Project: Flywheel Traction in Lightweight Rail Vehicles

Reference: CSU 28/4/57

Last update: 01/08/2003 15:12:18


To investigate the feasibility of sub-systems for small and intermediate capacity vehicles utilising flywheel energy storage.


Research will concentrate on the design of a larger capacity flywheel unit whose costs rise only linearly with energy capacity, rather than the exponential increase of currently available equipment. Associated vehicle sub-systems to make use of the flywheel traction system will be modelled, designed, constructed and tested.


Parry People Movers Ltd
Overend Road, Cradley Heath, West Midlands, B64 7DD
013 84 56 9171

University of the West of England, Bristol
Faculty of Computing, Engineering and Mathematical Sciences, Coldharbour Lane, Bristol, Avon, BS16 1QY
+44 (0)117 344 2637

Brush Traction
PO Box 17, Loughborough, LE11 1HS
01509 617050

AEA Technology Rail
PO Box 2, rtc Business Park, Derby, Derbyshire, DE24 8YB
01332 221000

Brecknell Willis &Co Ltd
PO Box 10, Chard, Somerset, TA20 2DE
01460 68111

Contract details

Cost to the Department: £139,451.00

Actual start date: 01 November 1997

Actual completion date: 27 May 2000


Flywheel Traction Light Rail Vehicles
Author: Mr E R C Marks
Publication date: 12/05/2000
Source: AEA Technology Rail, PO Box 2, rtc Business Park, Derby, DE24 8YB

Summary of results

  1. The technical objective of the research project was toinvestigate the potential for scaling up the power ofthe experimental flywheel-driven light rail vehicledeveloped by Parry People Movers Ltd (PPM) withoutproportionate increase in cost. The project includedthe matching of the power unit to an appropriatetransmission providing, inter alia, a facility for energyregeneration during deceleration.

    The economic objective was the design of a tramcar orrailcar with a capital cost closer to that of a bus thanto conventional LRT.

    These research objectives were generally achieved anddemonstrated in a running chassis and a narrow gaugelight railcar. The rationale for use of flywheel tractionin public transport vehicles is based on the ability totake in surges of clean electrical energy very rapidly atstops where passengers board and the provision ofadditional torque for acceleration in vehicles whichhave small, cheap and easily maintained prime moverequipment, such as a car engine, on board.

    Since completion of the research project the runningchassis has been developed into a finished 50 passengerproduction vehicle, which has begun to be marketed asthe PPM 50. The vehicle has been designed forproduction in either high floor or low floor versions,for rail and tramway applications respectively, and foreasy conversion between the two. In order toaccommodate the more powerful drive train under thelow floor a major switch wasmade from mechanicalto hydrostatic finaltransmission, an alteration facilitatedby the availabilityof the preciseperformancespecificationsestablished bythe LINK research.

    The first-of-class PPM 50 is due in June 2002 to enterexperimental public service as a railcar on the branchline between Stourbridge Junction and Town. Thevehicle has been undergoing shakedown trials anddriver training on a privately owned railway betweenthe towns of Kidderminster and Bewdley, in the courseof which it has received final approval from HMRailways Inspectorate for carrying the public. Its moveto Stourbridge is to introduce a Sundays-only railpassenger service with the objective, if successful, ofextending to daily operation in substitution for theexisting heavy rail service. PPM estimates that theannual costs of the existing service, £600,000, can thusbe reduced by half. The Stourbridge trial is beingundertaken at the invitation of CENTRO, the regionalpassenger transport authority, and is supported by thedti (by means of a SMART award).

    PPM now proposes to develop a twin version of thevehicle, with double the capacity and to be known asthe PPM 100. The cost per passenger place of PPMvehicles now works out at £6,000, compared withabout £3,000 for a high specification bus and £8-10,000 for a supertram (eg Manchester, Sheffield etc).

    The major significance of the PPM development is theintermediate scale of the vehicles. Smaller branch linesof the rail system are disproportionately costly inoperation because under the uniform GroupStandards which now apply, there is littledifferentiation between the design and method ofoperation of rolling stock on fast, complex trunkrailways and slow, simpler branches. By creating theopportunity for establishing a group of secondary linesmore like tramways, using the more appropriatelysized PPM vehicles, the economics of smaller railwayscan be brought under control. Moreover, these can beoperated with much greater service frequency ateconomical cost and the prospect of winningpassengers not only for the branch but also for themain line. Conversion of suburban heavy rail lines tolight rail has been seen to be spectacularly successful inattracting passengers in several parts of Britain.

    Similarly, as an urban tramway with very lightinfrastructure and intermittent electrical supply insteadof overhead wires, the PPM system will make emissionfreetransport affordable in small towns or for feederservices to suburban or light rail systems in large cities.The PPM system has the potential to bring popular railsolutions of the highest environmental quality to manynew situations where rail could never previously havebeen contemplated.

    The opportunities in Britain are seen to be replicatedover a wide variety of overseas countries

Departmental Assessment Status: Project completed prior to implementation of Departmental Publication Scheme.