Motors & Drives Information

Link-Belt Construction Equipment Co., Lexington, Ken., has developed a new 300-ton (272 metric ton) hydraulic lattice boom truck crane. The HC-278H all-hydraulic lattice boom truck crane can be used to place loads at a 340 ft. (103.7 m) radius or 404 ft. (123.2 m) in the air. Non-assisted stripdown is fast and the lighter weight modular components make the machine easy to transport according to the company.

The HC-278H cranes join the 200-ton (181.5 mt) HC-248H and the 150-ton (136 mt) HC-238H in the Hylab (Hydraulic Lattice Boom) series of lattice boom truck cranes. Since 1987 over 300 Hylab lattice boom cranes have been delivered in North America.

Among the key design targets of the Hylab cranes are roadability and quick, easy assembly and re-assembly, which allows the machines to more efficiently move from jobsite to jobsite. The weight-efficient design of the new HC-278H crane, with its Mannesmann Rexroth hydraulic system, allows the entire machine to be easily transported with a minimum of five trailers and only one load requiring any special permit. The new upper module weighs less than 80,000 lb. (36,288 kg) with live mast and base section in place for transportation. The six-axle carrier, with its innovative triple-box frame design, hits the scales at under 92,000 lb. (41,731 kg) with outrigger boxes and 71,000 lb. (32,205 kg) with the outrigger boxes removed. Total upper counterweight is 98,200 lb. (44,543 kg).

Hylab series truck cranes are designed to be self-erecting and self-stripping. The standard live mast or 10 ft. (3.05 m) self-assembly boom extension can be used. A specially equipped 10 ft. (3.05 m) boom extension is available with necessary sheaves for handling counterweight and boom during self-stripdown or erection without using a standard tip. This extension can also be used in the normal boom makeup, with no need to repeatedly remove or insert the extension once installed.

A self-undecking device is standard on the HC-278H crane. Four hydraulic jacks, controlled by a Rexroth 5SM12 control valve, are mounted on the upperstructure to allow it to be removed from or remounted on the carrier. This eliminates the need for a helper crane during any phase of undecking, Link-Belt said.

Link-Belt's patented, 30-second counterweight removal system, coupled with hydraulic boomfoot pins, enable the Hylab truck cranes to be put to work quickly. The HC-278H crane can self-erect in as little as two hours, according to the company.

# posted by Medical Information : 4:22 AM