MANAGERS who have never been signal operators have been told they must staff signal boxes during forthcoming rail strikes or be suspended.

Until now, only those who were once employed as signal operators have been instructed to work in the boxes during strike days. The signal staff plan a 48-hour stoppage from noon next Tuesday, and Railtrack has begun to 'turn the screws' on supervisors even though their background in the industry may be as drivers or booking office clerks.

The orders were issued as two dozen signal staff staged a 20-minute walkout in the West Midlands, halting rush-hour services. Strikers were protesting over the suspension of a signal box inspector who refused to do the work of colleagues taking action on Wednesday. The 'movements inspector', who now faces a disciplinary hearing, was sent home after he refused to take over a box at Aston, Birmingham, where he had never worked before. It was the first unofficial strike during the dispute.

The middle managers who are under pressure usually monitor signals workers to ensure they obey the industry's rules. But they have little knowledge of traffic movements.

The railway inspectorate, part of the Health and Safety Executive, said it was the responsibility of Railtrack to ensure substitute operators are properly trained. In an internal company memorandum on 8 June, before the strikes started, John Ellis, the company's production director, said supervisors and managers who decline to co-operate, 'will not be regarded as acting unreasonably'.

One supervisor in the South of England who has never operated a signal box told the Independent that he had been threatened with suspension if he did not obey orders. 'This is a significant change in the attitude of management. There is a subtle but very important difference between monitoring signalmen to ensure they abide by the Rules and Regulations and doing the job yourself,' he said.

The supervisor, a member of TSSA, the white-collar rail union, could be dismissed if he was named. He agreed more trains could be run if those who had never worked as signalmen were pressed into service. 'But most of us do not feel competent to do the job and there are bound to be safety implications.'

He said he and his colleagues had been told to operate boxes next week and written orders would be issued on Monday.

The Health and Safety Executive said that if someone was judged competent to assess the work of staff in a signal box, then he or she should be able to operate that box safely.

Railtrack said that everybody who worked signal boxes on strike days was '100 per cent competent'. Another company source said: 'It is not as if we are talking about piloting the starship Enterprise.'

Next week's 48-hour stoppage - which is likely to disrupt services for almost three full days - will be followed by a strike the following Wednesday and a 48-hour strike the week beginning 7 August.

Letters, page 17