The problem is one of logistics. Modern turbines weigh several hundred tonnes. On site assembly during construction and dismantling for periodic service are time consuming processes. Overhead cranes are essential to safely manoeuvre major sub-assemblies and enable a multitude of small parts to be located precisely.

Six overhead cranes with a total value of £450.000 were installed by ABB at their contract at Shoreham. Two of these in the turbine hall are double-girder cranes with twin-hoists of 20 and 70 tonnes respectively. The two cranes mainly operate independently, using the hoist that is most appropriate to the load. However, for major sub assemblies, weighing up to 123 tonnes, the cranes operate in tandem using the larger hoists.

The same principles were applied by Raytheon at Rochester who placed a £300,000 crane order. For mainstream usage the station has a double girder crane with twin hoists of 130 and 20 tonnes respectively. This crane could meet all construction requirements on its own, but to speed construction Raytheon specified a second crane with a 55 tonne hoist. This enables the full range of loads to be handled quickly and efficiently. To shorten construction time further in the hall, which requires a 22 metre height of lift, a double speed lift facility was provided.

The additional cranes supplied to ABB at Shoreham included units of 20 tonnes for the gas compressor house, 10 tonnes in the pump house, seven tonnes in the cooling water annexe and six tonnes in the workshop. In the case of the gas compressor house crane, special explosion resistant motors and controls were employed.

For stable handling of loads both contractors selected stepless inverter control. This assures smooth acceleration and deceleration so that load swing is minimised and components can be precisely located.

Street have a world-wide reputation for the supply of cranes for power stations and other manufacturing operations. For the end user they play a vital production process role and, as the power industry, they can also contribute to faster fit out, new capacity entering service more quickly and earlier returns on investment.. Shoreham will enter service during the last quarter of 2000.

Street Crane Co Ltd
Town End Works
Chapel-en-le-Frith
High Peak, SK23 0PH
United Kingdom

Tel.
+44 (0)1298 812456
Fax.
+44 (0)1298 814945

admin@
streetcrane.co.uk

www.streetcrane.co.uk

For more info please e-mail Ainsworth Maguire:
pr@ainsmag.co.uk

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