2.3 Model loading
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Statutory Documents - IMO Publications and Documents - Circulars - Maritime Safety Committee - MSC.1/Circular.1195 – Guidelines for the Conduct of High-speed Craft Model Tests – (2 June 2006) - Annex - Guidelines for Model Testing - 2 Model Design and Construction - 2.3 Model loading

2.3 Model loading

  2.3.1 Ballasting particulars should be developed for one loading condition prior to testing, viz: maximum operational weight (as defined in the 2000 HSC Code), combined with the most onerous bow down running trim or the condition with the bow aperture closest to the water in the running trim.

  2.3.2 The ballasting particulars should be such as to achieve:

  • .1 a mass corresponding to the loading conditions defined above;

  • .2 a vertical centre-of-gravity position corresponding to the maximum allowable in service (limiting KG) for the respective operational weight, or alternatively the maximum predicted operational KG plus a margin of 10%;

  • .3 longitudinal centre-of-gravity positions corresponding to the nominal and most forward and most aft positions envisaged by the loading restrictions contained in the craft operating manual;

  • .4 a longitudinal radius of gyration equivalent to that calculated for the full-scale craft ±8%, or (where this information is not available) within the range 0.23 to 0.27L, where L is as defined in the 2000 HSC Code; and

  • .5 a roll radius of gyration equivalent to that calculated for the full-scale craft ±8%, or (where this information is not available) within the range 0.35 to 0.4 B, where B is as defined in the 2000 HSC Code,

after ballasting for each condition:

  • .6 the total model mass should be verified by weighing;

  • .7 the actual vertical centre-of-gravity and longitudinal trim should be verified by physical inclining in air and/or water;

  • .8 the longitudinal and roll radii of gyration should be verified in air; and

  • .9 the natural roll period should be measured by a roll decrement test with the model at rest in calm water.

Parent topic: 2 Model Design and Construction
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