Enter the giant

BACKED BY FOREIGN INVESTMENT FROM France’s EDF (66.5%) and China General Nuclear (33.5%) the UK’s Hinkley Point C project was given the green light in September 2016 and construction work is under way. Some 52 cranes are expected to be used during civil construction work at the site, which is being managed by a Bouygues/Laing O’Rourke joint venture.

In the two decades since Sizewell B was built in the UK there have been significant changes in the safety and capacity of the cranes used for large construction projects, says Stijn Sarens, global account manager at Sarens, which is working on the project.

“More and more attention is [now] given to the safety systems in and on a crane,” says Sarens. In addition to load indicators and engine sensors, the way a crane can be put together onsite has been through a “tremendous evolution” with the addition of walkways, railings and fall-arrest systems. Significant effort has also been put into increasing the capacity of existing cranes. This was mostly driven by the booming wind industry, which had reinforced and longer booms with wind-jib attachments, Sarens says. For heavy lifting, the CC8000-1 and LR13000 were developed as the strongest off-the-shelf cranes.

Sarens has been awarded three work packages at Hinkley Point C and is hoping for more work in future. The company is supplying hydraulic cranes (100-500t capacity) to install a concrete batching plant, as well as two CC2400-1 crawler cranes for construction of the jetty. Work started on the jetty in 2017, and once completed this spring the 500m structure will enable 80% of the construction materials for the project to be delivered by sea. Sarens is also developing its largest-ever crane – the SGC 250 – for the Hinkley project under a £20 million, four-year contract.

The new SGC 250 crane, to be delivered next year, will be used for all the heavy lifts on site. It will be able to perform lifts ranging from 50t to 1150t, with radiuses of up to 165m, and will be used to install large prefabricated concrete structures for the outer building as well as heavy components like the reactor pressure vessel and the steam generators. A second CC 2800 will be used as a rigging crane with the SGC 250.

The crane looks a lot like the company’s other SGCs, except that it is a little better and a lot stronger. “With each new version, we challenge ourselves and improve gradually, not only on capacity but also on safety systems, environmental aspects, ease of rigging and transportability,” Sarens says.

The main advantage of the new crane, he adds, is its ability to move between three different lifting positions, without the need for disassembly and reassembly. This is achieved thanks to 6km of rail system embedded in the construction site floor, which allows the crane to turn 360° and move laterally.

The crane is CE certified and includes full redundancy of power packs or engines.

“The crane has to be delivered in early 2019,” Sarens tells NEI. “Normally it would take about six weeks to assemble the crane on a site, but a lot is dependent on the local circumstances.” Getting the crane ready on site is one of Sarens’ most complex tasks.

The SGC 250 will be moved overland from Gent, Belgium to a nearby laydown yard before it is shuttled to the project site. An estimated 280 trucks will be required to deliver the SGC. At the moment the narrow lanes leading to the site only allow ten trucks per day. A purpose-built access road is planned, but a lot of work is still required on logistics.

“The main challenge is upon the arrival on site. Everything before is pretty standard in our business,” notes Sarens. He says the team has to contend with limits to the number of trucks the site can receive, entrance formalities for truck drivers, the space available to assemble the crane onsite, whether it will have access to a preassembly area so that the boom parts can be put together at the same time as the main platform, and the other types of equipment and workers on site.

One way that transport is made easier is by using local materials for ballast. Instead of shipping hundreds or thousands of tonnes of steel or concrete counterweight pieces, the standard containers used to ship the crane can be filled with gravel or sand and used as ballast.

“Hinkley Point is an extremely prestigious project, not only in the UK and Europe but also globally,” adds Sarens project manager Mark Rowlands. “The eyes of the world will be watching how Sarens performs.”

Looking beyond Hinkley, Sarens sees nuclear power as a “promising and stable” market, with work in maintenance and upgrading existing plant as well as new build.