AC/DC Traction Motor Repair & Overhaul Services

AC DC Traction Motor Repair Service - Houghton International

Houghton International offers the broadest scope of repair and overhaul services for AC/DC traction motors. Our cradle to grave OEM manufacturing and life cycle management service produces the entire range of original motors to the train OEM’s specification, under licence if required, with options to provide life-cycle or in-warranty service and maintenance.

Houghton International are specialists in rewinding and overhauling AC/DC traction motors. Our pioneering HiTRAX™ life extending insulation system was originally designed as an AC solution, and subsequently transferred to DC motors.

We are the UK’s only traction motor repair company, with the capability to rewind and vacuum pressure impregnate (VPI) both epoxy and silicone resins. This is complimented by in-house coil manufacturing, rotor bar production and induction brazing technology.

Our aftermarket service is focused on train operators, owners, bogey overhaulers and OEM’s requiring scheduled maintenance, casualty support and in-depot condition monitoring. We have worked on a wide variety of AC traction motors covering fleets across the UK, Scandinavia and Asia. Hong Kong’s MTR Corporation specify our HiTRAX system for their AEG AC traction motor rewinds.

Our research and development division works closely with organisations planning to either solve a minor problem, through to exploiting our expertise and academic links to develop new intellectual property rights for commercial exploitation. We have worked with Porterbrook in the UK as life extension consultants for their 458 fleet Juniper AC traction motors in conjunction with Newcastle University.

We work with all the mainline Roscos in the UK as well as rolling stock OEM’s on a project basis, delivering quantified improvements.

All this complements our contracted volume, service, maintenance and manufacturing provision.

AC DC Traction Motor Repair Service 2 - Houghton InternationalTechnical Capability & Capacity

  • Capacity to process 100+ AC traction motors per month
  • VPI facilities: 2 x individual plants processing: Epoxy (Ultimeg 2002) and Silicone (Wacker H62) resins allowing 160°C Class F – 220°C Class C resin impregnation
  • HiTRAX™ insulation system proven over 10 years for both epoxy and silicone systems. The ideal life extension solution providing cutting edge composite insulation technology to maximise life cycle
  • 2 x Schenck balancing machines
  • Separate 11,000 sq. ft. coil manufacturing facilities
  • CAD function
  • Dynamic rotor bar crack detection
  • Induction brazing facilities
  • Load testing facility and capability
  • Winding and insulation system redesign services


Select a category for more technical details:

Traction Motors and Motor Alternator (MA) Sets Serviced

  • Brush EE507 traction motor
  • Brush TM21/41 traction motor
  • Brush MK 7/7A MA Sets
  • Brush MK12/12A MA Sets
  • Brush MK3 MA Set
  • GEC MK1 and MK1A MA Sets. These are also referred to as 313 or 776 MA’s
  • GEC 512 and Brush 1156 G310 traction motors
  • Siemens traction motor

Work Scope – Overhaul and Heavy Repair

AC DC Traction Motor Repair Service 3 - Houghton International

  • Receipt of motor into works
  • Dismantle and inspect
  • Remove old bearings
  • Datum all component parts to specification
  • Carry out static tests to field and armature windings against specification requirements
  • Steam clean and stove all windings
  • Carry out Non-Destructive Testing (NDT) / Magnetic Particle Inspection (MPI) checks where required by specification
  • Clean and paint all component parts
  • Replace / repair all faulty components
  • Supply and fit new bearings
  • Assemble motor
  • Test run motor
  • Paint motor
  • Quality assurance check prior to dispatch

A heavy repair will consist of the same work scope as above and all or some of the following work scope;

  • Full armature rewind with existing commutator, including the manufacture of new coils and VPI process
  • Full armature rewind with new commutator, including the manufacture of new coils and VPI process
  • Full field and interpole rewind, including the manufacture of new coils and VPI process
  • Full field and interpole re-insulation and VPI process
  • Supply and fit of new armature shaft
  • Weld repairs from failed NDT / MPI checks

Mechanical & Electrical Testing

Traction motors sent to Houghton International for repair undergo a series of mechanical and electrical checks that are governed by the overhaul specifications Houghton International adheres to using a route card system.

Route cards include an initial test and data report, assembly data report and test sheet and are populated at each stage of the repair process which highlights any defects that are present.

Route cards are derived from the traction motor specifications to ensure product output is as required.

Route cards have specific job numbers and are cross referenced with product serial numbers to identify each product.

The commutator profiles are carried out on receipt of the product, through each stage of the repair and also during the final inspection.

The severity of the repair will determine the checks and tests conducted. For example, if an armature fails an electrical check and is deemed as requiring a full rewind, the new winding fitted will undergo several tests including pressure tests and resistance checks throughout the rewind process. An overhauled armature will not need to undergo the same checks as a fully rewound one as the checks that are specific to this situation are different.