In the Colossus Class: This is one of the 12 ft. diameter back-wheels of an outsize in steam rollers which has been specially built for use at the new reservoir works at Abberton, North Essex as in building up the wall round the reservoir it was found that the ordinary roller's wheels sank into the soft soil. The reservoir engineer designed the roller himself.

From The Sphere 28 Jan 1939.
Date: 28 January 1939