3.7" aa

[David Dunlop]

Interesting thread, Thanks.

After reading it and some other items on the internet, it seems the 3.7" worked it's way into an effective anti-tank roll as WW2 progressed and the allies gained air superiority. Several articles indicated quite significant quantities of AP and SAP 3.7" ammunition were produced and the one photo from Valcartier looks very much like the loader is holding a sabot AP round. The 3.7" was undoubtedly a brute to move around, particularly the later marks built on the sleeved down naval 4.5" gun. The tapered rifle grooves and addition of the shoulder guide band on the shell apparently gave the later mark 3.7 incredible accuracy as a ground support and anti tank gun and at an effective range far better than the 6, 17 and 25 pounders were capable of achieving. Must have been a real eye opener for the first German tank crews to encounter one!

[REL]

Originally Posted by David Dunlop

Interesting thread, Thanks.

After reading it and some other items on the internet, it seems the 3.7" worked it's way into an effective anti-tank roll as WW2 progressed and the allies gained air superiority. Several articles indicated quite significant quantities of AP and SAP 3.7" ammunition were produced and the one photo from Valcartier looks very much like the loader is holding a sabot AP round. The 3.7" was undoubtedly a brute to move around, particularly the later marks built on the sleeved down naval 4.5" gun. The tapered rifle grooves and addition of the shoulder guide band on the shell apparently gave the later mark 3.7 incredible accuracy as a ground support and anti tank gun and at an effective range far better than the 6, 17 and 25 pounders were capable of achieving. Must have been a real eye opener for the first German tank crews to encounter one!

There's very little evidence of them being used in the anti-tank role, though from the photos in the other thread, they were used as field artillery more often by 1944/45. Presumably because the 17pdr. was available by then for anti-tank work, and perhaps because the change from AA fire to indirect fire probably did not require the gun to be brought into the forward combat area to extent that AT work would have. Still from what I've read of the campaigns in 1944-45 there was no surplus of AT guns on the Allied side, and 3.7s would have done a nice job against the Tigers at very long ranges.

Just another lost opportunity due to hide-bound thinking and negligence.

They do seem to have been remarkably accurate, like the German Flak 36.

More info here: http://www.mapleleafup.org/forums/sh...t=12815&page=2

[David Dunlop]

My father-in-law had trained at Shilo MB for Pacific Force, but when the war ended, instead of being De-mobbed, they upped his points requirement and sent him to RCAF Station MacDonald, which by then had been turned into a War Assets Storage and Disposal site. Train loads of equipment arrived every week and they used FWD Tractors to haul items from the nearby rail siding to the base. He commented it all seemed to arrive in organized batches and for a while it was nothing but light and heavy artillery. Boxed Polsten, Orlikon and Bofors guns had to be stored in the hangers, but the trailer ready units were all lined up outside. There were quite a lot of 40mm Bofors, 17 and 25 pounders and dozens of 3.7" AA pieces. Quite a bit of the smaller stuff was later returned to longterm military storage somewhere else in Canada, but every one of the 3.7" guns were sold to a Selkirk, Manitoba Steel Mill for scrap and they always went with a military escort to the mill to ensure they were properly disposed of on site. Though he did admit that by the end, the escort typically went off for lunch etc. in Selkirk and left the mill to their own tasks. A lot of Mk ! Carriers ended up there days at the mill as well.

[Doug Knight]

David

I am not sure if any are in Museums in Canada - there is none at the Canadian War Museum, but there may be one in Shilo, Manitoba.

We produced the 3.7-inch gun in Canada and by the end of the war, 1,740 C Mk 2 and 1,739 C Mk 3 mountings, and 5,129 loose barrels had been delivered, as well as about 6 million rds of ammo.

The 3.7 on the Ram was tested in January 1943 at Lydstep in the U.K, and the results were completely unsatisfactory. The test officer was Captain, later Lt-Col Willis Roberts, who is still alive in Fredericton NB. The gun and the tank were disassembled and returned to their normal function.

The story of the 3.7-inch AA gun in Canadian Service is the subject of an upcoming publication in the Service Publications Weapons of War series - probably early next year.
Hope I have wheeted your interest.

Regards

Doug

[Roger Lucy]

Pending the publication of Doug's book on the 3.7 inch gun pp 60-72 of my "Secret Weapons of the Canadian Army" (Service Publications, 2006) provides an account of the Ram 3.7 inch AA project. While the SP was deemed unsuitable in an anti-aircraft role, and too vulnerable, due to its high silhouette and lack of protection, for use in a ground role, CMHQ did give some mental consideration to mounting a 17-pounder or 3.7-inch AA gun mounted on the Ram Sexton chassis.
In Ottawa, in April/May, 1943, the Director of Artillery did a paper study of an assault gun using a 3.7 inch gun mounted in a Grizzly chassis, however the British were no it interested. The paper studies argued that compared to the 17-pounder, the 3.7 inch gun would have marginally (5mm) superior armour penetration out to 1,000 yards, and significantly better beyond that range. It could also fire heavier HE rounds.
I have just come across a memo written by Tommy Burns on 3 May,1943 reviewing the experiences of tank warfare in North Africa. He noted that German Mk.IV (specials) and Mk.VI tanks could successfully engage allied tanks out to 2000yards,and while the M3 75mm on the Sherman could deal with German 75and 88mm guns and SPs at those ranges, their tanks were invulnerable. There were three possible tanks under development that could take them on: the A30 Challenger with a 17-pounder, the US T20 with a 76mm gun and the British TOG2 with a 3.7-inch gun. Burns considered the HE round on the 17-pounder inadequate, while the TOG2 was too big and ponderous. Burns suggested that consideration be given to mounting the 3.7 inch gun in the Challenger or interesting the British in a heavy 3.7 inch SP.

[REL]

Where did the Archer 17Pdr. SPG fit into this chain of events?

[ARTY-BOY]

Anti-tank capability
The 3.7-inch (94 mm) gun was never used as an anti-tank weapon, except in one or two emergencies. This is in contrast to the German Army, which integrated their equivalent "88" into anti-tank defensive screens from 1940 onwards, or the American M2/M3 90mm, which also was capable in the anti-tank role from 1942 and onward.
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.
The gun was used as the basis for the Tortoise assault tank's 32-pounder anti-tank gun, but this tank, which is best described as a self-propelled gun, never saw service.