The Matilda with Carrot was produced by fitting an explosive charge on a frame mounted in front of the tank, and was designed to clear obstacles and minefields.
The Matilda with AMRA Mk Ia was a mine-detection device. Four broad heavy rollers were mounted on the AMRA frame, which was then attached to the sides of the tank. The rollers would set off mines as they ran over them, thus revealing the presence of the minefield.
The rollers would normally be damaged in the initial explosion, and so the Matilda with AMRA couldn't be used to clear a minefield. One of the weapons developed in an attempt to solve that problem was the 'Carrot', a high explosive device that was intended to set of the mines through sympathetic detonation.
The 'Carrot' came in three sizes. The two larger ones, a 75lb shaped charge and a 600lb charge, were mounted on the front of an AMRA roller, which was pushed along by an A12 Matilda. The roller would be pushed into the middle of the minefield, or up against another obstacle, and would be automatically detached from the tank. The tank would reverse out of the danger and the charge would be remotely detonated.
The smallest, a 25lb charge, didn’t need the complex rollers. Instead it was carried on the nose of a tank, pushed up against an obstacle, and detonated where it was, as it was too small to damage the thick front armour of the Matilda.
Forty AMRA sets were allocated to the Carrot test programme.