tubechallenge.com

Tfl have published a Periodic information notice in the Official Journal of the Euopean Union asking for Indicative tenders for the conversion of 85 8-car 92 stock trains from DC traction to AC traction.

London Underground Limited (LUL) is considering a proposal to replace the existing DC traction system on 85 Central Line trains with a new AC traction system. This notice is a request for interested parties to provide information which will enable LUL to assess the technical and commercial viability of the proposal prior to commencing a full tendering process.

My obvious comment is that this means 1-2 train sout of use at a time not to mention the closure time involved in converting the whole line from DC traction to dual traction and then removing the DC rails at a later date.

And the cost - just for the train coversion ...

Initial estimated cost:

Estimated value excluding VAT:
Range: between 90 000 000 and 130 000 000 GBP.

Full notice available at: http://ted.europa.eu/Exec?DataFlow=Show ... tatLang=EN

Sorry if this is a mighty stupid question, but why bother converting from DC to AC? If you were a Hornby train, you would be able to run of the mains supply without the use of a pathetically inefficient transformer, but I don't quite see that relates to Tube trains.

Maybe that's the reason - it's just more economical not to transform it to DC for the Tube. They must use a hell of a lot of electricity.

They are not planning on converting the power supply, just the motors on the trains. 95/96 stock trains already have AC motors which are more efficient than DC motors.

greatkingrat wrote:They are not planning on converting the power supply, just the motors on the trains. 95/96 stock trains already have AC motors which are more efficient than DC motors.

That makes more sense now.

If that's the case then it may be that they're looking for interchangability of stock in the future?