Seamanship Techniques 2011 E Part 13 potx

183Fire-Fighting INTERNATIONAL SHORE CONNECTION This is a fitment which is normally carried by all ships in order to provide a common link between shore hydrants and ships’ fire mains (Figure 7.8). It is employed either aboard the vessel itself or ashore in conjunction with local fire brigade tenders, in the event of fire breaking out while the vessel is in port. The shore connection is usually situated in such a position as to be easily accessible to Fire Brigade officers, e.g near the top of accommodation ladders, or mate’s office. Figure 7.8 International shore connection. 114 mm Blank is drilled for four bolts. The hose flange has four bolts and four slots for the shore hose if required. Indicator plate 305 mm 115 mm Brass keep chain 14.5 mm Blank flange SELF-CONTAINED BREATHING APPARATUS The Siebe Gorman International Mk II, self-contained breathing apparatus (Figure 7.9) employs two cylinders of compressed air, which the wearer exhales direct to atmosphere. The cylinders are of a lightweight design, so that, when fully charged, the apparatus complete with mask weighs only 38 lb. (17 kgs). The cylinder volume is 4 litres, providing enough air for 20 minutes when the wearer is engaged on hard work. Both cylinders have the same capacity. The amount of work carried out by the wearer will obviously affect the consumption of air, and, consequently, the time that person may continue working. The following are guidelines supplied by the manufacturer: Hard work rate 40 minutes (twin cylinders). Moderate work rate 62 minutes. At rest 83 minutes. Pre-operational Checks (monthly) 1. Ensure that by-pass control is fully closed. 2. Open cylinder valves. The whistle, if fitted, will be momentarily heard as pressure rises in the set. Check cylinders are fully charged. 184 Seamanship Techniques Pressure guage tube Warning whistle Pressure guage Mask supply hose Warning whistle adapter Bayonet fitting Harness Back plate Auxiliary air line adapter C Pressure gauge shut off Cylinder valve Emergency by-pass control Cylinder Vistarama face mask Demand valve Figure 7.9 Siebe Gorman International Mark II compressed air breathing apparatus. 3. Any leaks in the apparatus will be audible and should be rectified by tightening the appropriate connections, but do not overtighten. 4. Close cylinder valves and observe pressure gauge. Provided it does not fall to zero in less than 30 seconds, the set is leak-tight. 5. Depress demand valve diaphragm to clear circuit of compressed air. 6. Close pressure gauge shut-off valve and reopen cylinder valves. The pressure should remain at zero. Reopen first valve. 7. Gently open emergency by-pass control; air should then be heard to escape from the demand valve. Close control. 8. Close cylinder valves. Gently depress demand valve diaphragm and observe pressure gauge. When it falls to approximately 43 ats. (44.5 kg/cm 2 ), the whistle should sound. Preparation for Use 1. Demist mask visor with anti-dim solution. 2. Don the apparatus and adjust harness for comfortable fit. 3. Open cylinder valves. Put on the mask and adjust to fit by pulling the two side straps before the lower ones. 185Fire-Fighting 4. Inhale deeply two or three times to ensure that the air is flowing freely from the demand valve and that the exhalation valve is functioning correctly. Hold breath and make certain that the demand valve is shutting off on exhalation or that leakage, if any, is slight. 5. Close cylinder valves and inhale until air in the apparatus is exhausted. 6. Inhale deeply. The mask should crush on to the face, indicating an air-tight fit of both the mask and the exhale valve. 7. Reopen cylinder valves. There are several manufacturers of breathing apparatus, and the sequence of operations may differ slightly from that described above. Caution in following correct procedures is advised in all cases, together with regular practice drills in the use of this type of emergency equipment. EXAMPLE: CARGO FIRES LNG (Liquid natural gas) Natural gas contains numerous component gases but by far the greater percentage is methane (CH 4 ), which represents between 60 and 95 per cent of the total volume. This fact is important when considering the safety aspects for fire-fighters tackling an LNG fire. During the initial period of vaporisation of the gas, ignition may be accompanied by a flash of varying proportions. However, because the velocity of propagation of a flame is lower in methane than in other hydro- carbon gases, it is unlikely that future ignition will have flash effect. The fire-fighting plan should be well thought out in advance and a concentrated effort made rather than ‘hit and run’ tactics, as these will only consume the vessel’s extinguishing facilities without extinguishing the fire. Before attempting to tackle a large fire, you should seriously consider allowing the fire to burn itself out. Should an attempt to extinguish the fire be made, extensive use of ‘dry powder’ should be employed from as many dispensers as can be brought to bear. Fire-fighters should be well protected against heat radiation and possible flash burns, and approach the fire from an upwind direction. Power dispensers should sweep the entire area of the fire, but direct pressure of powder jets on to the surface of the liquid should be avoided. Should dry powder guns be used, fire-fighters should be well practised in their use and be prepared for some kick-back effect. They should also be made aware that there is no cooling effect from the use of dry powder, and that re-ignition after a fire has been extinguished is a distinct possibility. In the initial stages it is always preferable to isolate the fire by shutting off the source of fuel. This may not, however, always be possible. A final warning when tackling an LNG fire is that water should not be used directly, as this will accelerate vaporisation of the liquid. This is not to say that surrounding bulkheads and decks cannot be cooled down with water sprays, provided that water running off is not allowed to mix with burning LNG. 186 Seamanship Techniques Cotton (Class ‘F’ fire) Cotton is a cargo liable to spontaneous combustion and one which is extremely difficult to bring under control. Cotton cargoes are such that they are shipped in bales of 500 or 700 lb (227 or 318 kg). A heavy cargo, cotton is often stowed in lower holds for stability reasons and to form a base for later cargo. It is cargo where the prevention of the fire initially is preferable to knowing how to tackle it, should it occur. Cotton bales should be dry and free of oil marks, tightly bound and seen to be in good condition at the onset of loading. Stringent observation of ‘no smoking’ in and around cargo holds should be observed by stevedores and ship’s personnel. Bare metalwork in holds should be covered to prevent moisture contact with cargo and spar ceiling should be inspected to ensure that bales do not come into contact with the shell plate. Should an outbreak of fire occur, the only sure way of extinguishing it is to dig out the effected area. This practice is not at all easy for crew members, who are inexperienced at handling heavy bales for any length of time. Deviation to a port for discharge may become the only alternative, depending on the size of the fire at the time of discovery and the ability to extinguish it. If successful in digging out burning or smouldering bales of cotton jettison them overboard. Re-ignition of cotton bales can occur, even after they have been totally immersed in water. Bales which appear to be extinguished will all too easily flare up after a thorough hosing down. If breathing apparatus air supply is restricted and for other reasons it proves impossible to tackle the fire direct, containment should be the next consideration. This is probably best achieved by the battening down of the compartment and the injection of CO 2 while heading for a port with the necessary facilities. Boundary cooling should be carried out on as many of the six sides of the fire as are accessible. Any deviation of the vessel’s course should be noted in the ship’s log book. Coal (Class ‘F’ fire) All coal cargoes give off an inflammable gas, and when this mixes with critical proportions of oxygen, then explosion and/or fire may be the end result. The gas given off by the coal is lighter than air and during the voyage it will work its way to the upper surface of the cargo. It is essential that coal is therefore provided with ‘surface ventilation’ to clear away any build-up of accumulated gas. Surface ventilation is achieved during the voyage by raising the outer corners of hatch slabs (conventional hatches) or opening ‘booby entrance hatches’. Steel hatch covers should be raised on their wheels, provided at all times that weather permits such action. Ventilators should always be properly trimmed. All types of coal, whether of the ‘anthracite, lignite or brown coal’ varieties, are subject to spontaneous combustion. A close watch should be maintained on hold temperatures during passage and correct ventilation allowed to reduce temperatures in the event of over-heating. It is worth noting that coal increases its temperature by its absorption of oxygen. Correct ventilation for this cargo must therefore be considered to be surface ventilation only, for a limited period. 187Fire-Fighting Should fire break out, early positive hose action will probably be the best way of containing it. However, personnel may not be able to spend much time on fire-fighting because of the excessive heat or the amount of smoke within the space. Breathing apparatus will be essential and the air supply in bottles may further restrict conventional means of fighting the fire. The injection of CO 2 or steam smothering must be considered at an early stage, should conventional methods become impractical. It will be totally dependent on the size of the fire whether these two agents will effectively extinguish it. At the very best they will contain the blaze to a degree and will certainly buy time for the Master to investigate safe port options. Alternatively, the final option would be to flood the space with water. Close investigation of the ship’s ‘damage stability notes’ should be made before taking this action, with particular attention to the free surface effect of flooding such a large space, though in a compartment filled with coal there would be little free surface effect. Hold preparation before loading coal will play a major part in averting a fire, and the following points are recommended: 1. Clean the hold space of residual debris. 2. Remove spar ceiling. 3. Remove any dunnage clear of the space. 4. Make provision for obtaining temperatures at different levels of the cargo. 5. Trim the cargo throughout and on completion of loading. Fish Meal (Class ‘F’ fire) Fish meal is a bagged cargo which is probably one of the most likely to catch fire while the ship is on passage from the loading port, due to spontaneous combustion. Experience has shown that vessels employed in the carriage of ‘fish meal’ must take stringent precautions when loading (Figure 7.10). Extensive ventilation channels must be allowed for at the onset of loading and these channels must not be allowed to become blocked by falling bags of cargo. Bags stowed off steelwork Ventilation channels ’Tween deck Pillar Lower hold Double bottom tanks Double dunnage Supporting single dunnage Double dunnage Weather deck Figure 7.10 Fish meal stowage. NB. Coal fires when treated with water will generate considerable volumes of steam. This steam must be vented or the compartment may become pressurised. 188 Seamanship Techniques Deck officers should be particularly aware that during loading bags should be sighted to ensure they are in good condition and dry. Telltale damp stains on the bags indicate that the cargo has been exposed to rain and that the contents are wet. These bags should be rejected at all cost. Officers should be provided with injection thermometers for the purpose of testing bags during loading. Any batch with excessively high temperatures should also be rejected. Temperatures during the voyage should be taken at least twice a day and a watch maintained on the following temperatures for every space containing fish meal: 1. Hold temperatures. 2. Ventilation inlet temperature. 3. Ventilation outlet temperature. 4. Ventilation channel temperature. 5. Random bag selection temperature. The hold should be thoroughly cleaned and steelwork covered with insulation paper before stowage begins. Bilge suctions and scuppers should also be inspected and tested before loading. Temperature and condition of bags should be checked at the onset of loading. Large amounts of dunnage will be required for this cargo and where stowage is to commence on a steel deck, double dunnage must be laid. It is important that all dunnage is dry and free of oil marks. Single layers of dunnage should be placed at every height of seven bags. Ventilation channels of approximately 12 in. (30 cm) should separate double tiers of bags. Provision should be made for positioning thermometers at all levels of cargo, in all spaces containing fish meal. If there is an outbreak of fire, close off all ventilation as soon as possible after the alarm has been raised. Make an immediate assessment of the fire area, and attempt to extinguish small fires, preferably by use of dry powder. If it is found that a major fire is already well established, ensure that all ventilation is cut off and inject CO 2 . If this action fails to extinguish the blaze, then hose action may be the only alternative. Should hoses have to be brought to bear, then they should be as close to the fire as possible before being turned on. All bags of fish meal that are soaked by the hose action should be jettisoned as soon as the fire has been extinguished. Hoses should not be used except as a last resort to save the bulk of cargo and the ship itself. Considerable spoilage of the bags will occur with hose action, and the likelihood of further outbreaks of fire becomes more probable rather than less. Correct stowage in the first instance, with continual checks on temperature conditions throughout the passage, will limit the chance of fire, and give ample warning should it occur. 8 SEARCH AND RESCUE OPERATIONS ACTION BY VESSEL IN DISTRESS A ship in distress should transmit an appropriate distress alarm signal, followed by a distress message. This message should include the following main points: (a) Identification of the vessel in distress. (b) Position of the vessel in distress. (c) Nature of the distress and the assistance required, (d ) Other relevant information to facilitate the rescue, e.g. number of persons leaving the ship, number remaining on board, Master’s intentions etc. In addition to the main points mentioned above, further information regarding influencing factors should be passed on to assisting vessels. These may include: 1. Weather conditions in the immediate area of the ship in distress. 2. Details of casualties and state of injuries. 3. Navigational hazards, e.g. icebergs etc. 4. Numbers of crew and passengers. 5. Details of survival craft aboard and of craft launched. 6. Emergency location aids available at the scene of distress and aboard survival craft. A series of short messages is preferable to one or two long messages. Vessels in distress should use the time preceding a rescue attempt to minimise the risk of increased numbers of casualties. This could be done by reducing numbers aboard the stricken vessel by allowing non-essential personnel to disembark. Some companies now employ this technique as standard practice, but it should be used with extreme caution, and must depend on weather conditions for the launching of survival craft and the 190 Seamanship Techniques degree of danger present aboard the parent vessel, bearing in mind that the mother ship provides the best form of protection while it remains sustainable. MASTER’S OBLIGATIONS In accordance with the International Convention for the Safety of Life at Sea, Masters have an obligation to render assistance to a person or persons in distress, if it is within their power. Any Master of a vessel at sea, on receiving a signal for assistance from another ship, aircraft or survival craft, is bound to proceed with all possible speed to the scene of the signal. If possible, he should inform the distressed party that assistance is on its way. If the Master of a ship is unable, or under special circumstances considers it unreasonable or unnecessary, to proceed to the scene of distress, then he must enter that reason in the log book. The Master of a vessel in distress which has made a request for assistance has the right to requisition one or more of those vessels which have answered his distress call. It will be the duty of the Masters of those vessels so requisitioned to comply with their call to assist and proceed with all speed to the distress scene. The Master of an assisting vessel will be released from his obligations to assist when he learns that one or other vessels have been requisitioned and that, because they are complying, his own vessel is no longer required. He may also be released from further obligation to assist by an assisting vessel which has reached the distress scene and considers additional assistance is no longer required. OBLIGATIONS OF RESCUING CRAFT On receipt of a distress message any vessel in the immediate vicinity of the distressed vessel should acknowledge that the message has been received. Should the craft in distress not be in the immediate area, then a short interval of time should be allowed to pass before acknowledgment of the distress signal is despatched, so that other ships in close proximity may give prior acknowledgment. The Master should immediately be informed that a distress message has been received, and whether acknowledgment has been sent by other vessels, together with the positions of the vessel in distress and would-be rescue craft. The Master will cause an entry to be made in the radio log book, or radio telephone log. Bearing the latter statement in mind, the Master of any vessel in receipt of a distress message may repeat that message on any frequency or channel that he knows to be in common use in that area. 191Search and Rescue Operations WHEN ASSISTANCE IS NO LONGER REQUIRED Any casualty having despatched a distress message and finding that the assistance being provided is adequate may effectively reduce the level of communications to those pre-fixed by the urgency signal. Any decision to reduce communications from a distress to an urgency level must be the responsibility of the Master in command of the distressed vessel, or his authorised representative. Receiving stations should bear in mind that a very urgent situation exists and the resumption of normal working conditions must be made with extreme caution. Table 8.1 illustrates types of signal. TABLE 8.1 Emergency signals Type of message Prefix Prefix Frequency/channel radiotelephone radiotelegraph Distress Mayday, Mayday, SOS, SOS, SOS. 2182 kHz, Mayday Channel 16, or any other frequency at any time Urgency Pan Pan, Pan Pan, XXX, XXX, XXX Pan Pan Navigation Securité, Securité, TTT, TTT, TTT warning Securité SEARCHING THE SEA Vessels may be employed in search and rescue activities alone or with other surface craft (Figure 8.1), or with aircraft. It can be expected that a specialised unit like a warship or military aircraft would assume the duties of the On Scene Co-ordinator (OSC), and co-ordinate the other search units in the area. Communications will be established on 2182 kHz or VHF channel 16, if possible. Failing this, a relay should be established between surface vessels and a coast radio station (CRS) to aircraft. Surface vessels when engaged with aircraft in a co-ordinated search (Figure 8.2) could expect items of a specialist nature to be dropped into a search or rescue area. These items would probably be in the form of: 1. Parachute flares for illumination purposes. 2. Individual life rafts or pairs of life rafts joined by a buoyant rope. 3. Dye markers or flame floats. 4. Buoyant radio beacons and/or transceivers. 5. Salvage pumps and related equipment. Should specialist units not be engaged in the search area then the Master of the vessel going to the assistance of the distressed vessel must assume the position of On Scene Co-ordinator (OSC) and communicate with the coastguard. Figure 8.2 Ship/air co-ordinated search. Ship’s course – directed by OSC 4 4 12 816 8 Course approach 16 10 10 Parallel track search by two vessels (in miles) 4 4 4 4 4 Length of search 20 miles Width of search 24 miles Figure 8.1 Sea search by one and two vessels. Expanding square search by one vessel (in miles) 192 Seamanship Techniques AIRCRAFT IN DISTRESS The distress message may vary with the time available from the onset of the emergency and the effective landing or ditching of the aircraft. However, when time permits, civil aircraft will transmit a distress call and subsequent distress message as follows: Distress call by radiotelephony 1. The spoken words ‘Mayday, Mayday, Mayday’. 2. The words ‘This is . . .’ 3. The identity of the aircraft, spoken three times. 4. The radio frequency used in the transmission of the distress call. Distress message 1. Either ‘Mayday’ or SOS. 2. The call sign of the aircraft. 3. Information relating to the type of distress and the kind of assistance required. 4. The position of the aircraft and the time of that position. 5. The heading of the aircraft (true or magnetic). 6. The indicated air speed (in knots). 7. Any other relevant information which would aid and effect a recovery operation, e.g. intentions of the person in command, nature of any casualties, possibility of ditching, survival facilities available or not. The term ‘heading’ when applied to an aircraft refers to the direction of the aircraft when in the air. Allowance must then be made for wind effect to ascertain the true direction over the sea. Indicated airspeed does not take into account the effect of the wind. This should be estimated to obtain a more realistic speed over the water. If the aircraft is to be ditched, the aircraft’s radio transmitter may be left in the operative position, depending on circumstances. COMMUNICATION BETWEEN SURFACE CRAFT AND AIRCRAFT Merchant vessels engaged in search and rescue operations (SAR) with military aircraft should maintain a VHF watch on Channel 16. Surface vessels should use their normal call sign in communicating with an aircraft. Should the call sign of the aircraft be unknown, then the term ‘Hawk’, may be used in place of the aircraft call sign. When an aircraft is in the process of establishing communications with a surface craft without knowing the call sign of the vessel, the aircraft may use the inquiry call ‘CQ’ in place of the vessel’s normal call sign. Under the GMDSS legislation, vessels will be required to carry two Search & Rescue Transponders (SARTs). These operate on the 9 GHz for 3 cm radar. The effective range is approximately 5 nautical miles and their function is expected to enhance search and rescue operations. The radar signature from a SART would appear initially as a line of 12 dashes on the observer’s screen. This signature will change to a series of concentric circles as the range of the target is closed. [...]... moving ahead, the propeller exerts pressure on the water to create the forward motion Propeller slip occurs because water is not a solid medium and there is some ‘slip’ related to it Slip may be considered as the difference between the speed of the vessel and the speed of the engine It is always expressed as a percentage: Propeller slip = Actual forward speed (per cent) Theoretical forward speed The calculated... single screw vessel (see Figure 9.9) A distinct advantage of twin screws, apart from the increased speed created, is that if the steering gear breaks down, the vessel can still be steered by adjusting the engine revolutions on one or other of the propellers When turning the vessel, for instance, one propeller can go ahead while the other is going astern (Figure 9.10) Propeller Slip When the vessel is moving... created by the pitch angle of the blade If the two forces are themselves resolved, then it would be seen that the stern of the vessel is moved to starboard Consequently, if the stern is moved to starboard, then the bow may be seen to move to port The opposite will happen when the vessel is moving astern, the only difference being that the side component will be resolved with a sternway motion and the... theory of the right-hand fixed propeller, however, should be sufficient for the reader to understand the properties of other propellers The marine propeller could be considered as something like a paddle wheel Figure 9.4 shows the reaction and basic forces which affect the surface area of the propeller blades The resultant of the side components, caused by the rotation, may be resolved with the ahead... one-third the length of the vessel measured from forward when the ship was moving ahead The pivot point changed when the vessel was going astern Quartermaster In the modern merchant service a senior helmsman, is called a quartermaster especially in large passenger vessels The term was previously applied to a petty officer who assisted the Master and officers Set Set is a term used to describe the movement... a vessel which is being influenced by tide or current that the course being steered is not truly representative of the track the vessel is making A vessel under such influence if often described as ‘setting down’ Sheer (a) Defined as the angle that a ship will lie to her cable when at anchor (b) Sheer may also be used to describe the upward curvature of the uppermost continuous deck – hence the term... she is moving forward over the ground, irrespective of speed, she is making way When the speed of the vessel will still affect and obtain a correct response from the rudder, she has steerage way When the vessel is moving over the ground in the direction of the stern, under reverse propulsion, she has sternway When a vessel is under way and making way and proceeding at a speed considered excessive for... rescue vessel The question of the distressed vessel’s ability to remain afloat long enough to complete the operation will influence any Master’s decision In any event, where there is doubt, personnel would have to be removed Thought should be given to the prospect of beaching the distressed vessel if suitable ground is on hand and main engine power is still available to the stricken vessel See Chapter... vessel will continue to travel forwards after the main engines have been stopped is the headreach Helmsman A person designated to steer the vessel manually is the helmsman Helm orders used to apply to the tiller but after the First World War began to be accepted and related to the rudder List A vessel which is not on an even keel in the upright position but heeled over to one side or another is listing... the propeller has been tried and tested and shown to improve hull resistance as well as homogenise the flow on to the propeller Today’s concept is to build in a reaction fin which will generate a reverse flow on to the propeller, and so improve the efficiency Balanced bolt axle rudder Figure 9.2 Types of rudder 214 Seamanship Techniques Duct Reaction fin of the propeller by reducing transverse effects.This . fires when treated with water will generate considerable volumes of steam. This steam must be vented or the compartment may become pressurised. 188 Seamanship Techniques Deck officers should be. acknowledgment. The Master should immediately be informed that a distress message has been received, and whether acknowledgment has been sent by other vessels, together with the positions of the vessel. out, the need to avoid congestion on the frequencies and the need to comply with the requirements of the ICAO. ( g ) be tested and, if necessary, have their source of energy replaced at intervals