London facing meltdown

Commuter misery deepened today as temperatures soared towards record highs.

Rail chiefs warned they may have to introduce even tighter speed restrictions - down to 20mph in places - amid fears that tracks might buckle. Dozens of trains were also cancelled as timetables had to be rewritten.

On the Tube, ambulances will be ordered to attend any breakdowns because of concerns that passengers trapped in tunnels could collapse in temperatures of nearly 100F.

Rail companies announced they will be handing out thousands of bottles of water during the heatwave. At lunchtime weather forecasters said they expected temperatures to peak at 95F. Earlier predictions that they would go as high as 98F (37C) were downgraded.

Track temperatures, however, are several degrees higher than the surrounding air temperature - increasing the risk of rails buckling.

A Network Rail spokesman said the introduction of speed limits was based on a combination of track, traffic and environmental conditions.

Elizabeth Anetts of the PA Weather Centre said the high temperatures over the past two months had produced the third warmest June and July on record.

Forecasters predicted there would be no let-up for the rest of the week and temperatures could reach a record 100F. At 1pm, Network Rail ordered a 60mph speed limit across southern England.

This affected services run by the country's busiest commuter operators, Connex South Central and South West Trains. Although many commuter do not reach 60mph, the timetable was thrown into chaos by faster services having to slow down.

A 60mph limit was also imposed at 3pm on First Great Eastern services on the Chelmsford and Norwich line out of Liverpool Street.

Sir Richard Branson's Virgin Trains West Coast Main Line was restricted to 60mph between Euston and Crewe. Trains normally travel at up to 110mph. All Virgin's crosscountry services were also restricted to 60mph. Virgin had to cancel 19 services, including 15 between Euston and Birmingham New Street. Two morning rush-hour trains from Wolverhampton and Manchester to Euston were also cancelled.

First Great Western services out of Paddington to Wales and the West Country were limited to between 60mph and 90mph. It said it was cancelling 17 services today.

Both the East Coast Main Line between King's Cross and Peterborough, and the
Midland Main Line between St Pancras and Bedford, were restricted to 90mph.

GNER cancelled two Leeds-London services and warned passengers to expect longer journey times because of the speed restrictions between King's Cross and Peterborough. The restrictions are due to end at 8pm when track temperatures begin to drop.

Network Rail warned there would be more speed limits imposed tomorrow. Stewart Francis, chairman of the Rail Passengers Council, the national watchdog, said: "It is certainly going to be an uncomfortable experience for rail passengers today. The phrase 'melt-down' comes to mind."

For rail chiefs the news that the heatwave will continue into the weekend comes as a blow, as they had been hoping for a respite from Thursday. They warned it would mean a week of problems.

As conditions in the heat worsened, the TUC renewed its call for a legal maximum temperature in the workplace. While there is a minimum temperature below which nobody should have to work there is no equivalent if it gets too hot. The TUC wants a maximum working temperature of 30C or 27C for those doing strenuous work.