The RE units in the 2nd London Div were the 3rd London and 4th London Field Coys and the the 2nd London Signal Coy. All three units were from Chelsea, in June 1915 the 2/3rd London Field Coy joined the division. Originally formed in Oct 1914 as part of the 2/2nd London Divsion. Sometime in 1915 the signal Coy became the 47th (2nd London) Sig Coy and in Feb 1917 the Fld Coys were numbered and became the 517th (3rd London), 518th (4th London) and 520th (2/3rd London) Fld Coys.