British Rail Class 43

British Rail Class 43
Name	Class 43 (HST power cars)
Powertype	Diesel-electric
Caption	Class 43 power car at Paddington in InterCity livery
Builder	British Rail Engineering Limited
Builddate	1975–1982
Totalproduction	197
Primemover	Paxman Valenta / Paxman VP185 / MTU 16V4000R41R
Enginetype	Diesel
Whytetype	Bo-Bo
Uicclass	Bo'Bo'
Length	17.2 m
Topspeed	125 mph
Poweroutput	2,250 bhp (original)

British Rail Class 43

The British Rail Class 43 is the power car used in the InterCity 125 High Speed Train (HST) sets introduced on British railways in the 1970s. Conceived by British Rail Engineering Limited to modernize services on routes such as the Great Western Main Line and East Coast Main Line, the Class 43 became synonymous with high-speed diesel traction and long-distance intercity travel across England, Scotland, and Wales.

Introduction

The Class 43 power cars were produced by British Rail Engineering Limited and entered service as the motive power for the InterCity 125 sets, replacing older locomotives on routes operated by British Rail and later by post-privatisation companies including Great Western Railway, Virgin Trains, London North Eastern Railway, and First Great Western successor entities. Designed under the stewardship of engineers associated with the National Railway Museum era and the British Transport Commission’s modernization plans, the Class 43 established new reliability and speed standards for diesel traction on mainline services such as the West Coast Main Line relief workings and the Great Eastern Main Line.

Design and Development

Development originated from BR's need to achieve 125 mph running without electrification on routes like the Great Western Main Line and East Coast Main Line. The conceptual work involved teams from British Rail Research Division and BREL at Crewe Works, influenced by designers linked to projects like the Advanced Passenger Train and engineers with prior work on Class 52 and Class 55 designs. The streamlined nose and aerodynamic profile owed much to studies at the College of Aeronautics and consultations with suppliers including Paxman and English Electric subcontractors. Prototype power cars were fitted with Paxman Valenta engines; subsequent rebuilds or re-engining projects involved firms such as MTU Friedrichshafen and Brush Traction.

Technical Specifications

Power cars were built to Bo-Bo wheel arrangement with a lightweight construction enabling a 125 mph maximum speed certified for use on the UK loading gauge and signalling regimes such as AWS and TPWS. The original Paxman Valenta was rated around 2,250 bhp, later superseded in many units by the Paxman VP185 and MTU 16V4000 series for improved fuel economy and emissions compliance under regulatory frameworks influenced by the European Union directives on emissions. Braking systems incorporated electro-pneumatic and disc brakes compatible with Mark 3 coaching stock produced at BR Workshops like Crewe Works and Doncaster Works. On-board auxiliaries were provided by generators and control systems developed alongside suppliers like GEC and AEI.

Service History

Introduced in 1976, Class 43s rapidly became the backbone of high-speed diesel services, transforming timetables on routes operated by British Rail’s InterCity sector. Units clocked record-breaking runs that featured in media around the Royal Train era and public transport campaigns. With the 1990s privatisation of British Rail, Class 43s passed to a variety of train operating companies including Virgin Trains East Coast, ScotRail, and CrossCountry, continuing to operate until replacement by electric multiple units like the Class 395 or by new diesel classes such as the Class 800 and Class 802 under the Intercity Express Programme. Mid-life refurbishments, re-engining, and vehicle overhauls extended operational lives into the 21st century.

Operators and Liveries

Over decades, Class 43 power cars carried liveries ranging from the original InterCity grey/blue to the red and silver of Virgin Trains and the turquoise of First Great Western (later Great Western Railway). Other operators included East Midlands and Arriva Trains Wales, each applying bespoke liveries for brand identity. Leasing companies such as English, Welsh & Scottish Railway and rolling stock companies like Angel Trains and Eversholt Rail Group managed fleets that were sublet to TOCs, while workshops at Doncaster Works and Wabtec performed rebodying and repainting contracts.

Preservation and Heritage

A number of Class 43 power cars and complete HST sets entered preservation with organisations including the National Railway Museum, the Mid-Norfolk Railway, and heritage operators such as West Coast Railways and the Rutland Railway Museum. Preserved examples appear at events like Railfest and operate on charters for groups associated with the Transport Trust and Heritage Railway Association. Some units have been restored to historical liveries, appearing alongside preserved Mark 3 coaching stock and other iconic types such as Class 47 on mainline operator-certified railtour workings.

Incidents and Accidents

Class 43-operated HSTs have been involved in notable incidents investigated by bodies including the Rail Accident Investigation Branch and predecessor organisations. High-profile accidents and derailments prompted safety improvements affecting braking, track interaction, and cab ergonomics, leading to recommendations implemented across fleets and influencing subsequent designs such as the Intercity Express Programme trains. Investigations have referenced interactions with infrastructure managed by entities like Network Rail and examined factors including signalling compatibility and maintenance regimes at depots such as Trafford Park Depot and St. Philips Marsh.

Category:High-speed trains of the United Kingdom Category:British Rail diesel locomotives