4 Additional Scantling Requirements

4.1 Plate stem

4.1.1

The net thickness, t_Stm in mm, is not to be less than:

where:

S_B : Spacing, in m, between horizontal stringers (partial or not), breasthooks, or equivalent horizontal stiffening members.

Starting from 0.6 m above the summer load waterline up to T_SC + C_w, the net thickness may gradually be reduced to 0.8 t_Stm.

4.1.2 Breasthooks and diaphragm plating

The net thickness of breasthooks/diaphragm plates in way of bow impact strengthening area defined in [3.3.1], t_w, in mm, is not to be less than:

where:

s : Spacing of stiffeners on the web, as defined in Ch 1, Sec 4, Table 5, in mm. Where no stiffeners are fitted, s is to be taken as the depth of the web.

4.2 Thruster tunnel

4.2.1 The net thickness of the tunnel plating, t_tun, in mm, is not to be less than the net required thickness for the shell plating in the vicinity of the bow thruster.

In addition, t_tun is not to be taken less than:

where:

d_tun : Inside diameter of the tunnel, in mm, but not to be taken less than 970 mm. Where the outboard ends of the tunnel are provided with bars or grids, the bars or grids are to be effectively secured.