It’s not often that a tunnel opening brings both public joy as well as relief, but the long-awaited diversion of the regularly congested A3 trunk road in the Hindhead/Devil’s Punch Bowl area of south-east England through the new Hindhead Tunnel has brought both.
UK government transport secretary Philip Hammond cut the ceremonial ribbon at the official opening of the 1.1-mile (1.8-km) dual-carriageway, twin-bore tunnel on 27 July. Actually he only really ‘opened’ the southbound bore as the northbound bore was not available to traffic until 29 July after carriageway realignments.
With project completion claimed on both time and budget of which the tunnel itself cost GBP 371M (USD 598.3M) after a 4.5-year project construction period, the work has been hailed as a success all around.
In construction terms the Hindhead Tunnel (see T&TI Oct 2008) has included many innovations and state-of-the-art systems including accurate profile excavation with laser guidance of cutterhead and standard hydraulic excavators, and waterproofing measures including BASF’s Meyco Masterseal 345 sprayed membrane used with robotically sprayed concrete lining. Consequent savings were enhanced by the ability to employ the primary lining as part of the permanent structural lining. The Tunnel has it’s own control centre for supervising monitoring and control systems including the UK’s first radar incident detection system, linear heat detectors for fires etc, and LED motorist guidance system. There is also a resilient fire-fighting and rescue system to support emergency evacuation, with cross-passages at 100-m spacing.
The A3 road is the traditional main route between London and the port of Portsmouth on the south coast but, despite the availability of the M3 motorway, has been one of the most regularly congested roads in the UK, centred on a light-controlled junction in the village of Hindhead.
The vocal local communities in the area, who have suffered all the traffic congestion for many years, have been galvanised by various Internet media initiatives. Even a rumour that the tunnel was supposed to be opened at the beginning of July, but had to wait for the availability of the minister, bought many complaints. However most were in a party mood by the end of the month. A spokesman for main contractor Balfour Beatty said that it was always the intention to open the tunnel in July, and this had been achieved.
The project will also bring environmental benefits apart from transport. For the first time in almost 200 years the Devil’s Punchbowl will be reunited with Hindhead Common by replanting over the tunnel and removal of the old road, allowing transfer of heathland wildlife in the officially designated Surrey Hills ‘Area of Outstanding Natural Beauty’.
Ironically, as soon as the Tunnel was open to traffic there was instant traffic jam build-up although this was attributed to the British love of going just anywhere by car, rather than any flaws in the new road plan. The project was designed by Mott MacDonald, and will be used by an estimated 30 000 vehicles per day.
UK government transport secretary Philip Hammond cuts the ceremonial ribbon to open at least half of the country’s longest land-locked road tunnel
