Bulk Carrier Practice - Care of ship and cargo on the loaded voyage
Cargo temperatures and sampling of air in holds
When carrying some cargoes such as coal and grain the temperature of the cargo should be obtained regularly to detect signs of heating. Temperatures are usually obtained from thermometers lowered into the sounding pipes on the port and starboard sides at the after end of each hold. An additional temperature pipe may be sited beside the hold ladder at the fore end of the hold. The most accurate and reliable readings will be obtained by making sure that the thermometers are lowered to a level which is well below the surface of the cargo and that they are left in position for several minutes. Where possible there should be a thermometer for each position and thermometers should be left in place permanently and withdrawn rapidly when readings are required.
Mercury thermometers are considered to be less satisfactory for taking cargo temperatures unless fitted with a maximum temperature indicator and reset before the taking of each reading, and one authority23 recommends the use of suitably calibrated pyrometers.
When carrying coal it is necessary to test the air in the holds for hazardous gases. This process, like the taking of temperatures, is fully described in that part of Chapter 19 which describes the carriage of coal cargoes.
Fumigation to monitor
If the cargo was fumigated before departure from the loading port and if fumigation is continued in transit, regular checks should be made for leakage of the fumigant for so long as it remains active. (Fumigation is described in Chapter 21.) It is essential that ships make a declaration in their pre-arrival notice if the cargo has been fumigated243 and where possible cargo holds should be ventilated before arrival to ensure that the required safe level of gas has been reached.
Cargo lashings to check
Bulk carriers are required from time to time to carry cargoes which are secured with lashings. Steel coils carried below decks and sawn timber and logs on deck are cases in point. When cargoes are lashed a regular routine of inspecting the lashings daily, or more frequently, is essential. The frequency of the inspections must be increased early in the voyage before the cargo has settled, in bad weather and at any time when each inspection finds noticeable looseness in the lashings.
Lashings can become loose for a variety of reasons. If the ship is pitching and rolling heavily lashings will be stretched as the cargo is accelerated first in one direction and then in another. Wet logs will shrink significantly as they dry out. The cargo will settle as the ship works. Movement and vibration can cause fastenings to slacken or disengage if they have not been locked.
Any slackness in the lashing system will allow cargo to move and once it can move it will further damage the lashings and readily break adrift. It is essential that lashing systems are inspected frequently and thoroughly and that lashings are efficiently retightened as they become slack. When it is necessary to inspect and tighten cargo lashings on deck or in the holds in bad weather, the ship must be hove-to and the inspection must be carried out with the precautions described below.
Inspections in good weather: During a loaded voyage a bulk carrier has a low freeboard and is likely to ship spray and seas on deck and over the hatches even during moderately adverse weather. This calls for a high level of alertness from the Master and his officers to ensure that ship’s company, ship and cargo are brought safely to their destination.
In good weather it is prudent for the chief mate to carry out an informal inspection of the decks at least once a day and to satisfy himself that all is secure on deck before the end of the working day. Storeroom doors, access hatches and manhole covers if left open during the night can lead to flooding, damage or even, in extreme cases, the loss of the ship if the weather worsens. If bad weather is anticipated lifelines should be rigged along the length of the deck, port and starboard, in good time124.
Inspections during rough weather: During rough weather the blows which a ship receives from the sea when the bow strikes the swell and when waves are shipped over the decks and hatches can cause damage to her structure and can loosen fastenings and fittings or break them adrift. The ship’s violent motion can cause cargo, stores and spares to shift or break adrift. Damage of this sort can be disastrous and every effort should be made to ensure that the ship is all secure. In recent years ship design and equipment has been developed to reduce the need for dangerous physical inspections of holds and forecastle spaces during rough weather. Inspections should never be undertaken recklessly but are a valuable complement to WIDS alarms, gauge readings or information gained from binoculars or closed circuit TV.
Because conditions on deck are likely to be hazardous during rough weather an inspection will require organisation and planning. Wherever possible it should be undertaken during daylight hours. A procedure which can be recommended is for the Master to take the bridge, sending the chief mate, bosun and several seamen to make the inspection. The inspection party dress in high visibility heavy weather clothing and equip themselves with VHF radios, and with hammers, crowbars and such other tools as they anticipate they will need to tighten dogs, cleats, brakes and lashings.
When ready to commence the inspection they report by VHF radio to the Master on the bridge, who is also equipped with a VHF radio. The Master then heaves-to the ship by reducing speed and/or altering the heading as required to provide a deck which is reasonably steady and shipping no water. It is worth waiting for five or ten minutes (or longer on a big ship) for the changes in speed and heading to take effect to ensure that the ship is well hove-to and the decks are safe for the inspection party. When satisfied the Master will inform the inspection party which is the lee side and will instruct them to proceed.
Walking the length of the foredeck on the lee side and also inspecting between the hatches, the inspection party will check that hatch cover cleating is all tight and access hatches properly battened down. Loose fittings will be refastened and damaged items inspected and the damage assessed. If the ship possesses masthouses they will be checked for leakage or for items broken adrift. Soundings located on the lee side of the foredeck can also be taken.
The forward spaces of a bulk carrier are particularly vulnerable to flooding. They will be inspected and the forecastle WIDS alarm and high level bilge alarm, if fitted, will be tested. The proper securing of the anchors will be confirmed, as will the sealing of the spurling pipes to prevent water from flooding the chain lockers. Forepeak and chain locker soundings will be taken.
When all is secure in and on the forecastle, the chief mate will report this to the Master who will decide whether it is safe for the inspection party to inspect the remaining side of the foredeck. Before this can be done safely it may be necessary to put the weather on the other bow and whilst this is done the inspection party will either remain within the shelter of the forecastle or will have returned aft to the accommodation. The inspection of the second side of the foredeck, when it can be undertaken with safety, will be similar to the inspection of the side first inspected.
Hold inspections in rough weather: In addition to the inspection of deck and storerooms described above it will be necessary to inspect the holds if a cargo such as steel products is being carried and may have broken adrift or if the possibility of flooding is feared. Where possible inspections in bad weather should be avoided because of the hazards created by a rolling ship and men who are encumbered with heavy clothing, but when an inspection is necessary the normal safety procedures for entering an enclosed space must be followed (Chapter 21). The inspection is likely to be a slow process, though time will be saved if the inspection party has a really powerful torch and much of the hold can be viewed from the access ladder. When an inspection is undertaken during bad weather and it is necessary to heave-to, these facts should be recorded in the deck log.
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