Salvage Docket (1) PDF

CHAPTER I - INTRODUCTION TO MARINE SALVAGE ========================================== - Salvage definition, Kinds of Salvage, Types of Salvage problems - Management of Salvage work Definition of Salvage ===================== a. **True Salvage**: This is a time critical service usually rendered by volunteers in which operations are planned ad hoc as related to organization and forces are assigned to the task and the operational execution of the salvage. b. **Recovery / Clearance / Wreck removal work** These are generally not time critical, and operations are a thoroughly planned mobilization and execution of salvage. a. The towing, piloting, or navigating into safety of a ship which is in danger or distress. b. The rescue by landing or transshipment of cargo or other persons belonging to a ship circumstanced. c. Getting a stranded ship afloat. d. The raising of a sunken ship or cargo. e. The bringing into safety of a derelict or wreck. f. The setting in motion, fetching, or bringing of assistance to a ship in danger or distress. g. The saving of persons belonging to a ship who, having taken to the boats to escape from danger on shipboard, are afterwards picked up whilst still in danger at sea. h. The protection or rescue of a ship or her cargo or the lives of persons on board of her from pirates or plunderers. j. The supply of officers or seamen to a ship which, through disease or other calamity is dangerously short of hands to navigate or to work her. k. The supplying of tackle or gear to a ship, which would be imperiled by the want of it. l. The extinction of fire on board of a ship or assistance in such service. m. The rescue of life or property from a ship on fire. n. The removal of a ship or cargo from a place where it is in imminent danger of catching fire. p. Standing by a ship in danger or ascertaining by aircraft search whether a derelict vessel had sunk and giving information by radio that the derelict was still afloat in a specified position. q. The removal of a ship from a danger, such as a wreck or another ship which has fouled her. r. The saving, by purchase from the enemy, of a captured ship, and bringing her to a (Indian) port for the purpose of restoring her to her owners. s. The saving of a ship from an impending collision. t. Providing, albeit involuntarily, a floating platform upon which an aircraft could land to avoid crashing into the sea. u. Giving advice or information in order to save a vessel from a local danger. v. Towing out a ship on fire and holding it until the fire burns out. w. Assistance by one vessel in convoy to another to enable the first vessel to rejoin the convoy or the protection of escort vessels. x. Preventing a vessel from falling into the hands of pirates/revolutionaries. a. **Casualty Salvage Afloat**. Assisting vessels or objects to stay afloat or control a casualty arising from distress or damage caused by weather, collision, leakage, fire, enemy action, breakdowns, explosions, or navigational errors, or other related incidents. b. **Stranded Casualty Salvage**. The refloatation of stranded vessels or objects which have been driven ashore because of navigational error, enemy action, force of weather, machinery breakdown or a combination of these factors, which resulted in a grounding. c. **Salvage of Sunken vessels**. The refloating or lifting of sunken vessels or objects which may have sunk as a result of any causes noted under sub- paragraphs (a) and (b) when there is deliberate intention on the part of the owner and or the salvor to restore the vessel or object to its service, i.e. the task is one of casualty salvage and not one of wreck removal. d. **Oilfield Salvage Operations**. Providing services to reduce damage to prevent the loss of offshore drilling and/or production facilities, including fire- fighting and emergency stabilisation services to deal with casualties arising from e. **Cargo Salvage Activities**. The saving or removal of cargo from distressed or sunken vessels or aircraft, and in this context 'Cargo" includes bulk and general cargo, precious metals, and hazardous materials such as chemicals, oils, gases concentrates and ammunition. The purpose of cargo salvage may be either to recover the cargo itself or as part of the plan to salvage the carrying vessel itself. f. **Special Object Recovery**. This type of work involves the salvage or retrieval of special objects from sunken vessels or aircraft and may include the search for and recovery of lost objects such as weapons, spacecraft, special equipment, aircraft, or selected components from those objects. Special object salvage includes the recovery of aircraft for investigative purposes and or to ensure certain components do not fall into undesirable hands. g. **Pollution Control and Abatement**. These operations concern minimising the harmful effects to the seas and the coastline, to marine life and to society in general, from pollution and or hazards caused by the release into the seas (or rivers) of hydrocarbon products, chemicals, radio- active material and any other potentially toxic substances. h. **Wreck Removal Operations**. The refloating, demolition, or dispersal of sunken or partially sunken vessels which impede or restrict navigation, or access to wharves or port facilities, or which pose a hazard to other maritime traffic. Although the basic techniques of wreck removal remain much the same, salvors have identified three special areas of removal operations which they classify as: i. **Wreck Removal**. The clearance, refloating or demolition of one vessel which is causing an obstruction or hazard, on the basis of a 'one-off contract\', in the same sense as most casualty salvage is a 'one time' event per casualty. ii. **Harbour Clearance**. This involves the clearance of multiple vessels and objects including port facilities, bridges, lock and war debris which precludes the use of or restricts access to a channel or port. Such activities may be result of natural disasters such as typhoons, Tsunami or gale' force weather, industrial catastrophes; sabotage or enemy action; and in some cases, a gradual build-up of desired or abandoned vessels may obstruct a port or a navigable channel, requiring a Harbour clearance operation. iii. **Offshore Clearance**. This work is generally confined to clearance of navigational hazards or sub- surface debris from oil and gas-exploration or The Management of Salvage Work ============================== a. A competently led team-effort on the casualty b. A strong, well-organised logistics and technical back-up c. A firmly committed management team d. Rapid, secure, and effective communications from the casualty to Headquarters and to the 'forward-operating' base, when such a facility is established a. Salvage Team Leader b. Assistant Team Leader c. Salvage Engineer d. Naval Architect e. Salvage Foreman or Foremen f. Diving Supervisor g. Salvage Mechanic(s) h. Divers j. Support and Admin manpower CHAPTER II - SALVAGE SEARCH, SURVEY AND PLANNING ================================================ - Salvage survey, Check off list, Survey procedure, Search tools - Search Tools - Wreck Location And Marking - Survey Procedure - Methods of Reporting a. Soundings at close intervals around the work. b. Range of tide in the area. c. Tidal height at the time of operation along with accurate tidal predictions available for the duration of the work. d. How much of the vessel\'s length/breadth is in contact with the seabed. e. Survey of area around the salvage area. f. Possibility of explosion, oil leakage, chemical hazards etc. g. Point of start and end of contact at the bottom of work. h. Probability of risk or hazards to divers while working. j. Availability of time for carrying out actual salvage work. k. Availability of correct and adequate diving/salvage equipment at the site. l. Prevailing weather in the area during the entire position. m. Surf conditions in the area. n. Extent of damage to the structure / hull of the work. Search Tools ============ Wreck Location and Marking ========================== Survey Procedure ================ Methods of Reporting ==================== a. Is the area safe and / or practical for divers to work? b. What are the prevailing currents and expected underwater visibility? c. How much time will be available for divers to work under the prevailing conditions? d. How much work can the existing diving team accomplish? e. Do the divers have all the equipment they require to perform useful "work" after the survey aspects of the task are completed? CHAPTER III - BASIC NAVAL ARCHITECTURE IN MARINE SALVAGE ======================================================== - Ship geometry and terminology - Stability and Buoyancy - Ship structures and Strength - Loading and Ballasting Introduction to Naval Architecture ================================== Ship Geometry and Terminology ============================= a. **Length Overall (LOA).** The total length of the vessel from the forward-most to the aft-most point. b. **Beam.** The widest point of the ship, critical for stability and clearance during salvage. c. **Draft.** The vertical distance between the waterline and the bottom of the hull (keel), determining the depth of water a vessel can safely navigate. d. **Freeboard.** The distance from the waterline to the deck edge. A vessel with reduced freeboard may be at risk of flooding during salvage operations. e. **Displacement.** The weight of the water displaced by the ship\'s hull, equal to the vessel\'s weight. a. **Displacement Hulls.** Common in ships designed for stability and carrying capacity, displacing water equal to their weight. b. **Planing Hulls.** Designed to lift the vessel above the water at higher speeds, reducing drag. c. **Semi-Displacement Hulls.** A hybrid between displacement and planing hulls, balancing speed and load-carrying ability. Stability and Buoyancy ====================== a. **Static Stability.** Refers to the ship\'s ability to return to an upright position after being tilted by an external force. This is defined by the metacentric height (GM), where a positive GM indicates stability. b. **Dynamic Stability.** The energy required to move the ship from its upright position to a tilted one. Greater dynamic stability implies that more force is needed to capsize the vessel. c. **Transverse Stability.** Stability against side-to-side tilting (rolling). d. **Longitudinal Stability.** Stability against forward and aft tilting (pitching). a. **Center of Gravity (G).** The point where the total weight of the vessel is concentrated. Lowering the center of gravity increases stability. b. **Center of Buoyancy (B).** The point where the buoyant force acts, which shifts with the waterplane area as the vessel tilts. c. **Metacenter (M):** The point where the buoyant force acts vertically upward. The distance between G and M (metacentric height) determines stability. Ship Structures and Strength ============================ a. **Keel.** The backbone of the ship, running along the bottom, providing structural strength and stability. b. **Frames and Stringers.** Rigid components that maintain the shape of the hull and distribute stresses evenly across the structure. c. **Bulkheads.** Vertical partitions that divide the ship into watertight compartments, crucial for maintaining buoyancy and stability in case of hull breaches. d. **Decks.** Horizontal structures that provide support for loads and improve the vessel's rigidity. Loading and Ballasting ====================== Salvage Considerations in Naval Architecture ============================================ CHAPTER IV - CONCEPTS OF BUOYANCY ================================= - Archimedes principle, States of Buoyancy, principle of Buoyancy - Boyle\'s law applied for diving - LP Compressor delivery - Available gas and diver consumption 1. m submerged. What is the upthrust? a. If weight is greater than upthrust it will sink. This is known as negative buoyancy. b. If upthrust is greater than weight it will float up. This is known as positive buoyancy. c. If upthrust is equal to weight, the body will remain where it is. It may be floating on the surface or suspended mid-water. This is known as neutral buoyancy. Therefore in order to obtain 1 kg of lift in seawater it is necessary to displace less than 1 liter of water, i.e., 0.97 liters. ================================================================================================================================ 30.9 t can be placed on the pontoon =================================== The compressor must deliver 12.35 ft/min ======================================== [Example 9] A diver is working at 150 msw. How much gas will he use in 4 hours? Sample Questions ================ 1. A bell displaces 8 m of sea water and weights 8 t. How much weight must be added to make it negatively buoyant by 300 kg? 2. A welding habitat is 12 ft by 8 ft by 6 ft. It weighs 20 tons in air. What is its weight in the water? 3. A gas storage system consists of 30 tubes each with an internal volume of 1.5 m. How much gas can be stored when the whole system is pressurized to 180 bar? CHAPTER V - REFLOAT STRANDED OR SUNKEN OBJECT ============================================= - The effects of the Seafloor on Sunken or Stranded object - Ground Reaction - Reduction of Ground Reaction - Calculation of total lift force required THE EFFECTS OF THE SEAFLOOR =========================== a. Friction b. Suction c. Damage and impalement d. Seafloor movement e. Sinking into the seafloor f. Silting a. The ground reaction b. Seafloor composition c. Seafloor slope and uniformity d. Shape of the ship\'s underwater body e. Dynamic effects. CALCULATION OF TOTAL LIFT FORCE REQUIRED TO LIFT ================================================ -- -- -- -- Reducing Ground Reaction ======================== a. **Weight Management**. Weight removal is the preferred method for reducing ground reaction. i. Weights added or removed at the center of ground reaction cause a change in ground reaction equal to the weight change. Buoyancy remains unchanged. ii. Weights added or removed at the neutral loading point cause a change in buoyancy equal to the weight change. Ground reaction remains unchanged. iii. Adding weight forward or removing weight aft of the neutral loading point will increase ground reaction iv. Removing weight forward or adding weight aft of the neutral loading point will decrease ground reaction. b. **Induced Buoyancy**. Buoyancy is induced in a stranded vessel by removing the water from spaces that are flooded. The three most common means of doing this are by pumping, blowing with compressed air, and displacing the water with a buoyant material. v. **Pumping**. Pumping may be used to remove flood water from a stranded ship after the portion of the ship below the waterline has been made watertight. vi. **Compressed Air**. Compressed air is particularly suitable for removing water from double bottoms. It is also suited for removing water from tanks that are open to the sea in their lower part, where damage is in contact with the seafloor, or otherwise cannot be reached for patching. When compressed air is used, all portions of the compartment that are to be buoyant must be made airtight. vii. **Water Displacement**. Water may be displaced from a flooded compartment by filling the compartment with a buoyant material. The material may be buoyant objects such as drums or lift bags, chemical foam, or any of a number of water displacement systems. When water displacement systems are used, the compartment need not be as watertight as when the compartment is pumped or blown. c. **Ground Removal**. Removal of the ground under a ship allows the ship to sink deeper into the water and, thus, recover some of the buoyancy lost on grounding. The effectiveness of ground removal depends upon the nature of the seafloor under the ship. Sand and clay seafloors can be removed with relatively little effort and once removed will not fill in immediately. Hard seafloors cannot be removed easily, and very soft seafloors tend to fill in after initial removal. d. **Lifting.** Ground reaction may be reduced by physically lifting the ship. Methods of lifting the ship to reduce ground reaction include jacking, pontoons, helicopters, and cranes or sheer legs. e. **Temporary Reductions**. A temporary reduction of ground reaction during a pulling attempt can either reduce ground reaction or reduce friction or both. Jetting pumps rigged to establish a flow of water under the casualty\'s hull wash away the ground under the ship and make the seafloor more fluid. Air lances, pipes perforated with holes along their length and attached to a compressed air source by hoses may also be used to fluidize the seafloor to reduce the coefficient of friction. Properly set air lances can reduce the coefficient of friction of hard sand seafloors to that of soft mud. CHAPTER VI - PASSING LIFT WIRES AND CHAINS. =========================================== - Air lift, Principle of operation - Reaction jet, Principle of operation - High pressure water jet - Tunneling and Lancing - Methods of passing lifting wires EQUIPMENT USED TO PASS WIRES UNDER SUNKEN OBJECT ================================================ ![](media/image4.jpeg) Reaction jet/ Tunneling lance ============================= 1. shows such a nozzle. High Pressure Water Jet ======================= a. Check that the working pressure of the compressor does not exceed that of the gun and hoses. b. Check the condition of all hoses. c. Check all hose couplings and connections. d. Check the operation of all valves, triggers and safety catches. e. Check the condition of all nozzles and lances. f. Make sure that there are good communications between the diving supervisor, the diver and the compressor operator. Voice communication with the diver will be impossible while jetting is in progress and the supervisor should monitor his breathing rhythm and the noise of the gun and take immediate action if there is any significant change. g. Take special care when from a DP vessel, operating noise may interfere with acoustic reference systems. h. A water jet should never be used when there are two divers in close proximity in the water. j. Check that the diver is placed securely and is holding the gun firmly with both hands. k. High pressure must only be supplied to the gun when demanded by the diver. **The gun must never be lowered to the diver on load or returned to surface on load.** l. Do not allow the diver to tie back or wedge the 'trigger. It is essential that he should be able to stop jetting immediately. m. If the gun fails to shut off completely when the trigger is closed it is defective and the operation should stop until it has been repaired or replaced. n. After use, shut down the compressor and release the pressure from the system by operating the gun. METHODS FOR PASSING LIFTING WIRES ================================= a. Direct reeving b. Sweeping and sawing c. Lancing d. Tunneling e. Profile dredging. Direct Reeving. =============== Sweeping and Sawing. ==================== a. The seafloor is relatively soft material, such as mud, sand, or shingle. b. There is no extensive damage to the sunken ship that will foul the sweep. c. The sunken ship is reasonably upright, with either its bow or stern clear of the seafloor. a. The bight of a working messenger wire is passed under the end of the ship that is clear of the seafloor. b. Each free end of the messenger is secured to a small, powerful tug or workboat positioned on either side of the sunken ship. c. The towing vessels shackle another wire to the messenger to allow a good bight or catenary before towing the wire at full power under the ship. d. Both vessels tow until they come to a screaming halt. They then begin to seesaw the messenger by going ahead alternately. e. The process is repeated with each successive messenger until all the working messengers are in position at the lifting stations. a. Two salvage vessels moor, one on each side of the sunken ship, lying well away from and at a broad angle to the casualty. b. A light messenger is passed between the two vessels and positioned under the accessible end of the sunken ship by divers. c. A working messenger, usually incorporating one or two shots of 2 1⁄4-inch chain at its mid-length, is then passed under the sunken ship. d. The two salvage vessels alternately heave and slack the messenger, working the chain along the sunken ship in a sawing action. e. When the working messenger is in the final position, one ship shackles a new working messenger to it. This messenger acts as the messenger for the lift f. The second vessel hauls the complete working messenger on board, and in the process, passes the lift wire messenger. Figure 12-21 illustrates sawing wires with salvage vessels. ![](media/image6.jpeg) Tunneling and Lancing. ====================== a. Excavate a well or deep saucer alongside the sunken ship with a reaction nozzle to cut away the seafloor and a pump or airlift to take away the excavated silt. The width and depth of the saucer and the slope of its sides depends upon the seafloor material In hardpan or clay, the sides can be relatively steep and the width of the saucer much less than in mud or sand. The saucer, or well, is dug to about 7 feet below the mean bottom line of the sunken ship. b. When the saucer excavation is complete, a working face is made on the side next to the sunken ship, and tunneling operations begin. In soft material, a reaction nozzle washes away material without much trouble; in hard ground, a mining technique should be adopted. The tunnel face is cut away first to undermine the remainder, which then breaks down into the cavity created by the undermining. Correct slope on tunnel walls must be maintained to avoid slippage of the sides. c. All soils washed out of the tunneling area are fed to a diver tended pump or airlift suction operating continuously in the saucer area. This procedure keeps the work area free of soil and silt buildup and expedites work by the diver. d. Tunnels are driven through directly underneath the sunken ship using the ship\'s bottom plating as a tunnel roof and guide for the excavation. By forming the tunnel roof with the bottom plating, risks of tunnel cave-ins are reduced. e. As tunneling progresses, a second pump suction hose or airlift in the tunnel assists with removing excavated material. f. Where the seafloor is reasonably soft, it may not be necessary to drive the tunnel right through to the far side of the wreck. Sometimes, the last 10 to 12 feet can be penetrated by a reaction nozzle screwed to several short lengths of steel pipe. This jet digs its way through the last few feet to clear the far side of the wreck. An air hose is clamped to the steel pipe and compressed air is blasted through the pipe. g. A diver on the wreck\'s far side can locate these air bubbles easily, and jet or airlift a sump to dig out the reaction nozzle. The diver can pull the reaction nozzle through and remove the pilot wire. With the pilot wire in hand, the process of passing messenger wires can begin. Tunneling Lances. ================= a. A high-pressure jetting pump with a length of hose to deliver water to divers operating the lance. b. A reaction nozzle screwed to the first, or leader, pipe section of the lance. c. A series of extension pipes fitted with threaded couplings. d. A small-diameter messenger wire that is spliced or shackled to the outside of the leading pipe section. ![](media/image9.jpeg) CHAPTER VII -- LIFTING TECHNIQUES ================================= - Categories of lifts - Salvage pontoons and lift bags - Calculations for use of lift bags - Guidelines on usage of lift bags CATEGORIES OF LIFTS =================== a. Buoyant lifts b. Tidal lifts c. Mechanical lifts. Buoyant Lifts. ============== a. When laying out pontoons or lift bags, the deck or layout area must be clear of objects that might cause damage. b. Pontoons must not be dragged over or against sharp objects when they are being rigged. c. Pontoons should not be rigged underwater where they are likely to foul, snag, or tear on sharp objects, pier pilings, or damaged or torn plating. d. Inflatable pontoons should not be rigged into totally enclosed flooded spaces, except when there is no other choice. For example, inflating pontoons in machinery spaces will usually result in damage to the pontoon and total loss of lift. 0713. General Guidelines on the Use of Totally Enclosed lift bags. ================================================================== a. When rigging and installing totally enclosed lift bags it is most important to ensure that they are operated in a horizontal plane. Should they be inclined at more than 5 degrees, excessive torsion will be placed on the cradle strap and strap pockets to such an extent that the straps could tear away from the lift bag. b. Always use a total lifting force at least equal to the weight of the load, but remember too little will not lift, too much may cause the load to ascend out of control or be lost. c. Place the bags as to minimize stress differentials. Uneven lifting stress may well cause physical damage to the load as well as endanger the divers. Attach and inflate bags methodically when used in groups or clusters to avoid one forcing another to collapse. d. Do not allow a load to ascend at a rate faster than 2-3 feet per second. e. Bags should be inflated evenly on the load to prevent rolling or tipping. f. Use extreme caution when using excess buoyancy to 'break-out' a load initially. g. When attached to the underside of a load, great care is necessary to ensure that airbags are not 'pinched' or 'strangled' as for example by the bilge of the vessel. In such cases, air will not be free to pass to all the bags, reducing the potential lift. h. Towing speed should be kept to 2-3 knots depending on sea state. Exceeding this recommended speed could cause pressure build up in front of the bag and reduce volume. 0714. General Guidelines on the use of Open Bottom Parachute type lift bags. ============================================================================ a. Always use a total lifting force at least equal to the weight of the load, but remember, too little will not lift, too much may cause the load to rise to the surface out of control or be lost. b. Place the bag so as to minimize stress differentials. Uneven lifting stress may well cause physical damage to the load, as well as endanger divers. Attach and inflate bags methodically when used in groups or clusters to avoid one forcing another to collapse. c. Do not allow a load to make a free ascent at a rate faster than 2-3 feet per second. d. Bags should be inflated evenly on the load to prevent rolling or tipping. e. Use extreme caution when using excess buoyancy to 'break-out' a load initially. f. After use, whether in salt or freshwater, the bags should be washed off, lightly scrubbed if necessary to remove mud, oil, tar etc., then hung up to dry. Inspect all of the lifting straps carefully. Damaged straps or fastenings may govern the success or failure of the next task. It is almost impossible to avoid some damage, and straps showing exceptional wear should be replaced (refer to inspection & repair section) a. What is the net 'in water' weight of the wreckage ? b. What is total lift force required to break suction ? c. What is approximate time to inflate all bags and raise the object provided a 75 cfm compressor is used? Net underwater weight = Weight in air -- Upthrust ================================================= Upthrust = Weight of volume of water displaced by object ======================================================== Volume of object = Weight in air/ Density ========================================= Net underwater weight = Weight in air -- Upthrust Net underwater weight = 10000 -- 1319 = 8680 kgs ================================================================================================== b. Total lift force required to break suction, **F = G + R = (1+k) \*G** Total lift force required to break suction = 12586 kgs = 12.5 tons ================================================================== c. 1 ton salvage bag requires 1m3 of air at surface to inflate fully. Total time required to inflate all bags and achieve uplift of 13 tons is 31 min =============================================================================== - Hydraulic tools, Principle of operation, operation - Types, frictional losses, Start and Stop procedures - Maintenance, Safety precautions, Pneumatic vs Hydraulic tools ![](media/image14.png) a. Impact Wrench b. Drill c. Grinder d. Cut off Disc grinder e. Hydraulic pump f. Hydraulic bolt Tensioner g. Hammer Drill h. Marine growth and general de-scalator 0808\. **Starting Routine**. Generally, the starting procedure comprises of following:- a. Before starting the engine, check the fuel, engine oil and hydraulic fluid level. b. Check to make sure the flow Control levers are in the OFF position (Down). The power unit will not start if the levers are in the "UP" position (ON). c. It is not necessary to choke the engine. The engine is equipped with an electronic fuel management system and does not have a manual choke. d. Set the throttle control lever to the left (5-GPM) setting. Once the unit starts and is warmed-up the lever can be moved to the 8-GPM setting if desired. e. Turn the Ignition Switch to the START position. After the engine starts, release the switch. Allow the engine to warm up. f. Turn on the flow to the tool by lifting the flow control levers up into the "ON" position, lift both levers if running two circuits. 0809\. **Stop Routine**. Generally, the stopping procedure comprises of following:- a. Ensure the flow control levers are in the OFF position (Down). b. Move the Ignition Switch to the OFF position. a. Ensure that the rotational speed of the power tool is no greater than the safe maximum speed stamped on the disk. b. Only fit disks with the correct arbor size and the correct center fitting. The center of the disk will be either flat or dished. c. Use the correct tool for fixing the disk. d. Only fit or remove disks with the main power supply **off.** e. The choice of disk for a specific job should be based on the manufacturer's recommendations. But it should be borne in mind that underwater conditions may affect the efficiency of a disk. a. **Engine**. Standard 27 hp gasoline engine with electric starter is provided for driving the hydraulic fluid system. b. **Hydraulic system**. Tank has a capacity of 5-6 ltrs and Indian equivalent Servo 68 is being used. c. **Battery**. A 12 Volts DC battery is fitted for self-start of the engine. d. **Controls**. Unit provides two circuits of 5 GPM and 8 GPM. When the throttle control lever is in the far left position, it will produce 5 GPM to both circuits. With the lever in the far right position will produce 8 GPM to both circuits. This allows two tools that can run simultaneously at 5 or 8 GPM. The flow control levers, when turned "ON" (up position), turns on flow e. **Hydraulic connections**. The nominal pressure pack can produce 1500 psi/ 103 bars and maximum working pressure is 2000 psi/ 138 bars. Each hose has been provided with male thread ends compatible with quick disconnect coupling. The recommended hose length is 25 ft/ 8 m with a 1/2 inch/12.7 mm inside diameter. The hoses must have a working pressure rating of at least 2500 psi/175 bar. -- -- -- -- -- -- -- -- -- -- -- -- a. Increased power to weight ratio. b. Versatility and lower maintenance, since hydraulic tools run on a closed system, tool life is longer and routine maintenance involves only external cleaning and lubrication. c. Finer control and adjustment in terms of RPM and torque. d. The depth capability of hydraulic tools is just about limitless, whereas most pneumatic tools reach their limit at around 61 m. e. No exhaust bubbles are produced to hinder the diver's vision and are quieter to operate. CHAIN SAW DRILLER ================= ![](media/image19.jpeg) IMPACT WRENCH CUT OFF SAW ========================= CHAPTER IX - OXY-ARC CUTTING ============================ - Underwater cutting, Principle of operation - Main components, Polarity testing, methods of operation - Techniques of Oxy arc cutting, Fault diagnosis, general notes on operation - Maintenance ,Safety precautions, General precautions Introduction ============ Equipment Used in Underwater Cutting ==================================== a. Steel Electrodes: Commonly used for cutting ferrous metals, steel electrodes are designed to withstand high temperatures and provide consistent performance. Depending on the current setting, a steel electrode will last for about 40 to 60 seconds. b. Carbon Graphite Rods: These rods are ideal for cutting non-ferrous metals and materials that require precise cuts with minimal slag. These maintain an arc far easier than steel rods, but are very brittle and break easily. They also require higher amperage, in the order of 400 amps. c. Cutting electrodes come in various sizes and compositions, tailored to specific cutting tasks. Divers should select electrodes based on the material and thickness they intend to cut. Once ignited, they continue to burn as long as oxygen is supplied or until the rod is consumed. d. Power Supply. The power source must be able to provide DC (direct current) producing 80 -- 90V, 300 to 400. ***On no account should an AC (alternating current) generator be considered, or even tried as an experiment, since the diver will experience severe electric shocks which could well prove fatal***. Operating Instructions ====================== a. Assemble O2 supply or manifold, utilizing clean high-volume regulator. Make sure the regulator hose and torch are free from any grease, oil or particles. b. Set O2 pressure to 90 p.s.i over bottom or whichever is required due to depth or operation. Pressure must be increased with increased working depth. (Refer to **Table no. 1-"Setting O2 Delivery pressure for Depth"**) c. Purge regulator hose and torch. Check for leaks with soap suds. d. Tape Oxygen hose to power Cable at 2' intervals e. Connect the safety switch along the negative lead to the torch and within easy reach of the tender. The switch is activated only upon command from the diver. f. Direct current to be supplied. Verify correct polarity: negative to torch, positive to ground or "c" clamp. If there is any question about the efficiency of the cutting, check to see that the leads are properly connected and that the welding machine is delivering the indicated and that the welding machine is delivering the indicated amperage and correct polarity. g. The earth clamp must be well secured to the work task, which should first be wire brushed or scraped 'shiny' clean. The cable should have sufficient slack to ensure that it is not accidentally pulled free, and must be of the same gauge material as the lead to the actual cutting torch. h. To check polarity, immerse the rod and grounding clamp in a bucket of salt water, approximately 2" apart. A stream of bubbles will rise from the tip of the cutting rod when the current is turned on. If they don't, reverse the polarity, i. Establish that cable and connections are in perfect condition. j. Diver is to be dressed with authorized diving dress k. Consult Table no. 2 for "Setting amperages for cable length and size". ====================================================================== l. Attach eye shield to divers faceplate( No. 4 lens for muddy water and No. 6 lens for average conditions) a. Secure ground clamp to work. If any part of work is above water, the ground clamp may be secured there. Diver must face the work as he performs. Serious shock hazard to the diver and electrolytic damage to the divers helmet and equipment can result if his body comes between the rod and the ground. b. Call for "knife switch on" or "make it hot" and commence cutting operations. c. Never turn your back on the ground connection. General Power Supply Notes ========================== a. Ensure the machine frame is well earthed and that neither positive nor negative terminals are allowed to touch the frame and that all connections are clean and secure. b. Where possible ensure the power source is well insulated from any free flowing water, as for example might be found on the deck of a ship c. Keep welding cables as dry as possible and free from oil and grease. d. Where possible hang cables clear of any steel decking, but offer them support since when drawing heavy current, they will commence to sag as the copper conductor's heat up. a. The cutting torch and 'earth' lead must be completely insulated over their entire length, both on the surface and underwater. Current leakage underwater due to cracked or cut insulation will only result in a reduced work potential and is after difficult to trace. b. Sections of cable that are uninsulated and come into contact with any grounded metal fittings will cause arcing, melting the conductor and breaking the circuit. c. Long lengths of cable are both heavy and difficult to handle and when being lowered or raised over the side of a diving craft are subjected to a great deal of strain, particularly at the joints. Any damage to the insulation resulting should be rectified immediately. d. For cutting operations in deep water, loss of current flow due to the increased resistance of the cable can only be overcome by using cable with a larger cross-sectional area. e. All joints must be insulated with proper sleeves, and these can be given some support by taping the length of the welding cable to a length of rope, rather like an umbilical. Technique of Oxy-arc Cutting ============================ a. To start the cut, hold the electrode perpendicular to the surface to be cut, at the same time allowing the tip to touch the work. If manual control is employed the diver then opens the control is employed, the diver then opens the oxygen valve, calls to the surface to 'Make it hot', and withdraws the rod slightly from the contact to start the arcing process. After that it is only a case of maintaining a slow steady arc as the cut progresses. b. To advance the cut once started, drag the electrode along the desired line of cut, keeping the rod either perpendicular or else with a slight leading angle in the direction of the travel. The tip of the electrode should continue to lightly touch the working surface, the diver maintaining pressure inward to compensate for electrode consumption, and forward to advance the cut. With graphite rods, only the minimum amount of contact with the work is necessary. c. Should the cut be incomplete at some stage, due to a fault, or control of the torch, this will generally be indicated by a 'back flare', which will be visible even in the worst of underwater visibility conditions. Should this situation arise, the diver should lift the electrode out of the present area, go back along the cut a few inches and renew the cutting process. d. When the cutting electrode reaches the point at which it has been used to within about 2 in of the holder head, cease cutting, call for the torch to be 'made a. Commence the cut in the same manner as for carbon/graphite rods. b. Advance the cut in the same manner, except that the electrode is maintained in contact with the work without attempting to hold an arc and always perpendicular to the work surface. c. An incomplete cut will be indicated in the same manner as for carbon electrodes and should be treated exactly the same. d. The same safety precaution to avoid unnecessary electrical shocks to the diver should be observed. a. Touch the rod lightly on the steel plate at the desired position of the hole. The oxygen supply is turned 'on' and the current applied to the electrode. b. The diver holds the electrode stationary, withdrawing it momentarily if necessary to permit melting of the steel rod back inside its covering. c. Ease the electrode slowly inwards into the hole until the plate has been pierced. Steel up to 75 mm thick can be pierced by this method without any real difficulty. ![](media/image24.jpeg) O2 Supply Problems ================== a. Wrong torch volume or O2 to rod tip too low. Cutting torch designated for 5/16" rods. (Old arc air, crafts weld). b. Regulator incapable of delivering over 70 c.f.m. c. Dirt or obstruction in the torch, such as damaged flash arrestor, clogged or burnt monel screen, damaged O2 flow valve. d. Use of ¼" or 5/16" O2 hose clogging or obstructions of 3/8" hoses. a. Shut off power to the torch. b. Remove the rod from the torch and through the cutting rod to check passage. c. Check supply pressure at regulator for depletion of o2 supply. Check delivery pressure, normally 90 p.s.i at the tip while o2 is flowing. d. Remove o2 line from torch handle and flow o2 through the hose. If the flow rate is weak, the problem may be either in the hose or regulator. Check each independently, and clean and or replace. If the flow rate is strong at the end of the hose, then: e. Check torch cullet washer to establish that it is in place , that it is the proper one for the rod used , and that it is not obstructing the cullet. ( Note : Washer s for non Broco 5/16" or smaller diameter cutting rods will obstruct flow significantly.) f. Remove flash arrestor and screen from torch and inspect and replace as necessary. Blow O2 through the torch and valve to ensure clear passage. This should complete the checkout of o2 supply. Recheck symptoms to establish that problem has been solved. Current Supply Problems ======================= Inadequate Current Supply ========================= Safety Precautions ================== a. The welding power source must be grounded to the parent vessel on which it is mounted. b. No part of the electrode holder or submerged lengths of power cable, including joints, should be left uninsulated. c. A spring-loaded, quick action knife switch should be incorporated into the circuit, connected such that its operation will 'make' or 'break' the current to the electrode holder held by the diver. d. The position of the diver in relation to the 'grounded' work clamp should be such that at no time does he or his equipment become part of a secondary circuit. e. If cutting inside a compartment or a similar confined space, adequate provision must be made to ensure ventilation, to prevent hydrogen gas released by the cutting action from accumulating in a pocket. g. The diver should never hold a cutting torch in such a manner that the rod or electrode is pointing at either himself or another diver. h. Divers should always wear a pair of gloves made of an insulating material. j. No attempt should be made to remove or change the used stub of a cutting electrode until confirmation has been received from the surface that the supply current is 'OFF'. k. Protective clothing should be worn as recommended for both surface and underwater operation of thermic lance and thermal arc equipment. l. Welding visor, with at least a No.10 protective lens fitted is to be worn. m. Broco rods, as with other thermal arc type equipment, can only be extinguished by cutting off the supply of oxygen. It is therefore recommended that rods should not be allowed to burn down to less than 75-90mm length, to protect the holder, and avoid a 'blow-back' situation. a. Keep oxygen cylinders and fittings away from oil or grease. Oil or grease may ignite violently in the presence of oxygen under pressure. Oily or greasy substances must be kept away from cylinder, cylinder valves, couplings, regulators, hose and apparatus. Do not handle oxygen cylinders or apparatus with oily hands or gloves. Oxygen cylinders must never be handled on the same platform with oil or placed where oil or grease can fall on them. A jet of oxygen must never be allowed to strike an oily surface, greasy clothes, or enter a fuel oil or storage tank that has contained a flammable substance. b. Always refer to oxygen by its proper name, "oxygen," and not, for example, by the word "air." c. A serious accident may easily result if oxygen is used as a substitute for compressed air. Never use oxygen except for its specified use in the cutting torch. d. Do not store oxygen cylinders near highly combustible material. e. Oxygen cylinders should be protected against excessive temperature rises. f. Never discharge oxygen from a cylinder without first attaching an approved oxygen regulator to the cylinder valve or a manifold with regulator attached. g. Never tamper with nor attempt to repair oxygen cylinder valves h. When the oxygen cylinder is in use, the valve should be opened at least one full turn, preferably all the way, to prevent leakage around the valve stem. a. Less skill is required on the part of the diver, to achieve the same results. b. Although more oxygen will be consumed, this will not cost as much as the hydrogen content of gas cutting used in oxy hydrogen cutting. c. Greater thickness can be cut for the same effort. d. Oxy-arc does not require the same degree of surface cleanliness as does gas cutting. a. Considerable bank of oxygen cylinders will be necessary for prolonged tasks, or even the provision of a bulk oxygen supply. b. The high amperage necessary, which must be 'direct current' and not 'alternating current' which can generally only be produced by a diesel driven generator, hence the power source is bulky and heavy. c. The quality of the cut obtained is such that grinding may be necessary, if the remaining surface is to be flat. In gas cutting, by comparison a very clean surface would be obtained. d. Limitations with regard to the thickness of steel that can be cut, and that other metals may cause some difficulties. e. Will not cut concrete, rock or protective coatings because circuit will not be made complete. f. Requirement for the frequent replacement of the cutting electrode. g. Electrical hazards generally. -- -- ------------------- -- [PSI] 108 112 117 123 128 134 139 145 150 -- -- ------------------- -- 155 -- -- ----- -- 161 166 172 177 183 188 194 199 204 210 215 221 226 232 237 243 248 254 259 264 270 275 -- -- -- -- -- -- -- -- -- -- CHAPTER X - UNDERWATER WELDING ============================== - Underwater Welding, Types, Principle of operation - Welding terminology, Types of joints, Weld methods, Definitions - Welding techniques, Types, Welding defects, Terminology - Maintenance ,Safety precautions, Patching Introduction ============ Principle of Welding (FIG 10.1) =============================== Welding Terminology and Equipment Required ========================================== ![](media/image26.png) a. Stabilizes the arc, and allows an AC (alternating current) to be used. b. Causes impurities present on the surface of the work area to be 'fluxed' away. c. Forms a slag coating over the weld. This in turn protects the molten metal from contamination whilst it is cooling, and reduces the rate at which this cooling a. Wire brush b. Scaling hammer c. Ball pein hammer d. Cold chisel WELDING PROCESS =============== a. Flux shielded arc technique. b. Inert gas shielded technique. c. Friction welding. a. **Manual Metal Arc (MMA)**. This is the common "stick" welding. The rod will carry an electric current which when in close proximity of an earthed work piece will cause an arc to form. This melts the present plate and the filler rod to form the weld Electronics attraction of the charged molten drops to the earthed work piece means the weld can be done positionally. The flux which is carried around the rod is vaporized to form the shield. The rod is consumed as the filler material for the weld. b. **Automatic Metal Arc.** This method is similar to the above. The difference being that the filler rod does not carry the electricity. This is picked up by spirally wound wires on the outside of the flux coating. The rod is fed automatically to the work piece. Apart from these differences the process is the same as above. c. **Submerged Arc.** With this method electricity is again carried by the filler rod but the powdered flux is poured down a tube so that the weld groove is filled. The arc is produced inside or submerged in the flux. a. **Metal Inert Gas (MIG).** This method has the filler wire contained on a spool being fed through a copper gas nozzle to the work piece. The arc is formed between the filler wire which is carrying the electricity and the workpiece. The inert gas is fed continuously through the nozzle when the trigger is depressed. This method can deposit copper to the weld if the nozzle is dipped into the weld pool. b. **Tungsten Inert Gas (TIG)**. This method is much the same as above carried by the tungsten electricity inside a certain holder. The weld pool is shielded by the inert gas being fed through the nozzle. This method can deposit Tungsten into the weld if the electricity is dipped into the weld pool. WELDING DEFINITIONS =================== a. Parent plate - The metal plates which are to be joined by the weld. b. Filler rod -- Filler metal in form of a rod. c. Run or pass -- Weld metal deposited in a single run. d. Weld zone -- The area containing the weld and both heat affected zones. e. Heat affected zone -- The part of the parent plate which has been affected by heat which has not melted. f. Cap, Face of the weld -- This is the exposed surface of a weld, usually single, multi sided or weaved. g. Excess weld metal, reinforcement -- Weld metal lying outside the plane joining the weld toes or in excess of the specified weld size. h. Toe of the weld - The junction between the face of the weld and the parent and the parent metal. j. Root - The point at which the back of the weld in the parent metal. k. Root beam run - Weld producing beyond the plane of the back wall of the parents plates l. Root gap -- Separation between the parent plates to be joined. m. Root face -- The un-beveled portion of the parent plate adjacent to the root gap. n. Throat thickness -- The total thickness of the weld metal. p. Effective throat thickness (design throat thickness) -- Weld thickness for design purpose, usually a line between both toes or may be slightly raised. q. Weld width -- Shortest distance between the outer toes of the world r. Leg of a filled weld -- The distance between the outer toes of the weld. s. Residual welding -- stress remaining in the metal structure as a result of the welding t. Prepared face -- The beveled portion of the parent plate prior to welding. u. Single V Butt -- A butt weld in which the prepared faces will form a V in sections, welded from one side only. v. Double V butt weld -- A butt weld in which the prepared faces will form two opposing V, in section, Welded from both sides. w. Prepared angle weld prep -- The angle between the prepared face and the perpendicular line. x. Included angle of butt weld -- The angle between the prepared faces. y. Included angle of filled weld -- The angle between the parent plates. Types of Welding Joints ======================= a. **Butt joint.** Two parent plates fitted together at an angle of between 135 degree and 180 degree. These are used for circumferential and seam welds (Fig 10.3(b)). b. **"T" joint.** The two parent plates are fitted together at an angle of between 5 deg to 90 deg. This means the end of one piece and the face of the piece will come into contact, such as the joint between two tubular members as in a node (Fig 10.3(c)). c. **Lap joint.** The two parent plates are fitted on top of the other at angle of angle be 0 deg to 5 deg (Fig 10.3(c)). d. **Corner Joint.** The two parent plates make a connection at the edges to make a joint at an angle of between 30 deg to 135 deg (Fig 10.3(d)). e. **Cruciform joint.** A joint at which two plates or two bars welded to another flap plates at right angle and on the same axis (Fig 10.3(e)). Types of Weld ============= a. Butt joint b. "T" joint c. Lap joint d. Corner joint e. Cruciform joint PARENT PLATE 1 Defects in Welds ================ 1025\. There are basically six categories of welding defects, and these are as follows: a. **Cracks**: A linear discontinuity produced by fracture, cracks may be longitudinal, transverse edge carter, centerline, fusion zone, weld metal or parent metal. b. **Cavities**: There are a number of discontinues which fall in to this category: i. **Blowholes**. A cavity generally over 1.5 mm in diameter formed by entrapped gas during the solidification of molten metal. ii. **Porosity**. A group of gas pores can be located in a variety of locations. iii. **Elongated cavities**. A string of gas pores situated parallel to the weld axis. iv. **Shrinking cavity**. A cavity formed due to the shrinkage of the weld metal, whilst in the plastic condition. v. **Wormhole**. An elongated or tubular cavity formed by entrapped gas during the solidification of molten metal. vi. **Crater pipe**. A hole formed in the center of a crater due to incorrect welding techniques. c. **Solid Inclusions**. This can be due to slag or other foreign material entrapped during welding. The defect is more irregular in shape than a gas pore. The various forms are as follows:- vii. **Oxide inclusion**. Metallic oxide entrapped during welding. viii. **Tungsten Inclusion**. An inclusion of tungsten formed from the electrode during TIG welding. ix. **Copper Inclusion**. An inclusion of copper formed due to the accidental melting of the contact tube or nozzle in self adjusting or controlled arc welding or to pick up by contact between the copper nozzle and the molten pool during TIG welding. x. **Puckering**. The formation of an oxide covered weld run or bead with irregular surfaces and with deeply entertained oxide films, which can occur when materials forming refractory oxides are being welded. d. **Lack Of Fusion And Penetration**. Various forms are as follows:- xi. **Lack of fusion**. Lack of union in a weld can be either between weld metal and weld metal or between parent metal and weld metal. xii. **Lack of sidewall fusion**. Lack of union between weld metal, parent metal and metal formed at any side of the weld. xiii. **Lack of root fusion**. Lack of union formed at the root of a joint. xiv. **Lack of inter run fusion**. Lack of union between the adjacent runs of weld metal in a multiunit joint. xv. **Incomplete penetration**. It is the failure of weld metal, to extend into the root of a joint. e. **Imperfect shape**. Various forms are as follows:- xvi. **Excess weld metal**. Weld metal lying outside the plane joining the toes. xvii. **Excess penetration**. Excess weld metal protruding through the root of a fusion weld made from one side only. xviii. **Root concavity**. It is a shallow groove which may occur in the root of butt weld. xix. **Incompletely filled groove**. A continuous intermittent channel in the surface of a weld, running along its entire length, due to insufficient weld metal. The channel may be along the center or along one or both edges of the weld. xx. **Undercut**. An irregular groove formed at the toe of a run in the parent metal or in previously weld metal, due to welding. xxi. **Overlap**. An imperfection at the toe or root of a weld caused by excess weld metal flowing on to the surface of the parent plate without fusing it. xxii. **Burn Through**. A localized collapse of the molten pool formed due to excessive penetration resulting in a hole in the weld run. xxiii. **Unequal leg length**. Non--standard term, meaning the variation of leg length on fillet weld. xxiv. **Poor restart.** Non-standard term, meaning a local surface formed irregularly at weld. xxv. **Misalignment**. Non-standard term, meaning a local misalignment between the two welded pieces such that their surface planes are not parallel (or arc at an angle). f. Miscellaneous ============= xxvi. **Stray flash**. The damage formed on the parent material resulting from the accidentally striking of an arc away from the weld. xxvii. **Excessive dressing**. This is reduction in metal thickness which is caused by the removal of the surface of a weld and adjacent areas, to below the surface of the parent metal. xxviii. **Grinding Mark.** These are grooves in the surface of the parent metal or of weld, made by a grinding wheel or a surface tool. xxix. **Tool mark**. Identification in the surface of parent metal or weld, made from the application of a tool e.g., a chipping tool, during preparation. xxx. **Hammer mark**. This is identification in the surface of parent metal or of weld, due to a hammer blow. xxxi. **Torn surface**. A surface formed irregularly due to breaking off of temporary attachments. xxxii. **Surface pitting**. An imperfection in the surface of the parent metal formed usually in the form of small depression. xxxiii. **Spatter**. Globules of metal expelled during welding on to the surface of parent metal or of weld. Patching ======== a. Only use an underwater welding torch of approved design. ![](media/image29.png) b. The diver should use a welding visor to protect his eyes. c. Never use damaged electrodes. d. Keep the electrodes dry until use. a. **Before use routines**. Check the following:- i. Electrical connections are tight ii. Welding Electrode is firmly secured to its holder. iii. Amperage and voltage are as per setting. b. **After use routines**. Wash all parts in freshwater, dry and examine for damage or defect. The torch should be dry completely prior to stowage in order to avoid onset of or prevent corrosion. CHAPTER XI -- MISCELLANEOUS EQUIPMENT ===================================== - Underwater remotely operated vehicle - Magnetometer - Pinger locator - Contaminated water diving system UNDERWATER REMOTELY OPERATED VEHICLE ==================================== Classifications of ROV. ======================= a. **Class I -- Pure Observation ROVs.** Pure observation vehicles are limited to video observation and any sensors fitted are to aid navigation of the vehicle. Generally they are small vehicles fitted with a video camera, lights and thrusters although they may be able to carry one additional sensor (such as a cathodic protection (CP) probe). b. **Class II -- Observation ROVs with Payload Option.** These vehicles are fitted with two (2) or more cameras and sonar as standard. Two (2) or more of the cameras will be 'simultaneously viewable'. These ROVs can handle several additional sensors. They may also have a basic manipulative capability. They should be able to operate without loss of original function while carrying two (2) additional sensors. These vehicles, sometimes referred to today as 'intermediate' class ROV Systems c. **Class III -- Work Class Vehicle.** A Class III vehicle will be specifically designed from the outset to be able to carry additional sensors, and tooling, over and above its standard suite of navigation and camera sensors. All Class III vehicles should have a minimum of two (2) full size manipulators permanently d. **Class IV -- Towed and Bottom-Crawling Vehicle.** Towed vehicles are pulled through the water by a surface craft or winch. Although they do not have propulsive power, they may be capable of limited maneuverability. Bottom- crawling vehicles use a wheel or track system to move across the seafloor, although some may be able to 'swim' limited distances. e. **Class V -- Prototype or Development Vehicles.** This class includes those still being developed and those regarded as prototypes, i.e. one-off versions. Mission Specialist Series Defender, VideoRay. ============================================= MAGNETOMETER ============ PINGER LOCATOR ============== a. **Aircraft Recovery.** Acoustic pingers, also known as Underwater Locator Beacons (ULBs), are critical devices used in aviation to assist in locating aircraft that have ditched or crashed into water. Acoustic pingers are designed to activate automatically and emit acoustic signals at 37.5 kHz when they come into contact with water. Pinger locators can be used to find the location of ditched aircraft. b. **Marking of underwater objects.** Pingers can be placed at desired locations underwater for marking. Diver may use a pinger locator to swim towards the pinger by listening to the pings. ![](media/image32.jpeg) CONTAMINATED WATER DIVING SYSTEM ================================ Dirty Harry System ================== a. **Helmet with reclaim system.** A Superlite 17C helmet can be generally used for this purpose. The helmet neck ring is bonded to the dirty harry suit to prevent potential water ingress at the neck seal. b. **Diving panel.** It acts as an SDDE panel supplying breathing air to the diver. c. **Exhaust control panel.** This provides suction to the exhaust valve of the helmet. At depths where hydrostatic pressure is insufficient to vent the helmet unaided to the surface, the vacuum assist is utilized. d. **Dirty Harry Dry suit.** Dry suits are available in various materials. Usually it is made of polyurethane. The suit consists of dry gloves with locking rings. CHAPTER XII - COX SUBMERGED BOLT DRIVING AND PUNCHING GUN ========================================================= - COX submerged bolt driving and punching gun, main components, - Action of gun, Preparation and use of gun, Ammunition, Loading - Safety precautions, misfire drill, Applications, Maintenance COX SUBMERGED BOLT DRIVING AND PUNCHING GUN =========================================== a. **No. 1 Gun.** Weight is 6.35 kg, fires 12.7 mm bolts into a steel plate up to 16 mm thickness and punches a 5/8 inch diameter hole into a plate of ½ inch thickness. b. **No. 2 Gun.** Weight is 16.3 kg. It fires a 5/8 inch bolt into steel plate up to 1 inch thickness or punches a 17.4 mm diameter hole in plate up to one inch thickness. This is the one of the most commonly used in service. Main components =============== a. The Gun b. Barrel Holder c. Barrels d. Bolt or Punch Nose e. Arrester Blocks and Seal Washers f. Stabiliser g. Associated Equipment h. Extension Bolts j. Wooden Ferrules k. 'T' Adaptor l. Wooden Register a. 180 mm in length for firing solid screw bolts and for punching b. 305 mm in lengths for air bolts c. 380 mm in length for securing timber to metal plate a. **'C' (Contact).** The block marked 'C' is always used when the nose of the gun is in actual contact with the plate being period. b. **Patch( 13 mm, 19 mm,25 mm).** The 'Patch' blocks are used when firing the ammunition into a plate through a clearance hole in a previously drilled or punched patch, i.e. when the nose for the gun is separated from the plate to be pierced by the total thickness of the patch. Summary of Gun Assemblies ========================= a. Bolt nose and 'C' (Contact) arrestor block and two fiber sealing washers, when piercing a single plate with solid screw bolt ammunition of the correct number for thickness of plate being pierced. b. Bolt nose, two seal washer and an arrestor block of the correct size according to the total thickness of the patch (including any lining or filling), when securing a previously punched or drilled patch to plating. Gun loaded with screw bolt ammunition of the correct number for the thickness of plate being pierced and nose fitted with wooden register. c. Punch nose and one seal washer, which punch a hole in plate of thickness between 8 and 19 mm. Gun loaded with punch ammunition of the correct number for the thickness of plate being punched. Action of gun ============= Preparation and Use of the Gun ============================== Precautions in Handling ======================= a. Only persons trained, or being trained, in its use should be allowed to handle the gun. Persons being trained should be allowed to handle it only in the presence of a qualified instructor. b. A gun is always to be treated as being loaded unless the barrel has been sighted to be empty of ammunition. c. A loaded gun is to be carried close to the side of the body, under the right arm with the firing catch out of reach of the right hand. d. A gun must never be pointed at any part of one's own, or any other person's body. e. Never place your hand over the muzzle when inserting ammunition into the barrel, or when inserting a barrel into a holder. f. A loaded gun is never to be lowered to a diver.A loaded barrel may be lowered for the diver to insert in the holder. g. The firing catch must never be depressed until actually about to fire, and no attempt must be made to use the loaded gun with either the firing or retaining catch removed. h. When punching, it must be remembered that both the punch and the waste metal pass right through the plate and may retain sufficient velocity to injure a person on the other side, either directly or by a ricochet. Ammunition for Thickness of Plate ================================= a. Never knowingly use ammunition too strong for the plate to be pierced. b. The first shot with Bolting Air Bolting ammunition is always to be of an index number one less than that given in the table for the plate to be pierced. If this number gives satisfactory penetration, it must continue to be used. If the penetration is insufficient, the next highest number should be used and so on until the correct ammunition is found. c. Plates less than 8mm in thickness must not be dealt with by COX gun. -- -- -- -- -- -- -- -- -- -- -- -- -- -- Loading ======= a. Insert the bolt nose in the vice, engage the slots in the end of the nose over the stops in the bottom of the vice and secure with the hand nut. b. Insert one seal washer in the bottom of the nose, and then insert the correct size arrestor for the work in hand on top of the fibre washer, with the end marked. 'Top' uppermost. c. Insert a second seal washer on top of the arrestor block, then screw in the appropriate barrel and securely tighten with a 50 mm spanner. d. Insert the correct number screw bolt ammunition, then screw home the breech nut and tighten with the cross-key spanner to make a tight joint. a. Insert the 12.7 mm tommy bar through the holes in the vice. Insert the punch nose, engage the slots in the nose over the tommy bar and secure with the locking ring. b. Fit one seal washer in the nose, then screw in the 180 mm barrel and securely tighten with a 50 mm spanner. c. Insert the correct number round of punch ammunition in the breech, fit the breech nut and tighten with the cross-key spanner. a. 305 mm Barrel and air bolt nose. b. 'C' arrestor block. Firing and Misfires =================== a. Operator not operating the gun with enough vigor. b. Awkward position or insecure foothold of the operator. c. Friction of barrel in holder due to sand etc., or burrs on the moving parts. a. After the bolt has been fired and having removed the gun completely from the fired bolt, depress the firing catch to allow the barrel to move forward in the holder until it reaches the retaining catch and remove the barrel from the holder. b. Place the nose in the socket vice, as for loading, and unscrew the breech Nut. If attached, remove the copper detonating seal from the firing pin. c. Unscrew the barrel from the nose. Insert the drift in the front end of the barrel and knock out the firing block. d. Using the drift if necessary, remove the arrestor block, also the remains of the fiber block. e. Place the anvil on the vice, and using the drift and hammer, remove the piston from the arrestor block or punch nose. f. Carry out the 'After Use' routine. Applications of Gun =================== MAINTENANCE =========== a. Remove the firing and retaining catches, wipe them clean and examine for damage. Oil the catches and replace. b. Pour some oil into the gun holder and allow it to flush out through the holes in the rear. Insert an UNLOADED barrel and work it backwards and forwards in the holder to distribute the oil over the wall of the holder. It is not necessary to remove the buffer and spring for this purpose. c. Wipe dry all parts of the barrels and noses which have been used and examine for damage. Oil all parts and stow. d. Clean the barrel bore with the cleaning rod and apply a coat of oil. a. Unscrew the securing nuts and remove the bolt of the rubber hand grip. b. Remove the buffer nut and spring washer. c. Support the mouth of the holder on a wood block and drive out the buffer from the handle end with a 28 mm drift, recessed with a 22 mm hole to prevent damage to the thread. d. When replacing the buffer, ensure the spring is properly secured in the buffer, then slide the unit down the barrel. e. Stand the holder handle down on a wood block and, using a hammer and drift, drive plunger hove into the end of the holder and secure with the spring washer and nut. The drift must either be hollow or recessed to a depth sufficient to clear the striker point. 1. mm hole must be drilled through the pin after it has been fitted and checked for protrusion. ![](media/image36.jpeg) ![](media/image40.jpeg) CHAPTER XIII -BLANKS AND COFFERDAMS =================================== - Blanking - Installation of banks - Cofferdam - Installation of cofferdam Introduction ============ a. Refloating sunken and capsized ships b. To assist in carrying out internal repairs of parts of ship conn ected to open sea via suction/ discharge opening of machineries by creating a water tight envelope when the internal work is in progress. a. Sealing off openings or damage and leakage with **blanks**. b. Extending the height of either the hull or deck openings with **cofferdams**. BLANKING ======== a. Wooden plugs and wedges b. Small wooden blanks and concrete boxes c. steel plate/ aluminum blanks d. Combinations of the above, caulked and additionally sealed with epoxy resin or glass-reinforced plastics (GRP) Installation of Blanks ====================== ![](media/image45.jpeg) COFFERDAMMING ============= a. Repairs of hull plate b. Replacement of hull mounted fittings i.e. logs, sounders, gate valves, etc. c. Replacement of stern seals d. Repair and replacement of tunnel thrusters e. Replacement of rudders and stabilisers f. Repairs to concrete structures i.e. docks, jetties etc 1313. Cofferdams fall into three main categories: a. Fully enclosed 'top hat' type cofferdams used for a variety of repairs where an area needs to be sealed off from the sea or water environment b. Man entry cofferdams used where engineers or technicians need to have dry access to equipment that cannot be repaired in the wet c. Open bottom or hyperbaric cofferdams used where a dry space is required to carry out a repair below water, but that can be carried out by a trained diver. a. **Materials**. The cofferdam is typically constructed from steel or aluminium for strength and durability. Steel is preferred for its sturdiness, but aluminium offers a lightweight alternative. Rubber or neoprene gaskets are used along the edges to create a watertight seal against the hull. b. **Shape and Size**. The cofferdam is generally rectangular or square in shape, with dimensions that cover the specific area of the hull that requires repair. The sides of the cofferdam are made of rigid plates, typically around 1/4 inch to 1/2 inch thick, reinforced with ribs or stiffeners to withstand water pressure. c. **Flanges and Sealing Surfaces**. The edges of the cofferdam have flanges that extend outward, allowing for bolting or welding onto the hull. These flanges are lined with rubber or neoprene gaskets that compress when the cofferdam is attached, ensuring a watertight seal. The bottom edge of the cofferdam is often contoured or beveled to match the curvature of the hull, ensuring a snug fit. d. **Reinforcements**. Internal reinforcements, such as cross-bracing or stiffeners, are added to the cofferdam to ensure it can withstand the external water pressure once it is dewatered. The structure must be strong enough to resist buckling or deformation when exposed to the pressure differential. Installation ============ a. **Inspection and Cleaning**. The area where the cofferdam will be attached must be thoroughly inspected and cleaned. Any rust, marine growth, or debris should be removed to ensure a smooth surface for the cofferdam to seal against. b. **Measuring and Fitting**. Accurate measurements are taken to match the cofferdam's shape with the contours of the ship's hull. This ensures a tight fit and minimizes gaps that could lead to leaks. a. **Gasket Placement**. A rubber or neoprene gasket is applied around the edge of the cofferdam. This gasket is essential for creating a watertight seal between the cofferdam and the hull. It should be thick enough to compress and fill any minor irregularities on the hull's surface. b. **Sealant Application**. For additional security, a marine-grade sealant or adhesive can be applied to the gasket before attachment. This helps ensure a stronger bond and further prevents water ingress. a. **Bolting:** Small cofferdams are typically attached using bolts that pass through pre-drilled holes in the cofferdam and the ship's hull. The bolts are usually made of corrosion-resistant materials like stainless steel or brass. b. **Welding (for Metal Cofferdams):** In cases where bolting isn\'t feasible, small metal cofferdams can be tack welded to the hull. This method provides a strong and permanent attachment but requires skilled welders. c. **Clamping (Temporary Solution):** For temporary or emergency situations, clamps or shores can be used to press the cofferdam against the hull. However, this method is less reliable for long-term use and is typically used only when quick attachment is needed. Welded screw dogs may be used to fix the cofferdam on to the hull. a. Submersible Pumps b. Educators c. Compressed Air Dewatering 1320. **Testing and Adjustments**. a. **Leak Testing:** Once the cofferdam is attached, a leak test is conducted. Water is slowly pumped out from inside the cofferdam, and the seal is checked for leaks. b. **Adjustment:** If any leaks are detected, the bolts are re-tightened, or additional sealant is applied to ensure a proper seal. CHAPTER XIV - SALVAGE TRAINING AIDS =================================== - Work station, Salvage pontoon - Salvage mud boxes, Flanges a. Ship model with underwater fittings b. Submersible Salvage Pontoon c. Salvage Mud Box (Large) d. Salvage Mud box (Small) e. Damage control (DC) Box f. Various types of Flanges with nuts and bolts. ![](media/image49.jpeg) a. **Large**. The overall dimensions 4 ft x 4 ft x 4 ft with cuts/ opening for patching of comparable sizes. b. **Small**. Overall dimensions can be around 1.5 ft x 1.5 ft x 1.5 ft for use in any small diving tank/ pool. ![](media/image52.jpeg) CHAPTER XV - DIVING ON WRECKS ============================= - Types of wrecks, Regulations, protection of wrecks - Wreck diving, Types of wreck, Hazards - Special equipment Introduction ============ a. It is an artificial reef, which creates a habitat for many types of marine life. b. It often is a large structure with many interesting parts and machinery, which is not normally closely observable on working, floating vessels. c. It often has an exciting or tragic history. d. Presents new skill challenges for divers. e. It is part of the underwater cultural heritage and may be an important archaeological resource. f. It provides a first-hand insight into context for the loss, such as causal connections, geographical associations, trade patterns and many other areas, providing a microcosm of our maritime heritage and maritime history a. [Protection of Wrecks Act]: Certain designated, charted, historic or dangerous sites may not be dived without a license b. [Protection of Military Remains Act]: All military aircraft and ships are considered war graves that can only be dived with authorization/license. Other non-designated ships may be dived providing the divers do not enter, disturb or remove artifacts c. [Merchant Shipping Act]: All wrecks and cargoes are owned: each artifact removed must be reported to the Receiver of Wreck. a. **Non-penetration diving.** It normally consists of swimming over the wreck. Non-penetration wreck diving is barely more hazardous than conventional scuba diving. b. **Limited penetration diving.** This comprises diving within the \"light zone". Penetration within the light zone presents greater hazards due to overhead and greater proximity of the wreck\'s structure, but because of the proximity of visibility of an exit point, those hazards are more manageable. c. **Full penetration diving.** This form of wreck diving is beyond the \"light zone\". Full penetration diving obviously introduces a number of further risks, including the risk of getting lost and the inability to escape unassisted in the event of a disruption to air supply. a. **Ships and Boats**. Most wrecks are boats and ships. Historically, most ships were sunk accidentally but it is now quite common for many of the world\'s navies to deliberately scuttle decommissioned vessels for the use of recreational divers. There are many different types of ships that can be explored, from four hundred year old pirate ships to modern Navy warships and cruise liners. Most shipwrecks also serve as spectacular artificial reefs, attracting an incredible diversity of marine life. b. **Submarines**. These tend to have more of a mysterious aura surrounding them and this may be because they are less frequently found by divers. Submarines are usually not as easily accessible due to tight, confined spaces and the tendency for submarines to sit in very deep water. c. **Airplanes**. It is also fairly common to be able to dive the wrecks of airplanes, particularly fighter jets from World War II. There are many airplane wrecks found even in the Indian ocean region. d. **Vehicles**. These are less common as underwater wrecks, but can often be found in lakes, rivers, and dams. a. **Sharp Objects.** Rusted metal, splintering wood ,broken glass coral reef and other objects can pose a severe threat.The intentionally sunk wrecks tend to have fewer of these, however over time a rusty edge can become knife sharp. Use of good buoyancy control is recommended to minimize contact with the wreck and always wear protective gloves when wreck diving. b. **Entanglement.** The wrecks often have old ropes and other lines on them. Because wrecks attract fish, they're popular fishing grounds and sometimes fishing nets end up entangled on the wreck. Avoid these by watching where you go. Look up as well as around to avoid swimming into or under a potential entanglement. When wreck diving, carry a sharp knife with a smooth and serrated edge in case you encounter entanglement too difficult to handle by hand. c. **Aquatic life.** A wreck quickly becomes an artificial reef, so expect to find any aquatic life that can bite or sting on local natural reefs on a wreck. Avoid these at the same time as you would on a natural reef. Watch where you put your hands, feet and knees, always wear an appropriate diving suit with gloves and avoid contact with unfamiliar creatures. d. **Unstable structure.** As a wreck ages and deteriorates, portions weaken, support gives way and walls shift. In some wrecks, this presents a hazard from collapsing walls and falling objects. Avoid diving around wrecks with unstable structures. If you encounter a portion of a wreck that seems NOT TO BE firm and could possibly fall, get clear of the area. Don't swim under anything that could fall on you. e. **Surge pockets and suction.** Surge and water movement through a wreck can cause periodic suction or fast currents through restricted areas and hatches. If you find a surge present, be cautious for this kind of water movement a. **Wet and Dry suit.** It doesn\'t matter what area or type of wreck you\'re diving, some sort of thermal protection will surely need to be worn. Water conducts heat away from our bodies 25 times faster than air. Depending on the temperature and depth of the water, diving suits will vary drastically in design, thickness and thermal protection. b. **Mask.** Any mask that fits properly is perfectly suitable for wreck diving. Since many wrecks are accessible only by boat, divers will find they have to make a variety of different entries to get into the water. For this reason it is advisable to wear the mask strap inside your wet or dry suit hood. In case a wave or dive entry rips the mask off, usually the mask will not have been lost but still held on slightly by the hood. c. **Fins.** A diver\'s fins are a very basic piece of equipment and nothing has to be modified for them to be suitable for wreck diving. d. **Regulators.** Although there is no one brand of regulator that is recommended for wreck diving, divers who are planning to dive on wrecks should make sure that their regulator hoses are streamlined. Route all hoses as close to your body as possible. Depending on the regulator model, this can be easy or may require the use of wire ties or Velcro straps. The idea is to reduce the chance of a snag. e. **Divers knife.**It is essential for all wreck divers to wear at least one diver knife, and it is also highly recommended to have a backup knife.

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