Recognition and Equipment information
CLASS 23




The least successful of the English Electric built locomotives was this fleet of 10 'Baby Deltics' ordered under the pilot scheme of the Modernisation Plan, using a single 'Deltic' engine, powering English Electric equipment. The external design was a scaled down version of the EE built Type 4. The number series for the 'Baby Deltic' fleet was D5900-D5909.
After the order was given to English Electric, Vulcan Foundry was awarded the build contract, the first completed loco was ready in early 1959. When the BTC visited the works for a pre-delivery inspection many problems were identified, the most serious was an overweight problem that prevented the machine from being accepted onto BR tracks. By April remedial work had been taken and No. D5903 went to Doncaster Works for inspection. Although accepted by BR weight was still in excess of that required, preventing the machines from working over the desired routes. By the end of 1959 all had been accepted, and allocated to Hornsey for work on King's Cross suburban services. After a short period, power unit problems led to most of the fleet being relegated to local and shunting duties, and by February 1963 over half the fleet had been stored at Stratford.
By July 1963 the entire fleet was taken out of service and taken back to Vulcan Foundry for major rebuilding work. This operation took around a year, with the first 'new' locomotive, No. D5905 emerging in June 1964. By mid 1965 all 10 locos were back in Eastern Region stock, this time allocated to the new Finsbury Park depot. After rebuilding at Vulcan Foundry the fleet emerged with conventional 4-character alpha/numerical train reporting boxes. Once the complete fleet was in traffic their performance was considerably improved, being deployed on King's Cross-Hitchin, Peterborough and Cambridge duties.
Under the 1960s traction rationalisation plan the 'Baby Deltic' fleet, which under numerical classification became Class 23, were deemed as non-standard and identified for early withdrawal. The first locomotive to be withdrawn was No. D5906 in September 1968, with the complete fleet being eliminated by March 1971. One locomotive, No. D5901 was retained for several years by the Research Division at Derby as motive power for their Tribology test train. When built all locomotives were in standard green livery with a grey sole bar. After rebuilding a two tone green scheme was applied with small yellow and later full yellow ends, some locomotives still in service after 1969 received BR blue livery.


This official portrait of No. D5903 shows the 'Baby Deltic' in original condition, with dik train reporting equipment, front communicating door and early BR green livery with a deep grey and salmon pink solebar. The locos Nos. 2 end is on the left. CJM Collection.

Showing the revised front end layout, with central four character headcode box and side tail lights, the same loco No. D5903 is seen at Doncaster Works in mid 1966 after rebuilding at Vulcan Foundry. The locos No. 1 end os nearest the camera. CJM Collection.