| 摘要 |
<p>A tug 1 has a towing hook 6 mounted at the outer end of a towing arm 4, the inner end of which is mounted on the main deck 2 of the tug in a manner such that the arm 4 can swivel above the main deck 2 from one side 4a to the other side 4b of the tug about an upright axis under the control of a power-operated driving mechanism 17. The tow line 7 passes through a fairlead 16 and then to the drum of a self-tensioning winch 15. The drive to the arm 4 augments the steering capability and the characteristics of the winch 15 keep the power required for the drive within controlled limits. The arm 4 is also pivoted about a horizontal axis so that it can swing upwards and downwards and is mounted on a platform 12, mounted on a carriage 13 which is movable fore and aft on rails 14 on the main deck 2. These movements of the arm 4 are also controlled by power mechanisms and they adjust the position of the point of action of the tow line 7 in such a way that in whatever direction the tow line 7 extends, even exactly athwartships from the tug, the line of action of the pull in the tow line 7 produces only a small capsizing moment upon the tug.</p> |
