95001 Wet Coal

Wet Coal
- South Atlantic
- Report No. 95001

Having read previous MARS reports on flow state reached by cargoes due to moisture content being in excess of Transportable Moisture Limits, particularly concentrates, here is another case to which I would like to draw the fraternity's attention.

This incident concerns a bulk carrier which took on board a consignment of steam coal after obtaining the required certificates from the "authorities" which stated that the condition of the cargo was safe to load. Before arrival at the port, the Master sent a telex stating his loading requirements and requested the following information prior to loading:

Characteristics of the coal to be loaded.
Recommended safe handling procedures for loading and transport of intended grade of coal.
Whether the cargo is liable to self-heat or emit methane.

Five days later, the vessel was in position alongside ready to load. The Coal Cargo Declaration Certificates were received from the agents stating that the cargo had no historical record of self heating or emitting methane, the total moisture was 8% and the transportable moisture limit 10%. The certificates were however dated five days previously. The first parcel of coal was loaded into holds 2 and 4 from open stock piles by chutes fed by exposed conveyor belts in wet condition due to rain. A protest letter for loading of cargo in wet condition was issued to the agents.

The terminal where the coal was loaded boasts of being a thoroughly professional organisation with rules and regulations in line with its professionalism, some of which are quoted here:

Vessels to have a minimum draught restriction for entry.
Vessels are not permitted to interrupt loading operations for more than 8 hours for de-ballasting.
Delays, particularly on vessel's account, are noted to the nearest minute and any unreasonable delay renders a vessel liable to be shifted out of berth, losing her turn to load and rejoining the back of the queue.
Masters are reminded of their obligation under the Load Line Convention, their legal right to use the Dock Water Allowance and extreme care towards completion as the loading appliance is capable of a rate in excess of 6,000 tonnes per hour.
Masters are required to acknowledge receipt of these regulations.

Twelve days after sailing a sloshing noise was heard in holds 2 and 4. The holds were opened up for inspection and it was discovered that the cargo in these holds had reached flow state and the slurry was sloshing around. Closer inspection revealed that most of the impact was being taken by the lower hoppers and the structural integrity was not impaired. The water released from the cargo accumulated at a level of 0.5 – 1.0M above the surface of the cargo forming a slurry. Solid cargo was visible underneath the slurry when the ship was rolling. The cargo in holds 1, 3 and 5 appeared to be in a satisfactory condition. Stability calculations were made and the stability condition was determined to be satisfactory/adequate taking into account the free surface effect of the fluid state of the cargo amounted to nearly 4M. It was assumed that the cargo in holds 2 and 4 had reached flow state due to the moisture content of the cargo being beyond the TML.

Fortunately, the weather at the time was reasonable and the bulk carrier managed to sail on to her port of discharge. During this period the situation was monitored by six hourly inspections of all holds and six hourly taking of soundings of all tanks and bilges and regular inspection of the shell plating in way of 2 and 4 holds.

With respect to this incident the following points are pertinent:

Was the effect and consequence of rain on open stock piles realised by authorities allowing this grade of coal to lie exposed and then dumping same on board?
Was the effect and consequence of rain on open stock piles realised by the authority issuing the certificate of moisture content?
If yes, was the cargo re-sampled for moisture between the dates the certificates were issued and the date the cargo was loaded? The vessel was not in a position to determine how much rain had fallen at the port during that period and the effect that this would have on the moisture content of the cargo.
In the absence of any feedback from any of the concerned parties regarding action taken to remedy the situation, if any, are we going to abandon the safety of vessels and their crew into the hands of people for whom the issuing of certificates is a mere exercise in filling in blanks with figures? The two separate parcels of coal loaded had virtually the same figures on the certificates.
Are the said authorities answerable?
Had the cargo in all holds reached flow state the consequences would have been grave.

It is admitted that, in spite of the constraints imposed by the regulations of the port, ship's personnel failed to carry out a "Can-thumping" test as per Code of Safe Practice for Solid Bulk Cargoes section 8.3. The innocent appearance of the cargo betrayed us.

This experience has led me to be suspicious of all cargoes and their test certificates issued by "competent authorities". "Can Thumping" tests have become a routine where cargoes of concentrates and coals are concerned.