7.5.3 Remote Control Valves
Remote control valves, where fitted, are to be arranged so that they will close and remain closed in the event of loss of control power. Alternatively, the remote control valves may remain in the last ordered position upon loss of power, provided that there is a readily accessible manual means to close the valves upon loss of power. Remote control valves are to be clearly identified as to the tanks they serve and are to be provided with position indicators at the ballast control station.
7.5.4 Vessels Subject to Damage Stability
Ballast pipes installed in the regions of assumed damage under damage stability consideration are to be considered damaged. Ballast piping will affect damage stability considerations if:
• It is installed within the extent of assumed damage in damage stability consideration, and
• The damage to the ballast pipe will lead to progressive flooding of intact ballast tanks through open ends in the ballast piping system.
Affected ballast piping is to be fitted with valves in the pipes in the intact tanks to prevent progressive flooding of these tanks. The valves are to be of a positive closing type and operable from above the freeboard deck or from a manned machinery space. Where the valves are electrically, hydraulically or pneumatically actuated, the cables or piping for this purpose are not to be installed within the extent of assumed damage, alternatively, the valves are to be arranged to fail in the closed position upon loss of control power.