Manitowoc's new 2,535-ton Model 31000 is designed to drastically improve the operation of a heavy-lift crawler crane with its innovative moving counterweight tray, according to the company. The 31000 was officially launched today at ConExpo.
The 31000 includes the Variable Position Counterweight (VPC). This unique lift enhancer automatically extends when more counterweight moment is needed during the lift. It is mechanically locked to prevent the counterweight from inadvertently moving during operation. The system's mechanical actuator is controlled by the crane's EPIC control system and is deployed based on boom angle and applied load.
Because the VPC never touches the ground under normal working conditions, the amount of ground preparation work needed with a typical lift-enhancing attachment is greatly reduced. The VPC also allows for pick-and-carry of all rated loads, making it much easier to maneuver around the jobsite. The VPC extends from the rear of the crane and ranges from just over 27 feet when fully retracted to 95 feet when fully extended.
Larry Weyers, executive vice president of the Americas region, said that Manitowoc is creating the mega-sized 31000 to meet the challenging demands of global construction, where major projects require ultra high-capacity cranes.
“For some time, we've been receiving feedback from our heavy lift customers that the vessels and other components used in refineries, petrochemical plants and fabrication yards are growing in size,” he said. “With the introduction of the Model 31000, Manitowoc has once again applied its superior engineering capabilities and knowledge of the market to design an innovative and unique lifting solution.”
The Model 31000 is mounted on four separate tracks, rather than the traditional two.
Bill O'Neil, the lead engineer on the product development team, said this provides several benefits. “This track configuration provides the lowest possible ground bearing pressure with reduced matting requirements and site preparation time,” he said.
The four tracks are trunion-mounted. “This not only provides an efficient means of crawler assembly,” O'Neil said, “but also allows the crawler tracks to oscillate during travel to provide uniform load distribution.”
The swing assembly is configured on a roller path system, rather than the typical turntable bearing. The outside diameter of the roller path measures just over 40 feet. This design helps maximize load distribution and decrease ground bearing pressure. Wear plates on the top of the roller path help protect the surface.
The single-boom Model 31000 features FACT connection technology and comes in a variety of configurations. The main boom ranges from 180 feet to 344 feet. Fixed jibs range from 78 feet to 137 feet, with a maximum combination of 311 feet of main boom and 78-foot jib. Luffing jib configurations range from 118 feet to 334 feet. Maximum combination is 295 foot main boom and 334 foot luffing jib.
The Model 31000 is powered by dual 600-hp Cummins engines. This power plant configuration provides ample power for multifunction operation. In addition, the redundant design allows for single engine operation.
The Model 31000 is designed to be transported in 85 truck loads. Other than the main boom, all components are designed to be less than 11.5 feet for easy permitting and transport.
Once on site, the Model 31000 can be erected with a Model 2250 as an assist crane, an 80-foot aerial work platform and a telehandler. While there are many factors that affect the time it takes to assemble any crane, engineers are estimating that with 196 feet of main boom and 196 feet of luffing jib and excellent site conditions, the Model 31000 can be assembled in 12 days with minimal crew and equipment.
For more information, visit www.manitowoc.com.