Safety & stability solution for space restricted cranes

Retractable Crane Windsail

Safety & stability solution
for space restricted cranes

Working for Select Plant Hire, IDC developed the first retractable windsail for the crane industry. The windsail provided the perfect solution for luffing jib cranes facing tough space and safety restrictions in urban environments.

IDC developed a new solution for luffing jib cranes facing tough space and safety restrictions in cities.

Luffing jib cranes are a popular solution for space restricted urban sites as they have jibs that can be raised to suit the job and space available. When parked, the jibs are raised at steep angles and are fitted with a windsail to ensure the crane rotates in the wind like a weathervane and thereby minimises wind loading on the crane.

Previously, luffing crane windsails were in a fixed position on the crane and made from rigid materials such as steel, making cranes difficult to manoeuvre. Select Plant Hire recognised that if these windsails were made retractable, the cranes would have much greater productivity.

Select came to IDC to take this idea forward and IDC not only designed the windsail, but took it right through the development process to production in IDC Models’ production unit.

IDC’s first step in the development was to brainstorm ideas and explore potential concepts. Risk analysis was an important early consideration to understand how the windsail would react at varying windspeed and loading.

Once a concept was selected, the engineering team produced detailed CAD models, selected materials and undertook finite element analysis to understand the stress resistance of the design and ensure the system was able to withstand large forces. This was further tested using a full-sized prototype of the windsail, subjected to wind speeds of up to 100 km/h.

IDC Models played a key role in this project, producing 3D printed SLA models, followed by a full scale prototype of the system.

The production engineers then went on to manufacture and assemble ‘windsail kits’ - each comprising around 3,000 components, controls electronic and aluminium extrusions of up to 8.6m length - for installation into jib sections by Select at their depot in St Neots, Cambridgeshire.

IDC used its global network to influence the design and manufacture of required components.

The new technology has meant that Select’s cranes have a higher operational wind speed limit than competitors and improved stability. With a smaller park radius, contractors can also install more cranes on a single site, dramatically increasing productivity.

The new windsails have already been used on sites in Manchester and London. At one site on London’s south bank where 21 cranes will be used, 17 will require retractable windsails. On such an exceptionally tight site, utilising this many cranes would have been impossible without the retractable windsail.

IDC has manufactured 32 individual windsails to date, for four different models of Terex crane. Demand for additional systems remains high with further production runs programmed.