June 1983 - Maritime Reporter and Engineering News

Design And Construction Of Heavy-Lift Derrick Receives Arc Welding Foundation Award

The design and construction of a marine heavy-lift derrick recently received the Merit Award granted by the James F. Lincoln Arc Welding Foundation.

The award was presented to George W.

Adams and Ritner E. Walling. Mr. Adams is a partner of Adams & Chute, a naval architecture firm in Newtown, Conn. Mr.

Walling is president of East Coast Salvage Company, a marine salvage and construction firm in Camden, N.J. The award was given in the foundation's biennial professional award competition, for contributions to the art and science of arc welding.

The heavy lift derrick, which has a capacity of 500 tons and a maximum boom length of 127% feet, was designed and built for East Coast Salvage. To increase its versatility, the unit was designed to be readily transportable from one floating platform to another, and to have an easily variable boom length.

Tubular legs and head of the A-frame boom produced an efficient, simple structure which permitted confident use of relatively high stress levels. The boom can be lowered horizontal to a minimum vertical clearance of 20 feet while fully extended.

The rig was first used to lift and move two 230-ton leaves of an unneeded bascule highway bridge over the Lewes-Rehoboth Canal in Delaware to a new location. The State of Delaware, for whom the work was done, estimates the techniques saved about $l-million compared to erecting a new bridge at the site.

Winches, specially reworked for the derrick, were installed. A reworked Mundy Machine Co. double-drum winch provided precise control of the falls. It was powered by a turbocharged Cummins NT 855P 335-hp engine equipped with a three-stage Twin Disc torque converter.

A Clyde frame 5 single drum spud winch is installed, powered by a Minneapolis Marine engine. The luffing winch is a single drum Jaeger, powered by a Continental Red Seal engine. The wire was supplied by Henry Stewart Co., of Philadelphia, Pa., and the blocks are McKissick.

United Fabricators of Camden, N.J. built the derrick sections and feet for assembly and erection at East Coast Salvage. The derrick is mounted on the 180-foot barge Loveland 24, from the S.C. Loveland Co. of Philadelphia.

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