SNAME Chesapeake Section Hears Update Report On Design Of Multipurpose Mobilization Ship

The final meeting of the 1979- 80 technical program of the Chesapeake Section of The Society of Naval Architects and Marine Engineers was held recently at the Bethesda Naval Hospital Officers Club. George H. Levine and John F. Walter of the Maritime Administration, who were introduced by moderator Ronald K. Kiss, Director of the Office of Ship Construction, Maritime Administration, gave "An Update on the Contract Design of the Multipurpose Mo- bilization Ship and a Review of the Preliminary Design PD-214." The Maritime Administration has the responsibility for providing the shipping capability and military support during a wartime mobilization when massive movements of goods and supplies will be needed. An established, strong, and versatile U.S. merchant fleet will be required to react promptly to political and military challenges.

Ship designs which are versatile and efficient, yet suitable for mass production, also are necessary to provide the needed shipping capacity during wartime and to provide quick replacement of ship losses to meet postwar trading requirements.

As part of its defense planning effort, the Maritime Administration established a "Ship Designs for Mobilization" project in 1974 to develop modern ship designs suitable for wartime production.

This p r o j e c t has p r o g r e s s ed through the definition of requirements, feasibility studies of various alternate designs, and the preliminary design of the PD-214 Multipurpose Mobilization Ship.

Presently, the project is in the more detailed contract design phase which will result in the development of plans and specifications suitable for shipyards to prepare construction bid quotations.

This design is a single-screw, multipurpose cargo ship with designed- in flexibility and versatility that does not compromise efficiency.

The ship is capable of the simultaneous loading, transporting, and discharging of roll-on/ roll-off cargo and lift-on/lift-off cargo, including vehicles, containers, general breakbulk cargo, and heavy-lift cargo.

To avoid mobilization production problems and also to allow potential owners a choice, the ship is configured to accept a variety of main propulsion systems and substitution of the deck cranes and ramps by o t h e r types of equipment or elimination of any capability not required. The main propulsion machinery types include steam, medium-speed diesel, slow-speed diesel, and gas turbine.

Hull form has been developed carefully for superior hydrodynamic performance.

The base design incorporates flexibility to allow for a variety of configurations without major redesign effort. As a result, a lengthened vessel version modified to carry and store military equipment and stores for the Maritime Prepositioning Program has been selected for new ship construction.

Contract plans and specifications are being prepared by M.

Rosenblatt & Son, Inc. under contract to the Maritime Administration.

Dr. James Lisnyk, Maritime Administration, introduced Rodney Peltzer, a student of Virginia Polytechnic Institute, who presented a student paper on "The Effects of Shear and Roughness on Vortex Shedding Patterns Behind a Circular Cylinder at a Transitional Reynolds Number." Mr. Peltzer described the experimental results of laboratory tests on a circular cylinder to determine the effects of varying free-stream turbulence and surface roughness on dray and v o r t e x shedding.

These results are of interest in the design of the OTEC cold water pipe because of the forces induced by the oscillatory vortex system.

At this final meeting of the 1979-80 session, the f o l l o w i ng were elected to serve on the 1980- 81 Executive Committee of the SNAME Chesapeake Section: chairman, Robert Scott; vice chairman and Papers Committee, Frank Slyker; secretary-treasurer, Alexander Landsburg; elected members, Capt. Richard Gauthey, Donald Burklaw, and Jack Abbott.