"Deborah" has a triangle marking on both sides, but it's not an indication it was in A Company. In November 1917, Companies had ordinal numbers, not letters. This changed in 1918.
Thorst and I debated this when working on the Guy Martin programme. Our interpretation is that the triangle on "Deborah" is the Greek letter Delta for D Battalion. Unfortunately there is a dearth of photographs of other D Battalion tanks at Cambrai.
-- Edited by Gwyn Evans on Monday 12th of February 2018 09:26:03 PM