Appendix K
Committee Estimates of Oil Outflow Relative to MARPOL Standard (100%)

Outflow estimates were provided by Det norske Veritas (DnV) for several design alternatives; the committee made its own estimates for other alternatives using the DnV individual estimates of grounding and/or collision performance. This performance rating is stated as an outflow index relative to the conventional MARPOL tanker (designated by DnV as ''original" in their report) whenever possible.

The cases for which the committee made its own estimates are marked with an "x" in Table K-1. The figures and calculations leading to the committee estimates are on the following pages.



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Tanker Spills: Prevention by Design Appendix K Committee Estimates of Oil Outflow Relative to MARPOL Standard (100%) Outflow estimates were provided by Det norske Veritas (DnV) for several design alternatives; the committee made its own estimates for other alternatives using the DnV individual estimates of grounding and/or collision performance. This performance rating is stated as an outflow index relative to the conventional MARPOL tanker (designated by DnV as ''original" in their report) whenever possible. The cases for which the committee made its own estimates are marked with an "x" in Table K-1. The figures and calculations leading to the committee estimates are on the following pages.

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Tanker Spills: Prevention by Design TABLE K-1 Ratings Derived by Committee Design Alternative Tanker Size     VLCC (Table 5-5) 40,000 DWT (Table 5-6) Intermediate oil-tight deck with double sides × × Double sides with hydrostatic control × × Double hull with hydrostatic control × × Hydrostatic control Calculated by DnV × Small tanks   Calculated by DnV ×     VLCC       Reference: DnV Outflow Figures from Chapter 5:     Figure 5-13 Speed: 5 Knots Figure 5-14 Speed: 10 Knots Intermediate Oil Tight Deck with Double Sides DnV Arrangement Number     Double sides with hydrostatic control collision (3 B) 30 19 Intermediate oil tight deck grounding (8) 2 4     __ __ Total   32 23 Double Sides with Hydrostatic Control DnV Arrangement Number     Double sides collision (3 B) 32 × .91 = 29 19 × .9 = 17 Hydrostatic control grounding (9) 3 4     __ __ Total   32 21

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Tanker Spills: Prevention by Design     Reference: DnV Outflow Figures from Chapter 5:     Figure 5-13 Speed: 5 Knots Figure 5-14 Speed: 10 Knots Double Hull with Hydrostatic Control DnV Arrangement Number     Double hull collision (1A or 1B) 33 × .9 = 30 20 × .9 = 18 Double hull grounding (1A or 1B)2 (0 + 1)/2 = 0 (6 + 3)/2 = 4     __ __ Total   30 22   40,000 DWT TANKER     Reference: DnV Outflow Figures from Chapter 5:     Figure 5-15 Speed: 5 Knots Figure 5-16 Speed: 10 Knots Hydrostatic Control + Base DnV Arrangement Number     Base collision (1) 55 × .9 = 49 34 × .9 = 31 Intermediate oil-tight deck grounding (8) 3 3     __ __ Total   52 34     Reference: DnV Outflow Figures from Chapter 5:     Figure 5-15 Speed: 5 Knots Figure 5-16 Speed: 10 Knots Smaller Tanks       Assume base ship (1) with twice as many transverse bulkheads. This would make collision index about 0.5 and grounding index about 0.9 compared to MARPOL base. Base grounding × 0.5   55 × .5 = 27.5 34 × .5 = 17 Base collision × 0.9   45 × .9 = 40.5 66 × .9 = 59     __ __ Total   68 76

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Tanker Spills: Prevention by Design Intermediate Oil-tight Deck with Double Sides DnV Arrangement Number     Double sides collision (6)3 55 34 Intermediate oil-tight deck grounding (8) 2 2 Total   57 36 Double Sides with Hydrostatic Control       Double sides collision (2) 75 × .9 = 67 44 × .9 = 40 Hydrostatic control grounding (Use VLCC Values) 3 4     - - Total   70 44     Reference: DnV Outflow Figures from Chapter 5:     Figure 5-15 Speed: 5 Knots Figure 5-16 Speed: 10 Knots Double Hull with Hydrostatic Control DnV Arrangement Number Double hull collision [Avg. of (5+6+7)] × .9 = 60= 37 Hydrostatic control Average hydrostatic control + "Perfect"   - or = 1.5 = 1.5   (3 + 0)/2         - - Total   61 39 1 0.9 assumes all cargo tanks are 90% filled for the hydrostatic control design. 2 Grounding averages 1A + 1B (double hull) and 9 (hydrostatic control). 3 Uses DnV arrangement number 6 (double hull with centerline bulkhead) being the more representative of double side that would be DnV arrangement number 2 (with no centerline bulkhead).

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