The first two vehicles (79960/1) were delivered to Stratford via Parkeston Quay on the 31st March 1958. During the week of 4th April they were trialed on the Witham - Maldon and the Braintree branches, and 79961 was at Liverpool Street on 8/4/58 for inspection. While originally it was the intention to base the vehicles at Stratford, when the other vehicles arrived it was decided to place them at Cambridge, to reduce unnecessary empty workings. E79960/1 went there on the 19th April, and were joined by E79962-4, coming direct from Harwich of the ferry from Zeebrugge. At the end of April one car was to be found at Stratford. Crew training commenced in the week of 20th May.

A lack of crews meant the full use of the railbuses could not be made at the start of the summer '58 timetable. They started operations from the 7th July working the branches to Maldon, Braintree, Saffron Walden and Mildenhall.

Their introduction did nothing to please the locals. Previously the services on the Audley End - Saffron Walden - Bartlow branch had been operated by two locos and two sets of coaches. The revised timetable only saw one 'bus being used on the branch, meaning a reduction in workings. The loss of one of the early morning trips, meant that schoolchildren had to get up earlier to catch an earlier service, and the loss of a connection with the 16:36 from Liverpool St. did not suit city workers who now had to spend much longer at Audley End. There were complaints about the riding qualities of the vehicles, when compared to the previous stock, and the locals had been used to bringing prams, bicycles and heavy luggage, where there was now limited space.

Apparently the local staff could organise extra off-peak services if there was the demand. On the Saffron Walden branch parcels traffic were now conveyed by road to and from Audley End, but other freight traffic, which had been previously been integrated with the passenger services, was worked by 204hp shunter D2010.

The railbuses operated a four day cyclic diagram, which left one as spare at Cambridge. This was:

Day one - 06:22 Cambridge - Mildenhall; 07:36 Mildenhall - Chappel via Haverhill and Colne Valley line; empty to Witham via Marks Tey; Braintree branch services, stabled at Braintree overnight.

Day two - Braintree - Witham services until relieved by the succeeding railbus on arrival at Witham; Maldon branch service, stabling at Maldon East overnight.

Day three - Maldon branch service until noon; light to Marks Tey; 13:22 Cambridge via Halstead and Colne Valley Line; 16:27 Cambridge to Mildenhall; 17:46 Mildenhall - Newmarket; 18:35 Newmarket - Mildenhall; 19:21 Mildenhall - Cambridge; light to Audley End and exchange with branch railbus; evening turns to Saffron Walden where stabled overnight.

Day four - Saffron Walden branch services until relieved by railbus on day 3 diagram; light to Cambridge.

After 24 hours for maintenance, the vehicle started the cycle again.

While the trips on the Colne Valley were made primarily to get the railbus to Marks Tey and Witham, the diagrams were not always strictly observed. Sometimes the 06:22 from Cambridge was steam operated, and the railbus went out on the 06:35 Cambridge - Haverhill - Marks Tey, arriving at 08:10 and leaving empty at 08:16 to Halstead to form the 08:39 to Marks Tey, then going empty to Witham. When part of the Colne Valley line was closed and lifted, the morning train to Mildenhall changed to a 2-car unit, and the railbus worked the 06:33 Cambridge to Marks Tey via the Stour Valley line. The former 13:22 return became the 12:56 to Cambridge, also via the Stour Valley. The occasional journey along the Stour Valley caused confusion amongst regular travellers who thought the Stour Valley train was actually their Colne Valley train. The Colne Valley trains left Haverhill a few minutes after the Stour Valley trains - and got to Chappel before them. With the demise of the Mildenhall branch services, the railbus on the day 3 diagram remained at Cambridge until due to run empty to Audley End.

On the Witham - Braintree and Witham - Maldon E. lines the increase in traffic had immediately proved too much for the railbus, and steam traction was booked to cover the period of heavy traffic until Cravens twins were available at the end of summer '58. But in the event the 2-car arrived before reversion to steam.

The cars were subject to a number of failures when introduced, and barely a week after introduction, on the 14th July, E79662 failed on the Saffron Walden branch with gearbox trouble, something that had plagued the vehicle since it had moved to the branch. Another failure took away the only spare car, and so D2010 had to be used with two coaches for nearly two weeks until the 26th July. The arrival of the Cravens sets for the Maldon and Braintree branches freed a railbus for Saffron Walden. For many years after two coaches remained at Saffron Walden in case of an emergency. One driver on the Maldon branch was so impressed with the transformation of working conditions, that he turned up for work in his best suit. This was fine till the vehicle failed and he had to finish his shift driving a J15! The vehicle on the Mildenhall branch failed on Thu 28th Aug. '58. On the 7th January '59 a vehicle was derailed at Witham.

The Audley End - Bartlow 'bus failed at 17:00 on the 9th November '59, and road buses had to deputise till 19:00.

It wasn't unknown for passengers to have to push start the railbuses on the Maldon branch in the winter because the battery was flat. Being of limited capacity, if the railbus had been left outside on a cold night the battery couldn't start the engine.

June '58, and a railbus is seen leaving Long Melford for Cambridge. David Underwood

Vehicles saw some further trials on the Haltwhistle to Alston branch (ER) and for a period they operated services on the Millers Dale - Buxton line.