Delivery of 0/400 variant began in early 1918, and of the 549 built, over 400 had been delivered to the newly formed Royal Air Force before the November 1918 Armistice, serving with seven
squadrons as the standard British heavy bomber. On the night of 14-15 September 1918, forty 0/400s attacked targets in the Saar region of Germany.
It could carry the 748kg (1,650lb) bomb, the heaviest used by British services during the First World War.