Author: Zoe Tolman, Museum Archivist

Last time we looked at various devices used to clear out obstacles in a much safer way for the Sappers involved. One of these, the Goat, was fitted to the AVRE (Assault Vehicle Royal Engineers) and in fact there were many variants of this particular tank modification. 

The primary motivation for the AVRE was the same Dieppe raid which inspired the previous article’s explosive modifications. Engineers had been greatly obstructed in their work by the heavy rate of machine gun fire on the beaches, and it was decided that those RE units with armoured formations should also have some sort of armoured vehicle to protect both them and their stores. Interestingly, more modern variations of the AVRE went by Armoured Vehicle Royal Engineers instead, after some initial confusion as to the meaning of the acronym.

In 1942, the first AVsRE prototypes were made, based upon the Churchill tank. This was suggested due to its pannier doors on the side which would allow engineers to carry out their work without necessarily leaving the protection of the vehicle, or at least to do so within cover. A fake door on the other side of the opening and aprons on both doors provided further shielding. Later designs considered both the Sherman and the Ram, but the Churchill proved the most suitable foundation. Despite initial designs and modifications already being made, it turned out that Shermans simply weren’t available for the AVRE role and focus turned to the Ram instead. This however had ‘inferior obstacle crossing ability, smaller crew space, lighter armour’ than the Churchill. It was also noted that the side doors had worse placement than on the Churchill and there was generally less available stowage space.

The Churchill AVRE.

Stowage space in the AVRE was increased by removing the partitioning in the hull, as well as the ammunition bins. The turret basket was also removed and the seats suspended from the turret itself instead. New storage compartments were then put in which could stow up to 36 cubic feet of engineer stores – explosive charges, detonators, cordex fuse, primers, and various other equipment depending on the job in hand – and brackets mounted on either side of the tank for different special devices, such as the Goat, to be fitted to.

Focus then turned to arming the AVRE with a standard obstacle clearing device, the petard. To try and speed up development, trials were made at first with the 20lb anti-tank bomb already used with a 29mm spigot mortar. However, the explosive amount within this bomb wasn’t considered strong enough for demolition work - for just a 3ft breach in a 6ft reinforced concrete wall, it took a whole 14 rounds. They therefore decided instead to develop as large a round as possible which could still be safely loaded and fired.

A prototype petard on stand used for firing trials.

They came up with the ‘Flying Dustbin’. This took the form of a light metal war-head 9” diameter by 8.5” long, with a much thicker back plate further reinforced by 6 stiffening ribs, and all then fitted onto a standard 29mm spigot mortar bomb driving tube which contained the fuse and propellant charge. The war-head itself was filled with a mixture of two types of explosives with a total charge weight of 26lb (over 3 times as much as the first bomb), while the whole dustbin weighed in at 40lbs.

Ballistic data for the Flying Dustbin.

The recoil from this however was considered too strong to fit to the turret ring of the Churchill with a fixed spigot, and so a recoiling one was mounted instead. When cocked, the spigot remained in its recoiled position, upon firing it would fly forward into the driving tube of the dustbin and detonate the propellant cartridge, and the force from this would then put it back into position ready for the next round to be loaded. During testing, 9 rounds were sufficient to blow a 12ft wide gap in a 6ft reinforced concrete wall, allowing the Churchill to pass through with ease.

They further designed variants of the petard for different roles. For example, a timed fuse in the dustbin meant the explosives could be used to clear anti-tank minefields; an AVRE firing three rounds of dustbin, moving 50ft between each round, was capable of clearing a path 28ft wide through 90ft of minefield. Also, firing the original spigot mortar bomb filled with 8.5lb of smoke mixture instead could be used to create a large smoke cloud very quickly.

An AVRE being dropped off for repair.

Once the initial testing was over, the Department of Tank Design drew up the designs and passed them over to REME in 79 Armoured Division to carry out the conversions and create the next round of AVRE prototypes in June 1943. The instructions were carried out with a few amendments of their own, notably the retention of the turret basket, which were later approved and adopted into the final design in September. Over 600 AVsRE were produced during the war, including an initial 108 converted by REME in time for the D-Day landings where they proved incredibly successful.

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Information and images taken from E:00.0352 and E:05.0177.04.

Published in The Craftsman, December 2025.