MSC/Circ.908: uniform method of measuring bulk cargo density
The IMO circular giving the measurement method behind the SOLAS regulation XII/10.2 requirement to verify a declared cargo density in the 1,250 to 1,780 kg/m3 band.
MSC/Circ.908 sets out the uniform method for the measurement of the density of bulk cargoes. It is the footnoted reference behind SOLAS regulation XII/10.2, which requires that, for bulk carriers to which regulation XII/6 applies and which do not comply with all the chapter XII requirements for cargoes of 1,780 kg/m3 and above, any cargo declared to have a density in the range 1,250 kg/m3 to 1,780 kg/m3 shall have its density verified by an accredited testing organization.
The band matters because it sits between two structural regimes. Below 1,250 kg/m3 a cargo is treated as a light bulk cargo for the purposes of chapter XII; at and above 1,780 kg/m3 the full high-density regime applies, with its consequences for hold flooding survivability and double-side skin requirements. A cargo declared inside the intermediate band on a ship not built for the upper regime is the case the verification requirement addresses.
SOLAS regulation XII/10.1 is the declaration duty itself: before loading bulk cargo on bulk carriers of 150 m in length and upwards, the shipper shall declare the density of the cargo in addition to the cargo information required by regulation VI/2. IMSBC section 4.2.2.7 carries the corresponding item. The full article will cover the sampling and measurement procedure, who qualifies as an accredited testing organization and how a disputed density is resolved at the berth.