New Towboat Design At St. Louis Ship Results From Two-Year Research Program

The Super Hydrodyne, an improved towboat design that resulted from an extensive $500,000 research and development program, was unveiled recently by St. Louis Ship, a division of Pott Industries Inc., St. Louis, Mo.

The Super Hydrodyne, claimed to be more energy efficient and maneuverable than existing models, is already in service on inland waterways, following two years of development.

The design changes incorporated in the Super Hydrodyne have a performance improvement of 4.9 percent, the company reports, yielding a return on investment of 47 percent compared to the original design of the equipment.

Three 6,000-hp towboats are currently in service. The first two, M/V Paulina, and M/V Altonian (shown above), were delivered to the Peavey Company, and the third, the M/V Beth Armstrong, went to H & S Transportation Co., Inc. Several new Super Hydrodyne towboats make up St.

Louis Ship's backlog, ranging in horsepower from 4,500 to 9,000 and consisting of twin- and triplescrew designs.

The original Hydrodyne hull design was introduced in 1959, following an extensive model test program conducted at the Maritime Research Institute in the Netherlands (MARIN), formerly known as the Netherland Ship Model Basin.

Hydrodyne was the name selected to describe the hull shape optimized for push towing service on Western rivers. The design included appendages specifically designed to perform in the restricted channel environment utilizing high horsepower installations.

In most design applications, the hulls were fitted with Kort nozzles integrated into the tunnel stern. The Hydrodyne is designed to operate as an open propeller design as well. During the next two decades, additional model tests were completed at MARIN, resulting in continued refinements to the Hydrodyne.

Seventy-two Hydrodynes have been delivered and are still operating.

In the early fall of 1979, meetings were held at St. Louis Ship on whether the Hydrodyne could be further improved by incorporating a more efficient design.

Several weeks were spent planning and preparing a test program.

During February 1980, St.

Louis Ship representatives visited MARIN and established a model test program designed to investigate the optimum propeller diameter.

nozzle length, and nozzle profile. Strut design, steering rudder, and flanking rudder designs with the latest Hydrodyne concepts were used.

A nominal 3,000-hp per shaft was selected as the basic design requirement and models of twinscrew towboats were manufac- Qn a one-of-a-kind boat.

The Portland. Tlx only u'orking steam-powered stemwlxel tugboat in the u'orld After years of faithful sen'ice in Portland Harbor, we're retiring this historic i 'esse/ from her commercial duties Marking the end of an era. Marking a new beginning.

The Port of Portland has begun a search for companies that would be interested in comerting and operating this classic ship as a tour boat in tlx Portland Harbor on a lease basis.

For more infonnation, contact David N. Neset, Director, Marine Sen ices. (503) 231-5000 It's a rare opportunity.

Don't miss The Boat.

$ Port of Portland P.O. Box3529, Portland, Oregon 97208 tured for the tests. Beginning in April, overload tests were conducted behind a barge fleet representing 25 loaded jumbo barges and an eight-barge integrated unit tow in MARIN's shallow water basin.

Test data was collected for performance comparisons ahead, astern, steering, and flanking in different water depths with two different towboat lengths operating behind the two barge fleets.

Using the optimum propulsion system, the steering rudder and flanking rudder designs were further tested and refined for maximum operating efficiency.

After two and one-half months of testing for design optimization in the shallow water basin, another test program was prepared for the large cavitation tunnel at MARIN to test the optimum towboat model and appendage combination obtained from the shallow water basin tests. These tests were to insure a propeller design as free of cavitation as possible.

The tests resulted in changes to the strut design.

The following weeks were spent reviewing test results and comparing manufacturing costs versus performance gains. St. Louis officials contacted many barge line operating managers for their opinions of the relative importance of the various operating conditions that had been tested. Utilizing the operator requirements and information from model tests, the design was selected to give the optimum in push, steering, and flanking, and which also yields the best return on investment for the operator.