National Highways has moved a planned installation of a new bridge in Cornwall to the weekend of February 17-20.

As part of the company’s A30 Chiverton to Carland Cross upgrade, a new 137-foot accommodation bridge is due to be lifted into place at Tolgroggan, near Zelah.

The operation was initially postponed from February 3-6 to this coming weekend, but with the ground still not firm enough to accommodate the 600-tonne crane, National Highways has opted to move the installation to the third contingency weekend.

Neil Winter, National Highways’ senior project manager for the A30 Chiverton to Carland Cross scheme, said: “We’ve taken advice from our principal contractors and although ground conditions are improving they are still not perfect, and we have taken the decision now to move the operation further back.

“We allowed for contingencies in the programme, and feel it only right to reschedule to allow site preparations to be exactly how we want them and to be sure we can complete the lift under one weekend closure.

“Adverse weather over the past two months, a mixture of heavy rainfall and low temperatures, has thrown up circumstances out of our control, but a little extra time will ensure the ground has firm footings required for what is a large-scale and off-road crane lift.

“It won’t impact on our programme or future road opening date, and, based on traffic modelling from last year’s half-term, the weekend of 17-20 will cause lesser disruption to local communities and people making holiday journeys in Cornwall.

“And should strong winds and adverse weather interfere with that weekend, we also have a contingency in place for 24-27 February.”

The A30 was due to be fully closed this weekend between the Boxheater junction and Chiverton Cross roundabout to enable the installation of a new Tolgroggan accommodation bridge.

This closure has now been lifted and the A30 will now be closed from 8pm on Friday, February 17, and reopened to traffic by 6am on Monday, February 29.

Clearly signed diversions will be in place via the Boxheater Junction and Chiverton Cross roundabout, with eastbound traffic diverted via the A3075 to Goonhavern and the B3285 to rejoin the A30.

The westbound diversion will operate in reverse, with the B3284 remaining open under temporary traffic signals north and south across the Chybucca roundabout.

Mr Winter added: “We apologise for any confusion caused by the rescheduling but by announcing now, we hope this will give people more time to plan ahead for the closure, while making sure everything is 100 per cent on site for the lifting operation.”

The installation operation will see the new 137ft (42-metre) structure being lifted into place before the dismantling of the old accommodation bridge later in the year.

A 600-tonne crawler crane, constructed on site, will be employed to lift the newly constructed steel twin-beam overbridge onto recently constructed foundations east of the old structure.

The new bridge weighs 275 tonnes, the equivalent weight of 23 double decker buses or 887,097 standard Cornish pasties, and once completed it will span both the new dual carriageway and the old A30, which will be detrunked for improved local connectivity and traffic.

As part of the multi-million upgrade, the new A30 carriageway is scheduled to be open in winter 2023.