New-build regulations

Philip Marshall has made some misleading comments on the regulatory base for electrification ( Open Access, RAIL 821).

The base document, the Energy section of the European Technical Specification for Interoperability (TSI), specifies the ideal case of a new-build line and allows pages of derogations for national rail standards.

The Railways (Interoperability) Regulations 2011 are relevant, but the UK rules are the ORR/RSSB document GL/RT1210, which has taken the TSI specifications for new-build lines and made them apply to upgrades to existing lines - a typical example of civil servants ‘gold-plating’ external regulations in the belief that this ‘improves’ them.

The original Great Western electrification designs were to GE/ RT8025, which specifies the clearances that have been used since the East Coast was wired and the justification required when we want to deviate. The new GL/ RT1210 will require vast amounts of paperwork as it needs a safety case for every deviation - generic ones won’t do. Imagine trying to wire the Severn Tunnel to the TSI clearances! We still won’t have interoperability - continental trains still won’t fit down the UK mouseholes!

The Energy sub-system includes all of the electrified parts, but allows many variations from DC to the Germanic 15kV 16.66Hz to the French/UK 25kV 50Hz with or without autotransformer distribution.

To be pedantic, the UK legacy systems do comply with the TSI, as the TSI specifically states that UK railways comply with their own standards - even the Executive Director of the European Union for Railways, Josef Dopplebauer, has expressed surprise at GE/RT1210 and will investigate further. The TSI specifications were written as the ideal to aim for, but accepted that compromises must be made for existing railways.

I was there when Series 1 and 2 were developed - the reason was to reduce mechanical complexity and reduce maintenance requirements. The then Head of Contact Systems asked me to review the first and continuing costs of the F+F system versus the various Mk III systems, especially when installed by the then-new Wiring Train. The outcome was that the new system was more expensive to install, but the whole-life cost showed a considerable saving due to eliminating a lot of revisits for maintenance.

Line speed is irrelevant. Higher speeds tend to require higher tensions, gentler gradients and closer support spacings, but the old system could achieve this.

Line heights are a matter of mechanical setting when installing. The more interesting problem is the change to autotransformer distribution with a rise in prospective fault current from 6kA to 12kA. The increase in possible fault current will increase the mechanical stress. Mk III, if well maintained, can handle this, but the F+F has parts better designed for this. The integral electrical clearances are similar across all designs. Anthony J. Foster, County Durham