Blade runner

Vien Tek specialises in manufacturing blades for wind turbines. It is based in Juárez City in Mexico and serves the southern and western US wind power market, as well as the growing market of Latin America.

Like aircraft wings, handling and moving these vanes - which are typically 30m long and weigh 5t - is a delicate and tricky matter.

Vien Tek uses a straddle carrier produced by Shuttlelift, a US company based in Sturgeon Bay, Wisconsin.

Shuttlelift is is better known for its pick and carry mobile cranes but also produces a range of this kind of machinery, which it calls industrial mobile hoists, up to 800t lifting capacity.

The unit used by Vien Tek is a model ISL30B rated at 60,000lb (27.2t) capacity. It is used to transport, store and load windmill blades at the company's production facility.

The lifting frame was specially made for this application allowing Vien Tek to rotate and level the blade into the desired transport or storage position. The machine has a 6m inside clear width, 6m hook height and dual traversing trolley hooks for lateral movement of the suspended load. It was delivered in June 2002 and, according to Shuttlelift, has been performing well.

The ISL30B is powered by a Cummins diesel engine in standard version but a battery powered version is also available.

The hoisting mechanism has direct planetary gear drive with integral enclosed spring applied brake, fixed displacement hydraulic hoist motor and an automatic hydraulic load holding valve. With no load, the hoist lifts at a speed of 8.8m/min and under full load it lifts at 7.6m/min.