Solid Bulk Cargo Density Declaration

Introduction

Carrying solid bulk cargoes involves serious risks, which must be managed carefully to safeguard the crew and the ship. These risks include reduced ship stability (and even capsizing) due to cargo liquefaction; fire or explosion due to chemical hazards; and damage to ship structures due to poor loading procedures.

Before you can accept a cargo for shipment, the shipper must provide the Master with valid, up-to-date information about the cargo’s physical and chemical properties.

Regarding above and on the basis of SOLAS / Chapter XII (Reg.1~14) / Reg. 10, Prior to 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 providing the cargo information required by regulation VI/2. (information as required by section 4 of the IMSBC Code)

This article describes a review on the “Solid Bulk Cargo Density Declaration” method and requirement.

Uniform method of measurement of the density of bulk cargoes

Bulk density is the weight of solids, air and water per unit volume. It includes the moisture content of the cargo and the voids whether filled with air or water. (It should be expressed in (kg/m³))

This specification provides for the use of a container of known volume and tare weight. The container should be sufficiently rigid to prevent deformation or volume changes occurring during the test. Where the material contains lumps, or will not readily flow into corners, the container should be of cylindrical shape and/or of large size in comparison to the size of lumps. Its capacity must be large enough to contain a representative sample of the cargo for which the density is to be determined. The internal surfaces of the container should be smooth with any attachments such as handles being fitted to the exterior. Weighing should be done using a weighing instrument certificated by an accredited testing organization.

Procedure

A sample that is representative of the particle size, compaction and moisture of the material to be loaded on the ship should be selected. The container should be filled with a sample of the material so that it is trimmed level with the top of the container. The material should not be tamped. The weight of the filled container should be measured and the tare weight subtracted to obtain the weight of the sample. The density of the sample should be calculated by dividing the weight of the bulk material to be loaded by the volume of the container.

The result of the density measurement should be signed by a representative of the accredited testing organization.

Recommended record form’s data

1. Cargo : (name and relevant reference in the BC Code)
2. Shipper (name, address, telephone, etc.)
3. Sample origin (stock pile, ship's hold, etc.)
4. Date (sampling and density measurement)
5. Gross weight (GW) (container plus sample)
6. Tare weight (TW) (container)
7. Net weight (NW) (sample) (NW=GW-TW)
8. Volume (V) (container)
9. Calculated density (d) of the cargo (d=NW/V)
10. The accredited testing organization’s data (Signature, stamp)
11. Date & place of issuance