British Rail Class 303

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

The British Rail Class 303 electric multiple units, also known as "Blue Train" units, were introduced in 1960 following the electrification of the North Clyde and the Cathcart Circle lines in Strathclyde, Scotland. They were initially classified as AM3 units before the introduction of the TOPS classification system and were the dominant EMU on the Glasgow suburban railway network for over 25 years, before being progressively phased out by newer rolling stock. The final units were withdrawn from service in 2002. The fleet's lifespan was 42 years.

The units were used later on the Inverclyde and Argyle lines of the Glasgow suburban railway network, as various electrification schemes came to fruition, and in Greater Manchester, England.