MSC 85/26/Add.2 ANNEX 3 RESOLUTION MSC.268(85) - US Coast ...

MSC 85/26/Add.2ANNEX 3Page 333Table 1.1.4.1Typical cargoBulkdensity(kg/m 3 )Maximum cargo depth2 m 5 m 10 m 20 mTamper pressure (kPa)Coal100020 (1.4)50 (3.5)100 (7.1)200 (14.1)200040 (2.8)100 (7.1)200 (14.1)400 (28.3)Metal ore300060 (4.2)150 (10.6)300 (21.2)600 (42.4)Iron ore conc.400080 (5.7)200 (14.1)400 (28.3)800 (56.5)Lead ore conc.5000100 (7.1)250 (17.7)500 (35.3)1000 (70.7)(values in parenthesis are equivalent kgf when applied viaa 30 mm diameter tamper head)1.1.4.2 The preliminary flow moisture test:.1 Immediately after removing the mould, the flow table is raised and dropped upto 50 times through a height of 12.5 mm at a rate of 25 times per minute. If thematerial is below the FMP, it usually crumbles and bumps off in fragments withsuccessive drops of the table (see figure 1.1.4-3)..2 At this stage, the flow table is stopped and the material returned to the mixingbowl, where 5-10 ml of water, or possibly more, is sprinkled over the surface andthoroughly mixed into the material, either with rubber-gloved fingers or anautomatic mixer.The mould is again filled and the flow table is operated as described in 1.1.4.2.1for up to 50 drops. If a flow state is not developed, the process is repeated withfurther additions of water until a flow state has been reached..3 Identification of a flow state. The impacting action of the flow table causes thegrains to rearrange themselves to produce compaction of the mass. As a result,the fixed volume of moisture contained in the material at any given level increasesas a percentage of the total volume. A flow state is considered to have beenreached when the moisture content and compaction of the sample produce a levelof saturation such that plastic deformation occurs * . At this stage, the mouldedsides of the sample may deform, giving a convex or concave profile(see figure 1.1.4-4).*In certain conditions, the diameter of the cone may increase before the flow moisture point is reached, due tolow friction between the grains rather than to plastic flow. This must not be mistaken for a flow state.I:\MSC\85\26-Add-2.doc