A Crane Manufacturers Association of America (CMAA) member company has provided lifting equipment for the assembly of the world's first major airliner to use composite materials as the primary material in the construction of an airframe.
This aerospace project included the design, manufacture, and installation of an 80-ton custom underhung crane system with multiple bridges. The bridges can be interlocked to allow the trolley (carrier) to be transferred from one bridge to another throughout the system. There are 14 interlocking underhung bridges on the building runways. Twelve of the bridges are suspended in the main manufacturing facility, which is 1000ft long and 460ft wide.
The main bay houses four 1000ft runways, each containing three bridges. There are two auxiliary runways, one above the west mezzanine and one above the east mezzanine, with an underhung interlocking bridge on each runway.
The aerospace manufacturer uses three carriers, that each have the ability to rotate +/-180deg, to lift components anywhere in the manufacturing facility runway system by transferring from bridge to bridge. The operator can link up to three adjacent bridges together to lift very wide loads. Four 75ft long fixed carrier runways above the southwest mezzanine are used for carrier maintenance, while a moveable work platform is available to perform inspections.
Each carrier is controlled from an operator’s chair, which has access to 10 joysticks and numerous switches and pilot lights. The operator’s chair is located in the carrier, complete with color touch screen, providing critical real-time information about the crane systems. The operator moves the bridge, from which the carrier is suspended, using one of the joysticks. The lower carrier structure rotates 370deg. Two hoist beams, that move in and out, are suspended from the lower carrier structure.
Each beam has two underhung hoists, and each hoist is movable along the beam. Including the bridge and the hoist, each of the four crane hooks is movable along six axes. The hoists can be used singularly or in any combination up to a maximum of four. Each bridge can hold two 40-ton capacity carriers.
The bridges and carriers are powered by three phase 480 VAC conductor bars, which are installed on both the bridge runways and bridge girders. The bridges can be moved without a carrier using a local control panel with minimal pushbutton controls.
Crane Manufacturers Association of America are members of the overhead crane industry, serving the United States market from operations based in the United States, Canada, and Mexico.