Stahl special

Swiss railway carriage manufacturer Stadler Rail has ordered a total of 14 standard and three special cranes for approx. 700,000 Swiss francs (450,000 Euro) for its new train production line in Bussnang, Switzerland.

The factory building is 51m wide, and the customer wanted the 7.5t capacity cranes to span the distance. Carriage sections of up to 45t were to be lifted by the production line cranes along an 85m track length.

The span would normally be broken into two aisles. Spans of up to about 30m can be achieved with standard cranes. But Stadler Rail wanted a single span.

It takes heavy and tall bridge sections to span longer distances. The height of their box girders cuts into the available hook height. Such cranes would also require reinforcing the building's supporting structure. The customer did not like this alternative either.

So R Stahl's wholly-owned Swiss distributor Stahl-Fribos AG worked with the building's architect, Henri Frei, to come up with a combination design for the three cranes. The key design feature was that the three cranes hang from a suspension carriage hung from the centre of the roof. The three-point suspension permitted a crucial reduction in weight and headroom of the crane bridges.

Each of the three cranes has two 7.5t capacity R Stahl SH 50 electric wire rope hoists. An electronic synchronous controller was installed for the hoist motors to ensure coordinated hoisting and lowering movements. Using a radio remote control, the operator can select two hooks on one crane, four hooks on two cranes or all six hooks for coordinated hoisting and travelling.

The operating speeds specified for the cranes all two-step, at hoisting 6.3/1.0 m/min, cross travel 20/5 and long travel 40/10 m/min. They were also equipped with electric load monitoring and brake management.

The engineering team from Stadler Rail AG, led by Robert Zaugg coordinated the planning and completion of the crane installations, including erection and commissioning in the customer's plant in January 2004. The order follows another for the site commissioned in 2001.