Network
CONSTRUCTION of HS2’s 2.1-mile Colne Valley viaduct passed an important milestone during August, with installation of the 40-metre span over the main road through Harefield on the London/ Buckinghamshire border.
A three-week closure of the road, which ended on August 18, was planned to coincide with the lighter traffic during the school holiday period. Contractors brought in special cranes to lift 11 concrete segments (weighing 115-130 tonnes) into position, and to strengthen them with internal steel cabling.
Once complete, Colne Valley viaduct will be the UK’s longest railway bridge, crossing the Grand Union Canal, River Colne, local roads, and a series of lakes on the outskirts of London between Ruislip and the start of the Chiltern tunnels.
It is being assembled from a thousand segments that are being manufactured at a temporary factory set up close by, with direct access to the M25.
Most of these segments are slotted into place by a giant 700-tonne ‘launching girder’, the only one of its kind in the UK. However, engineers used a different approach at Moorhall Road in Harefield.
Further north, the ten-week blockade of the South Staffordshire freight line in Streethay cutting (near Lichfield) has concluded following the successful installation of the 2,600-tonne HS2 bridge.
The 25-yard structure, which was fabricated nearby, was wheeled into place at the end of July. Rail services resumed on August 16 following the completion of backfilling the sides and reinstating the track.
The work was carried out in parallel to the ten-week construction of the nearby Fulfen Wood bridge, which involved moving a 6,200-tonne single-span structure under the West Coast Main Line.
The next works in this area include construction of two HS2 bridges under the A38 road.
■ Recycled steel
Old car parts, radiators and shopping trolleys are being given a new lease of life, thanks to HS2.
The UK recycled steel initiative, which is helping HS2 to cut carbon in construction, is also supporting hundreds of jobs in South Wales, Yorkshire and Nottinghamshire.
In the past two years, the UK steel industry has benefited from a £170 million pipeline of orders from HS2’s contractors.
More than one million tonnes of steel are needed for standard construction materials, plus a further 200,000 tonnes for steel rail, switches and slabtrack, and an additional 15,000 tonnes for rolling stock.
Visiting supplier CELSA Steel UK’s Cardiff headquarters, HS2 Ltd Chief Commercial Officer Ruth Todd said: “HS2’s vast demand for steel over the next 20 years, as we extend Britain’s new railway to Manchester and the East Midlands, is a l
