time. Was thinkering about an AA gun that is similar to the Panther's gun, obviously on a AA carriage and with neccesarry extras.
Or, the bread butter 88 L-56, firing the HE shell 'core' wrapped in a carriage to make up to 88mm, looking sorta APCR. So instead of the 9 kg HE, firing the 5-6 kg 'HE-SV' round. The barrel wear should be increased with greater MV, though.
The Gerlich system (tappered bore) does offer a 1200 m/s speed, but barrel life was only 1000 rds for the 7,5cm pak 41, vs. 6000 rds for the 7,5cm pak 40, for example.

They used 85-90mm AA guns because the bigger shells had a bigger lethal radius than the 75mm shells. The bigger shells also retained their velocity better than the 75mm if they start at the same velocity for a shorter flight time. using a higher velocity 75mm might work but I don't know where the cross over point is.
BTW some sources claim only 150 shots for the 7.5cm pak 41. Barrel was made in several sections so the the one that wore the fastest could be replaced without changing the whole barrel.

 

[tomo pauk]

They used 85-90mm AA guns because the bigger shells had a bigger lethal radius than the 75mm shells.

Indeed. Though, not an issue if direct hit is desired.

The bigger shells also retained their velocity better than the 75mm if they start at the same velocity for a shorter flight time. using a higher velocity 75mm might work but I don't know where the cross over point is.

It is the 'heavier shells retained their velocity better', the 85-90mm shells being roughly 50% heavier than 75-76,2mm shells. The section density was greater for the 85-90mm shells, that being a more precise statement.
The 8,8cm 'full weight' shell was at circa 9-10 kg, fired at 800-830 m/s. The 'reduced weight' shot, like the APCR for example, weighted 7,3 kg, fired at 930 m/s. It would be interesting if we'd know the velocities for different projectiles at 2 or 3 km, though.
The Panther's gun was firing the 7,2 kg shot at 925 ms, should retain the velocity better than the APCR shot of the 8,8cm, due to less drag. The 4,75 kg APCR from the Panther was fired at 1120 m/s. Again, I don't know the velocities at 2-3 km to compare.

BTW some sources claim only 150 shots for the 7.5cm pak 41. Barrel was made in several sections so the the one that wore the fastest could be replaced without changing the whole barrel.

I have only this (open it separately):