Self erector proves its worth
By Alex Dahm06 January 2009
To reduce site operating costs a developer in Scotland is using a self-erecting tower crane to increase operational efficiencies while reducing manpower costs.
Specialising in the construction of affordable private housing developments, Discovery Homes (Scotland) Ltd is building a three storey block of 44 two-bedroom apartments in Dundee. The VC42 self erector is from Vanson Cranes' VC range developed by Trevor Vanson, managing director, to address specific requirements of the UK construction industry.
As with most urban development projects there is often an issue with site access. Discovery Homes recognised the value of using a compact and manoeuvrable pedestrian operated tower crane to improve material handling efficiency.
"Having the availability of the VC42 enables us to build when we want to, rather than having to wait for a crane to arrive on site. Also, instead of undertaking the labour-intensive process of manhandling materials such as blocks, windows and plasterboard, we have instead used the VC42 to offload materials from the forklift truck and then lift them straight to the required area of the site. This has been a godsend and has had a huge impact on our labour costs, as one crane operator is now able to do the job that was previously done by 10 labourers. The crane also saves time, as we now use the VC42 to crane a whole pallet of plasterboard onto the site instead of getting three or four labourers to carry individual sheets," a Discovery spokesman said.
Using the VC42 has also reduced the amount of damage to delicate materials, for example, sheets of plasterboard and some 2.7 m wide doors.
The VC42 is designed to be simple and user friendly, allowing it to be erected in a small working envelope to reduce erection and dismantling costs compared with conventional tower cranes of a similar size, Vanson said. It is self-contained and has its own ballast handling derrick so there is no need for third party lifting equipment. The crane can be taken down and erected in a different position on the site in five hours.
The VC has independent hydraulic cylinders in the inverted position, to retain oil, to avoid the potential for crane collapse during dismantling, Vanson explained. During erection the crane can be slewed through the full 360º, which reduces the time needed and also allows easier positioning.