Thread: Spar math

How educated do you want to get, the calculations can get pretty intense if you're honing to a fine edge? What if any engineering background do you have?

Originally Posted by PAR

What if any engineering background do you have?

He makes bows so this sort of thing is probably a passion of his, right Rick?

Richard

Paul, just looking to learn enough so I can make my own spars for dinghys and daysailers without having to ask "how big should my spars be?" every 5 minutes. I'm decent with math, no engineering per se but I have a pretty good grasp of what's what and what ain't. I know it all involves sail area and design, boat weight , beam, ballast etc. etc. just don't know how to put it all together.

Have you come accross a book , Elements of Yacht Design, written by Norman Skene ( spars & rigging,chapter XI ).

Thanks HUON, I found a copy and ordered it.

Originally Posted by HUON

Have you come accross a book , Elements of Yacht Design, written by Norman Skene ( spars & rigging,chapter XI ).

Hi Rick

Duckworks have good ones. See the other links too at the bottom of the linked page.

http://www.duckworksmagazine.com/06/...outh/index.htm



Also Michalik:

http://marina.fortunecity.com/breakw...HOLLOW%20SPARS

The "Duck Works" thing listed above doesn't even come close to establishing the necessary fundamentals for mast sections. In fact it shows errors in birdsmouth spar building.

Originally Posted by PAR

The "Duck Works" thing listed above doesn't even come close to establishing the necessary fundamentals for mast sections. In fact it shows errors in birdsmouth spar building.

No, they don't tell me what I'm wanting to know. What I want to know is, how does a designer come up with his spar sizes for a given boat and rig....yeah sure I can have someone tell me what size to use, but if I'm gonna make it and use it, I want to know how to figure it as well. Do you know of the above mentioned book by Norman Skene?

A discussion of radius of gyration, relative material strengths, the common approaches to columns, beams, static and dynamic forces, elasticity, etc. would be well beyond the scope of this format. In fact a book on this specific subject is due as it's not covered well in most yacht design texts, including Norman Skene's classic and it's revised and updated book (8th addition) of the same name by Francis Kinney.

Well Rick, it looks like you're going back to university,mate. I'm not sure most of (if not all) the boat building courses cover the above subject in such detail.Par, you mentioned that such a tome is due or overdue. Have I got a job for you. Time to sit down in front of the typewriter in the confines of your studious room and start tapping, old salt. And I expect to recieve the first book of the first edition hot off the press,signed " Brendan, with much relief,Par".
Cheers one and all ,Brendan.

Huon? Get in line

I can do the math if only I knew what the equations are.

Rick, got your book yet, several of those funky equations in there to help you out (or start you out). Darce, first in best dressed mate.
Cheerio.

No, not yet...just ordered it. I expect it'll be here sometime next week.