Although not required by regulations, many vessels use signs depicting Fire Plan symbols to identify equipment onboard. Currently there exist two sets of Fire Plan symbols.
SOLAS Consolidated edition 2001 Chapter II-2 regulation 20 and SOLAS amendments 2000 Chapter II-2 regulation 24 requires the use of fire control symbols on Fire Plans in accordance with IMO Resolution A.654(16), available as signs.
SOLAS Consolidated edition 2004 Chapter II-2 regulation 15 as amended requires the use of fire control symbols in accordance with IMO Resolution A.952 (23) which in turn refers to ISO 17631 and applies to vessels constructed after January 2000. Symbols to ISO17631 & IMO Resolution A.952 (23) are available as signs.
Vessels constructed before January 2004 may therefore continue to use symbols to Resolution A.654 (16) until such time as the Fire Plans require major modification or replacement. When this occurs, symbols to ISO 17631 should be used to compile the new plans regardless of the age of the vessel. If signs have been used to identify Fire Control Equipment, then these too should be changed to conform to ISO 17631.