Network Rail is to spend £50 million in improving equipment and technology on the troubled West Coast Main Line as a damning report said punctuality on the line had fallen.

Network Rail, which awarded six-figure bonuses to its top directors last week, has been criticised for its performance on the busy commuter route serving the West Midlands.

The company’s £9 billion upgrade of the West Coast Main Line has caused months of disruption with repeated signalling problems and points failures.

Rail watchdog Passenger Focus said punctuality and reliability for Virgin Trains – the main user of the line – had fallen six per cent to 79 per cent from spring 2008 to spring 2009.

It said satisfaction levels on the services of London Midland, which also operates on the line, fell eight per cent to 70 per cent.

Anthony Smith, chief executive of Passenger Focus, said: “Virgin Trains and London Midland passengers are fed up with not being able to rely on the timekeeping of their services, the key thing passengers want.

“Network Rail and these train companies must stay focused on restoring their passengers’ trust in the timetable.”

Last week the Office of Rail Regulation (ORR) strongly criticised Network Rail for bonuses paid to directors, with some getting performance-related packages of more than £300,000.

Now Network Rail has said it is extremely dissatisfied with performance on the line and has implemented a package of improvements.

They include £50 million for new equipment, technology and staff.

The package will incorporate dozens of specialist engineers during peak times, an entirely new maintenance team, remote electronic monitoring allowing Network Rail to predict problems before they happen, improved replacement of track, points and signalling equipment, mobile generators to deal with power cuts, a crack down on cable theft, investment in spare parts, more training and performance reviews.

The plan was formally presented to the ORR in response to threats of penalties for unsatisfactory delays and disruption on the line.

Robin Gisby, director of operations and customer service for Network Rail, said: “Train punctuality on the West Coast Main Line, particularly for Virgin, is not good enough.

“That is why Network Rail is investing an additional £50 million for more targeted resources to turn things around.

“For 16 hours a day we will have teams of specialist engineers and trouble shooters at dozens of key locations from London to Crewe to make sure that vital pieces of equipment keep working reliably.

“Network Rail has a responsibility to fix performance.

“It is only by working seamlessly with train operators that we will get this right. We are confident we’ll get there, but pullling performance around and pushing it to more acceptable levels will take time.

“The completion of the west coast project has delivered huge benefits with more and faster services running along the West Coast Main Line, but four out of five trains arriving on time isn’t where we want to be and we’re taking decisive action to improve this.”