When Wagstaff Crane got the call to dismantle a tower crane, it knew it was an excellent application for the company’s new Grove GMK7550 550-ton (450 t) all-terrain crane, the largest manufactured by Grove. The tower crane was used to build a public library in Salt Lake City, UT, by general contractor Big D, who contacted Wagstaff.
Jim Wagstaff said, “We could have used our Grove GMK6300 300-ton crane with full luffing jib but our new GMK7550 did the job with a shorter jib installed. The lift was about 26,000 pounds at a radius of 140 feet and the new machine handled the job easily. This also gave us the opportunity to showcase our newest Grove and it worked perfectly.”
The GMK7550 was supplied by distributor H&E Equipment Services LLC, formerly ICM Equipment Company, of Salt Lake City.
Wagstaff Crane was begun in 1963 by Ron and Evelyn Wagstaff with one Bucyrus-Erie crane. A Grove was then added and Wagstaff has been exclusively Grove ever since. Sons Jim and Ron Jr. are both active in this family business, which serves Utah, Idaho, Wyoming and Nevada from locations in Salt Lake City, Ogden, Provo and Park City, UT.
The second job for the GMK7550 was a lift that required three cranes. A heat exchanger from a nuclear plant arrived on a rail car and needed to be off-loaded to a transporter, taken to a radioactive disposal site, then off-loaded for burial. (The heat exchanger is low level radioactivity.) “We used two 300-ton cranes on one end to handle approximately 300,000 pounds at an 18-foot radius,” said Jim Wagstaff. “On the other end, our GMK7550 handled approximately 220,000 pounds at a 25-foot radius. The exchanger was placed on the transporter and hauled a quarter mile to the burial cell where we then picked it off and placed it in the cell. My understanding is that the exchanger was loaded on the rail car using jacks, a process that took days. We made the lifts in hours.”
The GMK7550 has a maximum main boom tip height of 207 ft. (63 m) and approximately 410 ft. (125 m) with the 240- ft. (73 m) luffing jib installed. The maximum working range reaches 263 ft. (80 m). The 52.5 to 197 ft. (16 to 60 m) five-section, MegaForm main boom is electronically controlled, hydraulically positioned and mechanically pinned. The TwinLock boom telescoping system allows for preselection of 32 different main boom extension configurations for optimum strength and stability. Grove’s new Electronic Crane Operating System (ECOS) automatically controls unpinning and extension of the boom sections. It also provides a constant update of all crane conditions.
The seven-axle GMK7550 has a drive/steer configuration of 14 by 6 by 14 with an optional 14 by 8 by 14 drive. Grove’s MegaTrak suspension features an independent hydropneumatic system with hydraulic lockout on all wheels. The suspension can be raised 6.5 in. ( 16.5 cm) or lowered 5 in. (13 cm) both longitudinally and transversely, and features an automatic leveling system for highway travel at speeds to 55 mph (89 kmh).
A wide range of configurations allow numerous axle loads to meet road restrictions. A standard quick removal system dismantles the entire boom assembly for transport. The cab mounted on the right side of the superstructure hydraulically swings to the rear for road travel. Counterweights are easily removed as well as the rear outrigger box. An auxiliary eighth-axle option, and various boom-transport and axle-raise options allow for selection of transport modes as required.
For more information, call 717/597-8121 or visit www.groveworldwide.com.