Merchant Shipping (Safety and Load Line Conventions) Act 1932

Superstructures.

RULE XXXVIII Height of Superstructure.

The height of a superstructure is the least vertical height measured from the top of the superstructure deck to the top of the freeboard deck beams minus the difference between D and the moulded depth (see, Rules XXXIV and XXXV).

RULE XXXIX Standard Height of Superstructure.

The standard height of a raised quarter deck is 3 feet for ships up to and including 100 feet in length, 4 feet for ships 250 feet in length and 6 feet for ships 400 feet in length and above. The standard height of any other superstructure is 6 feet for ships up to and including 250 feet in length and 7 feet 6 inches for ships 400 feet in length and above. The standard height at intermediate lengths is obtained by interpolation.

RULE XL Length of Superstructure (S).

The length of a superstructure is the mean covered length of the parts of the superstructure which extend to the sides of the ship and lie within lines drawn perpendicular to the extremities of the Summer load water-line, as defined in Rule XXXII.

RULE XLI Enclosed Superstructure.

A detached superstructure is regarded as enclosed only where—

(a) the enclosing bulkheads are of efficient construction (see Rule XLII);

(b) the access openings in these bulkheads are fitted with Class 1 or Class 2 closing appliances (see Rules XLIII and XLIV);

(c) all other openings in sides or ends of the superstructure are fitted with efficient weathertight means of closing; and

(d) independent means of access to crew, machinery, bunker and other working spaces within bridges and poops are at all times available when the bulkhead openings are closed.

RULE XLII Superstructure Bulkheads.

Bulkheads at exposed ends of poops, bridges and forecastles are deemed to be of efficient construction where the Assigning Authority is satisfied that, in the circumstances, they are equivalent to the following standard for ships with minimum freeboards under which standard the stiffness and plating are of the scantlings given in Table 3, the stiffeners are spaced 30 inches apart, the stiffeners on poop and bridge front bulkheads have efficient end connections, and those on after bulkheads of bridges and forecastles extend for the whole distance between the margin angles of the bulkheads.

TABLE 3.

Bridge Front Bulkheads. Unprotected Bulkheads of Poops .4 L or more in Length.		Bulkheads of Poops Partially Protected or less in Length than .4 L.		After Bulkheads of Bridges and Forecastles.
Length of Ship.	Bulb Angle Stiffeners.	Length of Ship.	Plain Angle Stiffeners.	Length of Ship.	Plain Angle Stiffeners.
Feet.	Inches.	Feet.	Inches.	Feet.	Inches.
Under 160	5 ½ x 3 x .30	Under 150	3 x 2 ½ x .30	Under 150	2 ½ x 2 ½ x .26
160	6 x 3 x .32	150	3 ½ x 2 ½ x .32	150	3 x 2 ½ x .28
200	6 ½ x 3 x .34	200	4 x 3 x .34	250	3 ½ x 3 x .30
240	7 x 3 x .36	250	4 ½ x 3 x .36	350	4 x 3 x .32
280	7 ½ x 3 x .38	300	5 x 3 x .38
320	8 x 3 x .40	350	5 ½ x 3 x .42
360	8 ½ x 3 x .42	400	6 x 3 x .44
400	9 x 3 x .44	450	6 ½ x 3 ½ x .46
440	9 ½ x 3 ½ x .46	500	7 x 3 ½ x .48
480	10 x 3 ½ x .48	550	7 x 3 ½ x .50
520	10 ½ x 3 ½ x .50
560	11 x 3 ½ x .52

Length of Ship.	Bulkhead Plating.	Length of Ship.	Bulkhead Plating.	Length of Ship.	Bulkhead Plating.
For ships intermediate in length the thicknesses of bulkhead plating are obtained by interpolation.
Feet.	Inch.	Feet.	Inch.	Feet.	Inch.
200 and under.	.3	160 and under.	.24	160 and under.	.20
380 and above.	.44	400 and above.	.38	400 and above.	.30