Organisation
Overview
The organisation of the British tank Corps changed somewhat as the corps expanded throughout 1917 and 1918.
Company organisation
In 1916 each of the six tank companies had an establishment of 25 tanks, split into four sections of six tanks each with a twenty fifth tank spare.
In early 1917 each Battalions establishment was 36 tanks, three companies of twelve tanks each.
In June 1917 each company was also allocated 2 supply tanks.
In July 1917 each company was allocated two spare tanks.
This remained the battalions establishment until the supply tanks were withdrawn in mid 1918.
Thus each tank battalion would deploy 42 fighting and 6 supply tanks, 48 in total.
Each Tank Brigade would have 132 fighting and 12 supply tanks 144 in total.
These totals were rarely realised, on the first day of Cambria and the first day of Amiens some battalions were missing some of their spare tanks.
In 1918 the two light tank battalion (3rd and 6th) were each allocated 16 tanks per company, 48 in total.
Brigade and Battalion Organisation
Brigade organisation
When the "Tank corps" (heavy branch machine gun corps) was established in 1918 it was decided to expand the four tank companies in France to nine battalions; three battalions would be allocated to each tank brigade. Initially only six battalions were available, two were allocated to each tank brigade with the third battalion in each brigade joining when it finished training. At Cambrai (November 1917) all three brigades deployed three battalions each.
In 1918 fourth and fifth brigades were formed to absorb the extra battalions deploying to France.
Battalions often moved between brigades, especially in 1918. Also, in 1918, battalions were often attached to other brigades for combat operations whilst remaining with their parent brigade for administrative purposes. Lastly the original sources often contradict one another. This can make finding information tricky as the battalions referred to in each brigades records varies as battalions moved around.