 John Buckley, using a case study of the British 8th and 29th Armoured Brigades, found that of their 166 Shermans knocked out in combat during the Normandy campaign, 94 (56.6 percent) burned out.Buckley also notes that an American survey carried out concluded that 65% of tanks burned out after being penetrated.United States Army research proved that the major reason for this was the stowage of main gun ammunition in the vulnerable sponsons above the tracks.