Product category:
Robotics, Handling and Storage
News Release from: R. Stahl | Subject: Crane kits
Edited by the Engineeringtalk Editorial
Team on 04 June 2004
Cranes come in kit form
Crane specialist R Stahl reckons it has finally solved the problem of transporting long and heavy crane bridges half-way around the world: send them in kit form.
Crane specialist R Stahl reckons it has finally solved the problem of transporting long and heavy crane bridges half-way around the world: send them in kit form R Stahl's new crane kits targeted at Crane manufactures worldwide contain the hoist gear, end carriage and all electrical fittings needed to assemble large and bulky crane bridges to a maximum width of 23m coping with loads ranging from 2000-10,000kg
The only item missing is the bridge itself: research by the company revealed that all of its overseas customers have local access to steel suppliers capable of supplying suitable beams and sheet steel panels.
R Stahl provides the basic design drawings required to produce the bridge.
As well as the reduced consignment length and weight due to the absence of the bridge, crane kit users enjoy a range of other benefits such as comprehensive documentation and standard plug connections.
R Stahl has also designed in many other features to make kit assembly as straightforward and quick as possible.
For example, all design calculations for the kits are based on using standard, easy to obtain materials (S235/St37) rather than exotics.
Up to 12m span, bridge design and weight are based on IPBl (HE-A) standard profile, whereas over 12m calculations assume a welded box girder design.
This is important because in some markets standard profiles are available only up to 12m, beyond which a welded design becomes mandatory.
The crane bridge itself can be either side-mounted or mounted on the top end of the carriage using a high-tensile screw connection.
Compact structural dimensions are achieved as a result of optimum wheel diameters from 125mm and wheelbases from 1250mm.
The trolley can be continuously adjusted to match flange widths up to 400 mm, which allows the hoist to be used without the requirement of conversion parts to suit the crane flange.
The C rails for power supply come in 2m lengths, minimising transport risk and ensuring ease of handling during assembly.
In another piece of innovative design, crane kits also come with adjustable end stops that are clamped to the crane girder.
This means that the ideal position for the end stops can be set on-site without the effort and cost of welding.
In addition, the motors for all three movement directions (hoist, trolley and crane) each have two-speed operation.
The trolley and crane drives are equipped with built in flywheel masses ensuring smooth starts and stops without jerk.
For crane construction companies, R Stahl's clever design ensures increased safety thanks to continuous monitoring of the attached loads.
Many competitor systems only record a possible overload situation when the hoist picks up the load from the floor.
More safety is provided with R Stahl's system, because permanent monitoring means that the hoist movement is switched off if the load catches while being lifted.
Hoist and trolley drive motors are continuously monitored for overheat.
For the hoist specifically the motor is located outside of the drum therefore heat dissipation is maximised which increases reliability.
Other features which add to the longevity of the crane kit are the use of a cast-iron rope guide ring, rather than the plastic alternative and the management of brake wear again through continuous monitoring.
Currently the single-girder travelling crane crane kits come in 2, 3.2, 4, 5, 6.3, 8 and 10t load capabilities.
Their span ranges from 6 to 23m and lifting height from 6 to 10m.
Hoist speeds vary from 4/0.6 to 7.5/1.5m/min.
Later this year a double-girder travelling crane kit is due to be released.
This will come with increased capacities up to 25t.
Its span will vary from 6 to 22m and its lifting height from 6 to 10m.
Hoist speeds with vary from 3.2/0.5 to 7.5/1.5m/min.
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