Maxim Crane Works L.P. (Maxim) was contracted to provide lifting services for a Mechanical Contractor in a New Jersey power plant. Maxim’s scope was to lift Air Cooled Condenser (ACC) units from a heavy haul unit and set them into place on top of a 75-foot-tall structure. A total of 12 lifts were required consisting of 8 double ACC module lifts (520,000 pounds each) and 4 single ACC module lifts (260,000 pounds each). The crane was to be hook ready on June 26th.
The pre-planning for this project started early in 2017, at which time a Manitowoc 18000 with MAX-ER was selected to make the lifts for the project. In mid-April, Maxim’s Engineering Group was consulted, tasked with the development of a wood mat support system, lift plans and rigging designs. Several key factors were evaluated early on: hook height, capacity, rigging arrangement and rigging weight. The Group determined traditional spreader bar systems were too heavy and consumed excessive vertical space for the crane to make the lifts given the crane configuration and ACC module lift weights. Additionally, as the project progressed, the weight of the double ACC module was increased to 590,400 lbs – a 14% increase over the already challenging pre-planning lift weight. The increase in weight necessitated a careful review of each piece of rigging.
It was determined that for the 18000 to complete this project effectively, an alternative approach would be needed to the rigging. A lift frame concept was conceived and adopted, and the official notice to proceed for design of the system was received on June 7th. A major driver of the design was the requirement to use off-the-shelf materials due to the extremely compressed schedule. Because the crane was approaching capacity limitations, it was essential that the lift frame be structurally efficient. From design to load testing of the lift frame took only 19 working days. Each member of the project team contributed to make this happen. The load test was successfully completed on July 5th with the 300-Ton rated lift frame lifting a weight of 755,630 pounds (377.8-tons). Immediately following the load test, the lifting frame was disassembled and shipped to the project site for the first lift on July 7th.