Chapter 10
Marine Emergencies
Fire, sinking, or injuries are constant dangers faced by crew members aboard ships at sea. The organization, training, and teamwork of the crew usually determine the difference between a marine emergency and a marine disaster. The emergency training that is given to the crew is the direct responsibility of the ship's master. This responsibility is the same for the coxswain on the LCM-8 as it is for the master of a category A-2 vessel. This chapter discusses the "how" and "what to do" during a shipboard emergency. Learn now--not during the emergency. Teamwork is essential for survival.
STATION BILL
| 10-1. The starting point for shipboard survival and survival training is the station bill. The station bill is a muster list that is required by federal regulations. It lists the emergency duty station and duty position for each crew member assigned aboard ship and also the signals for fire and abandon ship. 10-2. The station bill is prepared and signed by the ship's master. Each time a new master is assigned to the ship, one of his first responsibilities is to prepare a new station bill. When a new crew member is assigned aboard ship, the crew member will be assigned to a specific line and station bill number. When transferred, the crew member's name is removed from the station bill. 10-3. The ship's master is the only one who can sign the station bill. It is also his responsibility to keep it current. Copies of the station bill are posted in conspicuous places in the ship, such as the crew's quarters, crew's mess, and bridge. |
10-4. The following information should be included on a station bill (see also Figure 10-1):
2. Date station bill was filled out. 3. "US Army" or "Name of company". 4. Master's signature. 5. A numerical listing for each man authorized aboard the vessel. The Master is listed as A, the Chief Mate is number one. 6. Crew rating and crew member's name. The crew rating is listed according to precedence in rating and department. If carried, the sequence for departments is deck, engine, radio, stewards, and medical. 7. Location and specific emergency duty to be performed by crew member. 8. Specific lifeboat assigned to crew member. 9. Specific location and task to be performed by crew member. |
| 10-5. The crew member will also be issued an individual station bill card. This is usually posted next to the crew member's bunk. The card will list the crew member's station bill number, name and rating, fire and emergency station, lifeboat number, abandon ship, and boat station. |
| 10-6. The emergency duties assigned to a particular crewman should, whenever possible, be similar to the normal work activity of that person. For instance, steward's department personnel should be assigned to assist passengers; deck department personnel should be assigned to run out hoses and lifeboats; and the engineering department should be assigned to run out hoses in the machinery space with which they are most familiar. |
EMERGENCY SIGNALS
| 10-7. The signal for FIRE is a continuous blast on the ship's whistle or horn for not less than 10 seconds, supplemented by the continuous ringing of the general alarm bells for not less than 10 seconds. 10-8. The signal for ABANDON SHIP is more than six short blasts followed by one long blast on the ship's whistle supplemented by the same signal on the general alarm bells. 10-9. DISMISSAL from fire and emergency stations is signaled by three short blasts on the whistle or ship's horn supplemented by the same signal on the general alarm bells. 10-10. For man overboard, hail the bridge and pass the word "MAN OVERBOARD--PORT or STARBOARD SIDE." 10-11. Emergency signals, other than for FIRE and ABANDON SHIP will be determined by the ship's master. A special signal should be designated by the master to assemble the emergency squad. This signal should be one that will not be confused with the general alarm and navigational signals. Use coded signals to summon the emergency squad, so not to alarm passengers. |
Figure 10-1. Sample of a Station Bill
EMERGENCY SQUAD
| 10-12. An emergency squad is a group of crew members selected by the master for their special training to deal with emergencies. The chief mate (assisted by the boatswain) is normally in command of the emergency squad. The rest of the squad should be made up of crewmen trained in the use of fire, emergency, and rescue equipment. Candidates for the emergency squad would be crew members who are highly knowledgeable in emergency procedures. A mustering location for the emergency squad should be included in the station bill. The mustering location could be on either wing of the bridge, at a designated position on the main deck, or wherever the master feels would be best. However, the chosen location should be one that the members of the squads can reach promptly--for example, in less than 2 minutes. |
10-13. An emergency squad is a team. A team is a group of people brought together to accomplish a common goal. The word team brings to mind word coordination, cooperation, and training. Training is absolutely essential, since without it there can be little coordination or cooperation. Training consists basically of two parts and must be taught in the following order:
10-15. The master is responsible for all ship's functions, including those he assigns to subordinates. Although the master assigns the training of the emergency squad (and the rest of the crew) to his chief mate, he should review and approve the plans for proposed lessons and drills. These sessions are made more meaningful when the master personally observes them and then discusses them with those in charge. 10-16. The members of the emergency squad should attend periodic instructional sessions dealing with the variety of emergencies that could occur aboard ship. At each session, a problem could be presented, solutions discussed (until a satisfactory one is found), and the necessary tools and equipment should be handled for familiarity. Then the regularly scheduled fire drills would be demonstrations of efficiency rather than training sessions. |
| 10-17. The emergency squad may be called upon to deal with many emergencies, such as collision, man overboard, and a lost or damaged rudder. When the fire signal is sounded, all hands are involved. The station bill lists an assigned task and station for each member of the crew. Therefore, all crew members should receive some training in fire fighting. |
ABANDON SHIP PROCEDURES
| 10-18. During all shipboard drills and emergency operations, crew members must wear their life jackets. It is one of the most important pieces of equipment for your survival in the water. It will hold you in the upright floating position without your having to swim. Another safety point during a drill or the real thing is to always wear a hat or some type of headgear to protect you from the elements. |
10-19. If you have time, put on extra clothing. Include an outer layer of wind and waterproof clothing fitted if possible with headcover and gloves. Then put on the life jacket in the following manner (see also Figure 10-2):
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Figure 10-2. Donning Life Jacket
ENTERING WATER FROM A HEIGHT WEARING A LIFE JACKET
10-20. Make sure that your jacket is well secured. If it is not well secured, you could hurt your head when you jump. Then get down to a height of less than 30 feet if you can. Below 15 feet is ideal. If you jump from higher than 30 feet, you can hurt yourself (this depends on the height from which you jump and the angle at which your body hits the water). If worn, remove false teeth, eyeglasses, or contact lenses. Also remove any sharp objects from your pockets. Get in the jump position (see Figure 10-3) and do the following:
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Figure 10-3. Jumping in Water
10-21. Get away from the ship once you are in the water. Swim as slowly as possible toward the survival craft. DO NOT swim or thrash about any more than you need to because of the following:
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10-22. Drownproofing, also called water survival, is based on the natural buoyancy of the human body when the lungs are filled with air. It is intended to keep anyone alive in the water indefinitely, even a nonswimmer who is fully clothed. Drownproofing saves energy for the potential drowning victim. It is much easier to do the steps on drownproofing for long periods of time than to stay afloat by swimming. Each crew member should know drownproofing since it is an excellent way to stay afloat without a life preserver. This method can best be described in the following five steps.
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 Figure 10-4. Resting Position |
 Figure 10-5. Preparing to Exhale |
 Figure 10-6. Exhalation |
 Figure 10-7. Inhalation |
TRAVEL STROKE
10-23. This stroke is used in a water survival situation when you are required to swim, while conserving as much energy as possible. Here is how it is done:
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| 10-24. The most important thing to remember for your survival if you are forced to swim through a thick oil fire is to keep calm. The proper procedure for swimming through a thick oil fire is described in the following steps: WARNING: NEVER WEAR A LIFE JACKET WHILE SWIMMING IN A THICK OIL FIRE.
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Figure 10-9. Break the Surface |
 Figure 10-10. Fully Inhale |
Figure 10-11. Swimming Through Thick Oil Fire
SWIMMING THROUGH A THIN OIL FIRE
| 10-25. The most important thing to remember for your survival if you are forced to swim through a thin oil fire is to keep calm. The proper procedure is shown in Figure 10-12, and described in the following steps: WARNING: WEAR YOUR LIFE JACKET AT ALL TIMES WHILE SWIMMING THROUGH A GASOLINE OR THIN OIL FIRE. KEEP YOUR HEAD ABOVE WATER AT ALL TIMES.
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Figure 10-12. Swimming Through Thin Oil Fire
COLD WATER DROWNING
| 10-26. After reading the following, you and your crew, as would-be rescuers, should be more willing to attempt to revive a person who is supposedly "drowned." 10-27. Due to recent medical research, it has been discovered that the bodies of people "drowned" in cold water (below 70° F, 21° C) may go into a diving reflex. In this condition, the nervous system cuts off the flow of blood to all parts of the body except the brain and lungs. The heart slows so much that it cannot be heard without special instruments. The result is that a person can exist in seemingly a "dead" state for up to an hour, depending on the their age and the temperature of the water. The basic trigger that starts the diving reflex is cold water touching the face, specifically the area around the eyes and forehead. 10-28. However, the diving reflex does not always work. Studies show that the person's age combined with the temperature of the water are the main factors in deciding whether the reflex will start, and, if so, how long it will be effective. Its effectiveness is measured by how long it works before permanent brain damage begins. 10-29. The reflex is extremely active in youngsters. In infants and small children, it can be started by a water temperature of 65° F (18°C) and can, in theory, last for as long as an hour. As a person gets older, the water must be colder to start it and it is effective for a shorter time. The diving reflex may be one of those natural systems, which protects small children from their own inexperience. 10-30. A person's body weight also comes into play when the reflex is connected with hypothermia. Hypothermia simply means that the body temperature is below normal. However, when you take your temperature and it is 97.5°F instead of 98.6° F, it does not necessarily mean that you are a hypothermia victim. Hypothermia usually refers to the lowering of inside body temperature because of coldness outside the body such as cold water or a cold wind. Your arms and legs will become numb and you will lose the use of them if your body temperature gets down to about 93oF. When it reaches 80° to 86°F, you may lose consciousness; should it drop to about 79°to 77°F, it becomes fatal. 10-31. A person's weight is a factor when figuring how long it will take for all this to happen. Generally, the bigger a person is, the longer it takes for his body to lose heat because he has better insulation. Other factors that affect this heat loss are age, clothing, and physical activity. 10-32. It is the result of cold rather than the effect of drowning that begins the diving reflex. Hypothermia victims, even those not in cold water, often get some assistance from the reflex. In reaction to the cold, the vital body functions slow down to an almost unmeasurable level and thereby save body heat as well as oxygen. Again, this lengthens the time before serious brain damage begins. This extension can make the difference between whether or not a "drowned" person, or hypothermia victim, can be successfully rescued. 10-33. Tests during World War II revealed that a thin person in a flight suit and life jacket could survive up to 72 minutes in 40° F (5°C) water. However, he would be unconscious and apparently dead some time before that. 10-34. While this knowledge of the diving reflex may be consoling to a person drowning and going down for the final time, it is primarily important to his rescuers. Should your vessel be the first one on the scene of a cold water drowning, the things you and your crew do can determine whether the victim lives or dies. 10-35. Since you can never assume that medical assistance will be on the scene when a drowning victim is pulled from the water, his life may depend on you. The diving reflex stops as soon as the victim is taken out of the water. That means that you may have less than 4 minutes to get his blood flowing. Table 10-1, shows some DOs and DO NOTs to remember when reviving cold water drowning victims. |
Table 10-1. Reviving Cold Weather Drowning Victims
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Start CPR immediately. This is a form of mouth-to-mouth resus-citation and external heart massage. Only a person that is qualified should attempt CPR. Check with your installation's hospital about available CPR training programs. Keep the victim warm with a light blanket or jacket, and so on, but do not waste necessary time on this. Keep giving CPR until medical assistants take over or until the victim revives. |
Give the victim any alcoholic drink. Try to rewarm the victim with anything more than a light blanket, jacket, or so forth. Uncontrolled rewarming can cause severe injury. |
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10-36. Treatment will depend on the condition of the survivor and the facilities available. In more serious cases, where the victim is semiconscious or unconscious, contact should be made immediately with a ship or shore medical facility for detailed information on the care and handling of the victim. Administer the following first aid while waiting for medical instructions:
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| 10-38. This type comes from being exposed (from a few hours to several days) to cold weather. Most chronic hypothermia cases develop in air temperatures of 30° to 50° F. The victim usually overestimates how long he can withstand the cold and fails to recognize the danger of being wet at such temperatures. A victim can get wet from sweat, rain, or from the splash and spray of water from working on the deck of a vessel. Because chronic hypothermia takes some time to develop, the victim may undergo dangerous fluid and biochemical changes. For these reasons, you do not want to rewarm the victim. As with a cold water drowning victim, victims of chronic hypothermia should be taken to a hospital as quickly as possible. REMEMBER, DO NOT REWARM A CHRONIC HYPOTHERMIA VICTIM! |
10-39. This type of hypothermia is different and is the result of immersion in cold water. Since water can withdraw heat from the body 25 or more times faster than air, we can estimate that in water temperatures of, 72°F and lower, the body cannot generate enough heat to offset heat loss to the water. Depending on water temperatures and body condition, acute hypothermia may begin to develop in as little as 10 to 15 minutes. Because of the rapid onset, acute hypothermia victims do not generally have time to develop dangerous chemical and fluid imbalances. Therefore, without delay, begin to REWARM ACUTE HYPOTHERMIA VICTIMS IMMEDIATELY. Even conscious hypothermia victims have died following apparently successful rescues when attempts at rewarming were delayed or were inadequate. Any of the following warming methods are recommended, preferably in the order given.
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| 10-41. The following will teach you how to improve your chances of survival in cold water. As mentioned before, body heat loss is a gradual process and the diving reflex provides some protection. 10-42. The loss of body heat is probably the greatest hazard to the survival of a person in cold water. Knowing what steps to take to help your body delay the damaging effects of cold stress will help you stay alive in the event of cold water exposure. Try protecting your head, neck, groin, and the sides of your chest. These are areas of rapid heat loss in cold water. 10-43. Locate and wear personal flotation equipment such as a life jacket. If you are not wearing it when you enter the water, put it on as soon as possible after entering the water. This is probably the single most important item of survival equipment. Survival in cold water is tough enough without having to contend with staying afloat. Learn how the flotation device is worn and used before an accident occurs. 10-44. Try to enter the water in a lifeboat or raft. This will avoid getting your insulation wet and lost of valuable body heat to the water. Abandoning a ship by means of a lifeboat or raft will greatly increase the chance for survival. This is better than jumping overboard and attempting to be rescued. 10-45. Wear several layers of clothing. If you are fortunate enough to stay dry and enter the water in a lifeboat or raft, the trapped air within your layers of clothing will provide excellent insulation. However, if you become wet in abandoning your ship, the layers of clothing, although wet, will slow down the rate of body heat loss. 10-46. If conditions prevent you from abandoning ship in a lifeboat and you must enter the water directly, try to cut down the shock of a sudden cold plunge in the water. Rather than jumping into the cold water, try to lower yourself gradually. A sudden plunge into cold water can cause rapid death as a result of the severe shock to your nervous system. It may also cause an uncontrollable rise in breathing rate resulting in an intake of water into the lungs. If jumping is necessary, try to hold your breath, pinch your nose, and avoid swallowing water during the plunge. 10-47. The body position you assume in the water is very important in conserving your body heat. Tests show that the best body position is one where you hold your knees up to your chest in a "doubled up" fashion with your arms tight against the side of your chest (Figure 10-13). This position reduces the exposure to the cold water of your groin and chest sides, both areas of high heat loss. Try to keep your head and neck out of the water. 10-48. Another heat conserving position is to huddle closely to one or two others afloat, making as much body contact as possible (Figure 10-14). You must be wearing a life jacket to be able to hold these positions in the water. You should also wear a life jacket in the lifeboat or life raft. |
 Figure 10-13. Double-up |
 Figure 10-14. Buddy-up |
| 10-49. Try to board a lifeboat, raft, or other floating platforms or objects, as soon as possible, in order to shorten immersion time. Remember that you lose body heat about 25 times faster in water than you do in air. Since the effectiveness of your insulation has been seriously reduced by water soaking, you must now try to shield yourself from wind to avoid a wind-chill effect (convective cooling). If you manage to climb aboard a lifeboat, shielding can be accomplished with the aid of a canvas cover, a tarpaulin, or an unused garment. Huddling close to the other occupants of the lifeboat or raft will also conserve body heat. 10-50. Keep a positive attitude about your survival and rescue. This will improve your chances of extending your survival time until you are rescued. |
10-51. Immediately on seeing a crew member fall over the side, shout an alarm! Call out the words "Man overboard!" to personnel on the bridge. Be sure to include where on the vessel the person fell overboard. For example:
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10-52. Immediately after these vocal alarms are given, three things must happen at the same time:
10-54. When the bridge watch hears the man overboard signal, the helmsman must be told immediately to put the rudder hard over to swing the stern away from the victim. If the victim falls overboard on the starboard side, the helmsman would turn the helm "hard right rudder." If the victim falls over on the port side, then naturally the helm will be put to "hard left rudder." |
10-55. There are two procedures for marking the spot. One is used during hours of daylight the other is for hours of darkness. To mark the spot during daylight:
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| 10-56. Keep the victim in sight. It is easy to lose sight of the victim's position, especially in rough weather or at night. The person who saw the victim fall overboard usually makes the best lookout. It is also a good idea for the lookout to be posted on the forward part of the vessel for easier viewing. |
| 10-57. The Oscar Flag is raised to let other vessels in the area know that you have a man overboard. |
10-58. If circumstances permit (such as if you are not limited by narrow channels or landfalls, and so forth), the Williamson turn, used by large vessels, has proven to be the preferred maneuver for picking up victims (Figure 10-15). To make the turn you must do the following:
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Figure 10-15. Williamson Turn
Other Maneuvers
| 10-59. On large vessels equipped with lifeboats, a lifeboat is lowered and the lifeboat crew maneuvers into position to rescue the victim. A small vessel, especially one with two screws, often is so maneuverable that it is simpler, safer, and quicker to maneuver the vessel back to the person in the water and throw them a line than to make the Williamson turn. For example, an LCM or LCU could make the pickup at the ramp. The vessel must turn around until its course has been reversed. At slow ahead, when it has been determined that the propellers will not endanger the person in the water, the vessel can be maneuvered toward them. 10-60. The vessel must approach slowly on the windward side of the victim. If the vessel is placed so that it shields the victim from the waves and the wind, the water around the victim will be calm. However, caution must be exercised to prevent the vessel from coming too close to the victim (Figure 10-16). Lines with life rings must be prepared so they can be thrown as soon as possible. The only time maneuvers of this type may be used at night are when weather conditions make launching a boat impossible. 10-61. When having man overboard drills, it is a good idea to identify all crew members who are good swimmers, and designate them for special emergency duty. When an overboard victim is unconscious, a good swimmer with life preservers and lifelines can jump in and help with the rescue. The first thing a man overboard should try to do is to get clear of the vessel, especially the stern, so that he does not get sucked under or hit by the screw. |
Figure 10-16. Bringing Ship Into Wind
| 10-62. The overboard victim should stay in the same general area where he fell, especially at night and in foul weather. Staying in the same general area will make it easier for the ship's lookouts to spot him since they will generally know where to look. 10-63. Victims of a fall overboard can help the ship's lookouts by:
10-64. A victim can make themselves heard by the following:
10-66. Most falls happen while a person is moving, standing, or leaning over the edge of a vessel. However, falls may occur from a wide range of causes which include, but are not limited to the following:
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LIFE RAFTS
| 10-68. The inflatable life raft is as important a lifesaving device as the lifeboat. Shipboard drills with the inflatable life raft are not conducted because the raft container is sealed until ready for automatic or manual launching. Therefore, it is important to learn about the current design of rafts and keep informed of future design. |
| 10-69. Inflatable life rafts must be either Navy standard or Coast Guard approved. Life rafts have a range of sizes. Ships that do not make international voyages might have rafts that can hold 4 to 26 people. Ships that make international voyages might have rafts that can hold 6 to 25 people. The capacity (number of persons it will hold) of the life raft is marked on the container and the raft. The manufacturer's name is also shown on the container. An inflatable life raft (complete with case and equipment) does not weigh more than 400 pounds. |
| 10-70. Life rafts are kept in a cradle on an open deck (Figure 10-17). This is done so they can float free if the ship sinks before you can manually launch the raft. 10-71. The life raft container is strong, weathertight, and tamperproof. The raft container has small holes on the bottom for condensation drainage and air circulation. The container must be stowed with the words "THIS SIDE UP" on top to be sure the holes are on the bottom. Most containers are made of fiberglass. 10-72. The raft container is usually held together with packing bands, which break when the raft is inflated. A watertight gasket seals the two halves of the container together. 10-73. The container rests in a cradle. The cradle is permanently secured to the ship's deck. The container may be secured to the cradle with tiedown straps. A tiedown strap has a securing device called a hydrostatic release. A cleat provided near the cradle is used for tying the operating cord when launching manually. |
Figure 10-17. A Cradled Life Raft
LIFE RAFT DESIGN
| 10-74. Buoyancy tubes are located on the outer edge of the raft. They are made of thick nylon-reinforced rubber. The buoyancy tubes make the raft float. They are divided into at least two compartments. The raft is made to support its rated number of persons even if half the compartments in the buoyancy tubes are deflated. Note: Inflatable life rafts may be designed to be round, oval, octagonal (eight-sided) or boat-shaped. Specific design may vary among manufacturers. A typical oval inflated life raft is shown in Figure 10-18. 10-75. Carbon dioxide is usually used to inflate the raft. The CO2 cylinder (container) is on the bottom of the raft. It is activated by a sharp tug on the 100-foot long operating cord. The tug pulls the CO2 tripping lanyard out of the CO2 to enter the buoyancy tubes. The CO2 can escape through leaks in the tubes. The gas is odorless, tasteless, and colorless, so you must watch for leaks. If you breathe air with a large amount of CO2, you can suffocate, so always leave the curtains open if you know the tubes are leaking. Fix the leak as soon as possible. |
Figure 10-18. A Typical Oval Inflated Life Raft
| 10-76. Pressure relief valves are installed in most rafts. These valves are fitted in the tubes, so excess (extra) gas can automatically escape. It is normal for gas to escape right after the raft is inflated. You can tell it is escaping if there is a hissing sound coming from the valve. The sound will probably stop after a few minutes. 10-77. During the day, the rise in temperature might cause the gas to expand enough to activate the valves. At night, when the temperature drops, you may have to pump up the tubes with the inflation pumps because the air in the tubes might contract. 10-78. Sometimes, pressure relief valves do not work correctly. If gas continues to escape from the pressure relief valve, you can fix it with a safety valve plug from the repair kit. Then pump the tube back up. Deflation plugs are provided to deflate the raft after rescue. 10-79. The floor of the raft is also inflatable. In cold climates, the floor should be inflated with the inflating pump. This will insulate the occupants from the cold seawater. The floor should be left deflated in warm climates. This will allow the cooler seawater to cool the inside of the raft. If necessary, some inflatable floors can be removed and used for an extra emergency float. 10-80. A boarding ladder and towing bridle are fitted at each end of the raft. The two are usually combined. In addition to boarding and towing the raft, the raft can be hoisted aboard a ship by hooking onto one or both towing bridles. Lifelines are provided inside and outside the raft for survivors to steady themselves. 10-81. Two lights are installed on the canopy. These lights are automatically activated when the raft inflates. They are powered by either dry cells or water-activated batteries. The lights can operate for at least 12 hours. The external recognition light can be seen from 2 miles away. The other light is inside the canopy. Unscrewing the bulbs during the day will prolong battery life. 10-82. The canopy has two layers to insulate the inside from extreme temperatures. It erects (pops up) automatically as the arch tubes inflate. The canopy has tubes to collect rainwater. The canopy is colored Indian orange or some other bright color, which would stand out on a whitecapped sea. 10-83. Water pockets are located under the floor. They have holes in them to allow seawater to fill them up when the raft is launched. Water pockets have two purposes: to slow the drifting of the raft and to make the raft more stable (less likely to capsize). 10-84. The early designs of water pockets were simple, but did not always work well. In heavy seas or high winds, an empty or unevenly loaded raft with three or four small water pockets could easily capsize. Some inflatable life raft manufacturers have improved the basic stabilization design. 10-85. The Givens raft has a large stability chamber instead of the small water pockets. As the angle of the sea changes, the stability chamber adjusts the raft's center of gravity to compensate for the wave action. When the Givens raft reaches the crest of a wave, the raft bottom should not lose contact with the water, and should not be caught by the wind and capsize. The raft is not easily capsized in high winds with its minimum of 4,800 pounds of water ballast (on the four- to six-person raft). The stability chamber can be deballasted (emptied) so the raft can be towed. |
10-86. You are required to know how to manually launch a life raft. Do the following steps to successfully perform this task:
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 Figure 10-19. Throwing in Life Raft |
 Figure 10-20. Yanking on the Operating Cord |
Figure 10-21. Boarding Life Raft
AUTOMATIC LAUNCHING OPERATION
| 10-87. After the ship sinks to a depth of 10 to 15 feet, the hydrostatic release will automatically release and free the life raft container. The container will rise to the surface (Figure 10-22). The pull of the sinking ship will cause the container bands to part and trigger the inflation of the life raft. The life raft will be completely inflated and ready for boarding within 30 seconds. The buoyancy of the life raft will cause the operating cord to part (Figure 10-23). |
 Figure 10-22. Containers Rises to Surface |
 Figure 10-23. Operating Cord Parting |
10-88. The life raft may be boarded by any one of these procedures:
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 Figure 10-24. Jumping Into Canopy Opening |
 Figure 10-25. Boarding a Life Raft From the Sea |
10-90. Two people can help an injured person board an inflatable life raft as shown in Figure 10-26 and doing the following:
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Figure 10-26. Bringing Aboard an Injured Crewman
LIFE RAFT SURVIVAL EQUIPMENT
10-91. Inflatable life rafts are provided with equipment necessary for handling the life raft, surviving at sea, and alerting rescuers. The following list is for inflatable life rafts on ocean service ships. Ships on the lakes, bays, sounds, and rivers have considerably less equipment.
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PATCHING WITH SEALING CLAMPS
10-92. Six sealing clamps are also included in the kit for plugging large holes and any hole which cannot be kept dry enough to use cement. Use the following procedures:
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Figure 10-27. Pushing Bottom Plate Through Hole
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 Figure 10-28. Sliding Top Clamp Over |
 Figure 10-29. Tightening Wing |
SIGNALING
10-93. The importance of a good lookout cannot be overstated. Remember, when in a life raft, you are so small and the sea is so big that it is very easy for a search ship or plane to overlook you. An alert lookout will make the difference in survival. Once you have sighted a rescue ship or aircraft, use the following to attract their attention:
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Figure 10-30. Signaling Mirror
Figure 10-31. EPIRB Secured to a Life Raft
RIGHTING AN OVERTURNED LIFE RAFT
10-94. If a capsized raft can be righted (turned right side up) before the inverted (upside down) canopy fills with seawater, one person can easily right it using the following procedure:
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Figure 10-32. Getting Aboard an Overturned Life Raft
Figure 10-33. Standing On Edge
Figure 10-34. Knees Bent
| 10-95. Do not panic if the raft does land on top of you. Because the bottom of the raft is soft and flexible, you can create an air pocket by pushing your arms or head against the floor. This will give you a chance to catch a breath of air. Use your arms and swim face up to get out from underneath the raft. If you try to swim out face down, the raft may hang up on the back of your life preserver. If this happens, it will be difficult for you to get out from underneath the raft. 10-96. If one person cannot right a capsized raft, the canopy probably has filled with seawater that cannot escape. Try two persons pulling on the righting strap. If this does not work, then get several persons in the water on the opposite side of the raft (Figure 10-35). These persons should work the water out of the canopy by pushing up on the canopy while two people pull on the righting strap. 10-97. If the inverted canopy fills with seawater, the raft may be more difficult to right. Generally, round rafts have the righting strap parallel to the canopy openings. This allows the water to flow freely out of the raft while the raft is being righted. 10-98. If the raft is oval with the righting straps at right angles to the canopy openings, water tends to stay trapped in the canopy. It may take several persons to right this type of raft. Note: Figure 10-36, shows the overhead views of round and oval rafts. 10-99. A single person may be able to right a waterlogged raft. He can try by pulling and walking the righting strap through his hands until the opposite side is pulled over. This takes a lot of strength and may be very hard to do. It might be done without climbing aboard the raft. |
Figure 10-35. Several People Righting An Overturned Life Raft
Figure 10-36. Overhead Views of Round and Oval Rafts
SURVIVAL ABOARD A LIFE RAFT
| 10-100. Life rafts are important in a marine emergency. The life raft is the primary means of escape in a shipboard emergency. Survival aboard a life raft starts with the proper launching and inflating of the life raft. Survival can also include how to correctly board the raft, avoiding hypothermia, how to right an upside down life-raft, know how to properly use safety equipment, anchoring the raft, plugging leaks, dealing with seasickness, establishing a chain of command, and rescue. |
Preserve Body Fluids--Avoid Seasickness
| 10-101. Riding in a life raft is very uncomfortable. Your raft will be in constant motion even on a calm sea. A raft wiggles every time someone moves inside or the water moves underneath. You will be confined in a cramped and stuffy space. Even the most experienced seafarers tend to get seasick in a raft. Seasickness must be avoided if at all possible. It is a very miserable illness and can affect your will to survive. 10-102. If on hand, take a seasickness pill (if you can) before you abandon ship. If unable to take, take a seasickness pill found in the raft's supply kit as soon as all of your shipmates have been helped into the raft. The pills will keep you from vomiting. Vomiting empties your stomach of valuable fluids. You must preserve those body fluids. If you lose them, they will be difficult or even impossible to replace as long as you are in the raft. Remember how cramped your survival conditions may be. If one person vomits, others will probably do the same. |
| TAKE SEASICKNESS PILLS AS SOON AS YOU CAN! |
Urinate Soon After Boarding
10-103. If you did not urinate within a few hours before boarding the survival craft, you should do so within 2 hours. The traumatic effects of a disaster at sea may make urination difficult. You could damage your bladder if you do not pass urine. There are two methods that might help you urinate:
|
Sit on a Life Jacket for Protection
| 10-104. In moderate seas, when there is no danger of the raft capsizing, you should take off and sit on your life jacket. The rubber raft constantly moving under you tends to wear your skin until soreness occurs. Your life jacket will provide a cushion that will prevent such soreness. |
Cover Up
10-105. The dangers from exposure to cold are obvious, BUT do not forget the sun, wind, rain, and sea. The life raft comes with a built-in canopy to protect you. Do not cook yourself in the sun! Serious burns and loss of valuable body fluids could result from a sunburn. Wear light clothing or stay under the cover.
10-106. The following are some hot climate tips:
|
Drinking Water
| 10-107. The normal, healthy body (at rest) can stay alive for over 40 days with no food and as little as 11 ounces (one ration can) of fresh water each day. As little as 2 or 3 ounces of drinking water each day can keep a person healthy for up to 10 days. Without fresh water, a person often becomes delirious in about 4 days and might die in 8 to 12 days. |
No Water for First 24 Hours
| 10-108. Do not issue water during the first 24 hours unless you have an unlimited supply. The body is already full of water. If you drink more, it will probably be wasted in the form of urine. After 24 hours, your body will be drier and will absorb the water you drink, just like a dry sponge will hold water, but a wet sponge will not. If a survivor is injured, you may give him water during the first 24 hours. The survivor will need it to replace the fluid he lost through his bleeding or burns. Only give water if he is conscious. 10-109. After 24 hours, you may issue a full ration (1/3 of a 1-quart can) of water for each person. The ration should be divided into three equal parts. Drink one part at sunrise, one at midday, and one at sunset. |
Rainwater
| 10-110. You may collect more water by catching rainwater. Some parts of the inflatable life raft canopy are designed to catch water. Rainwater catchment tubes will take the water into storage bags on the inside of the raft. The storage bags are in the raft's equipment container. Salt spray may dry on the canopy. The salt might be washed in with the first few ounces of rainwater. It might be very difficult to collect uncontaminated rainwater when the seas are rough and waves are constantly being blown onto the canopy. 10-111. The lookout should alert everyone when it rains. Use and fill all available containers with rainwater (such as equipment accessories bag, ration packs, and empty tin cans). After all of the containers have been filled, everyone should drink as much of the rainwater as they can. |
Condensation
| 10-112. Water might condense on the inside canopy of the inflatable life raft. Use one of the cellulose sponges that is provided in the raft equipment to soak up the water. Squeeze the water out of the sponge to drink or store. Be sure to keep a sponge clean for this purpose. |
Snow and Ice
| 10-113. In the Arctic Sea, you can collect "old saltwater ice." It is bluish in color with smooth, rounded corners. It is usually pure enough to eat or drink. Do not make the mistake of eating "salt ice." "Salt ice" is gray and milky. It should not be eaten. 10-114. Remember, ice and snow will tend to chill your stomach and reduce your body temperature. If you are on the verge of hypothermia, you should not eat ice or snow. Allow it to melt and get as warm as possible. Warm it in your mouth before swallowing. |
Never Drink Seawater or Urine
| 10-115. Rain, ice, and condensation are good sources of water. Do not mix saltwater, urine, or animal fluid with fresh water to stretch your water supply. Drinking seawater will only worsen your thirst and increase water loss by drawing body fluids from the kidneys and intestines. The salt will go to the brain and cause delirium and convulsions. Drinking seawater and urine during a survival situation could cause madness and death. |
Obtaining Food
| 10-116. Do not eat during the first 24 hours. After 24 hours, you may eat 4 ounces each day. In a life raft the food will last 5 days. You will have extra rations (food and water) if the boat or raft is not carrying its full number of passengers. 10-117. Do not eat food if you do not have water. Your body needs water for digesting food. Eating without drinking fresh water could cause death. |
Getting Food From the Sea
| 10-118. The sea has many different forms of life. If you have enough fresh water, you will probably not starve to death. Remember that water is a MUST! Because fish and birds are rich in salt and protein, more water is needed to digest them. Do not eat food from the sea unless you have two or three times more water than your daily ration. DO NOT panic if you do not have enough water to drink with your seafood or if you cannot catch any seafood right away. 10-119. You probably abandoned ship with excess body fat. Your system will begin to use the fat if you do not eat. One pound of body fat will probably keep your system working at about the same rate as two meals. The rate at which body fat and protein are changed to heat and energy depends upon air temperature, your activity, and your mental state. You can live longer on your stored energy if you keep your mind and body relaxed. It also helps if you do not overwork yourself or expose your body to very hot or cold temperatures. |
Fish
| 10-120. Most fish that are found in the open sea can be eaten. If they are found closer to shore they might be poisonous. The puffer, porcupine, and parrot fish are poisonous. They are fish that blow themselves out or have spines or bristles. 10-121. The flesh of fish caught in the open sea is good to eat whether cooked or raw. The heart, liver, and blood of fish are good to eat. Intestinal walls are edible, but the contents may be dangerous unless they are cooked. The stomachs of large fish may contain small fish partly digested, which are good to eat. Fish eyes also contain a lot of water. 10-122. You can catch fish by using the fishing kit provided with your equipment. Complete instructions are inside the kit. If you have lost your fishing kit, you could use the following methods to catch fish:
10-124. If and when you catch more fish than you can eat, in order to drink, squeeze or chew out the juice of the flesh. Fish juice tastes much like the juice of raw oysters or clams. To squeeze it out, cut a piece of fish without bones or skin. Cut it into fine (tiny) pieces. Wrap it in a cloth with long ends. Have two people twist the ends as tight as possible. The juice will drip out. To chew it out, chew a small piece of fish in your mouth. Suck out the juice and swallow it. Spit out the remaining flesh. 10-125. Cut fish into thin, narrow strips and hang them out in the sun to dry. If it completely dried and kept dry, it will often stay good for several days. It may even taste better dried. |
Clean and immediately eat or dry your fish. |
 Figure 10-37. Fishhooks Made From Wood |
 Figure 10-38. Fishhook Made From a Jackknife |
Turtles
| 10-126. All of the meat, blood, and juice of a turtle are good. The best meat is found against the shell, under the backbone. Cut through the ribs to get to this meat. A hot sun brings a clear oil out of turtle fat in which you can dip your food. CAUTION: A turtle can still bite and scratch even after you have cut off its head. |
Seaweed
| 10-127. Raw seaweeds are tough and salty. They are difficult to digest. Eat them only if you have plenty of fresh water. 10-128. Small edible crabs, shrimp, and fish often live in the seaweed. Lift them out of the water slowly and carefully. Shake them over the survival craft. Get rid of the jellyfish and eat the remaining morsels. |
Birds
| 10-129. All sea birds are nourishing and can be eaten. The blood and liver are also good to drink and eat. Try to catch birds that will sometimes land on you or on or in the survival craft. 10-130. Catch birds by dragging a baited fishhook behind the craft. Pull on the line after they have swallowed the hook. The hook catches the bird like a fish. Catch every bird you can. Use the feathers as fishing lures and the meat and guts for fish bait. Birds can also locate fish for you. When feeding, they usually follow schools of fish. This will give you an opportunity to get right up to the birds to catch them. Also, do not forget to catch the fish they are feeding on. |
SEARCH AIR RESCUE
| 10-131. Upon receiving a signal from any source that a ship or aircraft is in distress, it is the responsibility of all vessels in the area to go to the site and give help to the ship, aircraft, or persons in distress. This signal can range from a ship that is sinking or on fire, a downed aircraft, man overboard, or serious illness or injury aboard ship. |
TYPES OF DISTRESS SIGNALS
10-132. A ship at sea can be alerted to an emergency by the following:
|
HOW AIRCRAFT DIRECT SHIPS TO DISTRESS SCENE
10-133. These procedures are used by an aircraft to direct a ship toward another ship or aircraft in distress:
|
 Figure 10-39. Aircraft Signal |
 Figure 10-40. Aircraft Dismissal Signal |
SURFACE SHIPS ACTION
| 10-134. Once your ship has been alerted to the distress situation, you will acknowledge the receipt of the message. You will also provide a continuous radio guard on 2182 kHz and/or channel 16 on the radiotelephone, and, if required, retransmit the distress message to the ships in the area. 10-135. The next step is to determine your exact position and the position of the vessel or aircraft in distress. If it is possible, you should communicate the following to the ship in distress:
|
ASSISTING AN AIRCRAFT THAT MAY DITCH
10-136. Make a smoke signal if possible to show the pilot direction of surface wind. At night, show deck lights and shine the signal lamp straight up in the air. Do not shine it on the aircraft. You may blind the pilot. Try to make radiotelephone contact with the aircraft and give the following information:
Note: Military aircraft are usually fitted with "ejection seats." Many times the crew will use their ejection seats rather than ditch with the aircraft. 10-137. When picking up survivors from a military aircraft, get the following information as soon as possible and, if necessary, pass the information to other rescue ships by radiotelephone:
|
PREPARATION FOR MEDICAL EVACUATION OF PERSONNEL FROM YOUR SHIP
10-138. If there is a serious injury aboard your ship, a helicopter may be used to remove the injured crew members. This may be a Coast Guard, Army, Navy, or Marine helicopter performing the rescue mission. The ship's master and crew should prepare for removing the crew member while waiting for the rescue helicopter. The following is a complete helicopter evacuation checkoff list. When requesting helicopter assistance:
|
HOIST OPERATIONS
10-139. Hoisting operations are used to rescue or evacuate personnel from a number of dangerous situations. The following are some guidelines to follow when using hoisting operations:
|
HELICOPTER HOIST PROCEDURES
| 10-140. The wind developed by the helicopter rotor system can be over 70 knots. It is important to have all loose gear, on deck, securely tied down or stowed below decks. The rotor system could be destroyed if any loose objects are blown into the rotor during the hoist. 10-141. It is important to plan ahead because your voice cannot be heard over the noise made by the helicopter engine. Work out problems that may occur before the helicopter hovers overhead. Do not forget to wear your life jacket! 10-142. A helicopter might be used to rescue survivors or evacuate injured mariners by rescue basket, rescue sling, and stokes litter (Figure 10-41). |
Figure 10-41. Rescue Basket Hoist
Rescue Basket
| 10-143. The US Coast Guard usually uses a rescue basket for survivors who can help themselves (Figure 10-42). The basket is very easy to use. Just climb into the basket after it touches the deck (to discharge static electricity), sit down, and keep hands and arms inside. |
Figure 10-42. Rescue Basket
Rescue Sling
| 10-144. A rescue sling is carried on board helicopters. Rescue helicopters from other countries, use the sling more often than by the US Coast Guard. The rescue sling is just a padded loop that is placed over the body and underneath the armpits. The arms are held around the sling as shown in Figure 10-43. |
Figure 10-43. Rescue Sling
Stokes Litter
| 10-145. This type of litter will usually be used to hoist those who have serious injuries or illnesses or who are unable to walk. To use the litter, it is necessary to get help from other crew members. The straps must be disconnected and spread out. The blankets must be removed. The patient should be put in the litter and covered with the blanket. The straps are then snugly fastened with the pad on top of the chest as shown in Figure 10-44. |
Figure 10-44. Stokes Litter
| 10-146. If the litter has to be taken below decks to the patient, it must be unhooked from the cable. This hook must not be attached to any part of the vessel. There is always a possibility that there may be an emergency aboard the helicopter itself. The helicopter may have to move unexpectedly. To decrease this type of danger, the pilot may hover off to one side of the vessel while waiting. 10-147. If a steadying line is attached to the basket, horse collar, or litter, it must be tended. This will stop the rescue device from swinging too much. It is very important that the rescue device touches the vessel before anyone touches it. As soon as the object being lowered touches the deck, static electricity (which builds up in the helicopter during flight) will be discharged. Never shine lights on the helicopter. It will blind the pilot. |
Ready to Hoist
| 10-148. To signal the helicopter pilot that all is ready for hoisting, give him a thumbs-up signal, or if you are a patient, nod your head if you are able. |
SHIPBOARD NBC DEFENSE
| 10-149. Much of your military training is dedicated to NBC training in a land combat situation and the protective measures to be taken for survival. This paragraph will discuss NBC countermeasures to be taken aboard ship for survival. Although a nuclear detonation is devastating, survival is possible, and aboard ship it is probable. Your survival will depend upon the actions taken before, during, and after the attack. |
| 10-150. The energy yield of a nuclear weapon is described in terms of the amount of TNT that would be required to release a similar amount of energy. A nuclear weapon capable of releasing an amount of energy equivalent to the energy released by 20,000 tons of TNT is said to be a 20-KT weapon. A nuclear weapon capable of releasing an amount of energy equivalent to the energy released by 1,000,000 tons of TNT is said to be a 1-MT weapon. 10-151. Weapon yields may range from a fraction of a KT to many MTs. Although a weapon's total yield is not significantly influenced by the environment about the burst point, the relative importance of weapon effects depends greatly on where the detonation takes place. The four types of bursts are high altitude, air, surface, and underwater. 10-152. Although the four types of bursts are defined below, there is actually no clear line of demarcation between them. Obviously, as the height of burst is decreased, the high altitude burst becomes an air burst, an air burst will become a surface burst, and so forth. The significant military effects associated with each type of burst follow. |
High Altitude Burst
| 10-153. This explosion takes place at an altitude in excess of 100,000 feet. It produces airblast, thermal radiation, an EMP, initial nuclear radiation, and atmospheric ionization. At altitudes above 100,000 feet, the proportion of energy appearing as blast decreases markedly, while the proportion of radiation energy increases. Due to the low density of the atmosphere, the range of the initial nuclear radiation increases. In contrast to explosions below 50,000 feet, the attendant atmospheric ionization from bursts above 100,000 feet lasts for minutes to hours. The important consequences of high altitude bursts are the damage to weapons systems or satellites operating in the upper atmosphere or in space, and the effects on electromagnetic waves (communications and radar) relying on propagation through or near the region of the burst. |
Air Burst
| 10-154. In this type of burst, the fireball does not contact the surface. An air burst produces airblast, thermal radiation (heat and light), EMP, and initial nuclear radiation (neutron and gamma rays) about the burst point. There will be no significant residual nuclear radiation (gamma and beta radiations from airborne or deposited radioactive material) except when rain or snow falls through the radioactive cloud. |
Surface Burst
| 10-155. The fireball touches or intersects the surface. A surface burst produces airblast, thermal radiation, EMP, initial nuclear radiation around surface zero, and residual (transit and deposit) nuclear radiations around SZ and downwind from SZ. Transit radiation is produced by airborne radioactive material (base surge/fallout) and deposit radiation is produced by radioactive material (base surge/fallout) collection on exposed surfaces. Surface bursts over water will also produce underwater shock and surface water waves, but these effects will be of less importance. Over land, earth shock will be produced, but will not be an important effect at any significant distance from the burst point. |
Underwater Burst
| 10-156. This burst occurs below the water surface. It produces underwater shock and a water plume, which then causes a base surge. Very shallow bursts may also produce airblast, initial nuclear radiation, fallout, and possibly some thermal radiation. These effects will be reduced in magnitude from those of a water surface burst and will become rapidly insignificant as the depth of burst is increased. The damage range due to shock is increased as depth of burst is increased. For a given weapon yield, greater hull and machinery damage will be produced by shock from an underwater burst than by airblast from an air or surface burst. 10-157. When a high yield weapon is detonated underwater in the deep waters adjacent to a continental shelf, large breaking waves may be generated by the upsurge along the shelf slope. These waves will appear on the shallow water side of the shelf edge. They are characterized by a long period with a sharp, possibly breaking, crest. They dissipate in amplitude as they progress toward the shore. Calculations and simulation experiments with the East Coast US continental shelf indicate that, in the near vicinity of the shelf edge (shallow water side only), these waves may be large enough to damage the largest combatant ships and swamp or capsize smaller ships. This shoaling phenomenon does not appear in deep water. Except in shoaling waters, water waves normally will not be a major hazard. |
UNDERWATER SHOCK
10-158. Underwater shock is the shock wave produced in water by an explosion. The shock wave initially travels several times the speed of sound in water, but quickly slows down to sonic speed (about 5,000 feet per second). Underwater shock produces rapid accelerations that may result in equipment and machinery disarrangements, hull rupture, and/or personnel injuries. Both the directly transmitted shock wave and the shock wave reflected from the sea bottom can be damaging. An underwater explosion produces a shock wave similar to an air burst. Four factors determine whether the greater damage will be caused by the direct wave or the reflected wave:
|
THERMAL RADIATION
| 10-159. Thermal radiation is the radiant energy (heat and light) emitted by the fireball. Thermal radiation travels at the speed of light and persists as long as the fireball is luminous. The duration of thermal radiation emission depends on weapon yield. It usually lasts less than 1 second for 1-KT yield and about 8 or 9 seconds for a 1-MT yield. Thermal radiation is effectively shielded by anything that will cast a shadow (opaque materials). Thermal radiation can produce combat ineffectiveness (that is, individuals unable to man battle stations) among exposed personnel by skin burns, flash blindness, or retinal burns. 10-160. Thermal radiation is modified by the height of burst, weapon yield, cloud cover, and terrain features. As height of burst is increased, the area of the earth's surface exposed to thermal radiation increases. This happens because there are fewer shadows from existing structures (such as vegetation, terrain features, and so forth). 10-161. As weapon yield increases, the range at which thermal radiation can cause skin burns and eye injuries to exposed individuals extends well beyond the range where blast and initial nuclear radiation are of significance. The rate at which thermal radiation is emitted from a high-yield weapon is slower than for a low-yield weapon. Therefore, the high-yield weapon must deliver more thermal energy to do an equivalent degree of damage because a target has more time to dissipate the heat being received. |
NUCLEAR RADIATION
10-162. The four basic types of nuclear radiation given off during a nuclear explosion are alpha particles, beta particles, gamma rays, and neutrons.
|
INITIAL NUCLEAR RADIATION
| 10-164. Initial nuclear radiation is defined as the radiation (essentially neutrons and gamma rays) emitted by the fireball and the cloud during the first minute after detonation. Depending on weapon yield, all significant neutron radiation is emitted in less than 0.1 second, gamma radiation up to 20 or 30 seconds. The 1-minute time limit is set as the maximum time for the nuclear cloud to rise beyond the range in the air at which gamma radiation is a significant hazard. Initial nuclear radiation generally may not produce significant material damage, but will produce combat ineffectiveness. |
NUCLEAR RADIATION INJURY
| 10-165. The radiological hazards described are those which might be of significance to the military effectiveness of marine personnel in combat operations. Injuries to personnel can result from exposure to sufficient quantities of either initial or residual radiation, or a combination of the two. Unlike injuries from other weapon effects, nuclear ionizing radiation injuries may not become evident immediately unless a high dose is received. All nuclear radiation, even in very small doses, has some harmful effect on the body and should be avoided whenever possible. 10-166. The biological injury to an individual from nuclear radiation depends on many factors. Some of these factors include the following:
|
FALLOUT
| 10-167. Fallout, a major effect of a shallow underground and underwater burst, is the radioactive material that falls from the nuclear cloud and deposits on exposed surfaces. The fallout primarily consists of fission products (gamma and beta emitters) mixed with material vaporized by the fireball and drawn up into the nuclear cloud. Fallout, whether airborne or deposited, is a hazard because it emits gamma radiation that can penetrate ship structures, buildings, and aircraft. It can also cause radiation injury or death to personnel. Deposited fallout also presents a personnel contamination hazard. 10-168. The area of fallout is determined by the wind structure up to the top of the cloud. In complete calm, the fallout pattern is roughly circular. A constant wind direction leads to an elongation of the pattern. Complicated wind patterns (wind shear) as well as variations in wind pattern in time and space lead to complicated ground patterns. Fallout is difficult to predict accurately except under calm and very stable wind conditions. 10-169. Reduction in yield or changing the height/depth of burst to a point where the fireball does not intersect the ground will reduce fallout, as will complete containment of an underground burst. 10-170. Fallout landing on water will sink and will not constitute a hazard to ships passing through the area after fallout cessation. Fallout over a land area will remain on the surface and will be a hazard to personnel living in or passing through the area. In time, the fallout on a land surface will decay to an insignificant level. |
PROTECTIVE SHIELDING
10-171. Protective shielding is one method of defense against nuclear radiation. The tremendous penetrating power of gamma rays makes it difficult to provide enough shielding to protect personnel from gamma rays. However, the structure of the ship provides some protection against them.
10-172. The main materials likely to provide shielding aboard a ship are steel plating, piping, machinery, water, fuel oil, and some types of wood. Shielding materials at storage facilities include concrete and earth.
10-173. The amount of shielding required to stop gamma rays is measured in half-value layer thickness or "half-thickness," for short. A half-thickness is defined as the amount of material necessary to cut down the amount of radiation to one half of its original value. The half-thickness value for each material is different. For example, a concrete shield about 6 inches thick or an earth shield about 7 1/2 inches thick will cut the gamma radiation in half. Suppose that you are standing at a plate where the gamma radiation is 400 roentgens. If you are behind a half-value layer thickness of some kind at the time, you will receive a dose of 200 roentgens. Now suppose you are standing behind two shields, each of which is a half-value layer. The 400 roentgens of gamma radiation is reduced to 200 roentgens by the first half-thickness and to 100 by the second half-thickness. With each additional half-thickness shield, you reduce the remaining gamma radiation by half. Remember that these thicknesses do not stop gamma radiation altogether; instead, they cut it in half. In a nuclear attack, one-half value layer of steel or concrete might be just enough of a shield to keep you from getting a lethal dose of gamma radiation.
10-174. The approximate half-thickness of some materials, listed in order of their effectiveness as shields against gamma radiation, are shown in Table 10-2.
Table 10-2. Materials Effectiveness Against Gamma Radiation
|
INITIAL |
RESIDUAL |
|
|
Steel |
1.5 inches |
0.7 inches |
|
Concrete |
6.0 inches |
2.2 inches |
|
Earth |
7.5 inches |
3.3 inches |
|
Water |
13.0 inches |
4.8 inches |
|
Wood |
23.0 inches |
8.8 inches |
PREVENTIVE MEASURES (BEFORE ATTACK)
10-175. Personnel should take preventive measures before an attack. The steps that are listed are not in a required sequence, they only list the things that should be performed. The situation at the time will determine the sequence.
Note: If the vessel is 1,000 yards or more from "ground zero," the crew should survive. With the crew below the waterline and in between the engines, the bulkheads, engines, ship's hull, and the water all provide a shield against radiation.
Personnel should also take the necessary actions against a nuclear attack. Table 10-3 shows the actions personnel should take during nuclear denotations.
Table 10-3. Recommended Personnel Action Against Nuclear Detonations
|
WITH WARNING |
NO WARNING |
||
|
BURST TYPE |
TOPSIDE PERSONNEL |
BELOW DECK PERSONNEL |
TOPSIDE PERSONNEL |
|
Air |
A |
B |
C |
|
Surface |
A |
B |
C |
|
Underwater |
B |
B |
|
|
A -LIE PRONE AND HOLD ON TO SOLID SHIP STRUCTURE. B - STAND WITH KNEES FLEXED AND HOLD ON TO SOLID SHIP STRUCTURE. C - HANDS-TO-FACE EVASION. |
|||
PREVENTIVE MEASURES (DURING AN ATTACK)
10-176. Personnel should take preventive measures during an attack. The following are some precautions to take:
|
PROTECTIVE MEASURES (AFTER THE ATTACK)
10-177. Personnel should take preventive measures after an attack. The following are some precautions to take:
|
RADIOLOGICAL DECONTAMINATION
| 10-178. This neither neutralizes nor destroys the contamination. Instead, it merely removes the contamination from one particular area and transfers it to an area in which it presents less of a hazard. At sea, dispose of radioactive material directly over the side. 10-179. Flushing with water, preferably water under high pressure, is the most practicable way of rapidly decontaminating topside surfaces. Aboard ship, a water washdown system is used to wash down all the exterior surfaces (from high to low and from bow to stern). The washdown system consists of piping and a series of nozzles that are specially designed to throw a large spray pattern on weather decks and other surfaces. Permanent washdown systems are being built into ships under construction or conversion. Interim washdown system kits are provided for ships already in service. 10-180. If the washdown system is turned on before the arrival of contamination, the system prevents heavy contamination of the ship by coating the weather surfaces with the flowing stream of water. The flowing stream of water carries away radioactive particles as they fall on the ship and keeps radioactive particles from settling into cracks and crevices. 10-181. If some areas of the ship become heavily contaminated before the washdown system is activated, it will probably be necessary to hose down such areas vigorously, using seawater under pressure. Hosing should proceed from higher to lower surfaces, from bow to stern, and, if possible, from the windward side to the lee side. Every possible precaution should be taken to see that contaminated water does not flow back over cleaned areas. Precautions must also be taken to see that contaminated water is not hosed into the interior of the ship through vents, doors, or hatches. The hose should be directed so that the water strikes the surface about 8 feet from the nozzle. The hose stream should sweep horizontally from side to side, moving lower on each sweep. The hosed areas should be overlapped somewhat on each sweep to ensure complete washing. The runoff should be directed into scuppers and deck drains as rapidly as possible to keep the contaminated water moving and to prevent pools of contaminated water from forming. 10-182. Hosing down will be most effective if it is done before metal or painted surfaces have dried after contaminating material has been deposited. However, contamination that has been deposited despite washdown will also resist hosing alone. Vigorous scrubbing with deck brushes and detergents, followed by hosing, is required. Ships without washdown systems will initially decontaminate by hosing down with seawater as soon as the tactical situation permits. |
CONTAMINATION MARKERS
| 10-183. Areas or objects that are contaminated by NBC attack must be clearly marked to warn personnel approaching the area of the existence of hazards. Contamination markers should outline dangerous areas and establish boundaries within which safety control must be exercised. Radiation hot spots--that is, areas having radiation intensities significantly greater than the general radiation level of the surrounding areas -- should be identified. 10-184. The standard NATO system for marking areas, that are contaminated by NBC attack, is used. Figure 10-45, shows these standard survey markers. Each marker is in the shape of a right triangle; one side of the triangle is about 11 1/2 inches long, and the other two sides are about 8 inches long. The markers may be made of wood, metal, plastic, or other rigid material. |
Figure 10-45. NATO NBC Markers
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