Underwater closure of ship hull

In order to salvage the wrecked ship or salvage the damaged and leaky ship, sometimes it is necessary to seal the cabin, fill the hole, plug the leak and so on. Ship block is widely used in marine accidents. In most cases, hull blockage requires divers to complete. There are many kinds of plugging devices and methods, which need to be determined according to the damage location and severity of the ship, plugging requirements and local objective conditions at that time. For example, when a floating ship suddenly breaks down and leaks due to marine accidents or wars, it must fight against time and retrograde to stop the leak and rescue it. If the leak is stopped or the leak has been controlled, it must be further disposed of. As for ships that have sunk, if they are salvaged by sealed tank pumping, underwater bottom sealing should also be carried out.

I. Underwater Blockage of Floating Vessels

Because of collision, grounding, reef striking or force majeure, some of the ship hulls are damaged. If the damaged part is below the waterline, the ship will be inclined by a large amount of water intake, or even lose buoyancy and sink. The principle of rescue is to stop leakage quickly, control water inflow and remove water as far as possible, so as to prevent damage from expanding and worsening the situation. The ultimate goal of rescue is to maintain the ship's ability to continue sailing, and strive for time to reach a safe place or continue to perform tasks.

(1) Major underwater sealing equipment for floating ships: leakproof plates, leakproof pads, hook bolts, leakproof boxes, bow fixture supports, waterproof mats, wooden wedges, corks, cotton wool and rubber pads of various specifications.

Some of the plugging devices are ready-made products, some can be prefabricated, and some must be made temporarily according to the situation at that time. Therefore, it is necessary to equip a sufficient number of special tools, such as saws, axes, planers, chisels, pliers, heads and wrenches. Keep it in a special toolbox for emergency use.

(2) Closing loopholes

1. The nature of the vulnerability and the size of the ship vulnerability. It is difficult to plug any part of the leak that has large area, serious damage and is difficult for divers to reach. The vessel leaks floating on the water surface can also be divided into underwater, near the water line and underwater according to their location.

2. Ways to find loopholes: After a ship floating on the water surface leaks, the water leakage situation can be judged according to the following phenomena: if the hull tilts to the left, right, front and back, indicating that a large amount of water has entered, the loopholes are in the inclined side; if the bottom water of that cabin increases, the loopholes will be in that cabin; the speed of the increase of the bottom water can be used to judge the size of the loopholes; if there is a sound in the cabin, the sound can be used to judge the size of the loopholes. The size and direction of the leak are determined by the size and location of the leak. Divers explore the hull outboard with bamboo slices, poles, mops or other tools. If you can hook the edge of the leak or feel suction, the exact location of the leak can be judged; divers exploring the leak must use tools, remember to explore directly with their hands or feet. Otherwise, the diver himself will be sucked into the cabin by the current outside the hull and unable to escape if there is a big leak.

3. Leakage plugging methods: small leaks and gaps can be plugged by wood wedges and corks; holes similar to portholes but relatively flat can be plugged by leak plugging board; holes are small and relatively flat, but when using leak plugging board is difficult, leak plugging pads can be used; when plugging cracks or small leaks, bow-shaped fixtures can be used with cotton floss, blankets, wood and other materials; small holes with high inner edges can be plugged by prefabricated methods. Leakage box plugging; Leakage is not too big, but the situation is critical, can use waterproof mat to plug leakage, and should be further plugged in the cabin; in order to prevent the spread of leakage, should be possible to leak to other cabins of all channels, such as hatches, doors and windows, various pipelines and wire holes completely blocked.