Worcester had been home to many of the former Great Western Railcars since before the Second World War, but this apart the diesels were relatively slow to threaten the domination of the steam locomotive.
First inroads came when Birmingham based suburban diesel multiple units arrived in 1957.
Followed by the Cardiff and Hereford to Birmingham Snow Hill services with Swindon 3-car "cross country" diesel multiple units in 1958.
Bristol (Bath Road) received an allocation of Sulzer "Peak" class diesel locomotives (later class 45) from new in 1961 and these were soon regularly seen at Worcester on inter-regional services to Derby and the north-east of England. They were soon joined by Midland Region based examples of the same class.
However, through all of these changes the London (Paddington) to Worcester and Hereford express passenger trains remained exclusively in the hands of steam locomotives of the former Great Western Railway "Castle" class, allocated to both Worcester and Old Oak Common (London) sheds.
Gerald R.Wadley, founder member of the Worcester Locomotive Society recorded in his many notebooks the coming of the diesels to Worcester.
First to arrive were Sulzer type 3 diesels (later Class 33) from the Southern Region. These arrived in the severe winter of January 1963. The first such example was D6518 (a photograph of which taken by Richard Moreton appears in the March 1963 issue of "Modern Railways" with Saltley's Stanier Black 5 No.44963 at Worcester Foregate Street station on 21st January 1963 on the 10:05 from Hereford to Paddington). This was replaced by others of the same type and trials continued during January and February 1963. For instance, Gerald Wadley records D6536 at Malvern Link on 21st February 1963.
The Sulzer type 3's were evidently not up to the job as the trials of these locomotives ended thereafter. The writing was nevertheless on the wall but when the diesels finally arrived for good it was in the shape of Beyer Peacock "Hymek" type 3 locomotives. 101 of this type of locomotive were built at Gorton, Manchester. The first to arrive at Worcester by my recollection and Gerald Wadley's notebooks was D7076 of Cardiff Canton shed. Gerald first recorded this locomotive at Malvern Link on 13th May 1963. Other of the same class were recorded by Gerald later that same week.
"Hymeks" took over about half of the Paddington express services during the Summer 1963 timetable but still working to steam locomotive schedules. The premier train on the line is "The Cathedrals Express"
Synopsis of the summer 1963 timetable
With much ado British Railways heralded the end of steam working from Worcester to Paddington with a full press turn-out and sparkling "Castle" No.7023 "Penrice Castle" (of Worcester shed) on the last Saturday of operation of the Summer 1963 timetable on the 13:10 to London on 7th September 1963. "Penrice Castle" was immediately retired to store outside the back of Worcester shed and that should have been just about been it for high speed main line steam at Worcester.
However, things did not go to plan, lack of adequate maintenance facilities for diesels at Worcester and Hereford combined with the fierce gradients, heavy trains and sharp timings led to a spate of steam substitutions as diesels failed on a daily basis. The Worcester Locomotive Society house magazine "The Big Four" reported that by 30th October 1963 steam locomotives were called upon to work the service one hundred percent.
By Christmas 1963, the situation had become so desperate that "Penrice Castle" was brought back into traffic (still looking immaculate) but more alarmingly a tranch of seemingly worn out "Castles" were drafted in from far and wide. Decrepit examples were even allocated to Hereford shed, a depot that had never before seen an allocation of "Castles".
Diesels slowly returned to Worcester but by April 1964 they had again virtually disappeared from the London service as the "Hymek's" were sent elsewhere to cover for defective "Western" class diesel locomotives.
The diesels situation had improved by June 1964 such that it was possible to release half of Worcester's "Castles" including some of the best engines, Nos.7011 "Banbury Castle" and No.7023 "Penrice Castle", to the Oxley and Tyseley sheds in the West Midlands.
Worcester favourite No.5054 "Earl of Ducie" was used on a number of railtours in July 1964 but with no scheduled London express duties from the Summer 1964 timetable, there was little work for the four remaining "Castles" at Worcester but they hung on with more mundane duties such as engineering and stopping trains. No.5054 (together with No.7022 "Hereford Castle") was released to Gloucester sheds in September 1964 but No.5054 was promptly withdrawn and dumped at Worcester.
With the end of the Summer timetable the last "Castles" at Worcester (No.7005 "Sir Edward Elgar" and No.7025 "Sudeley Castle") were withdrawn leaving only the small stud at Gloucester and in the West Midlands depots to survive into 1965. A correspondent to "The Railway Observer" noted Nos. 5054, 7005, 7025 and 5000 all dumped on Worcester shed on 6th October 1964.
Worcester's locomotive works continued to repair and overhaul steam locomotives including No.6435 that was restored to G.W.R. livery for a private owner. It is seen awaiting overhaul on 31st December 1964.