I ordered the Churchill (AVRE) forward to demolish the house with the petard...The petard fired and something like a small flying dustbin hit the house just above the front door. It collapsed like a pack of cards, spilling the defenders with their machine guns, anti-tank weapons and an avalanche of bricks into the courtyard.
Major Peter Selerie, of the Sherwood Rangers Yeomanry with the British 8th Armoured Brigade, describing the impact of a 290mm demolition charge fired from a Churchill (Armoured Vehicle Royal Engineers) at a German defensive position in a house near Gold Beach during the D Day landings.
A Churchill AVRE with a 290mm Petard (source)
The 290mm Petard was a spigot mortar based weapon, of the same family as the Blacker Bombard and the PIAT, designed by Major Millis Jeffris at MD.1. It used a powerful spring to launch its mortar bombs up to 100 yards. It was intended for use against fixed positions and bunkers.
Sources:
D-Day: Gold, Juno and Sword: The First 24 Hours, W. Fowler (2014)
Winston Churchill's Toyshop, S. MacRae (2010)