British Rail Class 303

The British Rail Class 303 is a type of electric multiple unit. They are also known as "Blue Train" units. They were introduced in 1960 for the electrification of the North Clyde and the Cathcart Circle lines in Strathclyde. At first they were classified as AM3 units before the introduction of the TOPS classification system. They were the dominant EMU on the Glasgow suburban railway network for over 25 years. The final units were withdrawn from service in 2002.

British Rail Class 303
Class 303 at Milngavie in 1983
In service	5 November 1960–30 December 2002
Manufacturer	Pressed Steel Company
Order no.	30579 (DTSO, 75566-75600) 30629 (DTSO, 75747-75801) 30580 (MBSO, 61481-61515) 30630 (MBSO, 61812-61867) 30581 (BDTSO, 75601-75635) 30631 (BDTSO, 75802-75857)[1]
Built at	Linwood, Renfrewshire
Family name	BR First Generation Mark 1
Replaced	Various steam engines/early carriages
Constructed	1959–1961[1]
Entered service	1960–1961
Refurbished	1984[2] - c.1990
Scrapped	1974–2003[2]
Number built	91
Number preserved	1[2]
Number scrapped	90[2]
Successor	Class 320 Class 334
Formation	3 cars per unit: DTS+MBS+BDTS (as built)[3] DTSO+MBSO+BDTSO (rebuilt)[3]
Diagram	EE206 (DTSO, 303/0) ED201 (MBSO, 303/0) EF202 (BDTSO, 303/0) EE241 (DTSO, 303/1) ED220 (MBSO, 303/1) EF217 (BDTSO, 303/1)[1][4]
Design code	AM3
Fleet numbers	303001–303091 (full sets) 75566-75600, 75746-75801 (DTSO) 61481-61515, 61812-61867 (MBSO) 75601-75635, 75802-75857 (BDTSO)[1]
Capacity	236 seats (as built) 160 seats (rebuilt)[3]
Operators	British Rail ScotRail (National Express)
Depots	Glasgow Shields Road[1] Hyndland Yoker[5] Longsight Electric TMD[6] Bridgeton[7]
Lines served	North Clyde Line Cathcart Circle Lines Weaver Junction and Liverpool Line Crewe to Manchester Line Glossop Line
Specifications
Car body construction	Steel[4]
Train length	199 ft 6 in (60.81 m)[3]
Car length	63 ft 11.5 in (19.49 m) (DTS, BDTS) 63 ft 2.25 in (19.26 m) (MBS)[3]
Width	9 ft 3 in (2.82 m)[3]
Height	12 ft 8 in (3.86 m)[3]
Floor height	3 ft 7.5 in (1.1 m)[4]
Doors	Twin leaf sliding, pneumatically operated
Articulated sections	3
Wheelbase	46 ft 6 in (14.17 m) (bogie centres, per car)[4]
Maximum speed	75 mph (121 km/h)[1]
Weight	124 long tons (126 t; 139 short tons) (set) 34.4 t (33.9 long tons; 37.9 short tons) (DTSO) 56.4 t (55.5 long tons; 62.2 short tons) (MBSO) 38.4 t (37.8 long tons; 42.3 short tons) (BDTSO)[1]
Traction motors	4 × MV 155kW[1][3]
Power output	618 kW (829 hp)[3]
HVAC	Electric
Electric system(s)	25 kV AC & 6.25 kV AC overhead[4]
Current collector(s)	Pantograph
UIC classification	2′2′+Bo′Bo′+2′2′
Bogies	Gresley ET3 (DTS, BDTS)[1][4] Gresley ED3 (MBS)[4]
Braking system(s)	Electropneumatic[4]
Safety system(s)	AWS[4]
Coupling system	Automatic drophead buckeye (outer) Automatic solid shank Alliance No.2 (inner)[4]
Multiple working	Within class, and Class 311[3]
Track gauge	1,435 mm (4 ft 8 1⁄2 in) standard gauge