Ore Cargo. Vessels carrying ore are usually designed for that particular trade. Where ore is to be carried in the usual type of freighter, special care must be taken to fit the required trunks and shifting boards. Heavy ore carried in the lower holds is liable to make a vessel crank, and the Chief Mate should see that means are provided for the lifting up of the weights, and the proper distribution, fore and aft. The usual plan, in a vessel with four holds, is to fill No. 2 and No. 3, and trim with No. 1 and No. 4. This keeps the cargo high amidships, and eases the vessel in a seaway.
Wooden Steamers. The shipment of ore cargoes in vessels of weak construction, should not be attempted unless the movement of the ore cannot be accomplished in any other way. The wooden steamers, built as an emergency measure, are a case in point.
The highest skill in loading, stowage and handling will be required for these vessels.
Grain Cargo. The carriage of grain cargo calls for special precautions to prevent shifting. The British Board of Trade and the underwriters have made special rules for the stowage of such cargoes. The Chief Mate should inform himself of these rules as a part of his stock of knowledge.
Cotton Cargo. The danger to fire when loading a cotton cargo is great and every precaution should be taken. Smoking, which should never be permitted in the holds or about the hatches at any time, should be specially guarded against when loading cotton.
Care should be taken that no sparks from the funnels, from passing or nearby tugboats, or from steam boilers on the wharf, find their way into the hatches. Have the fire lines connected up at all times and have the steam on the smothering lines.
Steam is the best agent for smothering a cotton fire. If a fire starts do not wet down the decks or side plating. This may get very hot, but do not play cold water on it. Strains would be set up in the plating or deck that might seriously injure it.
Keep all oil cans, oily waste, paint, paint pots or paint rags and brushes away from the cotton.
Keep all ventilator cowls closed, to prevent sparks finding their way into the cargo.
When hatches are closed down at night, or when battening down for sea, the Chief Mate should have an officer make certain that no fire is present in the holds.