British Rail Class 20

  • English Electric Type 1
  • British Rail Class 20
20134 & 20075 at Ryecroft Junction, 1978.
Type and origin
Power typeDiesel-electric
BuilderEnglish Electric at Vulcan Foundry and Robert Stephenson and Hawthorns
Build date1957–1962, 1965–1968
Total produced228
Specifications
Configuration:
​
 • UICBo′Bo′
 • CommonwealthBo-Bo
Gauge4 ft 8+1⁄2 in (1,435 mm) standard gauge
Wheel diameter3 ft 7 in (1.092 m)[1]
Minimum curve3.5 chains (70 m)[1]
Wheelbase32 ft 6 in (9.91 m)[1]
Pivot centres24 ft 0 in (7.32 m)[1]
Length46 ft 9+1⁄4 in (14.256 m)[1]
Width8 ft 9 in (2.67 m)[1]
Height12 ft 7+5⁄8 in (3.851 m)[1]
Loco weight73 t (72 long tons; 80 short tons)[1]
Fuel capacity380 imp gal (1,700 L; 460 US gal)[1][nb 1]
Lubricant cap.100 imp gal (450 L; 120 US gal)[1]
Coolant cap.130 imp gal (590 L; 160 US gal)[1]
Prime moverEnglish Electric 8 SVT Mk.II[1]
GeneratorDC
Traction motors
  • D8000–D8049: EE 526/5D
  • Remainder: EE 526/8D[1]
Cylinder size10 in (250 mm)[1]
TransmissionDiesel electric
Gear ratio63:17[1]
MU working★ Blue Star
Train heatingNone
Train brakesVacuum, Dual or Air
Performance figures
Maximum speed75 mph (121 km/h)
Power outputEngine: 1,000 hp (746 kW)
Tractive effort
  • Maximum: 42,000 lbf (186.8 kN)
  • Continuous: 25,000 lbf (111.2 kN)@ 11 mph (17.7 km/h)[2]
Brakeforce35 long tons-force (349 kN)
Career
Operators
NumbersD8000–D8199, D8300–D8327; later 20 001–20 228
NicknamesChopper[3]
Axle load classRoute availability 5
Withdrawn1976–present
Disposition6 in service, 22 preserved, remainder scrapped or in storage.

The British Rail Class 20, otherwise known as an English Electric Type 1, is a class of diesel-electric locomotive. In total, 228 locomotives in the class were built by English Electric between 1957 and 1968, the large number being in part because of the failure of other early designs in the same power range to provide reliable locomotives.

The locomotives were originally numbered D8000–D8199 and D8300–D8327. They are known by railway enthusiasts as "Choppers".[4][5]

  1. ^ a b c d e f g h i j k l m n o p Marsden & Fenn 1988, p. 71
  2. ^ Shipman, Mark (3 July 2004). "Class 20". Locomotive Photo Gallery. Archived from the original on 24 October 2004. Retrieved 30 December 2013.
  3. ^ Bellass, Eddie; Slater, Jim (December 1981 – January 1982). "BR's 'Chopper' squad". Rail Enthusiast. EMAP National Publications. pp. 6–9. ISSN 0262-561X. OCLC 49957965.
  4. ^ Oakley, Michael (1981). BR Class 20 diesels. Truro: Bradford Barton / D&EG. ISBN 0-85153-419-8.
  5. ^ "'At least 20 20s' for Barrow Hill diesel jubilee". The Railway Magazine. July 2007. p. 9.


Cite error: There are <ref group=nb> tags on this page, but the references will not show without a {{reflist|group=nb}} template (see the help page).