The two vehicles were listed as new to the ER in March 1957. Initially no depot was acknowledged, as the vehicles underwent testing before being allocated to 40A (Lincoln) in June '57.
Testing was on the LMR, with runs between Manchester Victoria and Rochdale, including the 1 in 27 Werneth incline. The two cars, which weighed 83 tons tare were loaded with 11 tons of brake blocks to simulate a complement of 200 passengers. The train was stopped on the incline and restarted without slipping, reaching a balancing speed of 14mph. Another series of trials were done between Carlisle and Skipton, without the load of brake blocks, but on several trips a tail load of 57 tons was attached and on one trip a dynometer car was added as well. With the tail load of 57 tons the unit was repeatedly started from rest without slipping on the 1 in 100 gradients and reached a balancing speed of 31mph. After these tests the unit was sent to Derby for bogie modifications.
At the end of 1956 the B.I.F. organisers requested that a 63'6" unit be exhibited at the 1957 fair. Derby would be building the suburban sets for the Westerm Region (Class 116s) at the time, these were considered unsuitable for exhibition. Instead thoughts turned to the Rolls Royce engined set 50000/56000, to which the ER agreed. However with just weeks to go the organisers then decided that on account of site difficulties displaying a unit in the exhibition would not be practicable, and the vehicles were exhibited at a Rolls Royce Exhibition from 6th to 11th May 1957 instead.
After this exhibition further modifications were done to the Rolls Royce equipment with delivery to Lincoln expected during the week ending 8th June 1957. It then worked from Lincoln with the rest of the Class 114 sets.
A survey in 1965 looking at DMU allocations and operations showed 50000/56000 along with 50001-13/24-7/9-49 and trailers 56001-11/3/6/24-49 being allocated to 40A (Lincoln). The depot's sets worked the following services:
Considered non-standard, they were withdrawn in October 1967. For some years they languished around Lincoln. What happened to them in that period? Jon Stubley recalls seeing them operating through Heckington over the Whitsun Bank Holiday weekend of 1968. He distinctly remembers them on three dates - 29th 30th May and 4th June 1968 - standing out from the 114s because they didn't change gear when accelerating away from the station. Did they get pressed back into service to increase accomodation for the holiday weekend? It is unlikely they would be cannibalised for parts, being non-standard. He also added: "One anomaly I do have is that on the 21st May 1968, I have noted E50000 paired with E56047. Now I did not think it was possible to run an hydraulic transmission power car from the controls of any other trailer car than E56000, but it must have been unless the unit ran a very strange circular diagram which managed to get it back to Lincoln without reversal."
They moved to Stratford Works around June 1970. They were noted there on the 16th, still in lined green but in poor external condition with several windows missing. 50000 was receiving attention underneath at the time, probably removal of useful parts. It was outside the Works by the 20th. Next reported sighting was at Trowse sometime in 1972, before they went for disposal at A.King, Norwich in October 1972. The picture below is believed to be 56000 / 50000 awaiting disposal, taken by Tony Wilkins.