Sponsons were built separately from tanks, not necessarily by the company that built the actual tanks.
This framework of wood and wire-netting (chicken wire the Americans call it) was devised as a means to prevent enemy stick grenades from lodging on the roof of the tank.
Historian Dan Snow presents this bite size history of the tank in the First World War, filmed on location at The Tank Museum.
At 6.20am, on 20th November 1917, a surprise attack by the British Army created a major break in the German lines to commence the Battle of Cambrai.
The British Mk I tank was unleashed during the Battle of The Somme in September 1916 – but the Germans were much slower to develop an armoured fighting vehicle of their