AN ACTUAL SHIP TEST OF THE CONTAINER SHIP HOTAKA MARU ON THE NORTH PACIFIC OCEAN
Results of tests of the container ship Hotaka Maru owned by Showa Shipping Co. Ltd and N.Y.K. Line Ltd are reported. The principal objective of the tests was to collect data on sea margin, seakeeping ability, and behaviour of deck containers. A special test container instrumented to measure stress, deformation, and acceleration was loaded on deck. Torque, thrust, and speed of the propeller shaft, angles of roll and pitch, accelerations due to ship motion, and lashing tension were also measured. Conclusions may be summarised as follows: 1) Sea conditions had a major influence on average sea margin. If a period of very rough sea amounting to 15% of total navigation time could be eliminated, the average sea margin could be decreased from 45.5% in course of a voyage. 2) In very rough seas with a wind force of over 8, ship speed was reduced to avoid heavy pitching of over 10 deg in double amplitude. Ship course was also changed to avoid heavy rolling of over 30 deg in double amplitude. 3) From the functional relationships existing between the tensions of container lashing members and accelerations of the test container, expectations of member tensions can be estimated. 4) The tensions of diagonal lashing members were larger than those of vertical members, and container stresses due to racking were negligibly small compared with stresses obtained during a container proof test.
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Corporate Authors:
Ship Research Institute, Tokyo
38-1, 6-chome, Shinkawa, Mitaka-shi
Tokyo, Japan -
Authors:
- Ohnaga, K
- Tanaka, K
- Publication Date: 1975-9
Media Info
- Features: References;
- Pagination: p. 45
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Serial:
- Volume: 12
Subject/Index Terms
- TRT Terms: Containers; Containerships; Decks (Ships); Lashing; Ocean shipping; Seakeeping; Ship motion; Stresses; Travel time
- Old TRIS Terms: Container lashing; Container stress; Deck stowed containers; Time at sea; Voyage time
- Subject Areas: Marine Transportation; Vehicles and Equipment;
Filing Info
- Accession Number: 00156265
- Record Type: Publication
- Source Agency: British Ship Research Association
- Files: TRIS
- Created Date: Jun 22 1977 12:00AM