NETWORK Rail has suspended the introduction of vital safety equipment for checking track welding across the entire rail network.
The rail operator has confirmed that the contract for carrying out radiographic inspections of thousands of track welds has been put on hold while engineers consider using alternative technology.
A contractor was due to be appointed to the £6 million three-year framework deal at the beginning of the year and work was expected to start next month.
Rail contractors First Engineering, Amec, Jarvis and Balfour Beatty returned tenders in August and the news is a further blow to the scheme after Construction News revealed the scheme was months behind schedule.
Contractors will receive plans from Network Rail this week to evaluate a method of checking welds using ultrasonic equipment before a decision on the deal is made.
A Network Rail spokesman said: 'The radiographic contract is not suspended indefinitely and we are looking at all our options before deciding the best way forward.'
The contract involves operating mobile radiographic equipment that uses gamma rays to penetrate the metal welds and check for defects.
But engineers at Network Rail have put the contract on hold while they conduct tests on equipment that can check welds internally by using ultrasonic sound waves which emit highfrequency sound waves through the metal and measure the time it takes for the signal to bounce back.
Testing and evaluation is expected to take several months to complete.
One contractor said: 'This contract was dead in the water anyway. If Network Rail opt for this new technology the deal will have to be retendered and could take many months to get group standard approval.'