A 90-tonne crawler on hire to Hawks helped shape the TBM launch pad at Mantle’s Wood
Align JV’s C1 package on High Speed 2 needed a launch platform for the Chiltern tunnel boring machines. A single Kobelco CKE900G-2 on rental from Dartford firm Hawks covered the civils lifting on a site running almost round the clock.
Six months on a 24/7 site
The 90-tonne capacity Kobelco CKE900G-2 arrived at Mantle’s Wood, north of Hyde Heath in Buckinghamshire, in July 2020 on a six-month rental contract. Its job was to support construction of the tunnel boring machine launch pad — a concrete podium roughly 150m long and 50m wide, sited next to what will eventually be the finished tunnel exit.
The crane came from Hawks, a Dartford-based rental company that bought the machine in 2015 as its first Kobelco crawler. By the time it reached HS2 it had around 6,500 hours on the clock.
What it lifted
Managing director Elliot Hawkins describes the work as “typical civils duties”. In practice that meant moving rebar for the launch pad itself, handling the 636 soil nails — some up to 20m long — that stabilise the 17m-high headwall, and placing pre-cast concrete elements, concrete delivery hoppers and smaller items of plant.
The site was operating virtually continuously, which put availability at the top of the specification list.
“The CKE900G is a very flexible and reliable crane, so was exactly what was needed to complete the work on time, especially as the site was running virtually 24/7. Having bought the machine in 2015, our first Kobelco crawler, we knew it had been maintained and serviced correctly over its 6,500 hours of operation, giving us the confidence that it was more than up to the job.”
— Elliot Hawkins, Managing Director, Hawks
Where the C1 package fits
Align — a joint venture of Bouygues Travaux Publics, Sir Robert McAlpine and VolkerFitzpatrick — won the £1.6 billion C1 package in July 2017. It covers 21.6km of high-speed rail infrastructure on a scheme costed at £98 billion overall.
The package includes a 3.37km-long viaduct, five ventilation shafts with their associated works, and the twin-bored Chiltern tunnel: at 16km and 9.1m diameter, the longest tunnel on the project. Everything the tunnel boring machines needed to start had to be assembled from the launch pad the CKE900G-2 helped to build.
A buyer’s view
Hawkins traces the company’s confidence in the brand back to a visit to Kobelco’s crane factory in Japan, and to what he saw of the manufacturer’s quality control from the beginning of the build process through to the finished machine.
“The machines may be ‘simple’ engineering-wise, but that engineering is top class, which gives us all the confidence we need to compete and win work on high-profile project, large-scale infrastructure projects such as HS2.”
— Elliot Hawkins, Managing Director, Hawks
Source: Kobelco — Photos: Kobelco