| 摘要 |
<p>Propulsion means for a marine vessel intended for operation under severe ice conditions comprises a multibladed propeller, which may be of fixed or controllable pitch, a stationary duct, which may take the form of a nozzle, within which the said propeller runs and is protected peripherally against ice damage, and, at the forward and aft ends of the duct, water-guide members in the form of vanes and/or blades which are more massive than is required by their water-guiding functions and which restrict the size of ice masses that can encounter the propeller by entering the duct at the said ends. The duct may embrace the propeller peripherally around the full 360.degree.. The water-guide members may be secured at their outer ends to the duct and at their inner ends to ring members co-axial with the propeller. The upper quadrant of the duct may be secured to the hull of the vessel and the lowest portion of the duct to a skeg extending beneath the duct.</p> |
