New from Manitowoc at CONEXPO-CON/AGG 2014 are the 330-ton MLC300 and 650-ton MLC650 crawler cranes that feature Manitowoc’s Variable Position Counterweight (VPC) system. The VPC system automatically positions the counterweight to accommodate the required lift, moving the counterweight along the rotating bed and positioning it based on changes in boom angle. According to Manitowoc, benefits include reduced ground preparation, lower ground-bearing pressure, and less counterweight—all without sacrificing capacity. Customers will not have to buy, transport, or install as much counterweight, says the company, compared with a conventional configurations, and counterweight boxes are designed to be common across multiple crane platforms.
“The VPC is game-changing technology,” says John Kennedy, SVP crawler cranes. “This new technology will have a significant impact on the lifting industry, as it enhances crane capacities, reduces mobilization time on the job site, and in the end, saves customers a significant amount of time and money.”
The MLC300 features 315 feet of boom and has the option of a fixed-jib attachment of 98 feet. A 315-foot luffing jib can be added to extend its reach to 473 feet. The MLC650 has a 341-foot main boom, which can accommodate a 98-foot fixed jib. A 331-foot luffing jib can be added to reach a maximum 515 feet. Both cranes, says Manitowoc, are ideal for energy-related projects, including refineries, petrochemical installations, and power plants, as well as infrastructure applications. The smaller footprint resulting from the VPC system enables the cranes to easily move around a job site, says the company, and a VPC-MAX capacity enhancing attachment allows increased capacity for heavy lifts that would usually require a wheeled-type lift enhancer.
The VPC-MAX attachment increases capacity and boom-and-jib combination lengths. The counterweight movement is based on the lifted load, boom length, boom and jib length, and load radius. The MLC300 can raise 394 feet of boom with the VPC-MAX attachment and a boom-and-luffing-jib combination of 551 feet. The MLC650 can raise 459 feet of boom with the VPC-MAX attachment and a boom-and-luffing-jib combination of 672 feet. The MLC650’s maximum capacity increases to 770 tons with the VPC-MAX installed.
For the MLC300, the VPC-MAX attachment increases the maximum load moment when a 100-foot fixed mast, a VPC-MAX counterweight beam, and an additional 88,185 pounds of counterweight are added to the base crane. The ground preparation area needed for the MLC300 using the VPC-MAX can be only one-tenth of that required for conventional cranes. For the MLC650, the VPC-MAX attachment increases the maximum load moment when a 118-foot fixed mast, VPC-MAX counterweight beam, and an additional 220,460 pounds of counterweight are added to the base crane.
Because the counterweight attachment of the VPC-MAX on the MLC300 and the MLC650 never touches the ground, higher capacity lifts on barges are now possible, says Manitowoc. In addition, with its long reach and high capacity, the MLC650 can install 394-foot and taller towers for the wind industry.
With their optimized component weights and dimensions, both the MLC300 and MLC650 are designed for easy transport., says Manitowoc. They have a removable live-mast shipping module, and their boom inserts are designed to allow luffing-jib inserts to ship within them, thus reducing shipping costs. In addition, both cranes use Manitowoc’s patented FACT connection technology and are operated via Manitowoc’s Crane Control System (CCS), a standard operating system across several crane models in different product ranges.
Additionally, the MLC300 has a crawler-tensioning system, a dedicated hydraulically activated cylinder and hydraulic supply that allows independent track tension adjustment via crane setup remote and standard hydraulic connection.