18 March 2008
Their design is simple, their use complex. Gantry cranes are basic machines that provide lifting solutions across a variety of industries, from marine to power plant construction to airplane manufacturing. While they have been a lifting mainstay for more than 50 years, widespread usage of gantry cranes is just starting to happen across North America.
ACT recently asked gantry crane manufacturers and users to “show and tell” us about their gantry crane projects. For those who didn't participate in our invitation, the offer still stands. Let us know about your gantry projects, challenges and innovations.
Bridging the gap
Traffic build up on the two bridges on Interstate 65 spanning the Alabama River had recently become a pressing issue for the Alabama Department of Transportation. The congestion prompted officials to propose a plan for eliminating the gap between the two bridges, and creating one large super structure. The proposal called for a third bridge to replace the gap between the two existing bridges, adding an additional northbound and southbound lane, separated by a concrete divider.
R.R Dawson Bridge Co. won the bid, starting construction in May of 2006 and finishing the project in June, six months before expected completion. The company credited the timely completion of the bridge to their utilization of two 40-ton Mi-Jack rubber tire gantry cranes. The Travelift cranes allowed R.R. Dawson to streamline the work, bringing the project in under schedule, and the company says the cranes help reduce costs by close to 20%.“Mi-Jack Travelift rubber tire gantry cranes are designed to work up to 40% faster than conventional cranes, giving construction companies the ability to complete projects in record time,” says Mike Lanigan, Jr. of Mi-Jack. “The Mi-Jack Travelift rubber tire gantry cranes have several unique features, that allow for more efficient use, such as customized dimensions to fit each application, and inward facing cab complete with a 180-degree swivel seat to allow the operator to always position himself facing the load.”
On the jobsite, the Travelift can service multiple functions: it can be used to remove the old structure, pour concrete in place and set the new structural elements all with the same machine.
R.R. Dawson received praise from the Alabama DOT for bringing the project in under time and under budget, and also for managing to complete the entire project without having to shut down traffic lanes on the existing bridges. The Travelift rubber tire gantry crane only requires a 5-foot aisle-way on either side, allowing traffic to remain uninterrupted throughout the course of construction.
“Our cranes are designed to work in tight spaces requiring very little space to maneuver, which allowed R.R. Dawson to straddle the gap between the two existing bridges, and keep traffic moving,” says Jerry Studer of Mi-Jack.
Wind power lift
Customer-inspired lifting solutions have always been a specialty for Shuttlelift. The gantry crane manufacturer provides custom lifting equipment for a variety of industries, more recently the wind power sector.
Manufacturers of wind power components across Canada and the US are using Shuttlelift's SL and ISL gantry cranes to lift and move a variety of wind power components. In the past, these companies relied on two forklifts, working in tandem, to move large wind blades and towers. But they have discovered the Shuttlelift industrial gantry crane can be a one-stop shop for wind turbine material handling.
Iowa-based Clipper Windpower recently purchased a Shuttlelift SL75 to handle its turbine generator housings. These huge components, weighing up to 50 tons, can be moved with ease with the aid of multiple rigging set up on a single spreader bar.
DMI Industries recently purchased a Shuttlelift SL100 gantry crane for its plant in Fargo, ND. The SL100 will handle the movement of wind towers from production to the paint shop and finally to the shipping area.
It is not just the handling of heavy components that makes a Shuttlelift gantry crane a good option for the wind industry. The 4-wheel steer function, which is available as standard on certain units, allows for greater maneuverability of awkward loads, particularly considering that current wind turbine bases are at least 100-feet in length and 16-feet in diameter. The dimensions of these bases could be further increased on components for off-shore wind farms in the future.
Shuttlelift gantry cranes are designed with main frames constructed of box sectional high-strength, low alloy steel for maximum durability. These machines feature articulated pivot trunnion, which allows the frame to flex over uneven terrain and O-ring facing seals to prevent leaks. The gantry cranes feature powder coated carbon steel hydraulic tubing, cadmium coated bolts and zinc covered pins, providing maximum resistance to corrosion. A Shuttlelift gantry crane can be custom-built with height, width and wheel base dimensions tailored to meet customer requirements.