STREET CRANE IN UNIQUE AEROSPACE COLLABORATION
The UK's most experienced crane builder, Street Crane Company, have just commissioned a series of unique cranes at a world class facility in Chester for processing aircraft wing panels.  The venture is a technical collaboration by Metal Improvement Company - an international leader in metal treatment and BAe Systems - the UK partner in the Airbus programme.
	"This was a technically challenging and immensely rewarding project," commented Street's managing director Andrew Pimblett.  Besides its contribution to productivity the novel mechanical handling system devised by Street has also enabled Metal Improvement Co to use space more efficiently.
	A total of seven double girder Street cranes have been installed with a maximum safe working load of five tonnes.  All units have street ZX hoists and two of the cranes are fitted with a turntable.  Some units are of twin hoist design with load summation.  The new overhead crane system handles single wing panels of up to 107 feet in length.  This allows them to be loaded and unloaded from the shot peening machines, transported along the bay and rotated through 180 degrees for location in storage racks.
	New Airbus models have greater wing panel lengths than earlier models.  Metal Improvement Co have therefore relocated their facility within the BAe site to avoid road transport.  By shot peening, the company impart a curvature to the wing, removing tensile stresses, imparting a compressive surface stress and greatly increasing the fatigue resistance of the component.
	Extreme care is taken in handling the wing panels - a requirement that is complicated by the need to rotate them.  Street's answer to this was a specially engineered handling system for the cranes.  A turntable is located between the beams of the double girder crane and a supplementary support beam enables the wing panel to be secured at several points for safe and stress-free handling.
	The wing panels are bulky, but light.  Load swing and instability were therefore potential threats.  These problems have been overcome by the use of Thyrister soft-start control to give progressive acceleration and deceleration on both long and cross travel.
	Street have made a speciality of engineering special systems for the aerospace industry.  Construction bays typically comprise wide bays with lightweight roof constructions.  Often there are limitations regarding crane depth to preserve maximum working height.  Street have developed a range of solutions to these problems featuring strong lightweight beam designs, compact lifting gear and even cranes that can flex as lightweight roof structures respond to snow loading and wind pressure.
		
More information: Gus Zona, Street Crane Co Ltd, Tel. +44 (0)1298 812456  Fax. +44 (0)1298 814945, E-mail: admin@streetcrane.co.uk  Web: www.streetcrane.co.uk