British Rail DP1
 | |
| Type and origin | |
|---|---|
| Power type | Diesel-electric |
| Builder | English Electric at Dick, Kerr Works, Preston |
| Serial number | EE: 2003 |
| Classification | Co'Co' |
| Build date | 1955 |
| Specifications | |
| Gauge | 4 ft 8 1â„2 in (1,435 mm) |
| Wheel diameter | 3 ft 7 in (1.09 m) |
| Weight | 106 long tons (108 t) |
| Prime mover | Napier Deltic D18-25 (2 off) |
| Traction motors | EE 526/A, 6 off |
| Performance figures | |
| Top speed | 90 mph (140 km/h) 106 mph (171 km/h) from 1956 |
| Power output | 3,300 hp (2,500 kW) |
| Tractive effort | 90 mph gearing: 60,000 lbf (266.89 kN) 106 mph gearing: 52,500 lbf (233.53 kN) |
| Career | |
| Operator | British Railways |
| Retired | March 1961 |
| Disposition | To Science Museum, London, April 1963 |
British Rail DP1
The prototype Deltic was a demonstrator locomotive built by English Electric in 1955. This locomotive resulted in 22 similar locomotives being ordered by British Railways, which became their Class 55.
Background and design
The English Electric company, which had absorbed the engine-maker Napier & Son into its group at the instruction of the Ministry of Aircraft Production in 1942, was a major builder of diesel and electric locomotives. The two George Nelsons (Sir George, and his son, known in the works as "Half") saw the potential of Napier's Deltic engine for rail traction and in 1954–1955 built a demonstrator at its Dick, Kerr works in Preston. Officially numbered DP1, its internal project title was Enterprise, and it was intended that the locomotive would carry that name. However, in 1954, before completion, Hudswell Clarke announced a range of small diesel-mechanical locomotives using the same name. After initial trials in 1955, the locomotive received the DELTIC in large cream letters on its sides, and the name became synonymous with the locomotive.
Long aluminium beadings on the sides were painted cream, a visual device to make the locomotive's high sides appear more slender and add to the impression of speed. Three curved chevrons on each nose, in the same cream, added to that effect. To British eyes, the locomotive's bulldog nose styling was reminiscent of American locomotives, such as the EMD E-unit or ALCO PA designs (partly because English Electric initially planned to offer the type for export), with high noses and small, somewhat swept-back cab windows set behind them. To add to the American look of the locomotive, a large headlight was to have been fitted to each nose (the lights were never installed but would have been of the rotating 'Mars Light' type as fitted to North American locomotives of the era). Two 18-cylinder Deltic engines were fitted, derated from the 1,750 horsepower (1.3 MW) of the marine engines in minesweepers to 1,650 horsepower (1.2 MW) each, generating 3,300 horsepower (2.5 MW) total. This derating reduced the stress on the engines, thereby increasing the service life and length of time between overhauls.
Construction
The English Electric company, which had absorbed the engine-maker Napier & Son into its vast empire at the instruction of the Ministry of Aircraft Production in 1942, was (among many interests) a major builder of diesel and electric locomotives. The two George Nelsons (Sir George, and his son, known in the works as "Half") saw the potential of Napier's Deltic engine for rail traction and in 1954-1955 built a demonstrator at its Dick, Kerr works in Preston. Officially numbered DP1 (Diesel Prototype number 1, although this was never borne on the locomotive), it carried the word DELTIC in large cream letters on its powder-blue sides. Plans to name the locomotive "Enterprise" never came to fruition and it was to be known to all just as "Deltic".
Long aluminium beadings on the sides were painted cream, a visual device to make the locomotive's high sides appear more slender and speedier; three curved chevrons in the same cream on the noses gave it the impression of speed. The locomotive's styling was reminiscent of American locomotives (partly because English Electric initially planned to offer the type for export) with high noses and small, somewhat swept-back cab windows set back behind them; to add to the American look of the locomotive to British eyes, a large headlight was to be fitted to each nose (these lights were never installed but would have been of the rotating 'Mars light' type as fitted to North American locomotives of the era). Two 18-cylinder Deltic engines were fitted, derated from the 1,750 horsepower (1.3 MW) of the marine engines in minesweepers to 1,650 horsepower (1.2 MW) each, 3,300 horsepower (2.5 MW) total. This derating reduced the stress on the engines, thereby increasing the service life and length of time between overhauls.
Service with British Railways
The locomotive first saw service on the London Midland Region of British Railways but the intention soon became to electrify the major routes on that Region. It also underwent extensive testing on the Settle - Carlisle route in 1956 with test trains, two mobile testing units and a dynamometer car, and the results of this are contained in British Transport Commission Test Bulletin No.19. On the Eastern Region, however, no diesel replacement of conventional design seemed to be available for Gresley's swift and powerful Pacifics, particularly the A4. Only the Deltic appeared to offer the power and speed required within the constraints of a sensible 20-ton axle load, and it was soon running on that Region.
Preservation
DP1 was in service until 24 November 1960 when a severe oil leak in one of the engines was discovered. The locomotive was sent to English Electric Company's Works at Newton-le-Willows, Lancashire the next day for repair. However no repairs were sanctioned and the locomotive was withdrawn from service in March 1961 having completed 450,000 miles (720,000 kilometres). Plans to test it in Canada fell through, and the locomotive was donated in April 1963 to the Science Museum, South Kensington and placed on public display.
After 30 years at the Science Museum, it was transferred to the National Railway Museum, York in October 1993. About 11 years later it was moved north to the National Railway Museum Shildon, County Durham in July 2004. In August 2012 it was loaned to The Ribble Steam Railway in Preston, Lancashire,] which is barely a mile away from where it was originally built, returning to Shildon in October 2015 where it remains as of May 2020.
Restoring the two Deltic engines installed in DP1 to running condition is not feasible. The engines (Type E158, D18-12) although similar, differ from those used in British Rail Class 55 locomotives (Type E169, D18-25B). Aside from the original issue with the severe oil leak in the phasing gear cover, significant engine components were removed for use as spare parts for the Royal Navy prior to DP1 being donated to the Science Museum as the locomotive was not owned by British Railways.
Models
The erstwhile Kitmaster company produced an unpowered polystyrene injection moulded model kit for 00 gauge. In late 1962, the Kitmaster brand was sold by its parent company (Rosebud Dolls) to Airfix, who did not release model kits of this locomotive. In time, the Airfix tools passed on to Dapol who rediscovered the moulding tools and have since produced the model kit.
- Bachmann released a model in OO gauge in 2008
- LH Loveless released an O gauge model in 2008
