A KEY project for the 2012 London Olympics is under threat, with one prospective bidder pulling out and others complaining the job is too risky.
The £180 million three-car upgrade of the Docklands Light Railway is due to be finished in 2010 and is expected to ferry vast numbers of spectators to and from Olympic venues.
But bidders are worried about how much they are expected to commit themselves to the deal. Work will involve strengthening bridges and viaducts as well as extending platforms for the longer trains.
Already Nuttall has pulled out of the bidding. It declined to comment. A source at another bidder said firms were unhappy about the amount of design work they are being asked to carry out up front without compensation if their bids end up being ditched.
The source added that client Docklands Light Railway had refused to warrant information produced by its own designers. He said: 'We don't know the state of all the assets but we are expected to take responsibility for it.
'They are extremely onerous contract terms and conditions, horrendous even.
You are looking at carrying out stuff like strengthening works on an operational railway in engineering hours.
'Say we had to do some welding to strengthen a steel bridge girder. If on closer inspection we find that the girder is corroded, we would have to replace it. That could have a massive effect on the running of the DLR. You only have to look at the costs associated with Gerrards Cross to see the downside is potentially huge. They are going down the full risk transfer route.'
A spokesman for Docklands Light Railway confirmed Nuttall had dropped out of the race but declined to add anything further.
Pitches from the remaining bidders - Amec/Balfour Beatty, Carillion/Taylor Woodrow and Costain - go back on December 11. A winner will be chosen the following month, with work starting on site on March 12.