Parry People Movers Ltd.
(PPM) is a British
company manufacturing lightweight trams
that use flywheel energy storage
(FES) to store energy for traction, allowing electric systems to operate without overhead wires or third rails, and railcars fuelled by small gas, diesel or hydrogen engines, offering very high energy efficiency and very low emissions, suitable for new-build or existing rail systems in a variety of gauges, serving both urban and rural communities in any part of the world.
, owner of the West Midlands franchise, began operating a single PPM50 (Class 999) unit on the Stourbridge line on Sundays in 2002, with a Class 153 Diesel multiple unit
(DMU) providing a weekday service. In June 2009, the Class 153 was replaced by two PPM60 units, classified as Class 139
(with another as spare), providing a 10-minute frequency in both directions. Although the capacity of the unit (60 passengers) is less than the DMU, overall capacity is increased due to the greater frequency, up from 4 to 6 trains per hour.
From 24 January 2011, Go! Cooperative
planned to be operating a trial service between Alton
and Medstead & Four Marks
on the Mid-Hants Railway
using the Class 999 unit.
The Parry flywheel storage technology was tested on the Stourbridge Town Branch Line
in the West Midlands
in 2006.... Read More