CW deployment of heavy AA?

[Wisbech_lad]

Any grogs know why the CW never used their excellent heavy AA (3.7" ISTR) as a stop gap heavy AT gun - rather waiting for the 17pdr? Given the iconic status the "88" had with CW troopers, couldn't have been that no-one thought of it

Doctrine? Unsuitable? (i.e. can't be layed flat/ no AT ammo) Boneheadedness? Better used elsewhere? (In the desert, could see an argument that the CW used their heavy AA better than Rommel and his 88's - i.e. defending the ports & logistics from air attack, rather than on the front line...)

[...................................]

I can't recall where I read it, but ISTR that when the suggestion was made to use the heavy AA guns in an AT role in the desert, the higher echelons turned it down. One reason given was that trials had shown that a large sand plume was thrown in the air when the gun was fired at ground targets, thus making it easy to spot it's postition.

I'm not sure what the PBI thought of that as an excuse (not much probably!), but the suggestion was definitely made and definitely declined by 'those who know better' at the rear.

[Redwolf]

Higher authorities don't want AA employed in the ground role because they don't want them used up and then not being available for AA purposes. In addition, those AA guns are very immobile and hard to conceal.

The Germans had no choice than to employ the 88s because the guns on their tanks were insufficient against some British models.

But the British guns didn't have primary penetration trouble before the Tiger came along.

Now, whether it would have been worthwile to use the AA guns for their better range, as the Germans did to great success, is a different matter but best not asked to British Generals before -say- mid-1943

[John D Salt]

Originally posted by Wisbech_lad:

Any grogs know why the CW never used their excellent heavy AA (3.7" ISTR) as a stop gap heavy AT gun - rather waiting for the 17pdr?

An AP round certainly existed, and AIUI "Middle East" sights existed for direct shooting.

I believe the "88" used a single gun-layer, whereas the 3.7" had two layers, no. 2 and no. 3, one laying in line and the other in elevation. This is doubtless a better arrangement when conducting AA fire attached to a predictor, which is what the 3.7" was designed to do (and, let it be said, it was a better gun than the "88" in all respects for its primary intended purpose). I would have thought, though, that pointing a gun accurately at a small, moving target like a tank using two layers would be a right bugger's muddle. The 3.7" is also heavier and clumsier than the "88", which must in itself have been a lot of work to emplace.

The anti-tank stopgap actually used, the 25-pdr, was probably a better choice against the targets of the time. I am not sure why more was not made of the old 3-in 20cwt AA guns that the 3.7" replaced in service; as far as I know a few were issued on 17-pdr carriages, some perhaps seeing action at Hunt's Gap, and there was a project that came to nothing to mount one on a fixed casemate on a Churchill chassis.

The 3.7" was eventually used a good deal in the ground role, but for indirect rather than direct fire (especially on counter-mortar targets), but this was for lack of air targets once air superiority had been permanently won. By that time in the war, plenty of 6-pdr and 17-pdr ATk guns were available, and, being purpose-built for the task, they would do a better job.

All the best,

John.

[JonS]

IIRC, the 3.7-in was used in a ground role several times during the desert war.

Towards the bottom of this page there is mention of them, and the note also refers to their use thus at Tobruk.

In addition to all the valid reasons above, I also recall reading somewhere that their minimum elevation would have made engaing tanks with it roblematic, but aven't confirmed that to my own satisfaction yet, so take it FWIW.

If I get a bit of spare time I may delve into "Development of artillery tactics and equipment", as I'm sure Pemberton had something to say about it.

[Denwad]

3.7HAA had an autoloader too

[Michael Emrys]

Originally posted by John D Salt:

...the 3.7" had two layers, no. 2 and no. 3, one laying in line and the other in elevation.

In USN parlance, respectively a trainer and a pointer. Handy bit of nomenclature, that.

Michael

[ October 09, 2004, 06:30 PM: Message edited by: Michael Emrys ]

[Wisbech_lad]

Many thanks for the replies

[JonS]

OK. Checked Pemberton.

Originally posted by John D Salt:

I am not sure why more was not made of the old 3-in 20cwt AA guns that the 3.7" replaced in service; as far as I know a few were issued on 17-pdr carriages, some perhaps seeing action at Hunt's Gap, and there was a project that came to nothing to mount one on a fixed casemate on a Churchill chassis.

100 x 3in. 20cwt were converted to A-Tk, and provided with a 12 1/2 lb. shot. 50 were mounted on early 17-pr carriages (which were ready well before the guns), and the remaining 50* were mounted on Churchills. The Churchills had only a limited traverse of 7°, and so were kept for home defence. 25 of the 3in 20cwt on 17pr carriages were also kept for home defence, the rest being sent to the Middle East. Date is a bit vague, but roughly mid-to-late 42-ish.

AIUI, they were seen strictly as a stop gap until the 17-pr came on stream in numbers. In that connection, it's worth noting that the first mock up of the 17-pr was ready in August 1941, with the first 200 operational models expected by late 42.

P. is strangely silent on the matter of using the 3.7in in a ground role, except to say that in performed well in that role (specifically, 'role' in this case means field arty) in Burma in early '45.

* Chamberlain & Ellis say that initially 100 3in Churchills were ordered, but this was subsequently dropped, and only 24 were produced. None used in combat.

[ October 09, 2004, 07:04 PM: Message edited by: JonS ]

[Michael Emrys]

Originally posted by JonS:

100 x 3in. 20cwt were converted to A-Tk, and provided with a 12 1/2 lb. shot. 50 were mounted on early 17-pr carriages (which were ready well before the guns)...

Okay, this is the part I don't understand. I have always read that the first 17pdr guns were mounted on 25pdr carriages because their own (split trail) carriages weren't ready yet. Can someone resolve this apparent contradiction please?

Michael

[Michael Dorosh]

Originally posted by Michael Emrys:

</font><blockquote>quote:</font><hr />Originally posted by JonS:

100 x 3in. 20cwt were converted to A-Tk, and provided with a 12 1/2 lb. shot. 50 were mounted on early 17-pr carriages (which were ready well before the guns)...

Okay, this is the part I don't understand. I have always read that the first 17pdr guns were mounted on 25pdr carriages because their own (split trail) carriages weren't ready yet. Can someone resolve this apparent contradiction please?

Michael </font>

[Michael Emrys]

Originally posted by Michael Dorosh:

</font><blockquote>quote:</font><hr />Originally posted by Michael Emrys: Okay, this is the part I don't understand. I have always read that the first 17pdr guns were mounted on 25pdr carriages because their own (split trail) carriages weren't ready yet. Can someone resolve this apparent contradiction please?

The first 25pdr were mounted on 18pdr carriages and called 18/25 pdrs....maybe you're confusing 17 and 18?</font>

[JonS]

Yes, Emrys is [gag]correct[/gag]. The MkI 17-prs were mounted on 25-pr carriages, and were referred to by the code name of Pheasant. The MkII, with its own carriage, came later and was referred to as Partridge.

Emrys,

I wondered about this apparent contradiction too, but cannot explain it. All I can say is that I did read the relevant passage correctly.

Jon.

[Koenig]

Bidwell in his 'Gunners at War' deals briefly with the question of the employment of the 3.7" gun in the AT role.

The lack of a good telescopic sight, being the weapon meant to aim following electrical data from a predictor (an elementary computer) was not seen as an insuperable technical difficulty.

The debate was over the opportunity to divert scarce AA resources.

The 25-pounder proved to be an effective stop-gap AT-weapon, waiting for the arrival of the 6-pounder.

To have any influence in the desert warfare, at least 50-60 guns would have to be converted to the anti-tank role.

Plus reserves, as losses among AT-guns were heavy.

Crews would have to be trained, but they should mantain they ability to use the gun in AA role.

A doctrine for the employment of these guns would have to be developed from scratch.

Moreover the Anti-Aircraft Branch of the Royal Artillery had become a highly specialized, somewhat separate service, with a very strong tie to the Royal Air Force. This meant both doctrinal and political difficulties in diverting them from their expected AA role.

Unfortunatly the author doesn't quote names and dates of this interesting debate, so the whole argument remains somewhat conjectural and clouded in mistery.

Bidwell only writes that General Sir Frederick Pile, chief anti-arcraft gunner in Britain, supported the adoption of the 3.7" as AT gun.

It is plausible to believe that the question was not given a high priority.

Anyway the 3.7" was given a chance to operate in a pure AT role during Operation Aberdeen, in June 1942.

The CO of 2nd R.H.A. was given an unasked troop of four 3.7" to bolster his AT defence.

As the position was already crowded with guns, he accepted only two of them and sent the rest back.

He was infuriated when he saw them uncamouflaged and surrounded with tables and chairs! It was clear that the crews had no proper training.

Anyway the position was not attacked by tanks, and it seems that it was the first and last attempt to use the 3.7" in this role (the 3.7" of Tobruk had previously fired at tanks, but from their AA positions).

Bidwell ends the controversy with the following statement: 'Whether the combined commanders-in-chief were right or wrong in deciding against any major reduction of the air defences is a finely-balanced question. The Germans were faced with exactly the same problem and decided differently, and most people agree that they were right.'

IMHO the situation was not the same. The Germans had to deal with the menace of the Matilda, which was nearly invulnerable to the guns of their 1941 tanks. The adoption of the 88mm was a necessity.

On the other hand, the British 25-pounder, widely and easily available, could dispatch most German tanks until the arrival of the Tiger.

The strategic, technical, logistical and doctrinal problems posed by the employment of the 3.7" in AT role were enough to discourage its adoption, considering that it was not a priority.

It is clear that the 17-pounder definitively solved the question.

Regards

Koenig

[Michael Emrys]

Originally posted by JonS:

Yes, Emrys is [gag]correct[/gag]. The MkI 17-prs were mounted on 25-pr carriages, and were referred to by the code name of Pheasant. The MkII, with its own carriage, came later and was referred to as Partridge.

Ta-daaaaa!

Emrys,

I wondered about this apparent contradiction too, but cannot explain it. All I can say is that I did read the relevant passage correctly.

Could have been an editorial error. Even the pros make mistakes sometimes, and if the proofreaders don't know the subject well, they aren't going to catch it.

Michael

[JonS]

Yeah, but he was quite specific about it. Strange. About the only way I can rationalise it is as a timing issue. I.e., the first few 17-pr barrels were ready before any arriages were available, so they were flown out to Africa and mounted on 25-pr carriages. Then carriage production got ahead of barrels, and someone had the 3in 20cwt idea.

[Michael Emrys]

That might work. Got a source that will give dates? I should think finding out when the 17pdr guns were mounted on the 25pdr carriages wouldn't be too hard. But the other...?

Michael

[JonS]

Sort of. The NZETC link to the 2(NZ)DivArty OH I gave above is fairly specific about when the Pheasants first became available, and I have reason to believe that the Kiwis were the first - or very nearly the first - to recieve them*. There were only a couple or 3 divisions really involved in the chase across North Africa - the Kiwis, 7th Armd, and ... 51st Highland maybe? Anyway. The point being that the date given in the above bool will suffice for the 17/25pr.

The 3in 20cwt is a problem though. I don't have anything about that gun other than the brief mention in Pemberton (which is extemely vague about dates), and an oblique reference in Chamberlain & Ellis. I'll just go check Bidwell, although if anyone has a copy of Hogg to hand, that would probably be more useful.

Jon

* As an aside, despite getting the 17/25 early the Kiwis had to wait about a year before they got the MkII. And they only got those because when they pulled out of the line on the Adriatic Coast to zippy over to Cassino the weather was too ****ty to pull the guns out of the positions they were in. So the gunners did a straight swap with the incoming division. The reaction of the British gunners to having their shiny new MkIIs swapped for clapped out old MkIs isn't recorded

[Michael Dorosh]

Originally posted by JonS:

The reaction of the British gunners to having their shiny new MkIIs swapped for clapped out old MkIs isn't recorded

Served them right for the vehicle deal they did with 5th Canadian Armoured Div in theatre, don't ya think?

[Michael Emrys]

Okay, you provoked me to dig out my copy of Anti-Tank Weapons (Chamberlain/Gander), part of the WW2 Fact Files series. As expected, the information is rather sparse, and perhaps not all of it is correct. But it is intriguing.

They agree that "...first deliveries were made in August 1942." They also state that "...100 of the 17 pr guns were flown out to Africa and mounted on 25 pr carriages." But then they go on to say, "The 17/25 combination was unofficially known as the 17 pr Mark 2, a designation correctly meant for the 17 pr tank mounted gun." Confused yet?

They say that once the proper Mk 1 guns (i.e., with the carriages designed for them) became available, the earlier Mk 2s were phased out.

Now here comes an interesting tidbit: "Later when there were more carriages available than guns, some elderly 3 in. AA guns were mounted on 17 pr Mk 1 carriages and used for home defence." They don't say when "later" was. Some time in 1943? By "home defence", I take it that it never left the British Isles.

Michael

[JonS]

heh, I came across much the same info.

Here is what I have in toto

Pemberton The development of artillery tactics and equipment (1950). Page 127.

With the introduction of the 17-pr. and the provision of high velocity shot for all British anti-tank guns, the advantages so long enjoyed by the Germans were about to be taken from them. But the immediate military situation was serious and something had to be done to tide over the interval that must elapse before the production of the 17-pr. got into its swing. With this object in view, 100 old 3-in. 20-cwt. A.A. guns were collected, provided with a special 12½ lb. shot, and mounted half in Churchill tanks and half on 17-pr. carriages, the production of which was in advance of that of the guns. The Churchill mounting was handicapped by its small internal traverse - only 7 degrees - and the guns so mounted were allotted for home defence only. Of the remaining 50 on 17-pr. carriages, 25 were allotted to the Middle East and 25 to Home Forces.

Bidwell Firepower (1982). Page 231.

As it happens there was an alternative solution. The arrival in service of the 3.7-inch heavy anti-aircraft amde the 3-inch 30-cwt medium anti-aircraft gun, with its excellent anti-tank potential, redundant. A conversion was put in hand, in England, the plan being to fit fifty 3-inch pieces on Churchill tank chassis to provide a self-propelled model, and fifty on field carriages. Unfortunately progress was so slow that it was overtaken by the production of the 17-pounders and the project was abandoned*. It would have been better to have shipped as many unmodified guns as possible on their wheeled anti-aircraft mountings out to Egypt. They would have been no more vulnerable than the unmodified German 'eighty-eights', or the British 2-pounders, which were habitually fired over the tail-boards of their 'portee' trucks.

* there is a note here that references Pemberton, page 127, as above.

Forty The British Army handbook 1939-1945 (1998). Page 215.

Ordnance QF 17 pdr The need for a really effective a tk gun was appreciated early in the war (1941), and 3 in was the chosen calibre. The resulting weapon - the Ordnance QF 17 pdr - was designed and produced in double quick time, the first deliveries being made in August 1942. These were 100 'guns only' as the carriages had not been completed in time, so they were mounted on 25 pdr carriages, this ad hoc gun and mount being known as the 17 pdr Mk 2. Once the complete gun was issued (Mk 1) the Mk 2 was phased out. Soon there were more carriages than guns, so some old 3 in AA guns were mounted for UK use. The 17 pdr was a very effective a tk gun, which could penetrate 130mm of armour plate at 1,000 yd. while its HE sell was also very useful.

Jon: this looks like a para-phrase of Emrys quotes from C&G above.

So, it looks like the Kiwi gunners got creative with the nomenclature, which isn't the first time I've seen that happen.

Anyway, the timeline as I see it:

Aug 1942: first 100 17-pr guns ready, but no carriages available yet. Guns flown out to Egypt and mounted on 25-pr carriages. (numerous sources)

Late 1942: Production of 17-pr guns takes a dip as mass production gets under way. Meanwhile production of carriages also gets under way. (Jons speculation)

Feb 1943: First issue of 17/25-pr Pheasants to frontline forces. (2nd NZ Div Arty)

Late 1942 - Early 1943: Production of 17-pr carriages surpasses that of 17-pr guns, leading to a surplus of the former (Jons speculation). Only the 100 17/25-pr are yet available at the frontline (probable, based on delivery of 17/25-prs). Someone decides to divert 100 3-in 20-cwt AA to A-Tk use (numerous sources, date Jons speculation). Gun will be mounted on these surplus 17-pr carriages (numerous sources).

Early - Mid 1943: Production of 17-pr guns and carriages is getting to the point where supply is about meeting demand (Jons speculation). As such, there is no longer a need for the 3-in/17pr conversion, which is only now nearly ready (Date speculation, based on several sources). Development continues, but on a reduced effort and for Home Forces only (several sources). Some guns may have made it to Tunisia (several sources).

Regards

JonS

P.S. 100 guns (ie, the early 17 prs) is roughly enough to equip 2 - 4 divisions, perhaps more, depending on the ratio of heavier guns to 6-prs. The 25 3-in/17pr sent out to Egypt (if they really were) would have been enough for 1 - 2 divisions. The effective frontline strength of 8th Army between mid-Nov 1942 (after ElAl2) and the end in North Africa in mid-May 1943 was never much higher than about 4 divisions. The main limiting factor being hyper-extended supply lines. There was also 1st Army (2-6 British divs?) in NW Africa to consider of course, and I don't know what arrangements were made for them, or whether they shared the available 17/25-prs and the 3-in/17-prs with 8th Army. Does anyone know if, having just come from England, they had their allotment in 'proper' 17-prs?

[ October 11, 2004, 05:24 PM: Message edited by: JonS ]

[Michael Emrys]

I have this notion (which may or not be valid; take it or leave it) that the 17/25 guns in Tunisia were not divisioned, but were held at the army level or higher and sent where they were thought needed.

Otherwise, Jon, I can't at the moment improve on what you have written.

Michael

[dieseltaylor]

Grogdom excelling itself!!!

Well done.

[Guest Mike]

I did read somewhere that a battery of 3.7's were allocated to the AT role, but they were promptly deployed in a Wadi somewhere that was already full of troops and was never attacked.

[Michael Emrys]

Originally posted by Mike:

I did read somewhere that a battery of 3.7's were allocated to the AT role, but they were promptly deployed in a Wadi somewhere that was already full of troops and was never attacked.

That sounds like what Koenig was referring to in his post above. The relevant passage is:

Anyway the 3.7" was given a chance to operate in a pure AT role during Operation Aberdeen, in June 1942.

The CO of 2nd R.H.A. was given an unasked troop of four 3.7" to bolster his AT defence.

As the position was already crowded with guns, he accepted only two of them and sent the rest back.

He was infuriated when he saw them uncamouflaged and surrounded with tables and chairs! It was clear that the crews had no proper training.

Anyway the position was not attacked by tanks, and it seems that it was the first and last attempt to use the 3.7" in this role (the 3.7" of Tobruk had previously fired at tanks, but from their AA positions).

Michael