Slim and Trim Grove AT Turns Heads

Last fall, Manitowoc unveiled the GMK 5135, the newest member of its five-axle Grove all-terrain (AT) crane lines, during an open house held at the Manitowoc, Wis., company’s Wilhelmshaven, Germany, facility. Equipped with a five-section telescopic boom, the crane was displayed in a demonstration event on the company’s test pad, one of several new introductions shown off to customers and dealers. Next week, the crane will also be shared with attendees at Intermat 2009 in Paris, France.

The crane was built to replace the Grove GMK 5120B, which AT product manager Andreas Cremer termed a “very successful” model. At 135 tons, the GMK 5135 falls in the AT line between the 115-ton GMK 5115 and the 165-ton GMK 5165-2.

“We asked our customers [for input],” says Cremer, “and even with the new Grove GMK 5165 in the market we found a high potential for a lighter crane with a shorter boom and the need to design a successor for the 5120B. Due to the popularity of the Grove GMK 5120B, we kept the main characteristics of this crane but increased the lifting capacity by almost 20 percent overall.”

Design improvements

Engineered with Manitowoc’s Megaform boom and Twin-Lock pinning system, the boom design boasts increased rigidity in the 166-foot main boom and weight savings without the loss of capacity. The crane has increased counterweight up to 44.2 tons, consisting of various sections with a hydraulic installation and removal system. Counterweight rigging is controlled from the superstructure cab.

The GMK 5135 also features an ergonomically redesigned cab for improved functionality, visibility and comfort. “New on this crane is the carrier cab, which was already introduced with the GMK 4115 models and later with the GMK 5115 and GMK 5165-2,” says Cremer “and compared to the GMK 5120B we have also upgraded the superstructure cab to the latest version already used on various other models”.

The AT’s state-of-the-art control system includes the electronic crane operating system (ECOS) and the EKS 5 Light load monitoring system. All crane operations, including both superstructure and carrier functions are controlled via ECOS. Working in tandem with ECOS, the load monitoring system tracks the crane’s lifting operations at all times and provides early warnings. The ECOS also provides error codes, which can be transmitted to any Manitowoc Crane Care center worldwide, allowing for fast and accurate diagnosis and rapid repairs.

“The crane also features the new integrated heavy-duty jib as part of the swing-away, which saves weight and allows high capacities,” says Cremer. The 36- to 59-foot hydraulic bi-fold lattice swing-away extension is hydraulically offsettable. Controlled from the crane cab, it offers additional reach, as do three inserts that boost reach for an additional 12 feet compared to the GMK5120B to a maximum tip height of 301 feet.

Structural features

The AT’s chassis runs on a Mercedes-Benz OM 502 LA 8-cylinder, water cooled, turbo-charged, 510-bhp engine. The superstructure houses a Mercedes-Benz OM 904 LA diesel, 4-cylinder, water-cooled, turbo-charged, 174-bhp engine. The crane’s two-stage outrigger beams can be set in five positions and controls are available on each side of the carrier and in the superstructure cab via the ECOS screen.

The crane is also engineered with Manitowoc’s Megatrak suspension and all-wheel steer system. This independent suspension allows each wheel to remain on the ground at all times to reduce the need for stresses and weights to continually be transferred between axles. Based on customer feedback the crane also features a new two-step transfer case designed to increase agility at low speeds. “In its class the GMK 5135 offers by far the best load charts, and with the patented Megatrak suspension system, the best driveline on the market,” says Cremer. “We have also improved the suspension layout for increased drivability with a boom dolly to suit especially the needs of our customers in the U.S. market.”

The crane was packaged for general construction, industrial work, moving HVAC systems, and tower-crane rigging, all of which make it ideal for the general rental market. That’s what AmQuip and Sterling Crane had in mind for the AT when they placed orders.

Both AmQuip, Bensalem, Pa., and Sterling Crane received their units earlier this year. Sterling’s unit joins the company’s taxi rental fleet in Fort McMurray Alberta. “It’ll go into general oil sands and construction work,” said Pat Carrigan, crane rental manager for the Alberta, Canada-based crane rental company.