British Rail Class 321

British Rail Class 321
Greater Anglia Class 321 at Colchester in 2018
Standard-class interior of an unrefurbished Greater Anglia unit
In service1988–present[1]
ManufacturerBritish Rail Engineering Limited
Built atHolgate Road Works, York
Family nameBR Second Generation (Mark 3)
ReplacedClass 307
Constructed1988–1991
Refurbished2013–2017
Number built117
(66 × 321/3, 48 × 321/4, and 4 × 321/9)[2]
Number in service8
(plus 12 converted to Cl. 320/4)
Number scrapped67
Successor
Formation
  • 4 cars per unit;
  • 321/3 and /4 units:
    DTCO-PMSO-TSO-DTSO
  • 321/9 units:
    DTSO-PMSO-TSO-DTSO
Diagram(See § Vehicle numbering)
Fleet numbers
  • 321/3: 321301–321366
  • 321/4: 321401–321448
  • 321/9: 321901–321903
Capacity
  • As-built:
  • 321/3: 313 seats
    (20 first-class, 293 standard)
  • From 2015:[1]
  • 321/3: 303 seats
    (16 first-class, 287 standard)
  • 321/4: 299 or 307 seats
    (16 or 28 first, 271 or 291 std.)
  • 321/9: 309 seats
    (all standard-class)
Owners
Operators
Specifications
Car body constructionSteel
Train length80.92 m (265 ft 6 in)[1]
Car length
  • DT vehs.: 19.950 m (65 ft 5.4 in)
  • Others: 19.920 m (65 ft 4.3 in)
Width2.816 m (9 ft 2.9 in)
Height3.775 m (12 ft 4.6 in)
DoorsDouble-leaf sliding pocket, each 1.200 m (3 ft 11.2 in) wide
(2 per side per car)
WheelbaseOver bogie centres:
14.170 m (46 ft 5.9 in)
Maximum speed100 mph (161 km/h)
Weight
  • DTCO vehs.: 29.3 t (28.8 long tons; 32.3 short tons)
  • PSMO vehs.: 51.5 t (50.7 long tons; 56.8 short tons)
  • TSO vehs.: 28.8 t (28.3 long tons; 31.7 short tons)
  • DTSO vehs.: 29.1 t (28.6 long tons; 32.1 short tons)
Traction motors
  • As built: 4 × Brush TM21-41C,
    each of 248 kW (332 hp)[4]
  • Renatus: 4 × TSA TME 52-35-4,
    each of 300 kW (402 hp)[5]
Power output
  • As built: 990 kW (1,328 hp)
  • Renatus: 1,200 kW (1,609 hp)
Acceleration
  • As built: 0.55 m/s2 (1.2 mph/s)[1]
  • Renatus: 0.60 m/s2 (1.3 mph/s)[6]
Electric system(s)25 kV 50 Hz AC overhead
Current collector(s)Pantograph
UIC classification2′2′+Bo′Bo′+2′2′+2′2′
Bogies
  • Powered: BREL P7-4
  • Unpowered: BREL T3-7
Minimum turning radius71 m (232 ft 11 in)
Braking system(s)Electro-pneumatic (disc)
Safety system(s)
Coupling systemTightlock
Multiple workingWith Classes 317–322
Track gauge1,435 mm (4 ft 8+12 in) standard gauge
Notes/references
Specifications as at October 1988[7] except where otherwise noted.

The British Rail Class 321 is a class of electric multiple unit (EMU) passenger train built by British Rail Engineering Limited's York Carriage Works in three batches between 1988 and 1991 for Network SouthEast and Regional Railways. The class uses alternating current (AC) overhead electrification. The design was successful and led to the development of the similar Class 320 and Class 322.

After operating for various trains operating companies after the privatisation of British Rail, they were latterly operated by Greater Anglia until April 2023. Some have been converted to Class 320 and are operated by ScotRail.

  1. ^ a b c d "Class 321 Electrical Multiple Unit" (PDF). Eversholt Rail. Archived from the original (PDF) on 5 October 2015.
  2. ^ Inman, Mark Lee; Pritchard, Robert. "Endangered species: the Class 321s". Today's Railways UK. No. 250 (December 2022). Sheffield: Platform 5. p. 52. ISSN 1475-9713.
  3. ^ Cite error: The named reference TRM1475 was invoked but never defined (see the help page).
  4. ^ Marsden, C. J. (2007). "Class 321". Traction Recognition. Hersham: Ian Allan Publishing. pp. 178–181. ISBN 978-0-7110-3277-4. OCLC 230804946. OL 16902750M.
  5. ^ "Class 321 EMU overhaul for Eversholt". Wiener Neudorf: Traktionssysteme Austria. Retrieved 28 January 2023.
  6. ^ "Class 321 Renatus". London: Eversholt Rail Group. Archived from the original on 9 January 2021. Retrieved 5 August 2021.
  7. ^ "Vehicle Diagram Book No. 210 for Electric Multiple Units (including A.P.T.)" (PDF). Derby: Mechanical & Electrical Engineering Department, British Railways Board. EC210, EE236, EE308, EH235 (in work pp. 88–89, 182–183, 206–207, 316–317). Archived from the original (PDF) on 21 January 2015. Retrieved 8 October 2022 – via Barrowmore MRG.