Page 63: of Marine News Magazine (June 1969)

M & T Units Accurately Position AG-162 Sonar Research Ship Propulsion pod being lifted aboard Mission Capistrano. The Mission Capistrano, a specially convert-ed T-2 tanker, is presently doing research work for the U.S. Navy Office of Naval Re-search. The ship is of the well-known Mission Class T-2, 524 feet long, 68-foot beam, and 31-foot draft. She is identified by the Navy as AG-162 Sonar Research Ship. In 1961 the Mission Capistrano had an over-size acoustical device in the form of an array of transducers installed. The ship was modified to conduct experiments on Project Artemis, sponsored by ONR to improve the country's ASW capabilities. The operating requirements called for holding the Mission Capistrano precisely on a selected station for extended lengths of time. The use of tugs and deep sea anchoring had proven unsatisfactory in some instances. As the oil industry had experimented with deep sea position-keeping, it appeared that their successful installations should be studied to see if they could be applied by the Navy. The first attempt to hold a vessel stationary at sea was attempted on the well-known pro-ject MOHOLE. Murray & Tregurtha, a Di-vision of Mathewson Corporation, supplied the large outboard propulsion units installed on the CUSS I used in this program. Out of this successful exploration the words, "Dynamic Positioning" were born, and the system successfully used on the exploration vessel Eureka and drilling vessel Caldrill. As greater power was required on each one of these drilling vessels, Murray & Tregurtha designed larger marine propulsion units to meet their needs. Station keeping requirements also became more sophisticated, and General Motors Cor-poration was selected to produce a system to meet the Mission Capistrano's exacting needs. After extensive reviewing of the operating requirements, Hudson Laboratories of Colum-bia University, under contract to ONR, award-ed General Motors a contract to design a sta-tion-keeping system that would hold the Mis-sion Capistrano within a 1,000-foot radius with concurrent beam winds of 25 knots, and cur-rent of 1 knot, operations to be in 20,000-foot depths of water. To satisfy the underway requirements of having the auxiliary propulsion units retract-able into the hull, the M&T Harbormaster Drives were specially designed. The M&T Propulsion System was selfcon-tained in a watertight housing containing the 1,250-hp GE vertical motor. Eaton Dynamatic coupling, motor and coupling controllers, heat exchangers for the motor and coupling, steer-ing motor and controller, emergency pumps, and alarm transmitters. An M&T Series 12 Harbormaster was di-rectly coupled to this power pod and incor-porated a kort nozzle, swinging an 84-inch diameter 4-bladed propeller. The total weight of the M&T thruster package was 118,300 pounds. The entire package is guided by rails and is firmly locked down in the operating position. The system was elevated by cable to the raised or stowed position. One unit is installed just ahead of the wheel-house, and the aft unit is positioned just ahead of the after quarters and pump room. The General Motors control system was de-signed and manufactured at the AC Electron-ics Defense Research Laboratories. The sys-tem utilizes an acoustic position measurement and an analog control computer that can be operated automatically, semi-automatically, and manually. Included as part of the system is a data recording subsystem which records positional information, heading information and discrete events on magnetic tape. In the automatic mode, the thrust levels and directions are determined by the control com-puter so as to maintain both heading and ship position. Using a coordinate transformation unit developed by Hudson Laboratories, some semi-automatic position keeping runs were made using loran C as a position input. Runs were also made in the automatic mode using the same unit with an Autotape for a position input. Actual performance of the system is demon-strated by the following data taken during sea trials: In 13,000 feet of water with winds aver-aging 28 knots and gusting to 35 knots, swell height of 11 feet, the standard deviation of the ship from the desired location was 142 feet with a peak deviation of 241 feet as determined by the Autotape. Although the Mission Capistrano was spe-cifically designed to service Project Artemis, the ability to hold station in deep sea oceano-graphic work has given the Navy a new, stable, precision tool, allowing an expanded study of our oceans. COST CONTROL ANALYST LOOKING FOR A JOB THAT OFFERS CHALLENGE AND GROWTH OPPORTUNITY? We want individuals to perform work pro-gressing and analysis of returned costs for heavy steel fabrications and machinery installations. This is an ideal job for the new engineer who is administration oriented. Send Resume Including Salary Requirement To: Mgr. Industrial Relations SUN SHIP Foot of Morton Ave. Chester, Pa. 19013 We Hire Minority?An Equal Opportunity Employer POSITION WANTED NAVAL ARCHITECT/MARINE ENGINEER 18 years marine experience with shipyards and design agents on both naval and commercial craft of all sizes. Many years of supervisory as well as design assignments on hull design, propulsion sys-tems and outfitting. Must relocate in either South-ern Florida or Southern California. Available immediately. Box 602 Maritime Reporter/Engineering News 107 East 31st Street New York, N. Y. 10016 ASSISTANT TECHNICAL DIRECTOR Ship Concept Design Division Naval Ship Engineering Center Starting Salary $22,835 The Ship Concept Design Division is responsible for the conceptual and preliminary designs of new ships in Navy shipbuilding programs; studies of advanced ship concepts; and support of these functions by developing and updating procedures, data and computer programs, and R&D efforts related to the basic design of ships and special craft. The position of Assistant Technical Director and Head of the Advanced Technology Branch is primarily concerned with the advanced ship concept studies, R&D, and design methods development aspects of the division's responsibilities. Experience in preilminary ship design and a basic under-standing of computer applications to ship feasibility studies and preliminary design are essential. Expert knowledge of naval architecture and a good understanding of marine en-gineering are also required. Applicant should be of recog-nized competence and established reputation in the fields of ship design and associated research and development. Career Civil Service position with full benefits. Location in suburb of Washington, D.C. offers excellent residential areas, good schools, varied cultural and recreational op-portunities. Send resume of SF-17i to: Ronald Smitley, Civilian Per-sonnel Division, Room 118-E NAVAL SHIP ENGINEERING CENTER Center Building, Prince George's Center, Hyattsville, Maryland 20788. An Equal Opportunity Employer PRODUCTS/SERVICES WANTED Sales / service representative contacting Government agencies and marine indus-try in Tidewater (Va.) and Washington, D.C. areas wants to represent marine in-dustry companies on retainer basis. Box 601 Maritime Reporter/Engineering News 107 E. 31st Street New York, N. Y. 10016 TECHNICAL SALES REPRESENTATIVE To call on shipyards, Govt, agencies and marine architects in Canada and U.S.A. and assist in preparation of proposals for custom built deck machinery, elevators etc. JOHN T. HEPBURN, LIMITED 914 Dupont Street Toronto, Ontario SHIPYARD MANAGER Small East Coast Ship Repair Yard with 500 Ton Railway. General Ship Repair Background Essen-tial. Welding, Ship Fitting, Carpenter, Machine, Sand Blasting, and Propeller Repair Knowledge Required. Right Man with Management Capa-bilities, Ability to Estimate, Purchasing, Personnel, Organize Operations, and Make Decisions. Can Head Company with Profit Sharing and Other Benefits. Rush Complete Resume and Work His-tory in Confidence to: Box 517 Maritime Reporter/Engineering News 107 E. 31st Street New York, N.Y. 10016 An equal opportunity employer June 1, 1969 65