Seamanship Techniques 2011 E Part 12 pps

40 325 0
Seamanship Techniques 2011 E Part 12 pps

Đang tải... (xem toàn văn)

Tài liệu hạn chế xem trước, để xem đầy đủ mời bạn chọn Tải xuống

Thông tin tài liệu

143Emergencies out the boats and make survival craft ready for launch without being hindered by frightened people. Roll on–roll off Vessels The essential feature of this type of vessel is the large amount of open space on the vehicle decks, and the main danger, if the stowage area is holed to any extent, that the speed with which water may flood the vessel could be critical. The time in which to take the decision to abandon the vessel and launch survival craft will be limited. The design of these vessels is generally such that they have a very large GM compared with the conventional type of vessel. They also tend to have large freeboards, with vehicle decks situated higher than the waterline. All these features reduce the risk of being holed below the waterline and in the stowage spaces but the possibility always exists, especially if a vessel has grounded, and the double bottom tanks and the tank tops have been pierced, allowing water to penetrate direct into the stowage areas. A speedy assessment of damage would be essential with a roll on–roll off vessel, and once the decision to abandon has been taken, then swift, positive action would be required from all personnel. Abandoning the vessel by bow and stern doors, as well as by shell doors, should not be ruled out if the circumstances of the case admit, and if a source of power to operate them is still available. Individual abandonment should be avoided, in view of the high freeboard, unless no alternative is left. Use should be made of disembarkation ladders, lifelines to boats etc. as a realistic alternative to direct entry into the water from the freeboard deck (upper deck). Scrambling Nets Nets could be usefully employed in many types of rescue, especially on high freeboard vessels and where there are large numbers of people to consider. Nets may not always be available at short notice and improvisation in the way of gangway or cargo nets may be a useful alternative. When nets or other similar rescue equipment is to be used for the recovery of survivors, the physical condition of persons to be rescued should be considered, e.g. the injured and stretcher cases. RESCUE AND RECOVERY OF SURVIVORS Circumstances affecting the rescue of survivors will vary considerably but might be categorised into three groups: (a) Recovery from survival craft or wreckage. (b) Recovery from the water. (c) Recovery from parent vessel before she sinks. Recovery from Survival Craft 1. Prepare hospital and other reception areas to receive casualties. Provide 144 Seamanship Techniques medical aid for burns, oil cleansing, and treatment of minor injuries with bandages, adhesive dressings and splints. Expect to treat for shock and hypothermia – blankets, warm clothing, hot drinks and stretchers should be made ready. 2. Rescue apparatus in the way of scrambling nets and boarding ladders should be rigged overside, together with a guest warp. Derricks and/or deck cranes may be swung overside to recover survival craft, provided the safe working load of the lifting gear is adequate. These may be used with or without cargo nets secured to the end of cargo runners. Cargo baskets may be useful for lifting injured people from boats. 3. Try to manoeuvre the rescue vessel to windward of the survival craft to create a lee, to aid recovery. 4. Establish communications with the survival craft as soon as is practical. Acknowledge distress signal flares by sound or light signals. 5. Have plenty of long heaving lines available, and also the rocket line throwing gear. 6. Maintain normal bridge watch, checking navigation hazards in the vicinity. Display correct flag signals and keep other shipping, as well as the coastal radio station, informed of movements and situation. Recovery from the Water 1. Preparation should be as in (1) and (3) above. 2. Depending on weather conditions, the best method of recovering a person or people from the water would be by use of own boats. A ship’s rescue boat is desirable, and this should be launched within sight of the survivor(s) in a lee made by the parent vessel. 3. Injured parties should be hoisted aboard individually with the aid of stretchers. 4. The condition of persons in the water, especially after a lengthy immersion, will be poor. Assistance may be required by ship’s personnel to bring survivors aboard. Crew members should always wear safety harness and lifejacket in this situation, or they may need rescuing themselves. 5. Shooting the rocket line towards survivors may prove a worthy option if the state of the sea is so dangerous that it would be foolhardy to attempt to launch a ship’s boat. 6. Persons in the water without flotation aids cannot be expected to remain afloat for long periods. It might be necessary to provide some form of buoyancy, such as a lifebuoy. Recovery from Parent Vessel 1. Should an order to abandon ship be given while a rescue vessel is on the scene, it is an obvious move to attempt to recover personnel direct from the stricken vessel. 2. This operation could be carried out basically in two ways: by bringing the rescue vessel alongside the ship in distress or by use of the rescue ship’s boats. Each case has its merits. A Master in a recovery operation For further reference, marine students are directed to Volume III, The Command Companion of Seamanship Techniques DJ House, ISBN 0 7506 444 35. 145Emergencies would probably not endanger a tanker full of aviation spirit by drawing alongside another vessel on fire. In this case he would probably use his ship’s boats. But, say, there were two vessels of different freeboards. The rescue vessel could manoeuvre her fo’c’sle head into contact with that of the distressed vessel, and allow those being rescued to cross via the two fo’c’sle head areas STRANDING This is physically the same action as beaching, but with the significant difference that beaching the vessel is an intentional action and under comparatively controlled conditions, whereas stranding is accidental. Circumstances will vary with different ships, but selecting a convenient position to ‘set down’ will in all probability never arise. In consequence, the double bottom area of the vessel will probably suffer considerable damage, especially if the ground is rocky. The method of procedure to follow on stranding can only be an outline, when one considers how circumstances may vary. Here are some suggestions: 1. Stop engines. 2. Sound emergency stations. 3. Close all watertight and fire doors. 4. Damage control party to assess damage. This must include sounding around the outside of the hull and checking the available depth of water. All of the vessel’s tanks, especially double bottoms and bilges, should also be sounded and visually inspected wherever possible, air pipe and sounding pipe caps being well secured after the soundings have been obtained. This will prevent oil pollution as water pressure forces oil upwards through the outlet pipes above deck. 5. Check position on the chart and observe depths of water around the vessel. 6. The Master should consider refloating, though that depends on the extent of the damage especially to tank tops. The tides should be assessed, and ballast tanks, together with additional weight (includ- ing fresh water), viewed for dumping in order to lighten ship. Damage stability data should also be consulted. There may be value in dropping an anchor underfoot to prevent a damaged ship from sliding off into deep water. 7. Consider whether assistance is required in the form of tugs to drag the vessel astern clear of the beach into deeper water. 8. As soon as practical, enter a statement into deck log book and inform owners and the Maritime and Coastguard Agency (on state of seaworthiness). BEACHING PROCEDURE Beaching is defined as taking the ground intentionally, as opposed to accidental stranding. It is normally carried out for either or both the following reasons: 146 Seamanship Techniques 1. to prevent imminent collision; 2. to prevent loss of the vessel when damaged and in danger of sinking, damage having occurred below the waterline causing loss of watertight integrity. The intention is to carry out repairs in order to refloat at a later time. Should time and choice be available, the mariner should attempt to beach the vessel on a gentle sloping beach, which is rock free and ideally with little or no current. If possible it should be sheltered from the weather, free of surf action and any scouring effects. Advantages and Disadvantages for ‘Bow’ or ‘Stern’ Approach When approaching bow-on, the obvious advantage is that a clear observation of the approach can be made and the vessel will probably have a favourable trim. The propeller and rudder will favour the deeper water at the stern, while the strengthened bow would cushion any pounding effects. The disadvantages of this approach are that the vessel is more likely to slew and the need for anti-slew wires used in conjunction with anchors, may become necessary. Also it is difficult to lay ground tackle from this position, to assist with the refloating. In the majority of cases stern power would be used for refloating the ship and the average vessel normally operates with only 60 per cent of the ahead power, when navigating stern first. Beaching stern first is just as effective, provided that time allows. It is easy to do, in the form of a mediterranean moor but allows the propeller and rudder to close the bottom with the obvious risk of additional damage. The vessel may also prove difficult to ‘con’ when navigating stern first. Actions Prior to Beaching Provided that time and circumstances allow, the vessel to be beached should take on full ballast. This will make the operation of re-floating that much easier. Both anchors should be cleared away and made ready to let go. Care should be taken to lay anchors and cables clear of the position that the vessel is expected to come to rest, so minimizing the bottom damage, if this is possible. Additional use of a stern anchor, if the ship is so equipped, would become extremely beneficial on the approach, with the view to refloating later. On Taking the Ground Drive the vessel further on and reduce the possibility of pounding. Take on additional ballast and secure the hull against movement from weather and sea/tide. Take precautions to prevent oil pollution. This can be achieved by discharge into oil barges, or transfer within the vessel into oil-tight tanks. Another alternative would be encircling the vessel with an oil pollution barrier, if one can be obtained quickly enough and positioned effectively. 147Emergencies Damage reports should be made to the Marine Accident Investigation Branch (MAIB), together with a ‘general declaration’, the Mercantile Marine Office being informed and entries made into the Official Log Book. DECK DEPARTMENT CHECKLIST FOR WATERTIGHT INTEGRITY OF HULL FOLLOWING GROUNDING OR BEACHING 1. Check for casualties. 2. Assess internal damage by visual inspection where possible. (Special attention being given to the collision bulkhead and the tank tops.) 3. Look for signs of pollution from possible fractured oil tanks. 4. Make internal sounding of all double bottom and lower tanks, followed by a complete set of tank soundings at the earliest possible time. 5. Sound for available depth of water about the vessel, especially around stern and propeller area. 6. Check position of grounding on chart. Determine the nature of the bottom and expected depth of water. 7. Obtain damage reports from all departments. 8. Determine state of tide on grounding, together with heights and times of the immediate high and low waters. 9. Order communications officer to stand by. 10. Check condition of stability if the vessel has suffered an ingress of water. 11. Instigate temporary repairs to reduce the intake of any water, and order pumps to be activated on any affected areas. 12. Cause a statement to be entered into the deck log book, with a more detailed account to follow. ENGINE ROOM DEPARTMENT CHECKLIST FOR MACHINERY SPACES FOLLOWING GROUNDING OR BEACHING 1. Check for casualties. 2. Assess damage inside the engine room and pump room and report to the Master. 3. Make ready fire-fighting equipment in case of fire outbreak. 4. Prepare pumps to pump out water from engine room spaces. 5. Inspect all fuel and steam pipes for signs of fracture. A build-up of oil represents a fire hazard and must be located and corrected as soon as possible. Regular checks on bilge bays must be continued for a minimum period of three days after taking ground. 6. Inspect all piping, valves and auxiliary equipment, before reporting to the Master on conditions. 7. Should water be entering the engine room, instigate immediate temporary repairs to reduce the ingress of water, and start the pumps on the affected areas. The general alarm should be sounded before grounding or beaching, but if this has not been done, it would become the first action in the above lists. 148 Seamanship Techniques Dog Hinge Wedge Beam Steel bulkhead Door Dog Frame Wedge Steel bulkhead Carling beam Half frame Vertical frame Beam Vertical frame Beam Gunmetal nut Sliding door Figure 6.3 Watertight door construction. WATERTIGHT DOORS There are many designs of watertight door and watertight hatch, the most common being those closed manually by means of ‘butterfly clips’ or ‘double clips and wedges’ (dogs), which are operable from either side of the door (Figure 6.3). The disadvantage of this type of closure is that it takes considerable time to secure. In an emergency it may even prove impossible to secure against water pressure on one side. Regular and extensive maintenance is required on the clips to ensure they are free in movement and can be easily operated. Oiling and greasing of moving parts, especially of weather-deck hatches and doors, becomes an essential part of any planned maintenance operation. Regular inspection and periodic renewal of the hard rubber seal around the perimeter of the access door will ensure watertight integrity. 149Emergencies Where electrical, hydraulic (Figure 6.4) or pneumatic systems are installed, as in passenger vessels, each watertight door should be equipped with audible and visual alarms effective on both sides of the door, a local emergency stop control, a manual operation system located close to the door, and emergency worming gear operative from an external point on deck. The obvious advantage of a bridge controlling point, which operates all doors simultaneously, increases the speed at which watertight integrity is achieved throughout a vessel, on all decks. The bridge control is fitted with a light ‘tell tale system’, which tells the operator at a glance which doors are closed and which are open. When operating in a guide system under power, they are also effective, even against an inflow of water pressure. Should loss of power occur, then similar results may be achieved by external manual operation. Figure 6.4 Control of hydraulic sliding watertight door. Header oil tank Pump Motor Emergency stop valve Bridge console ‘Tell Tale’ light display Stop/start control Audible operating alarm Emergency stop Manual operation worming gear Two-way changeover valve Watertight door Limit switches Guide Local visual and audible alarms Local emergency stop control 150 Seamanship Techniques DRYDOCK PROCEDURE Plates 20 and 21 illustrate a ship in drydock. Chief Officer’s Duties Preparation and precautions for entry 1. All hatches and beams should be in the stowed position to ensure continuity of strength throughout the ship’s length. 2. All derricks and cranes should be down and secured, not flying. 3. Any free surface in tanks should be removed or reduced to as little as possible, either by emptying the tank or pressing it up to the full condition. 4. Stability calculations should be made to ensure adequate GM to take into account the rise of ‘G’ when the vessel takes the blocks. 5. Consult dock authorities on draught of vessel and trim required. Generally a small trim by the stern is preferred, in normal circumstances. 6. Inform dock authorities in plenty of time of any projections from the hull of the vessel, as indicated by drydock plan. 7. Sound round all ship’s tanks before entering the dock, to be aware of quantities aboard. Note all soundings in sounding book. 8. Sound round all tanks once the vessel has taken the blocks, to ensure a similar stability state when leaving the drydock. 9. Lock up ship’s lavatories before entering the dock. 10. Ensure adequate fenders are rigged for entry into the dock and that dock shores are correctly placed against strength members once the vessel is positioned. If it is the custom in the graving dock, arrange for fo’c’sle head party to position shores on one side and the stern party to deal with the other side. 11. If required, endeavour to have the vessel cleaned and scrubbed as the dock water is pumped out. 20. Removal of ship’s propeller in drydock. The chain block arrangement and support rigging for changing the propeller, or inspecting the tail end shaft, may be seen. 151Emergencies When drydocking with cargo aboard 12. Inform dock authorities where to position extra shores or blocks to take account of additional stresses caused by the weight of cargo aboard. 13. Give cargo areas a lock-up stow whenever possible. When in dock 14. Obtain telephone/electricity/and water pressure fire line garbage and sanitation facilities as soon as possible. 15. Have documentation ready, inclusive of repair list, for dock personnel. 16. Should tank plugs need to be removed, sight their removal and retain the plugs for safe-keeping. Ensure that plugs are labelled after removal. 21. On the blocks in drydock the hull lines are clearly defined, with both anchors walked back either side of the bow. 152 Seamanship Techniques Draught and Trim The vessel’s required draught and trim will be decided by the drydock manager and the declivity of the drydock bottom. A small trim of between 12 in (30 cm) and 18 in (45 cm) is considered normal but will be dictated by circumstances. If a floating drydock is to be engaged, the drydock itself can be trimmed to suit the vessel, especially if the vessel has sustained shell damage. Drydock Plan This is a plan carried aboard the vessel which shows recommended positions for keel blocks and shores. Normally the frames are numerically indicated from aft to forward, and the strakes lettered from the centre- line out and upwards. Indicated on this plan will also be the position of any external projections from the hull, namely, echo-sounder units, stabilisers, scoops for condensers etc. Either a separate plug plan will be carried or the tank drain plugs will be indicated on the drydock plan. Stability of Vessel This is the responsibility of the vessel, and should be adequate to cope with the virtual rise of G as the vessel takes the blocks. The vessel should not be listed. Should damage be such that the vessel cannot counter an acquired list, then shoreside weights should be taken aboard to bring the vessel to an even keel. Position of Shores Side keel blocks are positioned in the drydock to offer additional support to keel blocks, especially for the broader beamed vessel. Some drydocks will position bilge shores at the turn of the bilge, these are not to be confused with the above-mentioned side keel blocks. Breast shores are usually only rigged in graving docks where the sides of the dock are stepped. Ideally the shores and blocks should be positioned at the intersections of frames and stringers. Side blocks should be placed at the intersection of an athwartship floor and a fore and aft member, such as an intercostal. Where the vessel is to drydock in a floating dock, then hydraulic cradle shores may be encountered. These are housed in side tanks set into the dock sides. Repair Lists It is normal practice to carry out repairs when entering drydock, these repairs may be expedited by detailed work lists covering expenditure limits, work monitoring, state of survey, maintenance of classification, and protection of owners’ interests. To Calculate the Virtual Loss of GM There are two methods for ascertaining the virtual loss of GM. In each of the two methods the force P must be known. Force P represents the Figure 6.5 Positions of shores relative to stepped sides of graving dock. Breast shores Stringer and frame intersection Wedges Side blocks Keel blocks Bilge shores [...]... of the two methods are acceptable when W represents displacement of the vessel KM represents the distance between the keel and the metacentre, KG represents the distance between the keel and the centre of gravity of the vessel C MAN OVERBOARD The actions of the officer of the watch and the ship will depend on the circumstances of each individual case.To take account of every eventuality would be impossible,... the operating area free of heavy spray or seas on deck? (c) Have side rails and, where necessary, awnings stanchions and derricks been lowered or removed? (d) Where applicable, have portable pipes been removed and have the remaining open ends been blanked off? (e) Are rope messengers to hand for securing the helicopter if necessary? (Note: only the helicopter pilot may decide whether or not to secure...Emergencies upthrust at the stern at the moment the vessel touches the keel blocks The time the keel first touches the blocks until the vessel has taken the blocks overall is considered to be the critical period (Figure 6.6) 153 ‘P’ force Centre of flotation W/ L W/ L L Force P (tonnes) = MCTC × t L where MCTC t represents the moment to change trim one centimetre, represents the trim in centimetres... personnel should raise the alarm, no matter what the size of the fire This will allow back-up teams to equip themselves with more effective fire-fighting gear while containment of the fire is being attempted by the portable extinguishers These can be used to great effect when employed with common sense The correct extinguisher for the job should be used, and probably the nearest extinguisher to the... supply, effectively reducing the spread of heat smoke and the fire itself, will not be accomplished Fire-fighters need to operate in teams of not less than two men because the average person’s courage in the face of danger is reduced considerably if he is alone Two or more men may also be necessary to achieve a success, or at least better efficiency than one Isolation of ‘live circuits’ is necessary because... should be ordered to prepare the hospital reception space Advice may be needed for the treatment of shock and hypothermia 7 The vessel’s speed should be reduced as the Williamson turn is completed, and the following points considered: 22 Emergency bridge lifebuoy, for use in ‘Man Overboard’ emergencies, with combined light and smoke float attached This one is secured in the stowage bracket on the after... been reduced to a level which will ensure that there is no discharge of gas during the helicopter operation (c) For all tankers The tank openings have been re-secured after venting STEERING GEAR FAILURE OR LOSS OF RUDDER The alternatives open to mariners who suffer the loss of steering facilities are limited to the type of vessel and the associated equipment which it happens to have on board at the... improve (k) Keep regular checks on the fire containment, by feeling the heat content and checking temperatures at different levels on adjacent bulkheads Spray branch lines can be most effective in boundary cooling to reduce temperatures, and their use lessens the risk of distortion of steel plate while covering a larger area than a jet Bulk Oil, Chemical or Gas Carriers Fires on board these vessels are... extinguishing to be employed Check the cargo plan and identify potential hazards within the compartment As a general rule, prepare fire-fighters for ’tween deck and/or lower hold entry, depending on the fire’s location Prepare fixed smothering or extinguishing systems with the idea of inerting the space except for nitrate or sulphate cargoes Steam smothering must never be used when explosives are present Should... the fire Watertight and fire doors should be closed as soon as possible for the safety of the vessel Engine room personnel should be well aware of emergency and tunnel escape systems Summary On the discovery of the fire, the alarm must be raised, casualties removed from the scene and the fire investigated and tackled with primary equipment Depending on weather conditions and the location of the fire, . P × Either of the two methods are acceptable when W represents displacement of the vessel. KM represents the distance between the keel and the metacentre, KG represents the distance between the. one centimetre, t represents the trim in centimetres on entering the drydock, L represents the distance between the centre of flotation and the vertical line of action of the P force, in metres. The. shores Stringer and frame intersection Wedges Side blocks Keel blocks Bilge shores 153Emergencies upthrust at the stern at the moment the vessel touches the keel blocks. The time the keel first touches

Ngày đăng: 11/08/2014, 21:21

Từ khóa liên quan

Tài liệu cùng người dùng

Tài liệu liên quan