Holding sway

Engineers at Belgian crane manufacturer

has developed innovative self-erecting mobile crane technology that is said to be safer and more efficient than the conventional alternative. Working with

funding from the EU, the team has employed a new anti-sway device.

The device was developed at the University of Leuven and aims to minimise or completely prevent the sway motion of the load during operation by controlling both the rotating motion and the movement of the trolley. Additionally, each aspect is independent of the load lifted, and the anti-sway controller adapts its parameters according to the length of the cable, taking into account the structural resonance of the crane.

Consequently, the crane does not require additional sensors to detect sideways movements and will reduce the sway motion by a factor of three, the developers claim.

Cranes, which often monopolise building sites, are highly inefficient in their current static guise. Typically, once they have been erected, they remain in the same place until the job is finished. David Janssen, project manager at Arcomet, the lead partner of the project in Belgium, explained that often cranes are erected and remain fixed in the same place for up to three months when in fact they are only needed for a few hours’ work in total.

Mobile self-erecting cranes eliminate this inefficiency by moving swiftly from one building site to another, completing the work in hours before moving on.

‘In the Netherlands it is very popular to have a self-erecting crane on a mobile carrier,’ said Janssen. ‘They have several job sites to do in a day, so they erect the crane in 15 minutes, dismantle it in 20 minutes and then drive to another site.’ Therefore one crane can do the work which previously required several installations. Janssen cited the better performance in a narrow building space, such as city renovation, as a prime example of the need for a self-erecting mobile crane over a conventional design since it is more efficient and work can be carried out much faster on the site.

Such changes to conventional crane technology had a knock on-effect on the design of related equipment, in particular the truck or loader which carries the crane. The chassis was remodelled so that it was lower and would be no higher than 4m, giving more stability to allow the crane to be moved to all parts of the site. Janssen said more engineering was required for the gearbox and a greater emphasis on electrical components was needed on the crane.

With the swift installation and removal of large machinery, coupled with the nature of its work, safety is a key issue.

Arcomet has secured 15 orders for the new cranes in the UK, Belgium and the Netherlands.