M25 Holmesdale tunnel – setting a new standard for safety

Abstract

Following a spate of fatal fires in European motorway tunnels, new EU road tunnel safety legislation was enacted in the UK in 2007. One of the first tunnels to be brought up to the new safety standards was the 25-year-old, 650 m long Holmesdale tunnel on the M25 motorway north of London – one of the busiest in Europe with up to 120 000 vehicles a day. This paper reports on the planning, procurement and management of the tunnel’s recent £75 million refurbishment, which included replacing all mechanical, electrical, operational and communication systems and installing passive fire protection – and all without closing the tunnel to traffic. The award-winning scheme was completed three months early, on budget and without a single reportable construction accident.