PPM railcars and trams are innovative: they do not follow pre-existing standards but instead combine techniques, designs and construction methods from other sectors into a new form of high-quality rail transport.  This development philosophy has enabled PPM to offer rail vehicles that are, efficient, environmentally-friendly and low cost.  However, approvals processes are frequently geared to existing technology.

Approvals for passenger operation of new rail-based rolling stock can be complex as they naturally have to ensure that all risks are controlled.  In general, approvals must be obtained for each vehicle individually and also for the combination of the vehicle and the infrastructure on which it will operate.

As shown elsewhere on this website, several PPM vehicles have been approved by HM Railway Inspectorate (HMRI) to operate in public service, carrying over 100,000 passengers in total.  They have run on a wide range of different lines, including temporary track laid on the street surface in Birmingham, Barking, Brighton and Swansea, the Bristol Harbour Railway, and existing railways such as the Severn Valley, Great Central and Chasewater heritage railways as well as the independent Wensleydale Railway and Network Rail's Stourbridge Town branch.  In all cases, HMRI approved both the vehicle was itself and the combination of the vehicle and infrastructure.


In North Yorkshire, the infrastructure of the Wensleydale Railway is leased from Network Rail, but Wensleydale Railway plc is the infrastructure operator and, indeed, the train operator.  The demonstration service in September 2005, using a PPM 50 Light Railcar running over five miles of track that had not seen regular passenger services for over half a century, naturally meant that the systems for operating the route had to be re-examined.  It was necessary for Wensleydale Railway plc to amend its safety case to include the operation of a light railcar.  In addition, the WR made several enhancements to its infrastructure, including the improvement of level crossings and the construction of a brand new platform at the Northallerton end of the line.  This was done, and passenger operation commenced within 50 days of the idea being raised for the first time.


The first ever operation of a light railcar on the Network Rail system deserves a full description.  This project was delayed by a period of confusion within the rail industry resulting from reorganisation in the wake of privatisation and then the collapse of Railtrack plc as the national infrastructure operator.  The principal sticking point was how to construct an approvals process given that existing procedures for all parts of the national network are based around traditionally-constructed "heavy" rail rolling stock (meeting the requirements of Railway Group Standards), even though the Stourbridge Town branch could be "locked-off" from the rest of the network and therefore did not intrinsically present any interface risks.

However, a new approach by Network Rail transformed the situation by identifying the essential steps needed.  As shown below, once the method for obtaining approval had been set out, progress was rapid and increased in pace towards the end of the process.

In May 2005, the route to final approval was mapped out between Parry People Movers Ltd, Pre Metro Operations Ltd and Network Rail.  This would rest on obtaining a derogation from Railway Group Standards requirements, allowing Network Rail to assess the proposed operation holistically in terms of its individual risks and control measures, instead of requiring adherence to Group Standards as a prime requirement.

Network Rail then submitted their proposed derogation (No. 05/090/DGN) from Group Standards to the Rail Safety & Standards Board (RSSB), where it was distributed to the Subject Committees - who represent the wider rail industry - for Rolling Stock, Operations and Infrastructure.

After agreement by the three Subject Committees, the RSSB approved the derogation on 5th October, permitting Network Rail to assess the proposed operation of innovative technology via its System Review Panel (SRP) procedure.  As part of the input to this procedure, CORREL Rail Ltd - a vehicle acceptance body (VAB) - undertook a safety examination of the railcar and a review of its maintenance before issuing a Certificate of Engineering Acceptance for the railcar on 17th October.

Having received the VAB certification, and after consideration of the proposed operation at Vehicle SRP on 1st November, Network Rail identified where a small number of outstanding issues were identified for quick resolution, and some extra conditions imposed.  One of the requirements was that the gauging of the vehicle on the Stourbridge Town branch should be proved.

At this point the railcar was moved to Stourbridge and undertook gauging trials on the branch line in tare and loaded condition on 6th November.  As the vehicle had not at this stage received full approval, all movements were undertaken within engineer's possession of the line.

Network Rail issued Certificate of Authority for Interim Operation No. NRAB/733, allowing the use of the railcar in passenger service on its infrastructure under specified conditions, on 9th November.

On 25th November, the Office of Rail Regulation approved the track access contract between Pre Metro Operations Ltd and Network Rail, and on the same day HMRI issued Certificates of Exemption from the Railway (Safety Case) Regulations 2000 Nos. 374a (to Pre Metro Operations Ltd) and 374b (to Network Rail) permitting non-passenger service for crew training purposes on 25th November.  Network Rail, as infrastructure operator, had provided confirmation that they had no objection to such operation.  Pre-service crew training - without engineer's possession of the line for the first time - was undertaken on 27th November and 4th December.

Final agreement of operational arrangements between Network Rail and Pre Metro Operations Ltd allowed NR to confirm it had no objection to passenger operation, and Certificates 375a and 375b - permitting passenger service - were issued by HMRI on 6th December.  The track access contract between Pre Metro Operations Ltd and Network Rail was formally signed off on 7th December.

The first passengers were carried on Sunday 11th December 2005.

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