Suggestions to install
The TUNNEL and the hull must make up a single body, in this way becoming part of the craft's structure. For this reason and in accordance with the building and installation rules of the various naval registers, for the TUNNELS supplied by HYSY the purchaser will be responsible for:
a) the material and thickness specifications;
b) the laying
RECOMMENDATIONS FOR POSITIONINS AND INSTALLATION
The thrust produced by the BOW THRUSTER wil be greater and best utilised if the following ideal conditions are fulfilled as far as possible.
- TUNNEL positioned as far forward as possible (dwg. 1);
- TUNNEL positioned so that the upper edge is below the water level by a sistance equal to the diameter of the tube (dwg.2);
- TUNNEL positioned so that the lower edge is above the lower limit of the keel by a distance equal to the diameter of the tube (dwg.2);
- TUNNEL positioned where the INLET and OUTLET are less sloped, i.e. where the angle X is as smal as possible (DWT. 2);
- TUNNEL positioned so that its lenght (measured along the axis) is twice the tube's diameter (dwt. 2);
- FOOT fastenig flange positioned so that the propeller is central in relation to the TUNNEL INLET and OUTLET (dwt. 2).
If the conditions listed above prove to be incompatible, as often occurs, the effective working characteristics may differ from those calculated; in this case, the measurements takes during the star-up and testing phases become important as thy can often be used to make corrections and so obtain the better results.