Did the US test the 88/L71?

[C.G.Erickson]

Cary, you mentioned the tests of 39-1 and 39/43. Was there any differences?

Well for this test in 1945 it was irrelevant to test the 39-1 projectiles as they all had been replaced by the later 39/43. 39/43 Considered to be the better of the two. So I guess in a round about way. No comparisons were made between the two.

[Mobius]

Well for this test in 1945 it was irrelevant to test the 39-1 projectiles as they all had been replaced by the later 39/43. 39/43 Considered to be the better of the two. So I guess in a round about way. No comparisons were made between the two.

Yeah, I don't see much difference. In the German Ordinance manual the 39/1 wt. 22.5 lb, charge is .33 lb. The 39/43 wt. 22.8 lb with charge .3 lb. little smaller cavity.

[L.V.]

Yeah, I don't see much difference. In the German Ordinance manual the 39/1 wt. 22.5 lb, charge is .33 lb. The 39/43 wt. 22.8 lb with charge .3 lb. little smaller cavity.

 

As you know, the US Ordnance intelligence manuals are not the best of sources. H. Dv. 460/1 indicates that both shells had the same sort of an explosive charge, 59 g of 90/10 RDX. As far as I know, the only difference between these rounds were the driving bands that were wider on the Pzgr. 39/43. The widening took place in order to prevent propellant pressure bypass.

[scotsman]

They would have to put sights on it first. Many other factors kept it an AA gun.

 

Actually they DID put DF sights onto the 3.7" - they were called tobruk sights - and were a field modification to the 3.7" in north africa...the installation of said sights was also eventually instructed in the 3.7" gunners course...

[scotsman]

THis from wikipedia, take it as you will;

 

"This was mainly because the 3.7-inch (94 mm) gun mobile mounting was almost twice as heavy as the German "88". Redeploying it was a slower operation, and the heavy AEC Matador artillery tractor normally used for towing could operate on hard surfaces only. Additionally, heavy AA Regiments equipped with the 3.7-inch (94 mm) gun were controlled by Corps or Army HQ, or at even higher level HQs, and command of them was not often devolved to the commanders at Divisional levels where the anti-tank role might be required. Prolonged firing at low elevations (not part of the original specification) also strained the mounting and recuperating gear."

 

AP ammunition was issued for self defence. Germans even issued AP rounds to the 12.8cm guns mounted on concrete flak towers in Berlin. Didn't make them real anti-tank guns.

 

British may have lacked the proper motivation beacuse after North Africa they had decent AT guns. 6pdr was no slouch and the 17pdr would see to most anything short of a King tiger.

German use of 88s was desperation. After a while as anti-tank guns they were worthless as AA guns. Predictor connections and fuse setters have been "lost" along the way to make them easier to set up and use as AT guns. I wonder how many tons of supplies were lost in North Afican ports due to British air attacks while a fair portion of the large AA guns were swaning about the desert;)

 

Towing the 3.7" was never easy but it had many features the 88mm did not as well...which in the end made for a better gun...certainly one easier to update with the improvements in fire control that took place during the war...

 

The brits did in fact push forward a considerable number of 3.7" in one instance...but the Germans declined to attack once they were present (which is ashame...*smile*). As for the prlonged firing comment...that too is somewhat open to question. The genesis of the comment is principally post war according to Larkhill...and 3.7" of the 2nd canadians (to name but one example) fired extensively at low angle during the normandy campaign with no damage noted. Enough rounds were put down range in some instances to actually warp the barrels...so I would say that experience definately counts as 'prolonged firing'...

 

I own a 3.7" AP war issue round...and the ammunition was most certainly issued as required. I have an interview of a 3.7" gunner that was delivered AP ammunition and told to engage some Tigers in Holland 1944ish as well... That battery dispatched its targets very quickly...

 

Your last comment really is the heart of the matter...the 6pdr is a sweet spot for a handy easy to serve ATG...and the 17pdr was one of the best of its type....but those guns weren't initially available. As they became available there would certainly be less engagement opportunities....but 3.7" was also sited in normandy to backstop attacks or stop counterattacks. In fact their are german documents for a tiger battalion in normandy that list the 3.7" as within the top 3 threats to the tanks of the battalion.

 

In summary..3.7" had all that was required to act in the same role as the 88mm...it did in fact perform analogous missions at different times and points in the war. Unfortunately for a great gun....many myths still circulate about it and are repeated as ground truth. That wiki article should certainly be updated to reflect the realities of post war research....

[JWB]

Why don't update it yourself?

[rmgill]

Towing the 3.7" was never easy but it had many features the 88mm did not as well...which in the end made for a better gun...certainly one easier to update with the improvements in fire control that took place during the war...

 

Derek is that you?

[scotsman]

Derek is that you?

 

 

!AYE!

[rmgill]

!AYE!

 

Welcome aboard.

 

You need to start a 3.7" HAA thread. Post your stuff. The guys here will eat it up.

[jwduquette1]

In fact their are german documents for a tiger battalion in normandy that list the 3.7" as within the top 3 threats to the tanks of the battalion.

 

Yes -- in fact I think Jentz also touches on this very bit briefly in either "Panzertruppen" or "Tigers in Combat".

[Mobius]

Compare it to the 88 projectiles for 3000 + velocities vs targets.

8" @ 0:Two complete penetrations with projectile passing through plate. 3124mv and 3257 mv. Two ABL penetrations. All Projectiles Intact. 3001 mv 3038 mv.

 

6 1/16" @ 30:Two complete penetrations, projectile through plate. All Projectiles intact 3008 mv 2971 mv

 

5 1/8" @45: One complete penetration, projectile through plate. Projectile fractured. One projectile shattered. 3288 mv 3211 mv

 

3 7/16" @ 55: Two complete penetrations. both projectiles fractured. Projectile fragments passing through plate. One partial penetration projectile fractured. 3334 mv on two penetrations. 3310 mv on 21/2 deep partial.

C.G., was there a firing table for the 88mm/L71 developed from these tests?

[C.G.Erickson]

C.G., was there a firing table for the 88mm/L71 developed from these tests?

What kind of table? Range/Firing table or penetration at range table?

 

Aberdeen used the German Firing/range tables, just translated. Aberdeen just lists MV for their penetration tests.

 

C.G.

[Mobius]

What kind of table? Range/Firing table or penetration at range table?

Yes. Like they did for the 75mm guns.

 

Aberdeen used the German Firing/range tables, just translated. .

So I suspected.

That's probably why some authors got their meters and yards mixed up.

Edited April 22, 2009 by Mobius

[kamel]

!AYE!

 

Welcome aboard.

 

You need to start a 3.7" HAA thread. Post your stuff. The guys here will eat it up.

 

As long as they don't eat you instead...

[jwduquette1]

I own a 3.7" AP war issue round...and the ammunition was most certainly issued as required. I have an interview of a 3.7" gunner that was delivered AP ammunition and told to engage some Tigers in Holland 1944ish as well... That battery dispatched its targets very quickly...

 

I'd love to see a photo of the 3.7" AP round.

[L.V.]

No photos, but HERE you can download the ammo manual of QF 3.7".

[jwduquette1]

Thanks LV, but I already have a copy of the manual. I always like having photos of the various AP ammuntion types used during this time period and I don't have any of 3.7inch AP or APCBC.

Edited April 23, 2009 by jwduquette1

[supertsar]

LOL...Do like I did and peruse the 200 plus boxes of the 156 Record Group.

 

 

Wow! When is the book coming out? Put me down for a copy!

[scotsman]

I'd love to see a photo of the 3.7" AP round.

 

Here is the AP round...sorry about the background but I had just finished restoring the shell casing. In this case it came up from the bottom of a river....having laid there at the bottom since WWII. I think it came out pretty well!

 

Edited April 24, 2009 by scotsman

[scotsman]

And here is a pic of a 3.7" with tobruk sights...you can see the open sights and then the rings for the telescopic sights above that...one telescope on either side...this gun is in the gun shed at Cranwell...

 

So the nonsense that some folks keep posting about the 3.7" never having had DF sights is simply that...nonsense...usually these are the same folks that can not bring themselves to admit that virtually all HAA units in everyone's army fired DF at some point or another...

 

The small plate close to the sight mount was put there to keep the gunner's head from getting smashed into the scope when the gun fired...which happens quite quickly with the autoloader in action...The 88mm can fire quickly, but it can not sustain that rate of fire for very long being manually loaded. The 3.7 with power assist on loading could keep up a sustained rate of fire much better than the 88mm...hence captured German troops asking to be shown 'the automatic 25pdrs' when they were on the receiving end of 3.7" ground fire in Normandy

 

The 88mm has become somewhat larger than life in the post war period...but the 3.7 is actually the better gun in terms of ballistics IMHO...and it certainly absorbed radar pointing, full powered mountings, and a loader assist without a redesign, all by the end of the war, which is something the 88mm never pulled off...

 

Edited April 24, 2009 by scotsman

[jwduquette1]

Here is the AP round...sorry about the background but I had just finished restoring the shell casing. In this case it came up from the bottom of a river....having laid there at the bottom since WWII. I think it came out pretty well!

 

Thanks for posting the photo scotsman. Very nicely preserved specimen. Looks like standard 1.4-crh head/nose.

Also thanks for posting the photo of the Tobruk gunsight.

 

For posterity what I have on 3.7-inch AP:

Weight of AP shot is indicated as 28-lbs 1-oz 12-dr.

O.B. tables indicate MV as 2600-fps.

 

APCBC is something like 34-lbs but I have no Muzzle Velcoity, nor do I know when 3.7-inch APCBC actually entered into service.

 

The following may be of some interest to you & rmgill. Below are some of the projectile testing results I have for 3.7” AP vs. 6” roll hardened armor. The test results were part of a comprehensive study initiated by the FVDD in Feb of 1944 to study limit velocity for a variety of armor steel recipes with varying tensile strengths. Armor steels for the trials were provided by several different manufacturers – ESC Ltd, Beardmores, Firth Brown and of course Hadfields.

 

In the case of the following table AOH is Acid Open Hearth Steel produced by English Steel Corporation Ltd. (ESC), and BE is Basic Electric Steel produced by Hadfields. Each of the two steel producers manufactured plates for each of the four armor steel compositions.

 

 

Others might be interested in the following:

 

The Milne & Henchliff Coefficients for 17-pdr & 3.7” AP vs. Vibrac 30, 60-tsf, is respectively 6.065 & 6.053. This implies both projectiles were – in terms of energy required for plate perforation – about equally efficient. The slightly lower coefficient for the 3.7” AP indicates it was actually a slightly more effective\efficient projectile vs. 6-inch plate at normal than 17-pdr AP. This was just a random pick and whether or not this trend holds true for all plate trials detailed in the table I don’t know.

[scotsman]

Thanks for posting the photo scotsman. Very nicely preserved specimen. Looks like standard 1.4-crh head/nose.

Also thanks for posting the photo of the Tobruk gunsight.

 

For posterity what I have on 3.7-inch AP:

Weight of AP shot is indicated as 28-lbs 1-oz 12-dr.

O.B. tables indicate MV as 2600-fps.

 

APCBC is something like 34-lbs but I have no Muzzle Velcoity, nor do I know when 3.7-inch APCBC actually entered into service.

 

The following may be of some interest to you & rmgill. Below are some of the projectile testing results I have for 3.7” AP vs. 6” roll hardened armor. The test results were part of a comprehensive study initiated by the FVDD in Feb of 1944 to study limit velocity for a variety of armor steel recipes with varying tensile strengths. Armor steels for the trials were provided by several different manufacturers – ESC Ltd, Beardmores, Firth Brown and of course Hadfields.

 

In the case of the following table AOH is Acid Open Hearth Steel produced by English Steel Corporation Ltd. (ESC), and BE is Basic Electric Steel produced by Hadfields. Each of the two steel producers manufactured plates for each of the four armor steel compositions.

 

 

Others might be interested in the following:

 

The Milne & Henchliff Coefficients for 17-pdr & 3.7” AP vs. Vibrac 30, 60-tsf, is respectively 6.065 & 6.053. This implies both projectiles were – in terms of energy required for plate perforation – about equally efficient. The slightly lower coefficient for the 3.7” AP indicates it was actually a slightly more effective\efficient projectile vs. 6-inch plate at normal than 17-pdr AP. This was just a random pick and whether or not this trend holds true for all plate trials detailed in the table I don’t know.

 

 

Great info - thanks JW - this one is going into my info file!

[Ken Estes]

And here is a pic of a 3.7" with tobruk sights...you can see the open sights and then the rings for the telescopic sights above that...one telescope on either side...this gun is in the gun shed at Cranwell...

 

So the nonsense that some folks keep posting about the 3.7" never having had DF sights is simply that...nonsense...usually these are the same folks that can not bring themselves to admit that virtually all HAA units in everyone's army fired DF at some point or another...

 

....

I would say that it is nonsense to expect to engage tanks [plural] at long [i.e. survivable combat] range using two sets of sights and a gunner and pointer doing elevation and training individually. It is even worse for the 88 in its original AA configuration. To repeat, these are not dual-purpose guns. Any gun can be pressed into bombardment duty, by some means.

 

Most medium and heavy AA guns had direct fire as an afterthought, for the method of AA was usually minimum four gun barrage under director control; nobody would expect a single 3.7 or 88 or 90 to pick off an aerial tgt by itself, unless the a/c might be diving on that gun.

 

Nice pics!

Edited April 24, 2009 by Ken Estes

[scotsman]

I would say that it is nonsense to expect to engage tanks [plural] at long [i.e. survivable combat] range using two sets of sights and a gunner and pointer doing elevation and training individually. It is even worse for the 88 in its original AA configuration. To repeat, these are not dual-purpose guns. Any gun can be pressed into bombardment duty, by some means.

 

Most medium and heavy AA guns had direct fire as an afterthought, for the method of AA was usually minimum four gun barrage under director control; nobody would expect a single 3.7 or 88 or 90 to pick off an aerial tgt by itself, unless the a/c might be diving on that gun.

 

Nice pics!

 

Two telescopes...but given the velocity of these weapons and the typical engagement ranges (often 500 meters or less even in a desert environment) you really dont have to worry about elevation...only training/azimuth. Even more so if you are fighting from a fixed defensive position for which you already have range cards. The presence of two telescopes --does not imply-- both are needed for an engagement Ken...especially the case for an 'average' range engagement which in the ETO was usually 800 meters or less...

 

The gun cdr can certainly have a separate eye on which tanks in a formation might pose the highest threat...the gunner doesnt need to worry about that..although communications will be slower to get the gun on target than a tank for example would be...

 

Russia might be another matter...terrain their favored longer range engagements...and both the 88 and the 3.7 were provisioned with range finding capabilities.

 

On the 'dual purpose' comment...we'll just have to agree to disagree. If the ammunition is provisioned for the gun, the engagement techniques are taught in the gunners course, and the weapon is so employed, then you are simply arguing symantics. It IS dual purpose by definition of its use... I understand the comments about removing pointers etc and rendering a gun unfit for the original purpose...but to the best of my knowledge that is a German and not British thing. I can't recall an instance in which the 3.7" was raped like that...the guns sited by Freyberg in the 2nd NZ in Africa were certainly not denuded of their AA equipment fit. 2nd Cdn history, AA command history, and numerous other sources don't document a case in which guns were denuded like that...although 3.7" did have their equipment fits smashed up when they were abandoned...probably SOP for every gunner/gun...

 

No arguement that its a secondary mission for any HAA...but the 3.7" engaged tank tgts during the battle or france (as did the 3" 20 CWT), and continued to do so well nearly to the end of the war as needed (certainly late 1944 as I have an interview with a 3.7" gunner where he states that to be the case) In his own words...the AP ammunition was dumped on the guns and his battery cdr told him simply 'to get on with it'...which he did...

 

I do understand where you are coming from..its not DP in the sense that say the 5"/38 was DP..but shipboard mounts are a different kettle of fish anyway. To my way of thinking though, if the tactical plan calls for use of said weapons (be they 3.7", US 90mm at the battle of the bulge, 88, etc etc etc) to be used in the AT mission, then the debate over whether they are 'DP'....its certainly rather moot to the gunners doing the shoot....

 

Also understand the points on survivable range...he who shoots and hits first though usually have the upper hand...and against early WWII with anemic HE, then the odds will lay with the gun and not the tank. Coax/MG certainly is a threat though...

Edited April 24, 2009 by scotsman

[rmgill]

ERgonomically, the Gunners on the 3.7 sit on seats and face the director pointers with their backs facing the muzzle and their faces looking towards the area where the ammunition handlers and loaders are tossing 3.7inch cartridges around. When they do a direct fire shoot, they get up, walk around the T and E handles and face towards the muzzle end and operate the same exact controls and look through the gunsights at their target. One gunner controls Traverse, one controls elevation. This isn't any different from a lot of larger ship and shore based guns if I'm not mistaken.