Common Structural Rules - Common Structural Rules for Bulk Carriers and Oil Tankers, January 2019 - Part 1 General Hull Requirements - Chapter 11 Superstructure, Deckhouses and Hull Outfitting - Section 2 Bulwark and Guard Rails - 2 Bulwarks
2 Bulwarks
2.1 General
2.1.1
Plate bulwarks are to be stiffened at the upper edge by a suitable rail and supported either by stays or plate brackets spaced not more than 2.0 m apart.
The free edge of the stay or the plate bracket is to be stiffened.
2.1.2
Within 0.6 L amidships, bulwarks are to be arranged to ensure that they are free from hull girder stresses.
2.1.3
Bulwarks are to be adequately strengthened and increased in thickness in way of mooring pipes. Cut-outs in bulwarks for gangways or other openings are to be kept clear of breaks of superstructures.
2.1.4
Bulwark plating and stays are to be adequately strengthened in way of eye plates used for shrouds or other tackles in use for cargo gear operation, as well as in way of hawser holes or fairleads provided for mooring or towing.
2.1.5 Openings in bulwarks are to be arranged so that the protection of the crew is to be at least equivalent to that provided by the horizontal courses in [3.1.2].
For this purpose, vertical rails or bars spaced approximately 230 mm apart may be accepted in lieu of rails or bars arranged horizontally.
2.1.6
In the case of ships intended for the carriage of timber deck cargoes, the specific provisions of the freeboard regulations are to be complied with.
2.1.7
Where mooring fittings subject the bulwark to large forces, the stays are to be adequately strengthened.
2.2 Construction of bulwarks
2.2.1 Plating
The gross thickness of bulwark plating, at the boundaries of exposed freeboard and superstructure decks, is not to be less than that given in Table 1.
Table 1 : Thickness of bulwark plates
| Height of bulwark | Gross thickness |
|---|---|
|
1.8m or more |
Thickness required for a superstructure side in the same position, obtained from Ch 11, Sec 1, [3.2.1], but not to be less than 6.5 mm |
| 1.0m | 6.5 mm |
| Intermediate height | To be determined by linear interpolation |
2.2.2 Stays
The gross section modulus of stays, Zstay-gr, in cm3, is not to be less than:
where:
hblwk : Height of bulwark from the top of the deck plating to the top of the rail, in m.
sstay : Spacing of the stays, in m.
In the calculation of the section modulus, only the material connected to the deck is to be included. The bulb or flange of the stay may be taken into account where connected to the deck. Where the bulwark plating is connected to the sheer strake, a width of attached plating, not exceeding 600 mm, may also be included.
2.2.3
Where bulwarks are cut completely, stays or plate brackets of increased strength are to be fitted at the ends of openings. Bulwark stays are to be supported by, or are to be in line with, suitable under deck stiffening. The stiffening is to be connected by double continuous fillet welds in way of bulwark stay connections.
2.2.4
At the ends of superstructures and for the distance over which their side plating is tapered into the bulwark, the latter is to have the same thickness as the side plating. Where openings are cut in the bulwark at these positions, adequate compensation is to be provided either by increasing the thickness of the plating or by other suitable means.
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