Page 19: of Maritime Reporter Magazine (January 1969)

New Developments In Grain Carriage On General Cargo Type Vessels Capt. S. F. Sammis Deputy Chief Surveyor National Cargo Bureau, Inc. As a consequence of a number of casualties to general cargo vessels carrying grain under the requirements of Chapter VI of the Conven-tion for the Safety of Life at Sea 1960, the Inter-Governmental Maritime Consultative Or-ganization (IMCO) Sub-Committee on Bulk Cargoes has been engaged in formulating amendments to those regulations. These amendments are a product of a series of surveys and experiments dating back to 1962 when the validity of the assumptions forming the basis of the 1960 Convention were ques-tioned. In order to evaluate the effectiveness of feeders a questionnaire was placed on board grain carrying vessels so that settlement of grain in feeders could be measured on various vessels in all weathers encountered on a num-ber of the world's trade routes. The results of these measurements indicated that in heavy weather there was some drop in feeders. The question then became, where did the grain go? There must have been void spaces under the deck but by what means were they caused? Was it the settling assumed by Chapter VI of the 1960 Convention or was it a condition of loading? These questions led to another research pro-ject wherein holes were drilled in decks im-mediately over grain holds and measurements made through them to the grain surface. The measurements were made immediately after loading, at two points during the voyage and just prior to discharge. In all cases, of which there were five conducted on U.S.-flag vessels and numerous others on British-flag ships, the voids were found to exist after loading and not to change during the voyage. Therefore, the settling assumed by the 1960 Convention was actually negligible and voids found were fairly constant in depth averaging about 18 inches in all of the vessels gauged. Having established that the assumptions up-on which the 1960 Convention was based were erroneous, the U.S. Panel on Bulk Cargoes, composed of representatives from the U.S. Coast Guard, National Cargo Bureau, Inc. and industry, set out to develop a pattern of grain behavior by the use of a model designed to simulate a transverse section of the forward half of a Victory ship No. 3 hold. This project was carried out in the fall of 1966 at the U.S. Coast Guard facility at Curtis Bay, Md., through the joint efforts of the National Car-go Bureau and the U.S. Coast Guard. The mod-el was built to a scale of one inch to the foot and was fitted with plexiglass bulkheads through which the pattern of grain movement could be watched. The model was suspended in gimbals so as to allow heeling to develop grain shifts. The relative amounts of force re-quired to resist such shifts were recorded and the arrangements compared one to another. The model was so constructed as to allow the removal of decks so that one, two and three deck arrangements could be studied. Void spaces found under the decks of the full size vessels were simulated in the model by load-ing the wheat up to lyi inches under the decks. Scale effect was established as negligible by January 1, 1969 using grain of another density, and deriving similar results. The U.S. Delegation to the Sub-Committee on Bulk Cargoes submitted a report based on the tests at the next meeting of the Sub-Com-mittee and after review by the assembled dele-gations a U.S./U.K. working group was es-tablished to conduct further tests at Curtis Bay in the early spring of 1967 pursuant to drafting amended regulations including stabili-ty criteria for the carriage of grain. The draft of amended regulations develop-ing from this project was presented at the next meeting of the Sub-Committee which decided on further revisions in an attempt to embrace the various smaller types of vessels operated by European nations. In general the objective of the working group was to couple the results of the research projects and tests with an engineering ap-proach that would treat each vessel in terms of its own ability to carry grain from the stabil-ity standpoint. This was done by assuming that an underdeck void space depending up-on the vessel's characteristics exists under all horizontal surfaces together with heeling mo-ments generated by a 15 degree transverse shift of grain in such voids. By establishing minimum stability values necessary to meet such conditions the minimum GM concept stated in the 1960 Convention has been ex-tended so as to also consider the dynamical aspects of the problem. The requirement for fittings in any vessel under the proposed criteria would then be limited to those that are necessary to restrict the possible total heeling moment generated by the 15 degree shift of grain to such a quant-ity as can be compensated for by the stability of the vessel in question. Thus it is anticipated that by allowing the characteristics of the vessel to dictate the amount of fittings required, that grain carriage will be more economical, commensurate with safety. The next meeting of the Sub-Committee on Bulk Cargoes will convene in London this month, immediately after the Sub-Committee on Subdivision and Stability finally establishes the stability aspects of the proposal leaving the Sub-Committee on Bulk Cargoes free to conclude its work. If agreement is reached by member delegations at this session the final draft will then be submitted to the Maritime Safety Committee prior to final review by the General Assembly in the fall of 1969. Since the General Assembly meets once every two years, agreement at the Sub-Com-mittee level in January is imperative if imple-mentation is not to be drastically delayed. Since the U.S. has placed great faith in the new criteria, it has applied it on an equivalent experimental basis to a class of new vessels. The first of these vessels sailed recently, in complete compliance with the proposed regu-lations, on a trans-Pacific voyage laden with grain but without any shifting boards or feed-ers. If agreement can be reached in time at IMCO, these vessels will be the forerunners of many more of various nationalities. Seven 200,000-Dwt Tankers Being Built In Norway To Have GE Powerplants General Electric Company has announced the receipt of orders totaling over $5-million to supply major parts for steam propulsion equipment for seven supertankers to be built in Norway. H. W. Ogilvie, manager of marketing for GE's Marine Turbine and Gear Department, West Lynn, Mass., said the company received the orders from the firm of Kvaerner Brug in Oslo for the manufacture of the rotating equipment for the steam propulsion units. Kvaerner Brug, an overseas manufacturing associate of General Electric, will make the stationary equipment to GE designs. The seven supertankers are being built in the Oslo shipyards of Akers Mek Verksted for the firm of Hilmar Reksten, Bergen, Norway. The 200,000-dwt supertankers will each be powered by 30,000-shp, 80-rpm steam propul-sion units. Using General Electric's MST-14 marine propulsion units with attached auxiliaries, the fuel rate of each vessel is expected to be less than 0.44 pounds per shaft horsepower hour. General Electric is also furnishing technical services and advance system design informa-tion to make possible the low fuel rate. Mr. Ogilvie pointed out that the orders are another indication of the great advances that have been made within recent years in steam propulsion. "The best proof of these improve-ments," he said, "is the many ships now changing from other forms of propulsion to steam. Of the 233 ships on order and under construction in the world today, rated 27,501 shp and over, 91.7 percent are steam powered, and of these ships GE is supplying equipment to 27 percent." Mr. Ogilvie said, "The MST-14 is the most efficient steam plant ever to be installed in a merchant ship." The first of the seven ships is scheduled for service around the middle of 1969. General Koisch Appointed Director Of Civil Works Brig. Gen. Francis P. Koisch has been ap-pointed as director of civil works of the United States Army Corps of Engineers, effective late January 1969. General Koisch succeeds Brig. Gen. Charles C. Noble, who has been reas-signed to Heidelberg, Germany. In his new post, General Koisch will be re-sponsible for direction of the engineer corps' nationwide water resources program. 17