They were designed by Alfred John Hill of the Great Eastern Railway and introduced in 1915.

They were, as London suburban locomotives, fitted with Westinghouse air brakes.

The first 22 were allocated numbers in the 990–1011 range when ordered by the GER, but the last 10 did not emerge until the grouping.

69621) has been preserved and is currently on static display pending overhaul at the East Anglian Railway Museum at Chappel & Wakes Colne.

It was the last engine built by the Great Eastern Railway's Stratford Works[5] in 1924 and was preserved in 1962.