All units were delivered new to Stratford on the following dates according to Wickham's
E50415 / E56170 on 8/8/1957
E50416 / E56171 on 29/10/1957
E50417 / E56172 on 29/11/1957
E50418 / E56173 on 16/4/1958
E50419 / E56174 on 25/8/1958
The units worked solely on the ER, mainly on branch lines and local services in East Anglia.
An exhibition was held at Battersea Wharf Goods Depot on the 28th, 29th & 30th June 1957 entitled "Modern Traction Travel Exhibition", to show the public some of the features of the modernisation plan. It featured coaches built by both British Railways and private builders, diesel locos, and the BTC also selected a Wickham set. The exhibition was devoted to show how BR and private manufacturers could do to provide comfortable and well designed passenger vehicles and the Class 109 cars were well praised for their attempts to achieve, ease of cleaning internally, and their improved front end design. The cars were a constructional innovation for British Railways, and to show the interesting features the trailer car was provided in skeleton form, alongside completed DMBS 50415. They can be glimsped in a British Pathe newsreel.
50415/56170 appeared on the Wickford - Southminster branch during the first week in September '57, working with Stratford Derby Lightweights. The services were altered to run hourly on weekdays and two-hourly on Sundays, all connecting with the fast trains from Liverpool Street and Southend instead of the slow trains as previously.
50416/56171 appeared at Southend on the 11th Dec. '57.
By Jan. '58 50415/6/7 with 56170/1/2 were regularly working the Upminster - Romford branch, and had the appropriate destination blinds.
In Dec '58/Jan '59 the Minister of Transport travelled on a set for a tour of the ER's London Area.
One lengthy service the cars operated at least in the Summer 1971 timetable was the 13:04 from Kings Cross to Harwich Town (arrive 16:51). The Saturdays only train (it terminated at Royston on weekdays) made 27 intermediate stops on the 124 ¾ mile journey.
They were surplus soon after introduction, and being a 'non-standard' design allowed BR to sell back two sets in September 1961 (50415/56170 & 50419/56174) at the request of Wickham & Co who had overseas buyers for them, the Trinidad Government Railway. They were exported to Trinidad & Tobago, and they operated for several years. By 1980 at least one car had been grounded and used as a road side cafe! An image taken in 1973 shows a vehicle out of use, painted in a grey livery, another grounded vehicle behind.
Some footage of the Class operating both in the UK and Trinidad can be found in Trinidad's Lost Railways Part 4 on youtube.
In 1967 50416 + 56171 were transferred to departmental stock, leaving just two sets in traffic.
The December 1970 Railway Observer (p415) noted that 50417 was now running with Class 100 DTC 56317, and 56172 was running with Class 100 DMBS 51125.
In April 1971 DMBS 50417 was withdrawn, and normal passenger service ended for the class in October 1971 when 50418/56172 and 56173 were condemned.