GWR 61XX 2-6-2T No 6100 near Mortimer with a Basingstoke to Reading local on July 28, 1956.

Peter kerslake says "The pioneer of Mr. Collett's "6100" class in the shape of 6100 itself is recorded here doing what it was designed for, working a secondary passenger duty when allocated to Reading in 1956, that depot housing fourteen of the class at that time with Old Oak having 15 and Slough the most with 16 on its books.
Designed to improve secondary passenger services in and around the Capital 6100 emerged from Swindon in 1931, construction continuing until 1935 when seventy had been built, the class lasting intact until 1958 when 6100 seen here was the first casualty, the last nine remaining until 1965.
Happily 6106, built in 1931 survives today at Didcot Rilway Centre".

Photo: A. Weatherill/Rail Archive Stephenson