Initially General Staff were reluctant to attach anti-mine equipment to tanks in case it impaired their fighting ability. However, the mine problem was severe enough by 1941 that designs such as spiked rollers and flail tanks were brought back into serious consideration. This article will focus on one of the first two iterations of the flail tank - the Baron. Though it is worth noting that many of these experimental designs were worked on at the same time. The final approved design borrowed from many initial trials.

The flail tank was the brainchild of Major Du Toit. He suggested that ‘the flexibility of the chains, combined with a point of strike well ahead of the drum’ would make the device comparatively indestructible by mines. In contrast, the roller devices received the direct force of each explosion. Whilst the Scorpion was trialled in the Middle East in battle, Major Du Toit was flown back to the UK to create and trial a flail tank under the Fighting Vehicle Division of the Ministry of Supply. This tank was soon known as the Baron.

 Side view of a tank with crane at the front and roller device, chains hanging off the roller.

Side view of the Baron MkIIIA.

Both of these tanks were built upon the Matilda II, with a flail rotor attached several feet in front of the vehicle and powered by a separate engine. This was mounted to the side of the tank, with the person controlling the engine also in this separate cabin. The flail rotor comprised of a large metal drum with chains attached at regular intervals and bob-weights attached at the end. As the drum rotates, the chains and weights fly outwards and strike the ground in front of the tank, destroying any mines in its path.

 Front view of a tank with roller device at the front with chains hanging off it.

Front view of the Baron MkIIIA.

Trialling the Baron was complex as there were many factors which affected its efficacy. These included speed and direction of rotation, length of chain, design of chain, chain material, number of chains, configuration of chains, distance from tank and from ground, speed of tank and, of course, terrain. Factors such as reliability and visibility still had to be considered as well.

Direction of rotation was first considered as mines were occasionally thrown back by the flails onto the tank track. However, if the rotor was run in reverse, a greater length of chain was destroyed with each detonation. This was due to the fact that a link higher up the chain would make first contact rather than the end. The earth thrown up by the flails also had a tendency to bury undetonated mines ahead, protecting them from subsequent flailing. Rotation was therefore set so that the flail struck the mines ahead of the roller. During trials on a later Scorpion variant, the throwback problem resurfaced as dummy mines were thrown onto the driver’s visor by the flails. As these would have resulted in fatalities had they been real, wire netting was fixed to the front to prevent further throwbacks.

 Document with typed numerical values in a table chart.

Mine detonating efficiency, albeit of the later Scorpion.

Visibility was an immediately noticeable concern. Dust thrown up from the flails blocked most, if not all, vision from the operator’s periscope. Multiple schemes were devised to keep the periscope clean. These included redirecting the exhausts to blast the dust clear, a small cover with a commercial windscreen wiper, a large scraper on a screen in front of the periscope, and even a piece of canvas placed over the flail similar to a bicycle mudguard. These helped to reduce the issue but none appeared to have solved the problem adequately. For example, redirecting the exhausts was fairly effective, but had the downside of the exhaust getting drawn into the tank. This made life very unpleasant for the crew. The scraper method also had issues, particularly with too much dust. It could require manual use every 2 or 3 minutes in bad conditions.

The Baron went through multiple developments, the main ones revolving around the issues of power and cooling. At first a more powerful auxiliary engine was selected, which was then increased to two engines. The cooling system for these was at one point piggy-backed from the main tank but this was found to be insufficient. Ultimately though, it was too wide for landing craft and suffered from various mechanical defects. Whilst the Baron stayed in use as a training tool for future flail tank crew, developmental focus shifted to the Scorpion in 1943. Our next article will do the same!

Information and images in this article are taken from E:05.0771.01 and E:08.0121.11.

Zoe Tolman, Assistant Archivist. Published in The Craftsman, 1 December 2022.