British Rail Class 89 - Design

Design

The Class 89 locomotive was designed by Brush Traction of Loughborough to meet a specification issued by British Rail, which subsequently changed the requirements, but not before Brush had already committed to build the prototype locomotive. It was initially delivered in the old-style InterCity livery, with no British Rail double arrows, but these were added later when British Rail bought the locomotive from Brush. As the development of the ECML Electrification continued the engine was painted into the new style "InterCity Swallow" livery and named Avocet.

The locomotive uses six DC traction motors. The main armature current for all the motors is fed from a common thyristor drive, whilst each motor has an independent field current controller. The field current controllers comprised a two quadrant chopper inside a thyristor bridge. The bipolar transistor based choppers provides a fast fine control of motor torque for electric braking and slip control, whilst the thyristor bridge is used to invert the field current polarity.

During the early summer of 1988 the International Traffic and Transport Exhibition (IVA88) was held in Hamburg, Germany. British Rail was asked to participate and sent a representative train of rolling stock to the exhibition. On 22 May 1988, Avocet along with a Class 90, Class 91 and a two car Class 150/2 unit left England in a special train for Hamburg, returning on 17 June 1988.

After being used as a test bed, the locomotive was used on passenger trains from London Kings Cross to Leeds. This continued until Sunday 5 March 1989, a week before the Class 91s entered service on the diagrams.

It was hoped that the Class 89 design would be used for electric locomotives for the Channel Tunnel, and some investigation was undertaken. It was also hoped the Class 89 would be a viable Class 86 replacement, which ultimately went to the Class 90. All hope and opportunity ended, however, when 89001 suffered a serious failure and was withdrawn from traffic. It was saved for preservation at the Midland Railway Centre (now Midland Railway - Butterley) by a group of Brush Traction employees. During this time the locomotive appeared at every major British Rail depot open day, in a slowly deteriorating Intercity Swallow livery.

Ultimately only technology and ideas from 89001’s internal design were used in the Class 9 Eurotunnel locomotives and some similarity in electronics lives on today in the Class 92 locomotive design. When 89001 failed, it was still owned by British Rail, and Brush had no contractual obligation with regard to it. Additionally, having no orders from BR for their design investment, there was little incentive for Brush to construct spare parts for it. BR had written off the locomotive as part of the ECML development and thus it was seen as a surplus and nil value asset. As such the locomotive was sidelined.

Brush did eventually win the contracts to build Channel Tunnel locomotives, and the similarities between these and 89001 enabled suitable spares to be constructed.