The Covenanter originated from a 1938 War Office requirement for a new cruiser tank. By this time, it was recognised that war was increasingly likely, and companies without prior tank-manufacturing experience were encouraged to apply in order to boost AFV production capacity.
One of these firms, the London, Midland, and Scottish Railway Company (LMS), was awarded an initial contract for 100 vehicles on 17 April 1939. Additional orders soon followed, with English Electric and Leyland Motors joining the programme. A total of 1,771 Covenanters (including 80 bridge-layers) were completed by the time that production ended in early 1943.
A mild steel pilot model, built by LMS at Crewe, began tests at the Mechanised Warfare Experimental Establishment in May 1940. Problems soon became apparent. The Besa machine-gun mounted alongside the driver had to be removed as it took up so much space that he could barely get into his seat, besides choking him with its fumes whenever it was fired.
Trials with production vehicles showed even worse faults. Both the oil and engine cooling systems gave constant trouble, with horrendous oil and water temperatures recorded after an hour’s test drive.
The radiators were fitted to the front of the hull on the diver’s left, and linked to the rear-mounted engine by long pipes running along the side of the fighting compartment. These pipes became dangerously hot, and they had to be heavily lagged to prevent the crew burning themselves. (Overheating was so bad that petrol in the side fuel tanks boiled during test drives.)
Strengths: good road speed
Drawbacks: poor engine accessibility, over-sensitive steering, chronic overheating
Yet more problems
Drivers cursed the cranky gear selector mechanism – one struggled for 20 minutes before being able to engage reverse. When the tank was running properly it had a road speed of 48km/h (30mph), but steering was so sensitive that keeping a straight course was almost impossible. Maintenance proved to be equally frustrating, as engine accessibility was appalling. It took an hour just to top up the batteries, and four hours to change them.
The first units to receive the type in early 1941 discovered yet more problems. Instead of having conventional turret hatches, the rear half of the turret roof slid back. In theory this was a good feature, as the large opening made it far easier for the three-man turret crew to escape in an emergency.
However, it was soon found that the retaining catch, which was supposed to hold the roof in the open position, was weak and liable to fail if subjected to sudden jolts, such as hard braking or high-speed cross-country moves. When this happened, the sliding roof slammed shut with enough force to cause several fatalities among unwary crew members.
Despite repeated modifications, the cooling problems were never fully resolved, and the type was so unreliable that virtually all those produced were restricted to training purposes. Only a small number of armoured bridge-layers saw service in north-western Europe in the final year of the war. •