Variable counterweight lets Manitowoc crane work in tight spaces

  • 19-Jun-2008 08:49 EDT
ohfmanitowoc.jpg

Manitowoc’s variable-position counterweight adjusts to payloads, keeping space requirements down.

A new counterweight technology is being deployed on a 2300-t (2535-ton) crawler crane that Manitowoc Co. plans to begin shipping in 2010. The new balancing technique reduces the amount of ground that needs to be prepared for the crane’s operation.

The Model 31000 crane employs a variable-position counterweight (VPC) to reduce its operating footprint to 50 x 66 ft (15 x 20 m), compact for a crane with main boom range of up to 344 ft (105 m) and fixed jibs ranging up to 137 ft (42 m).

The VPC lift enhancer is mounted on a rack and pinion mechanism so it can automatically extend when more counterweight moment is needed during the lift. That keeps its footprint low while letting the crane lift heavy loads.

“The counterweigth put the weight in the center, distributing it on all four tracks. That helps reduce the ground bearing pressure. With some cranes of this size you have to pour a concrete base,” said Larry Weyers, Manitowoc’s Executive Vice President.

The VPC’s mechanical actuator is controlled by the crane’s EPIC control system, which monitors the boom angle and applied load to determine where to position the counterweight. During operation, the counterweight is mechanically locked to prevent inadvertent movement.

The VPC extends from the rear of the crane and ranges from about 27 ft (8 m) when fully retracted to 95 ft (29 m) when fully extended. The VPC also allows for pick-and-carry of all rated loads, making it much easier to maneuver around the job site. 

The Model 31000 is mounted on four separate, trunion-mounted tracks, rather than the traditional two. “This provides an efficient means of crawler assembly and allows the crawler tracks to oscillate during travel to provide uniform load distribution,” said Bill O’Neil, Lead Engineer.

The crane, powered by dual 600-hp (447-kW) Cummins engines, can be assembled in 12 days. Excluding the main boom, most of its components measure less than 12 ft (3.7 m).

“It only takes 85 truckloads to deliver. Competitors take up to 200 truckloads,” Weyers said.

Share
HTML for Linking to Page
Page URL
Grade
Rate It
0.00 Avg. Rating

Read More Articles On

2016-12-07
The Boston-based startup believes the marine domain is even better suited for autonomous systems than aerospace, automotive and other off-highway sectors. The company is currently testing its technology on commercial vessels in Boston Harbor.
2016-12-08
Automation is one of three main technology areas—along with connectivity and alternative drivelines and fuels—that Volvo Construction Equipment is devoting significant R&D resources to further develop. The company recently demonstrated a prototype autonomous wheel loader and articulated hauler working together.
2017-02-28
SANY India, a manufacturer of construction, heavy machinery and renewable equipment, has entered into the mining segment.
2017-03-01
Ashok Leyland’s first Circuit electric bus is designed and engineered entirely in India, by Indians, for India.

Related Items

Training / Education
2017-11-08
Standard
2013-05-03
Training / Education
2018-05-21
Technical Paper / Journal Article
2011-04-12
Training / Education
2018-06-07