"A Fast Howitzer on a Light Chassis" Topic

"Unlike American light tanks, which towards the war reached perfection in their class, light SPGs did not work out. The first successful design, the HMC M8, appeared towards the middle of the war. It did not satisfy the military and work on light SPGs continued. The result of this work was the HMC M37, a good design that appeared far too late. The production run was limited and it only saw battle after the end of WW2…."

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Amicalement
Armand

When your forward elements advance at the speed of an M4 sherman, you only need organic artillery that moves at the speed of an M4 sherman, and for the simplicity of logistics you build your artillery on that chasis.

If you need faster artillery, the M4 HST can pull a 155mm at M4 speeds.

If you're advancing faster than that, you're using the organic mortars of the company and battalion. Those fit in halftracks, set up quicker, and deliver more "bang" for the buck.

If you're advancing faster than THAT, you stop giving patton gas for a week or so to give the rest of the army time to catch up.

BigNickR,

+5 for your last sentence.

Jim

(smile)

Amicalement
Armand

There was one of those in Kelly's Heroes !

The article is entirely focused on light chassis SPGs, which leaves out the core of US Army SPGs of WW2.

Not quite sure how the T19 and other halftrack SPGs fall in with light tank chassis SPGs, but I guess light is light regardless of wheels or tracks?

And as much as the author seems to like the M8 HMC, this was more on the US Army model of an "assault gun" than an SPG. It was primarily a direct-fire weapon to support light tank companies in combat, much along the lines of the British "Close Support" versions of Cruiser and Infantry tanks.

When your forward elements advance at the speed of an M4 sherman, you only need organic artillery that moves at the speed of an M4 sherman, and for the simplicity of logistics you build your artillery on that chasis.

Or the prior model medium tank, which gives you a more useful developmental timeline as your SPG can come into service closer to the time you introduce your next medium. This is why the M7 was based on the M3 "Lee" chassis. Over time it adopted many of the features of the M4, such as the differential housing, but it wasn't until late in the war, with the M7B2, that there was a version that was actually built on a Sherman chassis.

The main reason that US Army light SPGs didn't go very far was that the M7 105mm SPG set a very high standard for the utility to be expected from an SPG. It carried a good sized gun crew, and a decent ammo load, and had very good mobility. About the only criticism that could be leveled at it was that it was about as heavy as a medium tank (being built on a medium tank chassis). But US Army logistics were not over-strained, so M7s were shipped in the required numbers and supported to the required levels. It just cost a bit more than it needed to.

The heavy SPG, the M12 155mm, was a different story. That was never quite satisfactory, being a bit too small to carry a useful ammo load or for the crew to serve the weapon efficiently. It was never built or deployed in large numbers. The M40 which replaced it was far more satisfactory, but alas too late to see widespread use in WW2.

-Mark
(aka: Mk 1)

Many thanks!.

Amicalement
Armand

BigNick for the win!

Actually, when first authorized, the M8 HMC was assigned to the Medium tank battalion HQ to the assault gun company. They were eventually phased out of those units by introduction of the 105 armed Shermans. They were then moved to the Cavalry Squadrons of the armored division.
They were also authorized as the assault gun troop of Cavalry recce squadrons of the independent Cavalry recce groups. And finally they were authorized for the separate light tank battalions. I believe they were also authorized for the early separate medium tank battalions but like the medium tank battalions in the armored divisions the Sherman with the 105 became standard and replaced them.

The M12 Gun Motor Carriage was actually well liked by US forces. By D-day a total of 6 artillery battalions were equipped with the M12. During the breakout the M12 was often one of the only heavy artillery pieces which could support the rapid advance. The M12 was much in demand when American forces came up against the Siegfried Line where they were used in the direct fire role. Only 100 M12 were produced.

Thanks also!.

Amicalement
Armand