As part of the contract with GWR, Houghton International has carried out over 100 overhauls of their Class 43 HST alternators.
Houghton International was given the opportunity to demonstrate their technical electro-mechanical capabilities on an initial one-off alternator repair. The alternator, 019A, had suffered a catastrophic in-service failure. As instructed by GWR, Houghton International undertook a full repair which consisted of a full main stator rewind, a full auxiliary stator rewind, the rewind of the four auxiliary rotor coils and the rewind of the auxiliary exciter rotor to requested specification.
Following this first overhaul, Houghton International was then awarded the contract from GWR for the overhaul of their Class 43 HST alternators, moving the work from the incumbent supplier and actual alternator OEM. The overhaul consisted of 110 HST powerpacks and included coil manufacture and rewinding services over a two-and-a-half-year period.
Houghton International identified an original winding fault with the first alternator received for repair. During final stage testing of the alternator, the auxiliary exciter rotor was showing an unbalanced phase through the AWA 12kV Baker tester. Following further investigation by the Houghton International team and examination of another alternator in situ at Swansea’s Landore depot, which was also showing an unbalance, it was suggested that there could be a potential improvement to the original manufacturers’ design. After consultation with GWR and subsequent approval, the auxiliary exciter rotor was rewound to the updated specification, recommended by Houghton International to balance the rotor winding.
Why Houghton International
Houghton International’s reputation as a capable service provider with years of experience in the Rail sector
Equipped to deliver high value/volume contracts and one-off casualty repairs within the rail industry
Direct access to engineering support and technical expertise across a wide range of electro mechanical assets
Following extensive testing, the alternator was re-fitted on the train. Initial indications show that the HST alternator is now running cooler which would suggest that it will generate more power and improved performance. The fault and subsequent improvement were identified through standard ‘added-value’ specialist Houghton International expertise. This had now led to a permanent quality and performance improvement across GWR and other HST users.
With regards to the wider overhaul, Houghton International has completed approximately 128 overhauls to date, ranging from standard overhauls to full rewinds and have been successful in consistently delivering the schedule set out by GWR in their QL4 programme —with 100% on time delivery.
Since contract award, Houghton International has delivered the contract as agreed, mobilising within the agreed time period and supplying the product as per the agreed schedule to a high quality. Contract management via Chris Lisle and Chris Robson has been effective and any issues have been dealt with in a timely and collaborative manner. The operational and technical teams have met the high standard required by GWR and I would not hesitate to recommend them for future work.