ALL Erection Buys 10 of Manitowoc's New 330-Ton Crawler Crane

Enlarge Image   From left, All Erection's Rick Mikut, Larry Liptak, and Kris Liptak with the company's new Manitowoc MLC300 crawler crane.

March 18, 2014 - ALL Erection & Crane Rental Corp. has purchased 10 of Manitowoc’s newly introduced 330-U.S.-ton capacity Manitowoc MLC300 lattice-boom crawler cranes, which feature Manitowoc’s exclusive Variable Position Counterweight (VPC).

ALL Erection’s purchase took place at the ConExpo-Con/Agg trade show in early March, where the new Manitowoc MLC300 made its debut.

Typical crawler cranes sit more heavily on the rear ends of their crawlers during assembly and when no load is on the hook because the counterweight is located at the back of the crane’s upperworks. But when a crane makes a lift, the higher ground-bearing pressure typically transfers to the crawlers’ front ends as the load on the hook balances the effect of the crane’s counterweight. With traditional cranes, there is no way to avoid these shifting high ground pressures.

But the VPC moving counterweight on Manitowoc’s new MLC300 helps keep ground-bearing pressure more centered and well distributed over the length of the crawlers. The patented VPC system keeps the crane’s center of gravity near the center of the machine by automatically moving forward or backward on a rail system in response to the load on the hook and the boom angle. The VPC’s balancing act helps distribute ground bearing pressure more evenly over a larger area. Its efficiency eliminates the need for carbody counterweights, improving on-site mobility and reducing the amount of matting required to distribute loadings from the crawlers to the ground.

“We can reduce the number of required mats by half. That’s thousands of dollars in savings per month, and that’s saying nothing of the reduced counterweight [shipping] loads and the savings realized by reducing the required job site prep area,” says Rick Mikut, crawler crane division manager, ALL Erection & Crane Rental Corp.ALL Erection is scheduled to start taking delivery of its new Manitowoc MLC300s in about December of this year. Manitowoc plans to begin full production of the new model in about a year.

Enlarge Image  Manitowoc MLC300 with variable position counterwieght.

 

The new Manitowoc MLC300 has a maximum load moment of 14,410 kip-ft. (29,700 kip-ft. with the optional VPC-MAX system, which uses a rail that extends behind the crane’s rotating bed to allow the VPC counterweight to position itself even farther back than the standard VPC system does).

The MLC300’s lattice boom has a 98-ft. basic length, which can be extended to a maximum of 315 ft. with FACT-connected inserts. The maximum tip height is 320 ft. On the 98-ft. boom, capacities range from 661,300 lbs. at radii from 17 ft. to 21 ft., to 94,200 lbs. at a 100-ft. radius. On an intermediate boom length of 217 ft., capacities range from 376, 400 lbs. at a 28-ft. radius, to 26,200 lbs. at a 215-ft. radius. And on the 315-ft. maximum boom, capacities range from 158,200 lbs. at a 36-ft. radius, to 10,700 lbs. at 255 ft.

The maximum luffing-jib length is also 315 ft., and the longest boom-and-luffing-jib combination on the basic MLC300 is 197 ft. of boom plus 295 ft. of luffing jib—a total length of 452 ft. With that combination, capacities range from 43,900 lbs. at a 100-ft. radius, to 11,900 lbs. at a 295-ft. radius.

For efficient transportation, sections of the luffing jib can nest inside the boom sections to reduce shipping volume.

The MLC300 is powered by a Cummins QSG-12 diesel engine that puts out 450 hp at 1,800 rpm and meets EPA/CARB Tier 4 Final emission standards. Efficient, independent, full-power multi-function operation is provided by a combination of open- and close-loop systems. Operation is controlled and optimized by Manitowoc’s proprietary Crane Control System, which has a user-friendly interface with two full graphic displays and ergonomic joysticks.

For easy operator familiarity, the Manitowoc Common Control System assures that controls on nearly all Manitowoc cranes have the same positioning, look, and feel. The Manitowoc Vision Cab is fully enclosed, insulated, and climate controlled to give the operator a comfortable place to work. Large windows, power tilting, and cameras on all drums, the boom point, and tailswing give the operator a clear view of the load and entire crane.

The basic machine includes a main hoist drum and an auxiliary/luffing drum, both powered hydraulically and grooved for 28-mm wire rope. The main hoist drum delivers 36,760-lb. single-line pull on all layers, and the auxiliary drum delivers 30,000-lb. single-line pull on all layers. Each drum has a maximum line speed of 536 fpm. Additional hoisting drums are optional.

The hydraulically powered swing system rotates the upperworks on a 9’10” diameter, triple-row roller bearing. Maximum swing speed is 2.0 rpm.

The right and left crawlers measure 31’10” long, with 48-in. wide steel pads and have automatically lubricated rollers. Mounted to the carbody, they provide a 26’5” wide overall stance. The right and left crawler assemblies are interchangeable, in order to provide flexibility in assembling the MLC300. Each crawler is powered independently by a variable-displacement hydraulic motor, allowing excellent maneuverability and counter-rotation for pivot turns even when traveling with a full-rated load. Maximum travel speed is 0.8 mph.