This study is part of wider research work, at Delft University of Technology, on problems relating to the design of roll-on/roll-off ships. The layout of ro/ro ships, with their several decks, results in a much higher depth/draught ratio than that of other cargo-ships, and this, combined with a breadth limited by Panama Canal requirements, and large hold-capacity, makes stability criteria difficult to meet. The Author investigates the possibility of ro/ro ships utilising their surplus deadweight capacity, which might be divided into additional water-ballast to improve stability and additional cargo, if the latter would not be detrimental to stability. In this study, 18 variants of a Nedlloyd ro/ro-ship design were investigated; they consisted of three different lengths b.p. (200, 220, and 240 m), and three different draughts (10.2, 11.2, and 12.1 m), for both three- and four-deck ships; breadth was constant at 32.25 m. For each variant, design calculations were carried out in respect of hydrostatic curves, resistance, weights, centre of gravity, and stability. To compare the variants, the "Transportation Utilisation Index" was introduced; this is defined as the product of the two ratios (i) real dwt (i.e., cargo weight + supplies), dwt at design draught, and (ii) real service speed, service speed at design draught. It is mentioned that a more correct approach would have been a comparison based on an economic criterion. The investigation and its results are described and discussed in detail, and several conclusions are drawn on the transportation utilisation index of the 18 variants and the influence of ballast, principal dimensions, and other variables. It is also pointed out that the method of analysis used enables the optimum value of moulded draught to be determined.

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  • Corporate Authors:

    International Periodical Press

    193 Heemraadssingel
    Rotterdam,   Netherlands 
  • Authors:
    • Kulczyk, J
  • Publication Date: 1979-12

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Filing Info

  • Accession Number: 00311523
  • Record Type: Publication
  • Source Agency: British Ship Research Association
  • Files: TRIS
  • Created Date: Jun 26 1980 12:00AM