Parry People Movers Ltd. (PPM) is a British company manufacturing lightweight
tram
A tram (called a streetcar or trolley in North America) is a rail vehicle that travels on tramway tracks on public urban streets; some include segments on segregated right-of-way. The tramlines or networks operated as public transport are ...
s and
railcar
A railcar (not to be confused with a railway car) is a self-propelled railway vehicle designed to transport passengers. The term "railcar" is usually used in reference to a train consisting of a single coach (carriage, car), with a drive ...
s that use
flywheel energy storage
Flywheel energy storage (FES) works by accelerating a rotor (flywheel) to a very high speed and maintaining the energy in the system as rotational energy. When energy is extracted from the system, the flywheel's rotational speed is reduced as a c ...
(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.
On 29th of November 2022, The Registrar of Companies (UK) gave notice that Parry People Movers Ltd. will be struck off the Companies Register and dissolved unless "cause is shown to the contrary".
Current usage
London Midland
London Midland was a train operating company in England which operated the West Midlands franchise between 11 November 2007 and 10 December 2017. It was owned by the British transport group Govia.
London Midland was created as a result of Govi ...
, owner of the West Midlands franchise, began operating a single PPM50 (Class 999) unit on the
Stourbridge line on Sundays in 2006, with a
Class 153 diesel multiple unit
A diesel multiple unit or DMU is a multiple-unit train powered by on-board diesel engines. A DMU requires no separate locomotive, as the engines are incorporated into one or more of the carriages. Diesel-powered single-unit railcars are also ...
(DMU) providing a weekday service. In June 2009, the
Class 153 was replaced by two PPM60 units, classified as
Class 139 (with one 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. The trains were transferred to
West Midlands Trains
West Midlands Trains (WMT) is a train operating company in the United Kingdom. It operates passenger trains on the West Midlands franchise between London and the English Midlands under two trade names: West Midlands Railway (WMR) (within the ...
, operating under the West Midlands Railway brand, when the West Midlands franchise was refreshed in 2017.
From 24 January 2011,
Go! Cooperative
Go-op (full name Go-op Cooperative Ltd,) is an open access train operating company which is currently proposing to operate a service between Taunton and Swindon, via Westbury. It aims to become the first cooperatively owned train operating c ...
planned to be operating a trial service between
Alton
Alton may refer to:
People
*Alton (given name)
*Alton (surname)
Places Australia
*Alton National Park, Queensland
* Alton, Queensland, a town in the Shire of Balonne
Canada
* Alton, Ontario
*Alton, Nova Scotia
New Zealand
* Alton, New Zealand, ...
and
Medstead & Four Marks on the
Mid-Hants Railway
The Mid-Hants Railway(MHR) originated when local people promoted a railway line between Alton and a junction near Winchester, connected to the larger London and South Western Railway at each end. It was authorised as the Alton, Alresford and ...
using the Class 999 unit. This was abandoned after a series of mechanical and electrical failures and due to the unit proving to be unsuitable for the long and steep gradients on the line the unit is now being reconfigured to address the problems with a redesigned chassis and conversion from LPG to Diesel power and the trial will be repeated.
In January 2012, plans emerged for new bigger PPMs to be used on the
South Staffordshire Line between
Stourbridge Junction and
Brierley Hill
Brierley Hill is a town and electoral ward in the Metropolitan Borough of Dudley, West Midlands, England, 2.5 miles south of Dudley and 2 miles north of Stourbridge. Part of the Black Country and in a heavily industrialised area, it has a popu ...
, providing passenger services on the line for the first time since the
Beeching Axe
The Beeching cuts (also Beeching Axe) was a plan to increase the efficiency of the nationalised railway system in Great Britain. The plan was outlined in two reports: ''The Reshaping of British Railways'' (1963) and ''The Development of the ...
.
Earlier trials
Prior to entry into commercial service, testing took place on the
Severn Valley Railway
The Severn Valley Railway is a heritage railway in Shropshire and Worcestershire, England. The heritage line runs along the Severn Valley from Bridgnorth to Kidderminster, following the course of the River Severn for much of its route, and c ...
in March and April 2002 with a PPM50 unit operating between
Kidderminster
Kidderminster is a large market and historic minster town and civil parish in Worcestershire, England, south-west of Birmingham and north of Worcester. Located north of the River Stour and east of the River Severn, in the 2011 census, it had ...
and
Bewdley
Bewdley ( pronunciation) is a town and civil parish in the Wyre Forest District in Worcestershire, England on the banks of the River Severn. It is in the Severn Valley west of Kidderminster and southwest of Birmingham. It lies on the River Sev ...
. The Parry flywheel storage technology was tested on the
Stourbridge Town Branch Line in the
West Midlands
West or Occident is one of the four cardinal directions or points of the compass. It is the opposite direction from east and is the direction in which the Sun sets on the Earth.
Etymology
The word "west" is a Germanic word passed into some ...
in 2006. Since
Central Trains
Central Trains was a train operating company in the United Kingdom owned by National Express that operated a variety of local and inter-regional trains from 2 March 1997 until 11 November 2007.
Overview
Created out of the Central division of ...
had no Sunday service on the branch, the initiative was brought to test a PPM50 model at that time, with a view to replacing the
Class 153 single-car
Diesel Multiple Unit
A diesel multiple unit or DMU is a multiple-unit train powered by on-board diesel engines. A DMU requires no separate locomotive, as the engines are incorporated into one or more of the carriages. Diesel-powered single-unit railcars are also ...
that previously worked the Branch with a unit with much lower operating costs. The trial lasted for a year.
Parry People Movers have also been demonstrated on narrow gauge railways (
Welshpool and Llanfair Light Railway
The Welshpool and Llanfair Light Railway (W&LLR) ( cy, Rheilffordd y Trallwng a Llanfair Caereinion) is a narrow gauge heritage railway in Powys, Wales. The line is around long and runs westwards from the town of Welshpool ( cy, Y Trallwng) ...
,
Ffestiniog Railway
The Ffestiniog Railway ( cy, Rheilffordd Ffestiniog) is a heritage railway based on narrow-gauge, located in Gwynedd, Wales. It is a major tourist attraction located mainly within the Snowdonia National Park.
The railway is roughly long an ...
,
Welsh Highland Railway
The Welsh Highland Railway (WHR) or Rheilffordd Eryri is a long, restored narrow gauge heritage railway in the Welsh county of Gwynedd, operating from Caernarfon to Porthmadog, and passing through a number of popular tourist destinations in ...
).
Technology
PPMs utilise a rotating
flywheel
A flywheel is a mechanical device which uses the conservation of angular momentum to store rotational energy; a form of kinetic energy proportional to the product of its moment of inertia and the square of its rotational speed. In particular, ass ...
as a store of kinetic energy which is then used to power the vehicle. A typical PPM flywheel is made from steel
laminate
Lamination is the technique/process of manufacturing a material in multiple layers, so that the composite material achieves improved strength, stability, sound insulation, appearance, or other properties from the use of the differing materials ...
s, approximately in diameter and in mass, designed to rotate at a maximum speed of 2,500
rpm
Revolutions per minute (abbreviated rpm, RPM, rev/min, r/min, or with the notation min−1) is a unit of rotational speed or rotational frequency for rotating machines.
Standards
ISO 80000-3:2019 defines a unit of rotation as the dimensionl ...
.
The flywheel is mounted horizontally at the centre of the unit, beneath the seating area. The flywheel is driven by an internal combustion engine or an electric motor. The flywheel is connected to the rail wheels via a
hydrostatic variable transmission system. The wheels are driven without conversion into electricity as many other railcars utilizing flywheel energy storages do.
The flywheel allows the direct capture of brake energy (when slowing down or descending gradients) and its re-use for acceleration (called
regenerative braking
Regenerative braking is an energy recovery mechanism that slows down a moving vehicle or object by converting its kinetic energy into a form that can be either used immediately or stored until needed. In this mechanism, the electric traction mo ...
). When the vehicle brakes, the hydrostatic transmission feeds the energy back into the flywheel. Since the short-term power demand for acceleration is provided by the energy stored in the flywheel, there is no need for a large engine. A variety of small engine types can be used including
LPG,
diesel
Diesel may refer to:
* Diesel engine, an internal combustion engine where ignition is caused by compression
* Diesel fuel, a liquid fuel used in diesel engines
* Diesel locomotive, a railway locomotive in which the prime mover is a diesel engin ...
or electric traction.
On a route with stations a short distance apart it is theoretically possible to use the unit as a
tram
A tram (called a streetcar or trolley in North America) is a rail vehicle that travels on tramway tracks on public urban streets; some include segments on segregated right-of-way. The tramlines or networks operated as public transport are ...
without any engine or
overhead electrification at all. Instead, the flywheel could be re-energised at each station storing enough power to carry it on to the next.
Fleet
In April 2019, Parry People Movers announced plans to upgrade the original Class 999 PPM50 prototype with a diesel power unit and to seek approval for its entry into passenger service as 'No 139000'.
Parry News Issue 76, April 2019, p. 6.
Retrieved 29 February 2020. In February 2020, the refurbished vehicle was moved to the Severn Valley Railway
The Severn Valley Railway is a heritage railway in Shropshire and Worcestershire, England. The heritage line runs along the Severn Valley from Bridgnorth to Kidderminster, following the course of the River Severn for much of its route, and c ...
for testing.
See also
* Coventry Very Light Rail
Coventry Very Light Rail (CVLR) is a light rail tram system proposed to operate in Coventry, England. The system has been promoted as being the first of its kind in the United Kingdom. When finished, it will also be the first tram network to ope ...
References
External links
*
*{{Cite web
, url=https://find-and-update.company-information.service.gov.uk/company/02652429/filing-history
, title=First Notice of compulsory strike-off from Companies Register - Parry People Movers
Depot planned after sustained service to Stourbridge
Engineering companies of the United Kingdom
People movers by manufacturer
Tram vehicles of the United Kingdom
Hybrid vehicles
British Rail Departmental Units
Train-related introductions in 2006