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Heavy Weather Precautions on Ship

When heavy weather is expected, the ship would roll, pitch, yaw, sway, surge and heave. This movement in six degrees of freedom would pose dangers of several kinds – structural stresses, rolling of the ship resulting in a shift of cargo, a shift of equipment, injury to persons, damage to property, etc.

Several precautions have to be taken to minimize such risk to the safety of the ship, injury to persons on board, damage to equipment and property, etc. The precautions would generally fall into a systematic pattern as described below:

On all types of ships:

Inform Master.

Inform Chief Officer.

Inform the Catering staff.

Inform Engine Room.

Secure all moveable equipment on the bridge.

Switch on ARPA and commence plotting.

Switch on navigation lights. Later on, clouds may result in partial darkness; rain and/or spray may result in a decrease of visibility.

Switch on the second steering motor also.

Try out a pneumatic whistle, electric klaxon, and ale foghorn.

Keep a record of all relevant actions/events in the Bridge Notebook.

Inspect the chart and ensure that the intended course is safe bearing in mind the following points:

  1. More Under keel clearance would be required because of pitching, rolling and heaving (heaving is the bodily movement of the ship in the up and down direction due to wave action).

  2. The ship would be more difficult to manage in bad weather (less responsive to rudder movements) and hence it may be necessary to give dangers a wider berth than in cam weather.

  3. Failure of the main engine, failure of generators, failure of the steering system, etc, in bad weather, are some of the possibilities that must not be overlooked. These failures may render the ship incapable of being controlled to move along the intended path and thereby drift on to dangers.

The Chief Officer would ensure that the following precautions are taken by the Deck Department but the crew should be aware of all of them:

Anchor lashings are checked and doubled if necessary

Hawse pipe covers are shipped and secured.

Spurling pipes are covered and cemented over.

The booby hatch loading into the forepeak store is closed watertight

All mooring ropes are either secured in place (short passages) or stowed away below deck (long passages) as appropriate.

All movable objects on deck (including the poop deck), such as lubricating oil drums, hydraulic fluid drums, painting rafts, etc, are secured.

Additional lashings are put on accommodation ladders, If necessary.

The gripes of lifeboats are tight and that locking pins of davits are in place. Lifeboats and liferafts must NOT have any additional lashings as they would hamper quick launching in an emergency.

All weathertight doors on the upper deck, loading to Bridge, accommodation, etc., are closed effectively against the entry of water.

The upper deck is free of rags or dirt that could choke the scuppers.

All portholes on the bridge front bulkhead, and those near the waterline, are closed and secured.

Deadlights (steel porthole covers that fit over the glass ones), where provided, should be closed and secured.

All equipment and spares in a storeroom, paint lockers, deck office, etc have to be secured against shift due to the ship rolling in the anticipated bad weather.

Plugs of the open lifeboat to be kept open to prevent the accumulation of water inside them. Past experience has shown that boats have suffered permanent damage due to sagging resulting from accumulated water inside.

Inform the crew to secure all loose items in their cabins.

The work given to cadets and deck crew should not expose them unduly to danger either directly on the deck or due to rolling while indoors.

Additional for General Cargo ships:

Lifelines are rigged on both sides of the upper deck. It is NOT safe enough to rig a lifeline only on the leeward side. In case of a shift of wind direction, or alteration of course by the own ship, the other side would become the leeward side.

Lashings of cargo, above deck and below deck, are inspected and tightened as necessary

All hatches are battened properly. All top and side Wedges to be rechecked and tightened wherever necessary.

All derrick heads are secured properly, in their housing, against accidental unshipping in bad weather. This highly likely when pounding (slamming) occurs.

All derrick guys, preventers, etc., are properly secured. On long passages, these may be unshackled and stowed away in mast houses, tween decks, or in the storeroom.

All sounding pipe covers on the upper deck are inspected to ensure that they have been screwed tight.

All ventilator cowls to be trimmed to leeward. In cases where extreme bad weather is expected, the cows of ventilators on the upper deck may have to be unshipped and stowed away. The ventilator coamings would then have to be covered with wooden/metal covers, specially provided for this purpose, covered with canvas and secured

Additional for Tankers:

Scuppers on deck, which were closed during cargo operation in port, is open.

Drip trays are clean of oil and are unplugged for release of water, which may accumulate in them, to flow out on the deck.

All openings to the tanks - tank lids, sighting ports, ullage ports, purge pipes, etc must be shut watertight. This is not only to prevent seawater from entering the tanks but also to prevent oil from loaded tanks from splashing up on deck when the ship rolls. Normally, oil tankers would already comply with this because of the IG pressure to be maintained in the tanks.

Because of their low freeboard, tankers are very prone to shipping seas on deck. In view of this, a protective, central walkway (called the catwalk) is provided on tankers, in accordance with the Loadline Rules, for safe access between the accommodation and the forward part of the ship. The rigging of lifelines, like on General cargo Ships, is hence not necessary.

The heavy weather ballast tanks, designated in accordance with MARPOL 73/78, and the lining up of lines for that purpose, should be known to all Navigational Watchkeeping Officer.

The catering crew would ensure that the following precautions are taken in the Galley, Pantry, Dining Saloon, Smoke Rooms, etc. but the OOW should be aware of all of them:

  • The menu for meals is adjusted so that frying of food, during heavy weather, is avoided – the chances of the cook suffering burns from the spillage of hot oil, due to rolling, is thus considerably reduced, if not eliminated altogether.

  • It must be remembered that 100 degrees Celsius is the temperature of boiling water whereas the temperature of oil, during frying, is considerably higher, maybe around 400 degrees, and thus the cook would suffer more severe burns from hot oil than from boiling water.

  • Secure all loose items that could roll-off or spillover, in the galley.

  • The galley floor scrubbed free of any oily food spills that could cause feet to slip

  • Secure all items of crockery, cutlery, bottles, glasses, etc in the pantry, the dining saloon, and in the smoke-room/bar/lounge.

  • Attach the safety hooks provided beneath all chairs in the dining saloon, smoke-room/lounge, and in all cabins.

  • Raise the safety barriers provided around the periphery of tabletops in the dining saloon, smoke- room/lounge, etc.

  • Use damp tablecloths to provide anti-skid friction on the dining tables.

  • Secure all loose items in officers’ cabins.

  • All items in the provision store, bonded locker, and cold storage rooms are secure.

The Chief Engineer would ensure that the following precautions are taken by the Engine Department but the OOW should be aware of all of them.

  • The Engine Room skylight, if of the open-close type, should be closed. In many modern ships, the skylights are closed semi-permanently by nuts and bolts. The skylight is opened only to pass heavy machinery parts with a crane. Such engine rooms are provided with forced ventilation only.

  • All equipment, spares, stores, tools, paints, etc of the engine department to be secured.

  • The schedule of running maintenance, if any, to be altered, if necessary, to ensure that the work to be done is of a type-safe enough to be carried out while the ship is rolling.

  • Soundings of oil tanks in use would have to be high to ensure that pumps do not lose suction during rolling, especially the sump of the main engine crankcase.

  • The main engine fuel control setting may have to be adjusted to prevent excessive racing during pitching. In most ships, a device called a governor is fitted to prevent racing, wherein the upper limit of engine RPM can be pre-set by the EOW.

  • By way of abundant caution, a second generator may be started, and run in parallel, just in case the one in use trips during the bad weather.

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