Scotrail Press Release: Perpetuum awarded C334 fleet deployment

Trains running ‘perpetually’ with Perpetuum software

  • Expected lifespan increase of up to 25% for wheel bearings
  • Algorithms monitor and calculate wear on bearings and railhead
  • Class 334 fleet will all be fitted with sensors in 2017

Improving reliability and reducing time spent in maintenance depots for the ScotRail Alliance’s Class 334 fleet will be achieved with the fitting of wireless sensors to monitor wheels and wheel bearing condition.

Maintenance regulations require the Class 334 electric trains to have all wheel bearings replaced on hard time maintenance schedules every 600,000 miles whether they need the new parts or not. This means time out of service and sometimes unnecessary maintenance. The addition of this UK-developed system allows the continual monitoring of wheels, bearings and the track and should deliver a 25% increase in bearing lifespans, due to timely fault identification and monitoring.

Perpetuum wireless sensors use a patented ‘energy-harvester’ to provide readings to a centralised data concentrator. This information gives a real-time analysis of the wheel-rail interface showing if there’s bearing/wheel wear or some damage to the track that could impact on overall safety.

There are already over 10,000 of these sensors deployed by rail operators in England, the USA and Australia – with over 1.5 billion miles of ‘service experience’ to learn from – but the ScotRail fleet represents the first time Perpetuum has been used in Scotland.

Similar technology is already used in aviation for passenger aircraft where maintenance is ‘condition-based’ but its value in managing train fleets’ reliability and repairs is now becoming apparent.

The sensors are mounted onto the wheel bearing cover, where they capture data and transmit to a data concentrator. Algorithms calculate differences in the interface and this alerts the fleet manager when the train is ready for maintenance or of a potential fault developing.

Track officials can also see information which pinpoints changes in condition of the track, allowing prompt repair and subsequently lessening damage to the train wheels.

Three Class 334 trains were used in the Perpetuum pilot on the Scottish rail network, with the whole fleet scheduled for fitting in 2017. This is in addition to wifi equipment, which is now live across the 40-strong fleet and free to use for customers.

The ScotRail Alliance’s fleet director Angus Thom said: “Keeping our trains out on the tracks, delivering a safe and efficient rail service is essential to our operation. This technology helps our maintenance teams make informed and timely decisions around monitoring repairs and potential problems, so keeping our 334 fleet in optimal operating condition.”

Perpetuum’s chief executive Dr Steve Turley said: “If fleet managers know what condition a train is in they don’t spend time and budget putting it through an unnecessary upkeep and repair programme. ‘Condition-based’ maintenance means that trains spend more time on the track and improved customer service.”


For further information please contact ScotRail Alliance Comms on 0141 555 4105/4247 or