Works under water

devices ship

Change and installation of outboard fittings. When removing afloat outboard fittings, the diver’s works under water is reduced to sealing the holes from the outside. If grids of apertures fasten on hairpins or bolts after their removal on the same hairpins or sockets of bolts establish metal plugs with a rubber lining.

At fastening of lattices by electric welding of a plug establish on temporary hairpins, or apply plugs of a special design. For newly installed valves in the casing to cut the hole and welded navares (Waris). The body in the place of installation of fittings is isolated from water by means of a simple caisson-plaster installed by the diver. All the main work is done from inside the ship.Removal and installation of propellers, shafts and stern tube devices. In addition to measuring gaps in deadwood and bracket bearings and eliminating minor damage afloat, you can perform the dismantling and installation of propellers, shafts and deadwood bushings.

The pressure nut of the screw is screwed from the key, which is installed by the diver and at his command rotates the spire or hoists. After rolling the nut, the thread on the shaft is carefully protected from damage.The propeller is removed by means of screw and hydraulic pullers of various designs; wedges hammered between the nose end of the hub and the stern sections of the deadwood (bracket).

Works under water

The shifted screw is strapped to the divers and after screwing the pressure nut. The recess of the propeller shaft into the body is successfully performed only with the appropriate maintainability of the deadwood device works under water. Previously, the intermediate shaft is moved to the side or up and the pressure device of the gland is loosened. Under the supervision of a diver, the propeller shaft shifts into the bow so that you can install on shaft pipe plug (stopper) from the stern. In this position, the nasal neck of the shaft should not come out of contact with the deadwood gland. Then disassemble the pressure device of the gland, the shaft is removed from the deadwood pipe and a metal plug with a rubber gasket is placed on the standard studs of the pressure device.

Methods of dismantling and installation of shafts and deadwood bushings

works under water

a)Dredging the propeller shaft inside the vessel; б)Excavation of the hull; в)Pressing the aft deadwood bushing using the shaft; г)Pressing the aft deadwood bushing with a rod with flanges.

1)-Propeller shaft; 2)-aft stern tube bushing; 3)-bow stern tube bushing; 4)-gland sealing device; 5)-plug; 6)-a sealing sleeve; 7)-curly strap; 8)-falseval; 9)-hydraulic jack; 10)-the aft flange; 11)-rod; 12)-nose flange; 13)-gasket; 14)-washers; 15)-pressure nut.

works under water

When dredging the propeller shaft out under the aft valance, a special equipment is installed that allows to support and move the shaft strictly along the axis (for example, a monorail with hoists moving on trolleys). Removing the connecting flange, the propeller shaft is shifted to the stern if possible. The diver clogs the gap between the stern neck and the deadwood sleeve. Then disassemble the gland seal and on the regular studs of the pressure device, a sealing Cup made of steel pipe is installed.

Rigging for dredging the propeller shaft outwards

1)-propeller shaft; 2)-monorail; 3)-carts with hoists
; 4)-temporary rims; 5)-sealing cup with cable gland; 6)-holding the rope.

The propeller shaft is moved by a winch or other means using a cable attached to the shank. Heavy shafts when moving are held by cables passed through the gland in the bottom of the glass. During the winding of the shaft, this cable is used as a traction. The shaft of small diameter is taken out by means of the false shaft, which is a pipe muffled from the end with a well-treated outer surface. The diameter of the pipe must match the diameter of the nose deadwood sleeve. The false shaft, fastened to the bow end of the propeller shaft, is moved by the Jack and takes its place in the deadwood pipe. The pressure device is thus weakened.

The removing and fitting the bow and stern of the bushing is inside the housing when you installed the plug at the outer end of the stern tube. Removing the aft stern tube bushing is made either by the diver by using pullers of various designs or under his supervision from inside the body with the help of a dummy shaft or propeller shaft. For pressing of these bushings adaptations from a rod with flanges and pressing nuts are applied.

Repair of steering devices

Divers can perform defects in the steering Assembly: measure bearing gaps, check the angles of the crossbar, the correspondence of the position of the steering pen to the steering pointer and the tiller, check the tightness of the pen. Dismantling and installation works can also be performed afloat. The technology of these works under water and equipment depend on the design features of the device and differ little from those used in dock repair.

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