Loadhaul, Mainline Freight and Transrail Freight, employing a total of 7,000 rail workers, are thought to have been disposed of for pounds 225m - a tenth of the replacement costs of the rolling stock, according to Labour.
Ed Burkhardt, Wisconsin Central's president, warned he would cut costs and manpower. In a rail takeover in New Zealand, he virtually halved the workforce, and train drivers' union Aslef fears 3,000 jobs could go in the UK.
Managers, administrative staff and maintenance workers are expected to bear the brunt of cutbacks. But Lew Adams, Aslef's general secretary, said: "He has said he wants to work with us, and we want to work with him."
The US company has indicated that it wants to keep the "second man" on the footplate, but as a general worker doing a variety of jobs, including coupling and uncoupling trains. "Our main concern is to keep people in jobs," commented Mr Adams. "If that is one of the ways it has to be done, we will look at it."
Labour's transport spokesman, Brian Wilson, accused the Government of selling the freight businesses too cheaply. It would cost up to pounds 3bn to replace their 900 locomotives and 19,500 wagons, he claimed. Mr Burkhardt blamed the splitting of the infrastructure from the operators. "Railtrack is a potential problem, and for that reason these companies sold for less than they would have done."
News of the sell-off was marred by the suspension of two senior managers at Loadhaul, and an investigation into two others, after irregularities totalling pounds 500,000 were found in company ledgers.
And there was other bad publicity for rail privatisation. Leaked documents from Railtrack, the infrastructure company, revealed that new safety measures have been suspended until after it is sold off. Minutes of a management meeting refer to "temporary non-compliance" with new signals plans at 13 stations, including Clapham, scene of the 1988 disaster in which 36 people died.
Labour also accused the new privatised rail operators of offering fewer guarantees of service than BR, less than a month after privatisation began. The party's spokeswoman for transport in London, Glenda Jackson, cited the passengers' charter for South-West Trains, operated by the bus firm Stagecoach. Punctuality targets will no longer include peak-service guarantees, seating targets have been dropped in favour of a general promise to "minimise standing", and the pledge of free non-alcoholic drinks if a train is delayed has also disappeared.
"Every taxpayer is paying an average of pounds 73 a year to support privatisation," said Ms Jackson. "Yet under the new system they will not even be guaranteed a free cup of tea if their train breaks down."Reuse content