Telescopic Gantry

Bigge Crane and Rigging used a Hydrospex SBL 1100 telescopic hydraulic gantry to ofi oad and set all the turbines and generators during construction at Inland Empire Energy Center, in Riverside County, CA. The full-powered SBL 1100 has a lifting capacity of 1,100 tons, and at its fully extended height of more than 41 feet, it can lift 440 tons.

Construction of the billion-dollar cycle gas turbine power station by General Electric began in 2005 and is scheduled to come on line in 2008. Bigge has provided heavy lifting transportation and rigging services, hauling and placing 46 components weighing between 150 and 400 tons.

The final major heavy lift at Inland Empire came at the end of January 2007, and involved setting the Unit 2 Combustion Turbine. The 250 ton turbine had to be raised over the top of a generator that was already in position and maneuvered into place.

The SBL 1100 was mounted on a pair of elevated runway beams. Mounted on top of the SBL 1100 was a computer-controlled Hydrospex strand jacking system. In conjunction with a swivel bar, the strand jacks offloaded the turbine - as it had with each component previously - from a platform trailer, then rotated it, jacked it to the required height, and traveled it 230 feet for final placement. The whole operation took less than seven hours.

The Hydrospex SBL Super Boom Lift has several key features that differentiate it from other hydraulic gantries on the market. It folds away for transport to fit into standard 20 foot containers. It self-erects into the upright position in 60 seconds and has threestage, double acting hydraulic cylinders. All the hydraulics are inside the unit to keep out contaminants, which are the primary cause of leaks and breakdowns. This also does away with hazardous trailing hoses. Self-cleaning hydraulic seals are used to eliminate leakage. The octagonal booms are made from T1-100KSI high-tensile steel to reduce weight and achieve maximum possible strength. The maintenance-free bearing slide surfaces of the booms require no lubrication.

To reduce load bearing pressure by as much as 60%, the SBL runs on crawler-style tank rollers instead of wheels to eliminate wheel spin and help ensure smooth travel over track splices. “At Inland Empire it took us just three hours to travel the 250 ton load across 230 feet - half the time it would take with a traditional push-pull gantry,” says Pete Ashton, Bigge vice president of major projects.

The Intellilift control system ensures that the lift is kept under control at all times, continuously managing all the functions to work within prescribed tolerances. It automatically corrects the lift of the units to maintain synchronized tower heights. In the event of overload, the system alerts the operator and suspends the operation. The display panel shows the weight on each leg and elevation. The control system also allows the operator to choose either wireless remote control or hard wired operation.