Random Picture Thread

Aah! Thanks Jolly! a mystery solved. Very interesting - and the ingenuity and invetion that comes out - practical ways of solving problems.

 

Only if you get caught.
The new norm.

 

I'm not positive of the answer to that, but I don't think you even need to name your boat, just have the bow numbers visible.

 

There are no bow numbers. It is a yacht.

 

What does that mean?

As far as I know, which isn't a lot, there are two ways to register a boat, including a yacht, by state or by federal registration. I believe both provide you with a registration number that needs to be displayed. The federal registration may not need to be on the bow, but the coast guard has to be able to find it affixed to the hull in a consistent and accessible location.

I'll have to look up the regs. There's also something about having a declared home port too.

 

For documented vessels without state registration numbers, the name is required on bth sides of bow and across stern and homeport on stern. Official number carved into main deck beam. Fine is ten dollars per day for each omission on captain.

 

This is my grandmother, who was born in 1900. I think she was quite a beautiful woman. The photo was taken a little before my mother was born. My mother will be 100 in September. But it is the frame of the picture that is interesting. I had thought that it was a rather interesting art nouveau styled frame, but my mum is telling me new things she remembers even as other memories fade. If you look closely, you can probably work out what the frame is.

 

How beautiful she was!

 

Is that a piece of centerboard? Or a propeller tip?

 

It is, indeed a propellor tip, Hoyt - my Grandfather flew a Sopwith Camel in WWI, and this is from his plane. You can see the laminations, and if you look carefully, the oval cut out for the photo is a bit wobbly. Apparently, the rest of the prop was made into a fireguard, which was rather ugly, and I can't imagine it was a very good fireguard either!

 

Here's a view of the bottom, showing the foil section.

 

Is that cherry, mahogany or something else?

 

I don't know for sure, Hoyt, but a quick search suggests that they were made from mahogany. It looks very fine and straight grain, but I guess for such a crucial component they would select carefully, and I'm sure that, 100 years ago, there was a lot more to choose from.

 

Basic Propeller Construction - Materials

Types of Wood Used

Virtually every conceivable type of wood, at one time or another, has been used in the construction of propellers, and many examples of this can still be found today. Overall, mahogany was the wood of choice in early wooden propeller construction. Whether this made sense purely from its mechanical properties or whether it simply evolved from its widespread use in the furniture industry is a matter of speculation, and there is evidence that political pressures from suppliers may also have influenced its choice. It is light, stable, easily workable, has a uniform grain pattern and is reasonably strong. Walnut is similar, although perhaps stronger, and was used commonly along with mahogany by European manufacturers, and the in U.S. was used almost exclusively by Hartzell, which was a walnut lumber company when it began producing propellers in 1917. A variety of other hardwoods, as well as spruce, were used in propeller manufacturing prior to 1920 and examples of almost every kind of wood may still be found.

Around 1915 oak became the material of choice for Paragon propellers built by the American Propeller Company , after it had produced a number of beautifully constructed propellers of oak exteriors combined with spruce interiors prior to that time. The decision to use all oak was driven by demands of cost and speed of production. The company had experience with every kind of wood ever used for propellers, but firmly believed that quarter-sawn oak was "incomparably the best material we have ever used." They felt that mahogany was too soft and crumbly and had poor resistance to wear, and that walnut was too brittle to justify its increase in strength. As a testimonial to oak, they pointed out that of 8,000 oak propellers delivered in 1916 to the Canadian RFC over an 18 month period, only 4 failed to pass final inspection in Canada and not one was ever returned from the fields with any complaint​

 

That was interesting. They used grapefruit wood to make artillery shells for atmospheric scientific studies way back when.