UK: A proposal to join up suburban services east and west of London through existing metro tunnels, which has been put forward by Railtrack, owner of Britain’s national rail network, has caused the process of privatising London Underground’s physical assets to be put on hold for several weeks.

In March 1998, Deputy Prime Minister John Prescott announced a public-private partnership (PPP) deal under which, one, two or three companies would assume responsibility for maintaining and renewing LU’s infrastructure and trains under long term concessions. LU would continue to operate the network and collect revenue, paying agreed sums to the asset management companies over the 20 to 30 year life of their concessions.

The whole deal was supposed to be signed and sealed by March 31 2000, well before the transfer of responsibility for London Transport to a new Mayor of London to be elected in May.

However, a survey carried out by Construction News of 20 groups negotiating with a PPP team set up by the Department of the Environment, Transport & the Regions (DETR) and LT revealed that half the groups believed the scheme might never happen, and all believed it could be up to a year late.

Massive upgrade project

Railtrack is bidding for the Metropolitan, District and Circle lines, which were built through central London mostly by cut-and-cover to the main line loading gauge. London’s unique small diameter tube tunnels followed from 1890 onwards.

The company says it wants to acquire the sub-surface lines because it would use them to create high capacity through routes, similar in concept to the RER in Paris, and to the successful north-south Thameslink route across London that was opened in 1988.

Two distinct cross-London services are planned. The first would see Paddington and Liverpool Street joined by using the north side of the Circle line. It replaces the 1980s Crossrail plan for new high capacity bored tunnels joining the same termini which was postponed indefinitely in March 1996 because the £2·1bn cost was too high.

The second service, using the south side of the Circle, could see Fenchurch Street joined to Wimbledon, allowing through running between Southend and suburbs in South West London.

Use of the Circle line as a cheap substitute for Crossrail was earlier reviewed by consultants, at the government’s insistence. But the idea was rejected as impractical because of the many short stations and flat junctions, which limit capacity.

Railtrack proposes a massive construction programme that would see stations lengthened for 10 or even 12 car trains, moving block signalling permitting 36 trains/h, and elimination of flat junctions either by grade separation, or withdrawal of existing services as at Baker Street. Conversion to 25 kV overhead power has even been mooted.

At Paddington through running is no problem, but the former connection at Liverpool Street is long gone and costly tunnelling would be needed. Likewise, joining the sub-surface Circle to the London, Tilbury & Southend line on viaduct outside Fenchurch Street would be difficult.

London Transport is opposing the scheme on operational grounds, and because of the major disruption to the Underground that would be caused. Current rules governing the dimensions and safety features of underground stations would make the adaptation of existing structures extremely difficult and expensive, and the total bill is put at £5bn.

DETR is annoyed at the interruption to the PPP process, and is also worried by the impossibility of obtaining competitive bids for the sub-surface project since Railtrack owns all the connecting lines.

Railtrack points to the advantages, such as the ability to travel from Heathrow Airport to the City of London is just over 30min, which it argues would more than offset the loss of the Circle line and other long standing Underground services.