To answer this question we have to go back to 1990s, when following a series of losses of Bulk Carriers happened. A study was carried out by IACS at the request of IMO, the study revealed that if a Bulk Carrier is flooded in the forward hold, the transverse bulkhead between the two foremost cargo hold may not withstand the pressure that result from the cargo and the water and the transverse bulkhead may collapse causing progressive flooding of the cargo holds and the vessel will sink in minutes, which does not give time to crew to abandon the ship.
In 1997, IMO adopted new SOLAS Regulation containing specific safety requirements to improve the safety of Bulk Carriers, Chapter XII – Additional Safety Measures for Bulk Carriers, entering in to force on 01 July 1999.
At the very first stage the new Chapter XII stated that:
Under this new chapter XII, new criteria for damage stability and structural strengthening was introduced (URS 12, 17, 18, 20, 21, 25, 27…..), allowing surveyors to take into account restrictions on the cargo carried in considering the need for, and extend of strengthening of the transverse watertight bulkhead and double bottom. These restrictions can come, on the distribution of the total cargo weight between cargo holds and restrictions on the maximum deadweight. When such restrictions are imposed, them the ship shall be marked with a solid equilateral triangle, having sides of 500 mm and 300 mm bellow deck line, permanently in P&S sides at amidships.
Also loading instrument become mandatory, new Enhanced Survey Program was established to detect possible structural weakness and cargo handling practices were improved.
In December 2002 new amendments to chapter XII were done and included chapter XII/12, the installation of high level alarms to detect water ingress and new chapter XII/13 added with regard availability of pumping systems to drains any space forward collision bulkhead, among other strengthening of vent fittings and small hatches on forward decks.
In December 2004, when IMO at the 79th session of the Maritime Safety Committee adopted resolution MSC. 179(79)“Adoption of Amendments to SOLAS, 1974”. The existing chapter XII (1997) “Additional Safety Measures for Bulk Carriers” was reviewed and more specifically Regulation 8 amended and new Regulation 14 added.
The booklet required under Reg. 8 (SOLAS VI - 7.2) shall be endorsed by the administration or on its behalf, to indicate SOLAS XII regulation 4, 5, 6 and 7, as appropriate, are complied with. The booklet to be prepared by Ship’s Crew based in the info available on board from Stability Data, Ballasting and Deballasting Rates and capacities, Maximum Allowable load per unit of surface area of the tank top plating, Maximum allowable load per hold, Loading & Unloading instructions, any restriction imposed on the most adverse operating condition and Maximum permissible Shear Forces and Bending Moments and submitted for revision and approval, as above stated.
Any restriction as consequences of what is stated under Reg. 6 & 14 shall be recorded in the booklet and be permanently marked at amidships section with a Solid Triangle as well as. The ship trim and stability (loading) manual is to be endorsed with the restriction, in accordance reg.14 “The ship shall not sail with any hold loaded to less 10% of the hold maximum allowable cargo weight”
Therefore Reg. 14 apply only to BC of 150 m and more in length, single hold skin, carrying cargoes of more than 1,780 kg/m3 in alternate loading condition, were contracted for construction before 01 July 1998 or constructed before 01 July 1999 and when they reach 10 years and they are normally assigned with ESP notation.
The Amended SOLAS Chapter XII, finish in 14 regulations which are: