For the purpose of §§ 45.58 through 45.61—

1. (a) The standard height of a superstructure (Hs) other than a raised quarter deck and the standard height of a trunk (Hs) is determined by the formula:

   Hs=[6.0 + (L/300)] ft

2. (b) The length of superstructure (S) is the length of those parts of the superstructure which extends to the sides of the vessel and that lie within the length (L).
3. (c) The effective length (E) of a trunk is its length in the ratio of its mean breadth to B.
4. (d) The effective length (E) of an enclosed superstructure of standard height or greater is its length “S”.
5. (e) Where the height of an enclosed superstructure or trunk is less than the standard height (Hs),the effective length (E) is its length reduced in the ratio of its height to Hs.
6. (f) The effective length (E) of a raised quarter deck of 2/3 Hs or greater that has no openings in the front bulkhead is its length up to a maximum of 0.6L.

7. (g) The effective length (E) of a raised quarter deck of less than 2/3 Hs or that does not have an intact front bulkhead is its length reduced by the ratio of its height to Hs.

   Table 12(1)tables of p values

   Length of Ship (feet)	Value of P
   80	0.1100
   90	0.1136
   100	0.1172
   110	0.1208
   120	0.1244
   130	0.1281
   140	0.1318
   150	0.1355
   160	0.1393
   170	0.1430
   180	0.1468
   190	0.1506
   200	0.1545
   210	0.1583
   220	0.1622
   230	0.1661
   240	0.1700
   250	0.1740
   260	0.1780
   270	0.1820
   280	0.1860
   290	0.1900
   300	0.1941
   310	0.1982
   320	0.2023
   330	0.2065
   340	0.2106
   350	0.2148
   360	0.2190
   370	0.2233
   380	0.2275
   390	0.2318
   400	0.2361
   410	0.2400
   420	0.2437
   430	0.2472
   440	0.2506
   450	0.2537
   460	0.2567
   470	0.2595
   480	0.2621
   490	0.2645
   500	0.2667
   510	0.2688
   520	0.2706
   530	0.2723
   540	0.2738
   550	0.2751
   560	0.2762
   570	0.2772
   580	0.2779
   590	0.2785
   600	0.2788
   610	0.2790
   620	0.2790
   630	0.2789
   640	0.2785
   650	0.2779
   660	0.2772
   670	0.2768
   680	0.2760
   690	0.2751
   700	0.2740
   710	0.2728
   720	0.2715
   730	0.2700
   740	0.2684
   750	0.2667
   760	0.2648
   770	0.2628
   780	0.2607
   790	0.2584
   800	0.2560
   810	0.2532
   820	0.2504
   830	0.2476
   840	0.2448
   850	0.2420
   860	0.2392
   870	0.2364
   880	0.2336
   890	0.2308
   900	0.2280
   910	0.2252
   920	0.2224
   930	0.2196
   940	0.2168
   950	0.2140
   960	0.2112
   970	0.2084
   980	0.2056
   990	0.2028
   1000	0.2000

   Table 12(2)values of “a” for use in the expressionP1=P + “A” (L/D—L/Ds)

   Length of Ship (feet)	Value of “A”
   80	0.00864
   90	0.00806
   100	0.00750
   110	0.00696
   120	0.00644
   130	0.00594
   140	0.00546
   150	0.00500
   160	0.00456
   170	0.00414
   180	0.00374
   190	0.00336
   200	0.00300
   210	0.00266
   220	0.00234
   230	0.00204
   240	0.00176
   250	0.00150
   260	0.00126
   270	0.00104
   280	0.00084
   290	0.00066
   300	0.00050
   310	0.00036
   320	0.00024
   330	0.00014
   340	0.00006
   350	0.00000

   Table 12(3)values of l/ds

   Length of Ship (feet)	Value of L/D5
   80	6.50000
   90	6.76563
   100	7.03125
   110	7.29688
   120	7.56250
   130	7.82813
   140	8.09375
   150	8.35938
   160	8.62500
   170	8.89063
   180	9.19625
   190	9.42188
   200	9.68750
   210	9.95313
   220	10.21875
   230	10.48438
   240	10.75000
   250	11.01563
   260	11.28125
   270	11.54688
   280	11.81250
   290	12.07813
   300	12.34375
   310	12.60938
   320	12.87500
   330	13.14063
   340	13.40625
   350	13.67188
   360	13.93750
   370	14.20313
   380	14.46875
   390	14.73438
   400	15.00000

8. (h) Superstructures which are not enclosed have no effective length.
9. (i) When a lower deck is designated as the freeboard deck, that part of the hull which extends above the freeboard deck is treated as a superstructure so far as concerns the application of the conditions of assignment and the calculation of freeboard.
10. (j) A bridge or poop is enclosed only when access is provided whereby the crew may reach accommodations, machinery, or other working spaces inside the superstructure by alternative means that are available at all times when bulkhead openings are closed.