Vessel having demountable submerged propeller unit

A vessel having a hull and a submerged propeller unit demountably fitted to the hull and continuously rotatable through 360.degree. of azimuth relative to the hull to give full thrust in any required direction, comprising means defining an aperture in the hull of the vessel surrounded by a fixing flange, a drive input shaft for the propeller unit and at least one steering drive shaft, at least one steering drive motor mounted in the vessel and connected to the steering drive shaft to effect rotation thereof, a casing that fits in the aperture with a circumferential flange releasably bolted to the fixing flange, a stem depending from said casing and rotatably supported therein at its upper end to act as a steering tube for a propeller rotatably supported at its lower end, a steering gear wheel in said casing through which the stem passes and to which it is secured so as to effect rotation thereof, a steering drive gear means rotatably supported in said casing in mesh with the steering drive wheel and releasably connected to said steering drive shaft so that operation of said steering motor rotates the propeller unit, and a drive transmission shaft for the propeller extending through the stem and releasably connected at its upper end to the drive input shaft whereby when the propeller unit is dismounted from the vessel the steering gear wheel and the gear means are removed in the casing as part of the demountable propeller unit;

• an inner sealing plate at a vertical position between inner and outer skins of the hull attaches to said casing;
• access tubes from within the vessel lead through the inner skin of the hull to fixing bolts that pass downwardly through apertures in the fixing flange and threadedly engage bores in the circumferential flange of the casing;
• and the or each steering drive motor is fixed to a platform mounted for vertical movement so that in demounting the propeller unit the or each drive motor may be raised to lift the or each steering drive shaft clear from the aperture.

A vessel having a hull and a submerged propeller unit demountably fitted to the hull and continuously rotatable through 360.degree. of azimuth relative to the hull to give full thrust in any required direction, comprising means defining an aperture in the hull of the vessel surrounded by a fixing flange, a drive input shaft for the propeller unit and at least one steering drive shaft, at least one steering drive motor mounted in the vessel and connected to the steering drive shaft to effect rotation thereof, a casing that fits in the aperture with a circumferential flange releasably bolted to the fixing flange, a stem depending from said casing and rotatably supported therein at its upper end to act as a steering tube for a propeller rotatably supported at its lower end, a steering gear wheel in said casing through which the stem passes and to which it is secured so as to effect rotation thereof, steering drive gear means rotatably supported in said casing in mesh with the steering drive wheel and releasably connected to said steering drive shaft so that operation of said steering motor rotates the propeller unit, and a drive transmission shaft for the propeller extending through the stem and releasably connected at its upper end to the main drive shaft whereby when the propeller unit is dismounted from the vessel the steering gear wheel and the gear means are removed in the casing as part of the demountable propeller unit;

• and further comprising a demount rail pivoted to the vessel adjacent the aperture having a carriage that travels therealong and arranged for attachment to the shroud, a first control wire in a pipe extending downwardly through the hull of the vessel attached to the flange of the casing at a location opposite to the shroud and a second control wire attached adjacent a free end of the demount rail outboard of the vessel whereby, during demounting the propeller unit, the propeller unit may be lowered under the control of the first control wire until it hangs freely, after which the carriage may be moved along the demount rail until the propeller unit is outboard of the vessel.