Britain’s biggest industrial crane and hoist manufacturer, Street Crane Company, now has ten cranes installed supporting the Crossrail project. The latest a 40 tonne double girder Goliath crane on Oxford Street has now been in service for three months. The crane will be lifting spoil skips and lowering tunnel segments and other pre-cast elements for the Crossrail tunnel and new Tottenham Court Road Western Ticket Hall.
The Oxford Street crane is a double girder box beam design with twin custom built TVX hoists, each capable of lifting 20 tonnes. Twin hoists give maximum flexibility as they can be used singly or in tandem depending on the weight and geometry of the load to be moved. The crane has a total height of lift of 37 metres with a maximum normal speed of 15 metres per minute and a minimum 1.5 m/m. Hoist speed can be boosted to 23 m/m for light loads of two tonnes or less. A cab located on the crane bridge will give the driver clear visibility of the site.
Large ground beams, 1.5 metres deep, have been cast 31 metres apart on which the rails for the Goliath crane legs run. The crane spans the beams and has an additional 5.1 metre cantilever at one end so that spoil skips can be offloaded onto awaiting trucks that are outside the protected excavation area. The rectangular frame legs of the Goliath crane at the cantilever end have been designed to permit the passage of the skips between them. In addition to shielding the excavation shaft, the ground beams protect the crane from any minor ground movement due to excavation.
Elsewhere on the Crossrail development more cranes from Street are in use. Six ten tonne single girder cranes are used in the tunnel segment casting shops for de-moulding and transportation of the cast segments. In the curing yards three rail running Goliath cranes of a fully weatherproof specification are used for placement of the tunnel segments and subsequent retrieval after they have matured to full strength.
The developer, Crossrail Limited, is a subsidiary of Transport for London who sponsors the project jointly with the Department for Transport. Street Crane’s contract is with BFK, the main contractor for this western stage of tunnelling work from Royal Oak to Farringdon. BFK is a joint venture between BAM Nuttall, Ferrovial Agroman and Kier Construction.
The complete line will run from Heathrow/Maidenhead in the west to Shenfield/Abbey Wood in the east and has a total length of 73 miles (118 Km) of which 13 miles (21Km) is in twin bore tunnels. There will be 37 stations along the line. Over 90 per cent of the investment by Crossrail remains within the UK economy.