Page "Churchill tank" Paragraph 11

This hasty development had not come without cost though, as there had been little in the way of testing and the Churchill was plagued with mechanical faults.

Most apparent was that the Churchill's engine was underpowered and unreliable, and difficult to access for servicing.

Another serious shortcoming was the tank's weak armament, the 2 pounder ( 40 mm ) gun, which was improved by the addition of a 3 inch howitzer in the hull ( the Mk IICS had the howitzer in the turret ) to deliver an HE shell albeit not on a howitzer's usual high trajectory.

These flaws contributed to the tank's poor performance in its first use in combat, the disastrous Dieppe Raid in August, 1942.