Halter Marine, Inc. has begun construction of three second generation Ship Docking Modules (SDM) at its Lockport, La. shipyard for Hvide Marine, Inc. The new tugs, designated SDM Mark II, follow the three original Halter-built SDMs, New River
, St. Johns and Escambia. Two of the new vessels, Suwanee River and Peace River, are scheduled for delivery in 1999, and Kissimmee River, the third Mark II, will be delivered in 2000.
The patented, double-ended 90 x 50 ft. SDM design, which requires only two crew members to operate, was conceived by Erik Hvide, chairman and president of Hvide Marine and refined by the Elliot Bay Design Group, Seattle, Wash. The design is critical to maneuvering large ships in and out of narrow ports and harbors.
The revolutionary harbor tugs have skegs mounted on centerline at each end, and Z-Drives mounted diagonally offset 6.5 ft. from the center to provide 100 percent of their bollard pull in any direction.
The immediate success of the first innovative "flying saucer shaped" vessels and the experience gained from their operations led to the new order and a few design and propulsion changes which include: An expected increase in bollard pull from 110,000 pounds to 125,000 pounds by using two Wärtsilä 9L20, 2,000 hp diesel engines driving two Ulstein Z-Drives turning 94.5 in. diameter Nibral propellers in nozzles. The first generation SDMs are powered by Caterpillar 3516BTA diesels driving two Ulstein Z-Drives turning 86 inch diameter propellers in nozzles. An Aquapilot engine control system will monitor the main engines. Ship's service power will be provided by two 65 kW Caterpillar 3306 generator sets. Fendering on the first three vessels is a single-loop Schuyler Rubber design and the Mark II's will be equipped with Schuyler's multi-loop design.