The Wolfsheck plant, founded in 1905, is situated in the northern region of the Black Forest, Germany. The building in which the crane was to be installed was only 11m wide. For handling further paper reels and taking up other parts, two load hooks were required. The crane, or rather the two hoists, had to be set to different hook spacings at the press of a button.
During the handling procedures the paper reels were to be rotated horizontally. In addition to the usual three directions of motion (lifting, cross travel and long travel) a fourth dimension was added in the form of rotation. In fact, the distance between the hooks can also be adjusted by motorised hoist trolleys.
Apart from this, the hooks had to approach the end of the crane runway extremely closely as they had to take the paper reels up from a neighbouring crane runway.
Due to the difficulties of integrating the crane into the existing building – with obstacles underneath the crane and restricted space beneath the ceiling – the Employers’ Liability Insurance Association was consulted. In order to meet the rigorous operating conditions, the project planning engineers calculated a classification of H3, B4 in accordance with DIN 15018.
The hoists chosen were two original STAHL SH60 wire rope hoists furnished with independent load hooks, which were mounted on a rail and equipped with electric drives, and could thus be set to the desired hook spacing. The wire rope hoists were equipped with double-grooved rope drums to ensure true vertical lift.
A high-quality polyurethane-based paint will protect the crane in the warm, damp atmosphere reaching temperatures of up to 55°C. The tried-and-tested direct drives were planned with two speeds and provided the required 60% duty cycle even in this hot ambience.
The hoist motors in FEM classification 4m have power reserves to ensure long, trouble-free operation. The stable rope guides in cast metal, insensitive to high temperatures, are a standard feature of Stahl wire rope hoists.