by Simon Tulett

Highways chiefs are set to pump more than £8 million into the Dartford Crossing to improve its safety.

The cash will fund a sprinkler system in both tunnels, designed to control a fire until the emergency services arrive.

The safety upgrade, awarded to tunnel safety specialists Fogtec Brandschutz GmbH, will be similar to fire detection systems installed in the Channel Tunnel following a major blaze there in September 2008.

Paul Harding, project manager for the Highways Agency, said: “Fortunately, fires in tunnels are very rare, but improved safety in the Dartford River Crossing tunnels, along with all our roads, remains a priority.

“The Dartford tunnels are currently safe, and the fire suppression system will provide even greater protection for road users, our maintenance staff and emergency service staff should a fire occur.”

A spokesman for the agency refuted suggestions, made by fire safety specialists when the upgrade was first mooted in 2008, that it was to protect the tunnels from closure which would result in a loss of toll revenues.

Instead, he said, the improvements had been prompted by an EU tunnel safety directive .

The guidelines followed the deaths of 39 people in France’s Mont Blanc Tunnel in 1999 , and a blaze in a funicular train tunnel in the Austrian ski resort of Kaprun in 2000 which claimed 155 lives.

Work to install the sprinkler system in the Dartford tunnels, which is estimated to cost £8.1 million, starts in October and is due finish in 2012.