International Maritime Licence. STCW Certified ????????????

[jimmys]

I have just had a look at the Frazer River paddler a nice wee boat. I did not know Canada had one left. If you think of the paddle boards could be 18 inches deep by 12 foot long by 6 inches thick. When they enter the water for efficiency and noise the 6x18 portion enters the water near vertically and as the paddle moves to the bottom the board needs to be radial for maximum drive, this is the feathering. The boards are not radial at all times. There is two centres the paddle centre and the feathering centre.
Look at PS Waverley site quite clear there.
Voith Schneider unit is a propeller can drive through 360 degrees, port stb ford and aft.

regards

[Big Pete]

The first paddle steamers, such as the Charlotte Dundas had paddle blades that were fixed exactly radial to the shaft. The Victorian Engineers soon realised that if they could "Feather" the blades, as in rowing, and keep the blade vertical all the time it was moving through the water it would be much more efficient, and they developed feathering mechanisms to do this. With this technology a paddle wheel was more efficient than a screw propeller, in calm water.
The main drawbacks with paddle wheels were: -The extra beam required
Paddle wheels not efficent over a range of different vessel draughts and also when the ship was rolling.
When the ship rolled the lower paddle would always develop more thrust, causing the ship to zig zag.
Usually both paddle wheels were driven by a single engine so it was not possible to have one engine running ahead and the other astern to swing rapidly.

In the 1960's the Royal Naval built a Class of Diesel Electric paddle tugs especially for berthing aircraft carriers in Portsmouth Harbour. If I remember they all had names begginning with "A", Alert, Alecto etc. They had a seperate propulsion motor for each paddle and could spin round in circles. They had successful careers and were very good at there designed purpose.

BP