In Feb '59 the BTC ordered the power equipment for the first fifteen sets with British United Traction.
A 4-car set was on display at Marylebone Goods Depot in April '60, at an exhibition of British Railways locomotive, passenger & goods vehicles, and containers. It was for delegates attending the Institute of Transport Congress and for the press.
A rolling stock exhibition was held at the Marylebone parcels depot on May 13th & 14th '61, arranged by the BTC as part of the Golden Jubilee celebrations of the Institute of Locomotive Engineers, which included Class 115 power cars. Pictures of this exhibition appeared in the 19/5/61 issue of Railway Gazette.
In June '61 questions were raised in Parliament about the cost of the Marylebone - High Wycombe - Princes Risborough scheme (including alterations to stations, buildings and tracks, new trains and oil installations). The MP was concerned about the high expenditure for such a small scheme.
The Class worked services on the Chiltern Line out of Marylebone to Aylesbury, High Wycombe and Princes Risborough.
On 12/6/61 the number of DMUs on the Marylebone to High Wycombe and Aylesbury line were increased. First class facilities were re-introduced on the new trains.
Six sets were allocated to the Liverpool area for the CLC route to Manchester for a few years, before joining the rest of the Class at Marylebone.
Soon after the sets started on this line they received some criticism in the letter pages of a magazine. A reader who was already unhappy with DMUs where passengers must sit facing the wrong direction - he was fuming that all the worst features of compartment stock were now combined with the disadvantages of open carriages. They had large windows, but the seat were placed so no passengers obtained any advantage from them. The doors in every section were felt unnecessary for the express service. Lack of gangways and access between saloons (except one coach in four), and lack of toilets for 2nd class smoking passengers were also grumbles.
Bob Wells notes "Re. the Class 115 units used between Manchester & Liverpool on the Cheshire Lines. When first introduced these units ran in pairs of 8 cars working the hourly express service between the two cities calling at Widnes North & Warrington Central.; There was a problem however, at Warrington Central where the platforms could only accomodate 6 cars. This meant that once passengers had alighted from the 6 cars in the platform, the train was signalled by the guard to move forward to allow access to the rear coaches. I could never understand why passengers for Warrington were not advised of the problem and sit in the front portion of the train."
Ian Fleming has recollections of an interesting Allerton Class 115 turn c1970, on a Sunday working from Liverpool to Hull via Manchester and Sheffield (suburban sets were very rare in Hull!). It was always 6 cars, sometimes 3x 108s, but usually just 1x 108 and a 115.
Eric Stuart notes: "After the run-down of the GC and the Nottingham semis being the only main line trains left, steam was ousted from the London end. The cheap-ee option was taken and the 07.20(ish) Marylebone - Nottingham and balancing return were worked by a 115. One would have had to be carefull which car one got in if there was a danger of getting caught short on the long journey!!!"
In the early 1980s, and until they left Allerton depot, they had a summer Saturday only turn taking one set from Liverpool Lime St. to Llandudno direct via the freight only line between Halton Junction and Frodsham Junction.
It wasn't until 1987 that any major transfers were made. During a reshuffle of the LMR DMU fleet, Tyseley gained 22 power cars, and a number of trailers, to enable a fleet of 4-car sets to formed for the Cross City line.
About '87 some DMBSs were formed into hybrids with a Class 108 DTC. It involved fitting them with gangways.
Eric Stuart adds: "These later came to the Met and GC and we called them GTs! They worked as short trains or in 4/6/8-car rakes. Also, latterly, some 115s were mixed with 116s and, in one case, a 108/104/115 set was run for some months. The CLC sets also worked to and from Guide Bridge via the line (Manchester South District?)to connect with the eelctric line to Sheffield. This was included in the original electrification plans and some masts were erected, but it didn't happen and locos were changed at Guide Bridge on through trains or, latterly, DMU shuttles connected!"
A former underground driver noted: "One 5th Nov, the leaves had fallen and the rails were very damp. The 16:10 ex-Marylebone (a 4-car 115) arrived at Chalfont at about 5 mph and well over 30 minutes late.; It failed to leave the platform and was there 30+ mins later when the following 4-car arrived. The two finally managed to struggle off amid a cloud of smoke. I understand they then expired near Gt Missenden and an 8-car buffered up behind, the 16-car ensemble finally reaching Aylesbury. A lot of kids were going home on the 16:10 and their parents were going between Amersham and Gt Missenden, trying to find them! Added to the other mega-delays, Bonfire Night parties were upset! (There is an element of black humour there, though probably not at the time!). There was a Class 25 at Aylesbury for weekend track work and the spare crew were sent with it urgently to Rickmansworth. Subsequent trains were banked from Ricky to Amersham. The sight of a 8-car 115 roaring away with all powered wheels spinning uselessly, with the 25 giving it full power and full sand, with sheets of sparks coming from its wheels and a cloud of exhaust going up, is one of the most spectacular (safe!) railway incidents one could see."
The Marylebone sets, which were later transferred to Bletchley but remained on Chiltern Line duties, were declared surplus after the introduction of Class 165s, from '91 onwards. While at Bletchley depot the class was also used on the Barking to Gospel Oak line, units being formed as power twins. They were in turn replaced on this line by Class 117 power twins.
The final Class 115 working out of Marylebone was in July '92. The Tyseley sets survived a bit longer until Feb '94.