Drivers will be forced to make significant diversions, so that work on the tunnel and its surroundings can be done as quickly and safely as possible.
The scheme is being carried out by Dorset County Council in partnership with its street lighting service provider, SEC Lighting Services. The scheduled completion date is Sunday 29 November. Dorset County Council and SEC say they’ll try, whenever possible, to work at nights and weekends so as to minimize disruption to local people and road users.
Aim to stop cracked bricks damaging vehicles
Beaminster Tunnel cuts through Horn Hill, which is formed of wet and running Upper Greensand. Ever since the tunnel was opened in 1832, it’s suffered from problems with water trickling down from the Greensand through its semi-porous bricks. What happens if the water freezes? Brickwork cracks, and chunks of brick can drop down onto people’s heads… Dorset County Council took action in 1968, but now more needs to be done.
Council spokesman Michael Carhart-Harris explains: “In the 1960s, the inside of the tunnel was spray-coated with a cement mix known as gunite to prevent pieces of frost-damaged brick falling onto passing vehicles.
“Recently, the gunite lining has become detached from the tunnel’s brick lining. In April this year, the extent of the attachment was assessed during a special inspection. Specialists were brought in to inspect the tunnel and examine core samples taken from its arch vault. As a result, it was decided that the lining should be reattached to the brickwork backing.
“The work by the county council will involve re-fixing the gunite lining to the brickwork using bolts before painting the lining. The carriageway of the A3066 through the tunnel, as well as 100 metres to the north and 150 metres to the south, will be reconstructed to create a new road surface. Routine maintenance will also be carried out to drainage systems and the tunnel’s stone portals.
“SEC will be replacing the tunnel’s lighting with a system designed to meet current British Standards. This system will be the first in the UK to incorporate new technology that will improve day and night time safety, as well as reducing CO2 emissions by using energy more efficiently.
“The lighting upgrade is part of the county council and SEC’s ongoing private finance initiative (PFI) project that will replace 70 per cent of the council’s existing street lighting.”
SEC is also going to overhaul the tunnel’s electricity supply, and replace the street lighting columns on the approach roads to the tunnel.
Which way will I have to go instead?
These suggested alternative routes will be clearly signposted by Dorset County Council.
Vehicles weighing under 7.5 tonnes, wishing to get from the southern side of Beaminster Tunnel round to the north, will be asked to go from Prout Bridge in Beaminster up the B3163, out past Mapperton, up to the A356 Toller Down Gate crossroads, then down the A356 through Winyard’s Gap and South Perrott to Misterton in Somerset, where the A3066 would normally go. It’s vice-versa, obviously, for light vehicles on the north side of the tunnel wishing to go south.
Vehicles weighing over 7.5 tonnes, wishing to get from the southern side of Beaminster Tunnel to the north, will be directed southwards down the A3066 to Bridport, then sent along the A35 towards Dorchester, and from there pointed up the A37 and A356 towards Misterton Cross in Somerset. Again, obviously, it’s vice-versa for heavy vehicles on the north side of the tunnel wishing to go south.