The Skink in Canadian Service

One of the more curious offshoots of the US M4 Sherman family of tanks is the Canadian designed and built Skink, a four-gun dedicated antiaircraft variant that never got into full production. While all histories of the Sherman mention it, it is usually just as a footnote and little more is said about it.

Now Roger Lucy, who has thus far found some of the more fascinating subjects in this nice range of books from Service Publications of Canada, delves into its history and background.

When the British Army found it did not have anything to counter low-level attacking aircraft, they began a search for an effective self-propelled weapons system to keep up with their armoured columns. A 6 x 4 truck armed with multiple 20mm weapons was proposed, but the only two that got into service were the lackluster Crusader AA Mk. I with a single 40mm Bofors gun and the Crusader AA Mk. II with twin 20mm Oerlikon weapons. While the British wrestled with their shortcomings, the Canadians, who had decided on equipping their combat formations with the Grizzly or US M4A1 Sherman tank, did not want to have to maintain oddities in their formations but instead have a common chassis. The Sexton self-propelled 25-pdr used the compatible M3/Ram derived chassis, so using a Sherman chassis seemed most logical.

The Canadians pressed on and developed a new turret mounting four 20mm guns – while the Canadians wanted to use a Canadian designed weapon, the British wanted the 20mm Polsten lightweight Oerlikon-derived gun; but as it was not ready, the prototypes used 20mm Hispano-Suiza guns made in the US. A welded turret was developed for testing, and the four guns and their feed mechanisms were mounted in it during testing in November 1943.

In the meantime, due to futzing around the Canadians decided to drop production of the Grizzly but due to commonality of components simply manufacture drop-in turret sets that would fit any of the first five models of Sherman – I-V or M4, M4A1, M4A2, M4A3 or M4A4.

Once the welded turret had been sorted out, a cast turret was developed. But this immediately needed redesign due to the switch in early 1944 to the Polsten gun from the US made Hispanos. Nevertheless, most of the changes were kept to a minimum and the changeover was very easy to make. This gave the Canadians the option of using the proven Hispano if the Polsten came a cropper.

But by this time it was now late July 1944, and Field Marshal Montgomery had decided the Commonwealth forces did not need a dedicated AA tank. To add insult to injury, he then unilaterally decreed that the Hispano was not to be used in Europe by any Commonwealth forces.

The orders for Skinks had gone from 275 machines to 130 turrets to zero. Unfazed, the Canadians sent Skink Production Model No. 1 to Europe for trials, where it served in combat with no less than six different Canadian armoured regiments, all of whom liked it and appreciated its ability to subdue enemy resistance when used in a ground support role.

When the dust settled, only eight Skink turrets were made, and all but two have gone missing since the end of the war and the Skink program. While the US was interested in this fearsome AA weapon, they made do with the M16 quad .50 caliber and M19 twin 40mm weapons at the end of the war and in Korea, using them again in a ground support role.

The concept was revived by the Soviets as the ZSU-23-4 "Shilka" some 20 years later, and they proved themselves in Afghanistan the same way as the Skink did – ground support against dug-in enemy infantry.

Thanks to Clive Law of Service Publications for the review copy.