Unions and managers were entrenched in a bitter war of words yesterday as thousands of rail users suffered train disruptions when signal workers staged the first of two 24-hour strikes.

An estimated 40% of more than 2000 train services in Scotland ground to a halt as a result of yesterday's walkout and many others were drastically altered. A repeat performance is expected when the strike resumes tomorrow.

The Rail Maritime and Transport (RMT) union and Network Rail management will meet for more talks today in an attempt to resolve the dispute.

But, before the two sides meet, they fired some stinging accusations that are expected to strain today's discussions, facilitated by conciliation service Acas.

The RMT began by claiming Network Rail was risking the safety of passengers by resorting to the use of managers to keep trains running yesterday.

Bob Crow, the RMT general secretary, said: "If Network Rail was so concerned about safety it wouldn't be staffing signalling centres and boxes with scab managers with scant route knowledge and competency to try to keep some services running."

Network Rail said the RMT's accusation was "nonsense", adding that 45% of signal boxes remained in operation following the walkout at noon.

Out of a total of 74 signal boxes, 20 were being manned by "trained managers" and a further 13 by the normal workforce.

DESERTED: Queen Street station at rush hour yesterday.

Network Rail, in turn, accused the RMT of being "strike-happy", claiming they do not have the same issues with other unions or trade bodies.

David Simpson, Network Rail's route director, claimed it was the 17th strike the RMT had threatened in two years.

A Network Rail spokesman added: "Fundamentally, it is a very left-wing union. I think they see this as an opportunity in the current financial climate to create friction.

"To say the managers operating signal boxes are untrained is nonsense."

Services wound down after the morning rush hour yesterday, affecting all major routes north of the border.

Most services north of Perth were not running and reduced services were operating in the central belt.

Services on the major commuter route between Edinburgh and Glasgow were reduced by about half, with the last service at 6pm.

The last train left Aberdeen for Edinburgh at 8.51am and an hourly replacement bus service operated to Edinburgh and Glasgow throughout the day.

In Inverness, replacement bus services were in operation between Inverness and Aberdeen and Inverness to Glasgow. In Dundee buses were running to Edinburgh and Aberdeen.

Virgin Trains cancelled yesterday evening's Edinburgh to Birmingham and Glasgow Central to Manchester trains.

Network Rail said it was "bitterly disappointed" by the failure of negotiations.

Mary Grant, managing director of First ScotRail, said: "Our customers are caught in the middle of a strike which has nothing to do with us. We will continue to run as many trains as possible but there are limits to what can be provided."

Disputed motives
Nearly all of Scotland's signal workers, some 450, took part in the first of two planned days of strike action orchestrated by the Rail, Maritime and Transport Workers (RMT) union.

The cause of the dispute is in itself a point over which union leaders and management are in disagreement.

The RMT says the main issues are roster changes at short notice and the transfer of staff.

The union is also disputing the mechanics of promotion, saying that this should be based on seniority and length of service if the employees are equally able and qualified.

Network Rail have argued that appointments should be based purely on ability.

But the company says these areas have already been ironed out during talks, and that compulsory safety assessments are at the bottom of the dispute.