What prevented the QF 3.7-inch AA gun being used in the Anti Tank role.

[Sheldrake]

I've read a number of different reasons why it was never employed in an anti tank role, the British preferring to use detached 25 pounders instead.

• • The inability of the mount to absorb the recoil when firing at low elevations
  • Lack of an AP round (even though regular HE with the fuze deactivate was found to be effective)
  • Lack of direct fire sights on the gun
  • The large size of the making it difficult to emplace
  • Heavy Anti Aircraft regiments being Army level assets
  .

Are there any additional reasons people might be aware of? Or are some of the reasons above inaccurate?

Also with regards firing at low elevations, my understanding is the gun could depress below 0 degrees unlike a gun such as the American 90 mm Gun M1, so perhaps the issue with the mount is overstated? perhaps it was only a factor with prolonged fire?

The 3.7" AA Gun was (eventually) used in the Anti tank role at Tobruck and El Alamein in June-July 1942. 103 HAA Regiment in Home Forces had a secondary role from July 1941 as Heavy Anti tank guns in the event the Germans landed heavy tanks in Britain. The Heavy AA guns defending the D day beaches all had a secondary anti tank role.

There were technical problems that had to be overcome - lack of AP ammunition and suitable anti tank telescopes. Semi mobile Heavy AA gunners would need additional vehicles and training to fight effectively as anti-tank troops. But all of those could have been overcome with determination , teamwork and co-operation. In the UK the C-in-C Home Forces, Brooke took a personal interest and thumped tables and demanded that Beaverbrook the minister for supply provide AP ammunition.

The real question is why didn't the British use the 3.7" AA Gun in the Western Desert 1941-42? (Or divert some some of the thousand surplus 3" 20cwt (76mm) AA guns).

Three main reasons:-

#1 Lack of senior interest determination to overcome the organisational issues.

At the start of WW2 the Royal Artillery was separated into the Field and AA Branches. There was no cross posting between branches. AA Branch had a priority of dealing with the Luftwaffe which posted a significant threat. There were plenty of AA guns defending Alexandria, Haifa and Suez, but no one below C-in-C middle east transfer resources from there to 8th Army. Neither Wavell nor Aukinleck was asked or took the trouble to get involved.

#2 Doctrinal blind spot(s).

The commanders in the field don't seem to have noticed the effect of German anti-tank guns on the outcome of battles.
British early war combined arms doctrine, such as it was, didn't have a place for anti-tanks working with tanks and infantry. No one in the infantry or armour was screaming for British 88s.

3# Technological/ procurement blind spots.
No one seems to have noticed that the 3" 20 CWT gun had pretty much the ideal characteristics of an anti-tank gun. It was within one mm of the main anti tank guns used by the German, British, Soviet and US Armies. The ministry of supply was focused on building as many 2 Pounders as possible and the Army with the introduction of the 6 Pdr. There was no one in a position to know of the disposal of the 3" guns with the interest or authority to direct them to the ME. Too many Colonel Blimps with thumbs up their bums. There were also organisational rivalries, The RAC and RA bickered over mounting 50 3" guns on Churchill tank chassis.

This was not the finest hour for the Royal Regiment, which is why so many of the excuses were raised post war.

The fame of the 88mm AA gun might also be a matter of luck. The Germans entered the war with tanks and anti tank guns too weak to penetrate heavy Allied tanks and happened to have under employed heavy AA guns. (Though they also had the foresight to train and equip their Heavy AA gunners for a dual role.

[MarkN]

Hello Sheldrake,

The real question is why didn't the British use the 3.7" AA Gun in the Western Desert 1941-42? (Or use some of the thousand 3" 20cwt (76mm) AA guns in the anti-tank role.

Three main reasons:-
#1 Organisational. At the start of WW2 the Royal Artillery was separated into the Field and AA Branches. There was no cross posting between branches. AA Branch had a priority of dealing with the Luftwaffe which posted a significant threat. There were plenty of AA guns defending Alexandria, Haifa and Suez, but no one below C-in-C middle east transfer resources from there to 8th Army. Neither Wavell nor Aukinleck was asked or took the trouble to get involved. In the UK the C-in-C Home Forces, Brooke took a personal interest and thumped tables and demanded that the minister for supply provide AP ammunition.
#2 Doctrinal blind spot(s). The commanders in the field don't seem to have noticed the effect of German anti-tank guns British early war combined arms doctrine, such as it was, didn't have a place for anti-tanks working with tanks and infantry.
3# Technological/ procurement blind spot. No one seems to have noticed that the 3" 20 CWT gun had pretty much the ideal characteristics of an anti-tank gun. It was within one mm of the main anti tank guns used by the German, British, Soviet and US Armies. The ministry of supply was focused on building as many 2 Pounders as possible and the Army with the introduction of the 6 Pdr.

I agree with all of the above. Nevertheless, the elephant in the issue remains.



Where are the 'excess' guns that can be taken off HAA duty to go off tank hunting?

Please note the above table also includes the 3" HAA guns that in the process of replacement.

The fame of the 88mm AA gun might also be a matter of luck. The Germans entered the war with tanks and anti tank guns too weak to penetrate heavy Allied tanks and happened to have under employed heavy AA guns.

And yet, despite being too weak, the 37mm 'door knocker' and various infantry panzerbuechse made a terrible mess of 2nd and 3rd Armoured Brigades on the Somme in May 1940. Not an 88mm in sight.

Up to and including Operation Crusader, the Germans employed just 24 x 88mm guns with Wehrmacht units in the front line in Libya/Egypt. They were used dual role. The Luftwaffe 88mm guns were held in rear areas and had as much ATk effort as British 3.7mm HAA. Those 24 guns generated a 'myth' that even today seems to grip some to the point of delusion. It was/is a 'myth' that conveniently papers over the reality of abysmal British battle tactics and effort.

[Gooner1]

I've read a number of different reasons why it was never employed in an anti tank role, the British preferring to use detached 25 pounders instead.

• • The inability of the mount to absorb the recoil when firing at low elevations
  • Lack of an AP round (even though regular HE with the fuze deactivate was found to be effective)
  • Lack of direct fire sights on the gun
  • The large size of the making it difficult to emplace
  • Heavy Anti Aircraft regiments being Army level assets
  .

Are there any additional reasons people might be aware of? Or are some of the reasons above inaccurate?

All of the above plus at near 10 tons and requiring the AEC Matador to move it, its tactical mobility would have been poor.

OTOH in April '42 60 of the guns were fitted with sights enabling them to shoot at ground targets.

[Gooner1]

Where are the 'excess' guns that can be taken off HAA duty to go off tank hunting?

Please note the above table also includes the 3" HAA guns that in the process of replacement.

Just answered your own question.

[Sheldrake]

Where are the 'excess' guns that can be taken off HAA duty to go off tank hunting?

Even a small number of Heavy AA guns used in the anti tank role may have made a significant difference. Even one regiment of say 24 guns might have encouraged Rommel's tanks to be a little more circumspect.

The British could not be strong everywhere. After the invasion of Russia they could have taken a bet that the Luftwaffe would not mount a serious threat to Egypt and the Suez Canal, They could have deployed one of the nine HAA regiments in the Middle East.


There were about 1000 3" guns which were withdrawn and shipped to the USSR or mounted on DEMS merchant ships, Or extracted a digit from the numpties that failed to mount 50 3" guns on 25 Pdr carriages.

[Damper]

#1 Organisational. At the start of WW2 the Royal Artillery was separated into the Field and AA Branches. There was no cross posting between branches. AA Branch had a priority of dealing with the Luftwaffe which posted a significant threat. There were plenty of AA guns defending Alexandria, Haifa and Suez, but no one below C-in-C middle east transfer resources from there to 8th Army. Neither Wavell nor Aukinleck was asked or took the trouble to get involved. In the UK the C-in-C Home Forces, Brooke took a personal interest and thumped tables and demanded that the minister for supply provide AP ammunition.

I wonder if at some point the QF 3.7 inch guns in places like Alexandria and Suez, lost elements of mobility, prime movers, manpower etc and became much more static emplacements. A weapon system as complicated as the QF 3.7 was always going to do perform better when located near a depot. Where the supply of spare barrels, parts and ammunition was easier to come by. It may have always struggled if it was dragged through the desert behind the main force.

#2 Doctrinal blind spot(s). The commanders in the field don't seem to have noticed the effect of German anti-tank guns British early war combined arms doctrine, such as it was, didn't have a place for anti-tanks working with tanks and infantry.

Yes, but maybe it was because the Germans had other options from the begining of the desert war other than the PAK 37. They had Skoda 47mm guns, as well as various French and Italian 47mm weapons, the PAK 38 arrived in early 1941 well ahead of the British 6 pounder. The Germans seemed to do well at integrating all their Anti Tanks assets. I don't believe that the 3.7 inch would have been a success in the Anti Tank role, I'm just curious about what consideration was given to employing it at the time.

3# Technological/ procurement blind spot. No one seems to have noticed that the 3" 20 CWT gun had pretty much the ideal characteristics of an anti-tank gun. It was within one mm of the main anti tank guns used by the German, British, Soviet and US Armies. The ministry of supply was focused on building as many 2 Pounders as possible and the Army with the introduction of the 6 Pdr.

Well they did notice it, and a 100 were converted either on SP Churchill mounts or bodged towed mounts (my understanding of the towed mounts was that they were sent to the Soviet Union), they just took too long to do it, and they were only available at the same time as the 17 pounder was entering service.

[MarkN]

Where are the 'excess' guns that can be taken off HAA duty to go off tank hunting?

Even a small number of Heavy AA guns used in the anti tank role may have made a significant difference. Even one regiment of say 24 guns might have encouraged Rommel's tanks to be a little more circumspect.

The British could not be strong everywhere. After the invasion of Russia they could have taken a bet that the Luftwaffe would not mount a serious threat to Egypt and the Suez Canal, They could have deployed one of the nine HAA regiments in the Middle East.

The thread originator (TO) seems to consider the period September 1939 to summer 1942 as the period of concern: ie. prior to the arrival of the 6-pdr ATk gun. So what date in that frame are we to consider?

On 1 January 1941, Wavell had a grand total of 92 HAA guns at his disposal for the entire command (3", 3.7" and 4.5"). An additional 32 had just arrived in WS.4 and were awaiting dockside space to be unloaded. 16 more arrived on WS.5 in February. Another 24 arrived in April on WS.6. So, by the end of April, 164 HAA guns all told against an establishment of 484.

During April and May, 40 of those 164 were lost in Greece and Crete and another 21 bottled up in Tobruk.

On 17 November 1941, when Op Crusader started, the British had 220 HAA guns to hand in the entire ME Command. Still 264 short of then establishment set over 12 months earlier when the 'field force' to be equipped was significantly less.

You are right, the British could not be strong everywhere. But given the HAA holdings were already less than 50% of establishment, was this an area they could 'afford' to denude even further?

The decision taken at the time appears to be a categorical NO!

Moreover, in the ME the decision taken was to place 'excess' 18-pdr field guns into ATk units. Maybe that was not the 'right' decision. But to suggest (I know you didn't but others over the passage of time have) that nobody was bothering about this issue is painfully false.

We have been around this, or at least similar, bouy a few times already Sheldrake. Against the Germans, British battle tactics and effort circa 1941 was woefully inadequate. During the first few days of Op Crusader, 7th Armd Div managed to lose the majority of their 430ish starting pantsers to Axis guns which were NOT of the mythical 88mm variety. From the other side, German pantsers sliced through British formations without any ATk protection at all. Repeating the earlier quote...

In an acerbic vein, Bidwell and Graham commented, “In any case even if the guns [3.7-inch] had been made available it is doubtful if the desert commanders would have used them correctly, in view of the hash they made of the employment of all their own artillery.”

Personally, I don't believe 24 pretty immobile 3.7" HAA guns trundling around the battlefield circa Op Brevity, Battleaxe or Crusader would have made the slightest difference to either the outcome or events or the tactical thinking. The Germans were already a bit twitchy due to the influence of the 25-pdr.

There were about 1000 3" guyns which were withdrawn and shipped to the USSR or mounted on DEMS merchant ships,

Or extracted a digit from the numpties that failed to mount 50 3" guns on 25 Pdr carriages.

Didn't all those guns become 'available' after the introduction of the 6-pdr ATk gun?

[Knouterer]

While the calibre was similar at 94 mm the 3.7" HAA gun was nearly twice as heavy as the German 88 mm guns, at 9350 kg in action and well over ten tons in towing configuration, which made it a bit cumbersome for an AT gun. Nevertheless it was so used in emergencies. On the 23rd of May 1940 gunners of 4th/2nd HAA defending Boulogne engaged German tanks over open sights with their 3.7s and claimed two destroyed.

[Sheldrake]

There were about 1000 3" guyns which were withdrawn and shipped to the USSR or mounted on DEMS merchant ships,

Or extracted a digit from the numpties that failed to mount 50 3" guns on 25 Pdr carriages.

Didn't all those guns become 'available' after the introduction of the 6-pdr ATk gun?

I need to check the source, (AA Command HMSO or EH) but IRRC the replacement of the 3" 20 Cwt guns in AA Command took place 1940-41 as part of the response to the Blitz.

[MarkN]

The real question is why didn't the British use the 3.7" AA Gun in the Western Desert 1941-42? (Or divert some some of the thousand surplus 3" 20cwt (76mm) AA guns).

The TO's original start point presumed the oft repeated falsehood of "over a thousand" 3.7" HAA guns sitting idle somewhere in the Middle East. A falsehood that litters the internet as various people try to prove they know better how to defeat the pantsers.

From primary documentation, I have shown that on 1 January 1941, the entire Middle East command had 92 HAA guns in total in service (3", 3.7" and 4.5"). I have no located a document specifying the state at the end of the year, 27 December 1941, against a requirement for 472 HAA (Egypt, Libya, Palestine, Syria & Cyprus), there existed only 244 under British control of all types: (3", 3.7", 4.5" and captured Italian and French guns). There were no secret warehouses full of 3.7" HAA guns sitting unused that could have been used to stop Rommel's pantsers. Any 3.7" HAA gun co-opted into an ATk role had to be taken away from its primary AA role - for which the theatre was already significantly below establishment.

Another claim I see liberally dotted around the internet is the "thousand surplus 3" 20cwt (76mm) AA guns". Really?

In September 1939, 157 3" HAA guns were in service with ADGB. Others were in service in other parts of the world. 48 of those were sent to France to defend the AASF aerodromes and were lost. However, there remained a number in storage in the UK. Different numbers are quoted by different sources. However, documentation shows that in September 1940, 341 were now in service. That points to at least 230 stored guns being reactivated. These guns soldiered on well into 1941. Some beyond that.

So where were these thousand surplus guns hiding?

I know the RN had a range of different 3" AA guns in service. Are you counting them too?

[Gooner1]

From the other side, German pantsers sliced through British formations without any ATk protection at all.

Harsh but fair reflection of the ineffectiveness of the 2-pdr.

Personally, I don't believe 24 pretty immobile 3.7" HAA guns trundling around the battlefield circa Op Brevity, Battleaxe or Crusader would have made the slightest difference to either the outcome or events or the tactical thinking. The Germans were already a bit twitchy due to the influence of the 25-pdr.

The 25-pdr was not all that spectacular in the anti-tank role. The 3-inch 20cwt gun probably had a third more penetration.

A few troops of relatively immobile 3.7-inch guns would have been a tasty addition to the Boxes at Gazala.

[MarkN]

Personally, I don't believe 24 pretty immobile 3.7" HAA guns trundling around the battlefield circa Op Brevity, Battleaxe or Crusader would have made the slightest difference to either the outcome or events or the tactical thinking. The Germans were already a bit twitchy due to the influence of the 25-pdr.

The 25-pdr was not all that spectacular in the anti-tank role. The 3-inch 20cwt gun probably had a third more penetration.

No it wasn't. But reading German diaries, they had a healthy respect that it hurt them at distance and thus had a similar effect on twitching German nerves at a range somewhat greater than the 2-pdr.

And who was still operating 3" guns in the Mediterranean, when and where? Solve that riddle and you'll see it was a bit of a non-starter.

A few troops of relatively immobile 3.7-inch guns would have been a tasty addition to the Boxes at Gazala.

Some where placed in the rearward boxes and had some fun against the pantsers: Knightsbridge and El Adem boxes spring to mind. Key point was that they were in the rearward boxes that hopefully were defences of the last resort and thus didn't require mobility.

Whenever the 3.7" HAA gun found itself in range of pantsers, it was used: Boulogne 1940, Benghazi 1941, Gazala/Tobruk 1942. There was no ban on its use as an ATK asset, it just wasn't often in a location to have a go.

[Gooner1]

No it wasn't. But reading German diaries, they had a healthy respect that it hurt them at distance and thus had a similar effect on twitching German nerves at a range somewhat greater than the 2-pdr.

And who was still operating 3" guns in the Mediterranean, when and where? Solve that riddle and you'll see it was a bit of a non-starter.

Respect for the 25-pdr could have been replaced by fear of the 3-inch ...

As to where they were in the Med., I suspect you will have better information on that. I know there were more than 400 in AA Command in September '40. But, to be fair, the inadequacy of the 2-pdr only really hit home after Crusader so by the time anything could reasonably be done with Blighty stocks, the 6-pdr would be shipping.

Some where placed in the rearward boxes and had some fun against the pantsers: Knightsbridge and El Adem boxes spring to mind. Key point was that they were in the rearward boxes that hopefully were defences of the last resort and thus didn't require mobility.

I know they had the guns in Tobruk, didn't know about Knightsbridge or El Adem. Wonder if they had the improvised ground sights fitted.

[MarkN]

I know there were more than 400 in AA Command in September '40.

Sources vary on how many there were in the UK. For September, I have 341 noted. The highest total I can see is for June at 366.

But, to be fair, the inadequacy of the 2-pdr only really hit home after Crusader so by the time anything could reasonably be done with Blighty stocks, the 6-pdr would be shipping.

And that is, perhaps, the key to understanding the issue. At the time, the powers that be considered the 2-pdr was still doing a good job and there was no need to reinforce them with HAA guns denuded from scarce AD resources. Part of the problem was the enduring issue of frontline units overclaiming by a wide margin and this misleading everybody as to how (in)effective the gun now was. By the time the true extent of the 'problem' had emerged, the 6-pdr solution was arriving.

Some where placed in the rearward boxes and had some fun against the pantsers: Knightsbridge and El Adem boxes spring to mind. Key point was that they were in the rearward boxes that hopefully were defences of the last resort and thus didn't require mobility.

I know they had the guns in Tobruk, didn't know about Knightsbridge or El Adem. Wonder if they had the improvised ground sights fitted.

Some did...

292 HAA Bty WD

28th April
A.tk practise carried out by gun detachments from all batteries in the area on section 2's guns. Damaged German and Italian tanks at ranges between 600-800yds used as targets. Practise also carried out on towed targets. Special open sights designed by S.O.M.E 12 AA Bde used. H.E and S.Ap fired with good results. Firing on second day witnessed by Eight Army Cmdr, A.O.C and B.R.A. Eight Army.

13th May
Ant-tank sights fitted to 3.7 guns.

12th June
Troop used in role of field arty under orders from C.P 76 rounds were fired against enemy columns consisting of tanks, armoured cars, lorried infantry and M.T. Section 3 engaged 3x 88mm guns which took up positions at ranges of 2600-4000 yds. A direct hit was secured on the nearest, using open sights and the other two withdrew. During the day the Troop destroyed 1x 88mm gun and one A.V.F and inflicted damage on two tanks (probably destroyed) and M.T. Brig Reid DSO MC visited sites and congratulated troops on days work.

Also, 94th HAA Regt WD.

8th August 1942
Brigade Commander, Brigadier P.G. Calvert-Jones, visited the Regiment to observe 292nd Battery demonstrate the capabilities of the 3.7 inch anti-aircraft gun the anti-tank role.

4th September 1942
Regiment practised Operation JUPITER, where, in the event of an overwhelming assault, all 40 of the AA brigade’s 3.7 inch guns would be withdrawn to form a defensive anti-tank screen on ‘Skinners Ridge’ near Alam Shaltut.

25th and 26th September 1942
Tanks which had been recovered from the battlefield were taken to Alam Shaltut. These tanks were used as targets during a four day, brigade anti-tank (AT) shoot starting on the 27th September 1942. The live firing exercise was to be attended by General B.L. Montgomery and members of his general staff.

[Damper]

Personally, I don't believe 24 pretty immobile 3.7" HAA guns trundling around the battlefield circa Op Brevity, Battleaxe or Crusader would have made the slightest difference to either the outcome or events or the tactical thinking.

That's my view as well, however I'm curious about whether employing the guns in the Anti Tank role was investigated and then rejected after considering all the factors, or just never considered at all.

Regarding one issue, that of removing Anti Aircraft assets, I would suggest that prior to the invention of the proximity fuze, HAA effects against high altitude bombers were pretty limited particularly considering the amount of resources consumed, ammunition and barrels in particular.

Also if the Army couldn't afford to misemploy HAA in the Anti Tank role, I would suggest that it could even less afford to misemploy field artillery such as the 25 pounder in the Anti Tank role. In particular prior to developing an effective AP shell.

The obvious solution would be to use the 3 inch QF, my understanding was that there were a lot of these guns in storage, missing sights mounts and other various components. It was these guns that were used in Anti Tank trials, and later shipped to the Soviet union.