75-Kv. Submarine Cable for Deepwater Station

This paper describes the problems attending the laying of eight 75-kv. submarine cables across the Delaware River in the vicinity of Wilmington. To insure against injury the cables were laid in a backfilled trench, the depth of which was determined from experiments. By terminating the cable on platforms just inside the pierhead lines it was possible to use a cable of 4,050 ft. (maximum length one of the accepted manufacturers could make) as compared with a river width of 5,100 ft. To avoid excessive heating of that portion of the cable out of water at the cable platforms, the steel armor was replaced by one of nonmagnetic material so designed to avoid corrosion and electrolysis. The problem of laying the limited lengths of cable in the trench with minimum deviation was satisfactorily met with specially developed methods. The construction work was completed in five months under winter conditions and heavy river traffic.