Inspection and Troubleshooting of Underwater Part of Ship Hull

I. Inspection of underwater part of hull

(1) Inspection contents: propellers, rudders, submarine doors, shrouds and underwater parts of the hull, etc.

(2) Storage before inspection

First of all, contact the captain of the inspected ship, put forward the requirements of stopping the rotation of the vehicle, rudder, flying diving flag and arranging the bottom cables, and prepare special tools according to the requirements and inspection contents of the inspected ship.

(3) Divers submerge along the bottom line for inspection

1. Check the rudder to see whether its appearance is perfect and deformed, rudder rod and rudder blade are damaged, etc.

2. Check the propeller to see if the propeller blade is perfect, whether there are any twisted objects on the propeller shaft, and whether the fixed screw of the shield and the guide hood is in good condition.

3. Check the submarine valve to see if its shape is intact and blocked.

4. Inspection of other underwater devices, such as shroud, cathode protection device, bow propeller and hull, is in good condition. The results of the inspection shall be recorded in the Diving Operations Record Book by the telephone operator. After the diver leaves the water, the contents of the Diving Operations Record Book shall be confirmed and signed. Divers shall submit the inspection results in writing to the ship.

2. Troubleshooting

(1) Release of the entanglement on the propeller

When the propeller is entangled by ropes, wire ropes or fishing nets, the lighter will affect the speed of the ship and cause mechanical wear, while the heavier will cause the ship to stop sailing. In this case, divers are required to release the entanglement. Before release, the diver first checks the situation and sequence of entanglement to determine the method and tools for release. If the end of the twisted rope is not tightened, the end can be released first, and the end can be wrapped around the twisted object in the opposite direction. A guide cable is tied at the end, and the mechanical force on the surface can be released one by one. It can also be commanded by divers, and the engine room can be freed by manual turning in the opposite direction. If the entanglement is too tight to release, chisel, hand saw, special scissors and underwater oxygen arc cutting can be used to release, but should not damage other parts as the principle.

(2) Cleaning up submarine doors

Seabed doors are generally blocked by aquatic organisms, weeds and floating matter. Cleaning method is simple, scrape with a scraper, iron pen can be removed. If the protective shield is blocked, the diver can remove the protective shield to clean up. Once the protective shield is rusted and can not be unloaded, the leak stoppage method can be adopted, and the cabin can be unloaded to clean up, and then the diver will unload the leak stoppage equipment.