British Rail Class 143
| Class 143 Pacer | |
|---|---|
A GWR Class 143 at Dawlish in 2018 | |
Great Western Railway refurbished saloon | |
| In service | 1985–2021 |
| Manufacturers | |
| Order nos. |
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| Family name | Pacer |
| Replaced | BR first-generation DMUs |
| Constructed | 1985–1986 |
| Refurbished |
|
| Number built | 25 |
| Number preserved | 13 |
| Number scrapped | 12 |
| Formation | Two cars per unit: DMS-DMSL |
| Diagram |
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| Fleet numbers |
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| Capacity |
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| Specifications | |
| Car body construction | Steel underframe, aluminium alloy body and roof |
| Car length | 15.546 m (51 ft 0 in) (over couplers) |
| Width | 2.695 m (8 ft 10.1 in) |
| Height | 3.515 m (11 ft 6.4 in) |
| Doors | Double-leaf folding (three per side) |
| Wheelbase | 9.000 m (29 ft 6.3 in) |
| Maximum speed | 75 mph (121 km/h) |
| Weight |
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| Axle load | Route Availability 1 |
| Prime movers | |
| Engine type | Inline-6 4-stroke turbo-diesel |
| Displacement |
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| Power output |
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| Transmission |
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| Minimum turning radius | 70 m (230 ft) |
| Braking system | Electro-pneumatic (tread) |
| Safety systems | |
| Coupling system | BSI |
| Multiple working | Within class and with Classes 14x, 15x and 170 |
| Track gauge | 1,435 mm (4 ft 8+1⁄2 in) standard gauge |
| Notes/references | |
| Specifications as at March 1985 except where otherwise noted. | |
British Rail Class 143 Pacer diesel multiple unit passenger trains were introduced between 1985 and 1986.
During the 1980s, British Rail (BR) was interested in replacing its first-generation diesel multiple units, particularly in the use of railbuses to service its lightly used branch lines. It was decided to develop such a vehicle with a high level of commonality with the widely used Leyland National bus, leading to its modular design serving as the basis for the design. Several single- and two-car prototypes were constructed and evaluated, leading to an initial production batch by British Leyland, designated Class 141 units. BR, seeking to procure improved derivatives, placed an order with the manufacturers Hunslet-Barclay and Walter Alexander to construct its own variant, the Class 143.
Entering operational service during the mid-1980s, the Class 143 embodied several advances over the original model in terms of ride quality and reliability. During its operating lives, the type operated various passenger services across the United Kingdom; initially operated in the North-East of England, all units were transferred subsequently to other regions, including Wales and South-West England.
Due to their non-compliance with the Rail Vehicle Accessibility (Interoperable Rail System) Regulations 2008, the Pacers began to be withdrawn during the late 2010s ahead of the 1 January 2020 deadline. Some fleets were given dispensation to operate until 31 December 2020. While modifications for compliance were proposed by rolling-stock companies, no train operator took up the option. Great Western Railway retired its Class 143 fleet in December 2020, while Transport for Wales was granted an extension and ran its trains until 29 May 2021.