"German tanks in the desert, does anyone know?" Topic

Did the DAK replace the shorter 50mm with longer ones on the tanks they already had, or could that only be done at a factory -was it only new tanks when they arrived that had them?

As far as i am aware new tanks were shipped with the long 50mm. But I don`t see why DAK engineers couldn`t swap barrels from damaged tanks if they had the fascilities?

Greetings

As far as I know factory only.

Regards

Edward

Wow that was quick! Similarly what about long for short 75mm guns?

I think not. It's to do with the mantlet. Modification is a factory job not just a bloke with a gas axe.

Jentz Panertruppen may have information you need.

I am seeing the Asuf J Pzr III with eh L60 50mm listed in ranks with remarks "arrived" to the theatre. So that makes me think they came that way from factory. ON strenght in lat May 1942 DAK shows 19 of these in the ranks.Pg 144

august they show 74 Js. 27 of the Panzer IV F2 Long 75. Pg 148.

Hope the numbers help and they look like they would be arrived this way but we all know the armies in Africa (all sides) were resourseful and used all and everything. I could imagine turret swaps from damaged machines.

My source used was "Knights of the Black Cross" Bryan Perrett. pages noted if you wanted to look. Think the book is on scribd.com I just so had mine out and read about this PzrIII J numbers yesterday.

Jonathan H

While no expert on this I think that, talented as they were, changing the main gun would be beyond even DAK field repair crews

I'm with Jonathan. Always it's "arrived" or "received," never "modified" or "upgraded." As Jonathan says of swapping out turrets, I won't say it's impossible. Mind you, if a tank was sent back to the factory, my understanding is that it was policy to upgrade to the most recent model--given the tank was still in production, of course.

This suggests from a modelling standpoint that every now and then there should have been a Pzkw III or IV with late model armament but some of the peripheral features of an earlier mark which didn't affect performance or weren't worth the cost of modification. Has anyone seen a photo of such?

How's the mantlet different?
I thought you literally unscrewed the barrel out and screwed the new one in.
I think you'd have to lift the turret.

I too am of the belief that they kept the guns they arrived with. I would not be _too_ surprised if someone finds some cases where a tank was upgraded. But I am pretty confident it was not common.

But I don`t see why DAK engineers couldn`t swap barrels from damaged tanks if they had the fascilities?

I think not. It's to do with the mantlet. Modification is a factory job not just a bloke with a gas axe.

Indeed, it is substantially more than a barrel swap. It seems to be a reasonably common misunderstanding among wargamers that a longer barrel = higher velocity. It is true that the two issues are correlated (higher velocity guns usually do have longer barrels) but that does not mean you just change the barrel and get higher velocity.

In the case of the KwK39 (the 50mmL60 tank gun) the whole gun was larger and heavier than the KwK38 (the 50mmL42 tank gun). It used a larger cartridge, which fired at substantially higher chamber pressure. That meant a more massive breach assembly and a more capable recoil system. It also meant different sites to aim accurately given the different ballistic performance, and different trunions to balance the very different weights of the gun. Then, for a tank, you need a mantlet to house and protect it all.

It ain't just a barrel.

…we all know the armies in Africa (all sides) were resourseful and used all and everything. I could imagine turret swaps from damaged machines.

…changing the main gun would be beyond even DAK field repair crews

Swapping turrets from hull-dead tanks seems to me the most reasonable approach. But then you would also need to rebuilt all the ammo stowage in the hull of the tank that got the new turret. Since that was mostly sheet-metal work (and some was even wood and leather), that could have well been done in-theater.

However, there isn't much evidence that any force in WW2 took tanks out of combat for upgrades. The Brits upgraded Churchills to the 75NA standard (taking 75mm guns off of dead Shermans), and Patton's 3rd Army up-gunned Sherman Jumbos with 76mm guns in the winter of 44/45. Other than that, I think almost all cases were major depot or factory jobs.

In the case of the Churchill 75NAs -- the work was done AFTER the campaign in North Africa had ended, and before they were deployed to Italy. The tanks themselves were idle -- not in the hands of units that were deployed in combat.

So also, but to a lesser extent, with the Sherman Jumbos. Most units with Jumbos only operated a small number among a larger population of regular Shermans. The upgrades occurred at about the same time that a new influx of theater-made Jumbos (made by adding armor from recovered tanks to incoming Shermans) was reaching the force. So although they were in fact for units that were actively engaged in combat, it was possible to withdraw (or hold back) a few at a time for upgrades while still maintaining existing numbers in the front line units.

The key issue is that a tank in combat is a very valuable resource. A tank with a better gun might be nice, but not at the price of not having the tank available at the time of battle.

In Africa it was always a race to build up forces for the next major battle/campaign. Whichever side built their forces faster had a significant advantage. Giving up time for the marginal improvement in performance of the KwK39 over the KwK38 would probably not have been seen as a useful trade-off at any point in the campaign. But mixing and matching turrets and hulls from recovered wrecks could well have provided the opportunity for some upgrades.

Or so I would think.

-Mark
(aka: Mk 1)

I have seen the odd photo where a new turret has clearly been married to an old hull (different paint jobs!) but as noted above, the 50L60 was a completely different gun to the 50L42, you can't just swap them over. Same for the 75L24 and the 75L43/48.

Then you have the problem that your shiny new gun has much bigger shells which don't fit in the stowage bins…

Very interesting discussion, thanks everyone.

I thought you literally unscrewed the barrel out and screwed the new one in.

In the case of the KwK39 (the 50mmL60 tank gun) the whole gun was larger and heavier than the KwK38 (the 50mmL42 tank gun). It used a larger cartridge, which fired at substantially higher chamber pressure.

I thought I might take a few moments to go further into this topic.

I have seen similar perspectives offered in many conversations with wargamers and military history buffs in general. Somehow, as we so often describe the different guns according to their barrel lengths, people have come to understand that the difference is just the barrel length.

So here is some new data to look at, and digest.

This picture is of actual German WW2 tank cannon cartridges.

From left to right you can see the cartridges for the 37mm KwK36, the 50mm KwK38 (L42), the 50mm KwK39 (L60), the 75mm KwK37 (L24), the 75mm KwK40 (L43 or L48) and the 75mm KwK42 (L70).

In the particular cartridges shows, the KwK38 round is a Pzgr. 40 (APCR by Brit-speak or HVAP in Americanese), while all the rest are Pzgr. 39s (APCBC).

Despite the difference in projectile, you can clearly see the significant difference in the cartridge size between the KwK38 and the KwK39 rounds. If you picture the gun, you can see that you will need a much longer breech for the KwK39. Since it fires at higher chamber pressures you will also need thicker metal for the whole length of that breech (unless of course you were wasting metal and carrying unneeded weight to start with in the KwK38).

In this progression there is only one case, from the L43 to the L48 of the KwK40, that the Germans managed to improve performance by simply elongating the barrel. That is only because the L43 was poorly designed … the barrel was too short to effectively use the power of the cartridge. So lengthening it allowed some added acceleration for the round. But if you had elongated it more than L48, you would have actually SLOWED the round down, because the friction of the barrel would impact your velocity more than the incremental amount of time you were pushing the round.

Any well designed gun has a barrel that is about the right length for it's cartridge. If not, you are either wasting powder (burning it off out in the air beyond the muzzle) or unnecessarily slowing the round (continuing the barrel friction after you are done burning the powder). Sometimes a bit of fine-tuning, by two three (or five?) calibers after you get it into production, but seldom more.

It is a fundamental mis-understanding of the physics of gun fire to think that you just put on a longer barrel and get higher velocity. Ain't the way it works.

BTW this picture is cropped from a larger image of the collection of Tony Williams, who's excellent website provides a wealth of information on autocannon and AT gun ammunition: quarryhs.co.uk . You can also see how much more massive the 88mm cartridge for the Tiger II was, compared to the 88mm cartridge for the Tiger I. And lots of other interesting stuff.

-Mark
(aka: Mk 1)

This was a good topic. Hope we helped Paul in the end.

Mark--thank you for adding in the image of th shells. We tend not to model the interiors of our wargames tanks so it is an out of sight out of mind type of thing.

I use Bandai 1/48 models with interiors and do a few of the interiors just becuase why not. Hull top not glued down just so the work is not gone to waste.

Now I wonder; my Nashorn has spare rounds as does my Tiger II. Same size rounds on those but I take that as model limitation. I am a guy that had to buy a $7 USD metal muzzle break for a model as theone modeled with it was not correct. Now you have me thinking my interior shells are all wrong.

Jonathan H

Yes as far as the DAK MBTs, the main gun they left the factory with remained in the turret and was not "swapped" out.

If you look at those rounds in the pic Mark posted, different gun designs even if they are the same size, i.e. German 50mm short and long barrels, etc., etc., are not interchangeable, etc., I believe he is correct in all he stated, AFAIK.

Yes, our higher level maint. units can replace a damaged barrel with a new one. And they can do it in the desert, e.g. the 105 on an M1IP. But that was in 1988 not 1942 …

The reason the kwk39 has a totally different cartridge is because it's based on the pak38 and the kwk38 was not.
The KWK38 wasn't just a sawn-off pak38, it's an entirely different weapon.

My understanding is on the pz3 the armoured sleeve is the same for both guns though. The significant measurement being it's internal diameter.
I may well be incorrect.

I thought the sleeve was used to mount the gun.
The barrel is kind of screwed into that to mount it. There's also some furniture bolted around the gun.
If I'm incorrect and the gun is mounted to the mantlet then this is bolts on the pz3.

And of course the sights.
There are minor differences between the l42 and l60 sights. They're both tz5f but something like d and e versions. Longer range fire in the desert would usually involve bracketing anyhow but changing out optics is definitely within field workshop capabilities.

Gun barrels wear and are quite prone to damage so (like most tanks) the design allows for workshop gun replacement.

The L60 also has a torsion bar gizmo bolted to the turret roof which is to do with balancing out the longer gun somehow.
Attaching such a device is pretty simple.

AFAIK changing guns out therefore did not involve major structural changes.
Taking the turret off is not exactly a minor operation.
Changing all the ammo storage would take some effort and maybe some blow torching.

OTOH.
If the sleeve is a different diameter and the gun essentially won't fit through the hole then I think changing the mantlet would be necessary and that's a way bigger job.

The Germans motored about in 50L42 tanks until well into 1943. I somehow doubt they would have done that if it had been an easy fix.

Example, on 23 Oct 42, the Panzerlage of 15.PD was:

37x Pz III 50L42
42x Pz III 50L60
2x Pz IV 75L24
8x Pz IV 75L42

They had had quite a bit of time at that point to change over the guns, had they wanted to.

All the best

Andreas

I think there are other potential factors.

They would need guns to change, ammo to use.
They also need motivation to do so. There was less need for the more powerful gun in the desert than Russia. Dak had lower priority for special ammo. I would imagine lower priority for any l60 replacements.

It would not be easy in any case.

Bravo two zero Didn't the Tiger two and the Nashron have the same gun?

One thing that many militaries try to do is to limit the different types of ammo in their inventory. It is just more efficient and effective logistically etc. Now that being said, the WWII Germans were generally very much in "violation" of the paradigm in many cases …

E.g. as Andreas pointed out, you had at least 4 different main gun type rounds for the 15th Panzer Divs MBTs …

And yes, the Nashorn & Tiger II mounted the same 88mm gun, the Pak 43 L/71, IIRC …

"There was less need for the more powerful gun in the desert than Russia. Dak had lower priority for special ammo. I would imagine lower priority for any l60 replacements. " Yes, but… 50L42 equipped tanks were still very common in Russia in 1943 as well.

Also, September was four months after they encountered the M3 Grant for the first time…

I honestly don't think this was a field mod.

All the best

Andreas

I agree … I'm @ 99.9% sure it was a Not a field mod …

Interesting read.
That's a topic I never gave any thought to.

It's an interesting progression from "I would think that…" to the hard facts.

It's one of the things I like about TMP.
But that won't stop anyone from asking the same thing six months from now.

I think it's an unlikely choice BUT I'm fairly sure this could be done in a field workshop.
Whether you'd really want to and whether you'd have an L60 gun hanging about… these I'm less confident about but anyhow.

The panzer 3j was produced with both L42 and L60 variations.
I took a quick look in encyclopaedia of german tanks ( first suitable book to hand ).
That says the only difference between a pz3j with l42 and l60 was stowage and gun.
Meaning same mantlet and mount.
AFAIK the mantlet on the pz3j was the same as the H.
I think the way the main gun was mounted would also be the same on the G.

If you had an L60 gun you could fit it in a pz3j or H and probably G without substantial change to the mount or mantlet.
You need the gun, of course.
I'm not sure you'd even need to lift the turret to fit it.
The barrel and breech are separate pieces.

It's quite possible the major difficulty of such work would be changing stowage.

OT but…
@ Mark 1 The 75mm Kwk L43 and the PaK L46 have the same barrel rifle travel.
The L46 was called longer because caliber length includes the distance to the end of the breach and the L46 used a longer cartridge.
There were variants of the L46 cartridge loads that had muzzle velocities up to 790m/s as opposed to the L43 740m/s.

76.2 × 385 mm. R was used by the Russian L-11 L30.5, F-34 L42.5 and F-22 L51.5. Each had a different muzzle velocity commensurate with the barrel length.

Yes, our higher level maint. units can replace a damaged barrel with a new one. And they can do it in the desert, e.g. the 105 on an M1IP. But that was in 1988 not 1942 …

German field workshops were entirely capable of removing and replacing gun barrels (and more) in 1942. Get a copy of "Repairing The Panzers" by Lukas Friedli

German field workshops were entirely capable of removing and replacing gun barrels (and more) in 1942…

Which is not really the question.
Nobody denies that they could replace an identical gun. The question is whether they could replace it with an entirely different type (not caliber) barrel.

Thank you Winston … that is what I meant. And yes, deephorse I am well aware of that. That the WWII DAK could replace an MBT's barrel. But with a replacement barrel of the same type…

E.g. Not a short barrel 50mm with a long barreled 50mm. Those are two different weapons systems even though both 50mm. But you and we all know that …

Plus even if that could be done, you not only have to look at the physical difference between the two 50mm types guns, but ammo storage in the turret, turret basket configuration, etc.

Just like IF one of our M1IPs with the 105mm was being upgunned to the newer M1 variants with the 120mm. It's more than just swapping out barrels its about changing caliber, etc.

And yes I've never been in a WWII German Pz Mk.III but I have been in an M1IP and was Mech Hvy Bde Maint OIC. I know very well about those kind of topics.

As I explained above. It was possible to fit an l60 in exactly the same mantle as the l42. This was done in the pz3j.

Yes, but do we know if it was done by the DAK Maint crews ? I wouldn't think so … But again … I was not there.

And as I and you noted Andy, ammo storage would have to change to adapt to the new rounds, etc. Nothing impossible AFAIK, … but certainly another consideration, etc.

You probably would not want to change just the odd tank even if you could. Imagine the nightmare if all the platoons had a mix of guns. You would need disproportionately more ammo. You would need a full load for the one tank but probably only an average load for the rest as some would have used more than others and you could even out a bit and save transport.

The L/60 rounds were stored horizontally rather than vertically.
I suspect changing ready storage would have been a fairly small job.

I think the main problem would be in obtaining a spare L60 to fit.

Even if it were possible to swap out the guns, I doubt that the DAK had a bunch of spare L60 guns laying around to make the conversion.

The guns could be transported easily enough by air. Certainly easier than the tanks. Was there a shortage of L60 guns in Germany?

Regardless … I don't think the DAK did any main gun swap outs from one size to another … They had many more problems when it came to supply and maintenance. I think that is the point of this topic(?) i.e. all the DAK AFVs came stock from the factory(s) … and remained so. Until destroyed beyond repair or withdrawn from North Africa(if any ?).

Not aware of any withdrawals. A big problem for the D.A.K. was the total loss of its workshops during operation CRUSADER. These were conveniently but somewhat stupidly sited between Tobruk and Bardia on the coast. A usually undervalued aspect of holding on to Tobruk.

I doubt they sent any tanks back to Germany.

I wouldn't underestimate the capabilities of DAK repair crews though. They were known for getting tanks back in the field that had previously been knocked out or heavily damaged.
As a result, British standing orders were to demolish any abandoned german tanks up if they hadn't brewed. Lots of the post battle photos showing panzers blown to bits are such tanks.

Forget ammo standardisation as a factor.
They had a mix of short and long pz3 and the L60 took the same ammo as a PAK 38. Which they had a number of.

It's been pointed out they could fly an L60 out if anyone really wanted one.
I think that's unlikely – because they'd probably be flying any such spare out to the eastern front up to the point when the DAK needed pretty much all it's tanks replaced anyhow.

I'm not at all sure what lifting equipment would be involved in the process.
This would hinge on the practicality of attaching breech to barrel without lifting the turret.
If that was practical then I guess a couple of light frames might be enough.

I doubt they sent any tanks back to Germany.

Maybe to Sicily or Italy. IIRC some of the Tigers that made it to Tunisia may have made it to Sicily. But no doubt most AFVs, rolling stock was probably lost, e.g. destroyed, abandoned, etc.

I wouldn't underestimate the capabilities of DAK repair crews though. They were known for getting tanks back in the field that had previously been knocked out or heavily damaged.

I don't, not at all … you still need parts, etc. Even after to scavenge from wrecks, "hanger queens", etc. As in many case it came down to resupply of all classes of supplies.

As a result, British standing orders were to demolish any abandoned german tanks up if they hadn't brewed. Lots of the post battle photos showing panzers blown to bits are such tanks.

Yes, I've seen those photos too. Was a pretty good idea to keep the Panzer numbers as small as possible.

I've read the Germans even booby trapped some vehicles, etc., that they could not recover, etc. Seems like at least an attempt at a counter measure. If nothing else it may kill off some of their enemies …

I'm not at all sure what lifting equipment would be involved in the process.
This would hinge on the practicality of attaching breech to barrel without lifting the turret.

They probably could replaces main gun without removing the turret. But I'd think they'd still need to use some sort of lifting equipment/devices. Even if they had to "Jerry rig" something …

Forget ammo standardisation as a factor.
They had a mix of short and long pz3 and the L60 took the same ammo as a PAK 38. Which they had a number of.

Yes, but they still had to get the rounds from Europe to North Africa to the weapons that needed them. Always challenging the longer your supply lines are, etc.

As Mark I noted, it isn't about just swapping out a barrel. The whole receiver mechanism has to be changed. This probably involved some reshaping of the turret.

As to priority, the DAK had priority for these long gun "specials" as their normal engagement ranges were longer.

By receiver do you mean the recuperator?
That's in the armoured housing sticking out the mantlet.
That remained unchanged, as did the armoured sleeve.

It did not involve any reshaping.
The pz3j was built with l42 and l60.
Initially the same sight was used.

The changes involved are the gun and ammo stowage.
Broadly speaking.
The 50mm was muzzle heavy – the l42 had a lead weight on the breech to balance it.
The L60 was initially fitted with a leaf spring and later torsion bar mechanism. These are simple bolt ons.

It must have been a relatively routine procedure to upgrade the gun because it was standard procedure to do so.

Where do you get the idea that the DAK had priority for L60?

A receiver is generally where the barrel mechanism attaches to the breach/firing mechanism, as I was taught and understand it. E.g. an M2 .50 cal is broken down into 3 pieces : barrel, receiver and tripod. But again, I was never in or around any Pz IIIs of any type.

That being said, the Germans were "masters" of "jerry rigging", adapting, modifying, converting, retrofitting, etc., many items, including captured equipment. But swapping out cannon/barrel sizes, may be a bit of "work" …

I thought only small arms had receivers.

I read some of my Haynes book.
It seems the L60 is chambered the same as the pak 38 but might not be based on it. Or at least the adaptations made meant it was much more like an L42 than one might think.

From Panzer 3: Hitler's Beast.
"
The L/60 was introduced in 1941 to replace the 37mm anti tank gun [ on the pz3 ]. It was developed by fitting a longer barrel in the 42 calibre weapon, so the breech rings and mountings were identical. This longer barrel with a lengthened chamber could take the 50mm Pak38 anti tank gun round. Although almost identical to the PAK the muzzle break on the tank gun was omitted and an electrical firing system installed.

"

From Haynes:

"the barrel length was increased to L/60 and the chamber to 1250ccc…

Because of the increase in muzzle velocity the recoil system was modified to cope with the increased trunion pull on firing…
The breech mechanism was much the same.
.

Haynes mentions that guns made by rheinmetal tended to have a particularly long recoil.
The L42 was made by Rheinmetal and recoil length was 335mm.
Alkett in Spandau came up with the L60 – this was a rush job to satisfy the fuhrer's demands. He noticed the L42 at a demonstration 18 April 1941 and alkett managed to produce a suitable gun by the end of that month.

The recoil length of the L60 is not mentioned but clearly it was not significantly greater than the L42 because the commander was directly behind the gun.

I thought only small arms had receivers.

That may be correct, but I'd think where the barrel fits into the Breach Block may be the receiver ? Depending on the design or the weapon …

But those are some interesting facts there about this topic. Like I said I was never in or around any Panzer IIIs, etc., …

Andy

"It must have been a relatively routine procedure to upgrade the gun because it was standard procedure to do so."

Sorry, that is a bit circular. Is there any evidence that it was standard procedure? I thought this whole thread was about this being an open question.

"Where do you get the idea that the DAK had priority for L60?"

The first J versions with the L60 were produced at the tail end of 1941. The first deliveries to the D.A.K. were in March 1942, which means they must have been despatched from the factories almost as they rolled off the assembly line.

I believe some tank recovery vehicles had the capability to lift a complete turret. I could see them replacing an entire turret, taking a long-barreled one from a destroyed tank and placing it on a functional short-barreled tank. Storage or shells is still an issue, but would not think that was an elaborate deal.

But how often would a long-barreled tank get shot up to the point of no repair, where the turret was still perfectly fine and usable?

Where are the bolts? Anybody who has modified a car is aware that blot patterns change sometimes same company same year different model, same engine, yet they wont fit without changing or even making different motor mounts.

So with a different recoil system, did all the bolts and holes stay in the same place? I suspect not. As noted above, the DAK repair crews where very good. If it had been as simple as pull one out, put one in, they would have done it. Also as noted guns are much easier to move than full tanks.

Sorry if I was unclear Andreas.
It was standard procedure to change the gun on any tanks returned to Germany.
There's a standing order somewhere you could find which says this.

"Did the bolts and holes stay in the same place?"
From the quotes above
"Identical fittings"
Sounds like a yes to me.

Bear in mind 18th to 30th is what… 11 days to do the work.
Hitler saw the L42 on the pz3 on the 18th.
Had a fit.

That's not the big gun I told you to put on those things.
I want my big gun.
I want it now.
I want it on those tanks you're making right NOW.

Alkett saw their chance to move up the pecking order a bit by winning favour.
On the 30th Alkett demonstrated a working gun in a pz3.

The whole idea was a gun that would fit in existing tanks.

Hitler said
That's great.
That's what I wanted, I knew you guys could do it.
And I want any tanks that you're fixing up to have one of those big boys in em as well.

( My translation German to Scouse may not be too exact in places ).

I believe some tank recovery vehicles had the capability to lift a complete turret.

Certainly, I've seen photos from WWII, and the Germans and pretty much everybody else have ARVs. E.g. here's some from GHQ : a Pz III Rec Veh w/wheeled crane – link I'd think some of these made to the DAK …

The PZ V Rec Veh … these never made it to the DAK. ghqmodels.com/store/g82.html And I've even seen pics of a Tiger I Rec Veh too …

Plus here's the US WWII M31 and M32 Rec Vehs, etc., … for context and comparison – link

And obviously still do today, back when I was a Bn then Bde Maint. Ofc, e.g. each Mech Bn had 6 M578 Light VTRs and 2 M88 Heavy TRs. Both had lifting cranes, etc. IIRC Tank Bns had 8 M88s …

And I want any tanks that you're fixing up to have one of those big boys in em as well.

As the War progressed and the Germans had to go toe-to-toe with the ever growing heavier USSR AFVs, starting with the T-34/76, KV-I, etc. They got it – Bigger is Better, but then they got a little Too Big, [jumped the shark, err … Tiger. etc. !] and had a number of "problems" because of it, etc. E.g. Tiger II, JagdTiger, etc., and that stuff/some bad ideas on the drawing boards like the E-100, Maus, etc., etc.

Hi Andy

"Sorry if I was unclear Andreas.
It was standard procedure to change the gun on any tanks returned to Germany.
There's a standing order somewhere you could find which says this."

Thanks for clarifying. That bit doesn't surprise me since any tank returned to Germany would have to be in pretty bad nick.

All the best

Andreas