Section 2 Bulwarks, Freeing Ports, Side Scuttles, Ventilators

201. Application

Bulwarks, freeing port, side scuttles, ventilators are to comply with the followings and Pt 4, Ch

4. of Rules for the Classification of Steel Ships.

(1) Ventilators

(A) Ventilators to spaces below the datum or decks of enclosed superstructures are to have sub- stantially constructed coamings efficiently connected to the deck. Coaming heights are in

general not to be less than 100 mm for ventilators to weathertight spaces the datum, and 380 mm elsewhere. For craft of 30 m in length and under,

on decks above coaming heights

may be reduced to the maximum which is consistent with the safe working of the craft.

(B) Ventilators the coamings of which extend to more than one metre above the deck or which

are fitted to decks above the datum need not be fitted with closing arrangements unless they face forward.

(C) Except as provided in the above mentioned (B), ventilator openings are to be provided with efficient weathertight closing appliances.

(D) Ventilator openings are to face aft or athwartships wherever practicable.

(4) Freeing ports

(A) Where bulwarks on weather decks form wells, ample provision is to be made for rapidly freeing the decks of water and for draining them. The minimum freeing port area ( ) on each side of the craft for each well on the weather deck of the main hull(s) are to be:

(a) where the length of bulwark ( ) in the well is 20 m or less:

(b) where exceeds 20

and, in no case, need be taken as greater than 0.7 .

(B) If the bulwark is more than 1.2 m in average height, the required area is to be increased by 0.004 square metres per metre of length of well for each 0.1 m difference in height. If the bulwark is less than 0.9 m in average height, the required area is to be decreased by

0.004 square metres per metre of length of well for each 0.1 m difference in height.

(C) Such freeing ports are to be located within the height of 0.6 m above the deck and the lower edge is to be within 0.02 m above the deck.

(D) All such openings in the bulwarks are to be protected by rails or bars spaced approximately 230 mm apart. If shutters are fitted to freeing ports, ample clearance is to be provided to prevent jamming. Hinges are to have pins or bearings of non-corrodible material. If shutters

are fitted with securing appliances, these appliances are to be of approved construction.

(E) Craft, having superstructures which are open in front or both ends, is to comply with the provisions of the above mentioned (A).

(F) In craft, having superstructures which are open at the aft end, the minimum freeing port area is to be:

m

where:

: the breadth of the craft at the exposed deck (m ).

(G) Ro-Ro craft fitted with bow loading openings leading to open vehicle spaces is to comply with the provisions of Pt 3, Ch 1, Sec 407.