fastening planks to ribs?

[jimnmad]

I have the paperback version of "The Dory Book" by John Gardner. On page 116 in the 5th paragraph it says to not fasten the garboard to the ribs anywhere except through the lap. The whole paragraph seems contrdictory to me. I have read and re-read but continue to be unclear. I have fastened the garboard to the bottom boards and to the transom and to the stem. Shoud I not put any screws into any ribs and just into the stem and transom and rivet the laps together? Or put a screw into the plank only on the intersection of the lap bevels and the ribs? I'm building a 16' Swampscott dory and am confused where to fasten with screws and where to fasten with rivets. Additionally, I used 5200 along the bottom board bevel and where the garboard lays along the transom and stem. I also spread a little down the ribs. Any help on this would be appreciated.

[Don Danenberg]

From what I see, you understand this better than most. Reread the instructions and prioritize. DonD

[Don Danenberg]

The garboards do not follow the curve of the steam-bent frame, they must bridge the gap (structurally, as well), to the keel plank rabbet.
A fastener in the center of this (possibly quartersawn) plank might cause a 'split'.

[Classic Boatworks - Maine]

Lapstrake planking is normally only fastened to the ribs thru the laps.
Your garboard plank is fastened to your bottom, transom and stem. Then the next plank is riveted or clinch nailed to the garboard, fastened at the stem and transom and one fastening at each rib thru the lap.
This is standard for dory and regular lapstrake construction.

[htom]

There is a line of fasteners going along the lap, with a fastener going into the rib. There is not a line of fasteners going along the rib (other than those that are in the line going along the lap.)

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cool. you can use funny ANSI characters in Windows by turning on numlock, holding ALT and typing nnnn, where nnnn = 0149 for the large bullet. I'm not sure how it's going to display elsewhere.


[This message has been edited by htom (edited 01-10-2001).]

[jimnmad]

Thanks, that seems to help. When I fasten through the laps do you mean through both boards at the bevel? On a 16' boat what spacing would be appropriate for the rivets? what spacing for the screws aong the bottom boards? Along the stem and transom? Any spacings or patterns that would increase the strength? I'm going through 1/2" cedar into white oak. Thanks again

[neptune]

Jimnmad, Did you ever get a response/answer to the rivet spacing?

Originally posted by jimnmad:
Thanks, that seems to help. When I fasten through the laps do you mean through both boards at the bevel? On a 16' boat what spacing would be appropriate for the rivets? what spacing for the screws aong the bottom boards? Along the stem and transom? Any spacings or patterns that would increase the strength? I'm going through 1/2" cedar into white oak. Thanks again

[Bob Cleek]

Yep, Gardner means "at both boards through the bevel" when he says "at the laps." You fasten "lapped" planks one to the other where they overlap all along between the frames... at the bevel, if you will. All along the plank. BUT, when you get to a frame while fastening planks together "along the bevel," at those points you fasten the planks to each other AND the frame (not "ribs," PLEASE!) "at the lap." Don't fasten planks to frames except through two planks overlapping. In other words, don't run a fastening through the planking into the frame anywhere unless it goes through two planks "at the lap." (i.e. where they overlap) Another way of putting it is only fasten two planks to the frame with one rivet. Or, rather, only fasten two planks at a time to the frame. (I'm making myself crazy!) As said, if you fasten between the laps to the frame, you likely have a little space between the frame and where the plank's inside face is. Clinching up the plank there will pull the frame out of true and likely split or crack it... if not when heading the rivet, then maybe a few years later you will find a cracked frame. It is all about engineering the longitudinal strength of the lap "seams" and transferring those stresses to the athwartships strength of the frames. You want the stresses to "cross" at the strongest points in the planks (the laps) and the frames (where the planks rest on them.) Does that help? Hope so... Good luck!

[Alan D. Hyde]

Bob-------

Why can't we call steam bent white oak 3/4 x 3/4 (or thereabouts) frames for a lapstrake boat ribs?

That seems to be the traditional usage in this part of the country, and in NE Massachusetts, too.

When I was a boy, I did have a USPS instructor who insisted that no frames were EVER ribs, and who enumerated the few ropes on boards a vessel (bell rope, bucket rope, etc.), when telling us that everything else was properly a line.

This is all very well, and exactitude in language makes for better communication, but it CAN be carried too far.

Alan

[Thad]

On the question of fastening schedule for the laps: For boats with 1/4 inch planking Herreshoff's schedule was every 2 inches. For boats with thick planking on the order of 5/8 to 3/4 inch it was not unusual for lap fastening to be every 6 inches. I think for most lapstrake boats 2 to 4 inches is the right range, depending on the plank thickness. For the 16 foot dory I would go with 3.

[Bob Cleek]

Alan, actually, I do believe that "ribs" is common usage in the UK. As you say, perhaps it is here in the US as well, at least in New "England." But, I guess I'm with that old Power Squadron guy... to my ear, "ribs" is lubberly. I put it in the same category with calling the bow the "prow" and so on. I suppose you could say "Her ribs were sticking up out of the sand." referring to an old beached hulk. But as long as they are offering some support to the planking, I'd opt for "frames." I say tomato and you say tomatoe, and Dan Quale says...

[Mike Field]

I'm with you, Bob, about using the correct language. I saw a thread a little while back (can't remember where,) where someone was complaining about having to teach sailing newbies the language as well as the art. (Major complaint, not like Alan's -- this guy didn't see why seamen couldn't refer to call "port" as "left," and so on.)

He was told, very firmly and quite rightly in my view, that jargon in any form of skilled endeavour allows for explicit, rapid, accurate, and parsimonious communication between the endeavour's practitioners. (Sorry about any redundancies there.) The only time it shouldn't be used is when the skilled person is trying to communicate technical material to an unskilled one who's going to remain in that category.

People professing to be professionals should be prepared to learn the professional language.

Having said that, I suppose there are some professional synonyms. Perhaps frames and ribs might be one such set?

[Scott Rosen]

I try to use the words that cause the least confusion. Frames and ribs are easily recognized as the same thing. You might not like the sound of one or the other, but when someone refers to "ribs" in a wooden boat, you know exactly what they mean.

Port and starboard is another story alltogether. They refer to a specific side of the boat. Even if you are facing aft (not backwards), the port side is the same even though it is to your right. Use of the words left and right on a boat refer strictly to the direction relative to the person. "The rigging knife is in my right pants pocket" is clear, easy to understand and leaves no room for misinterpretation. If you were to try to be nautical about it and say "the knife is in my port pants locker," no one would have any clue as to where to find your knife.

Windward and leeward are another example of technical words that add clarity. There's no substitute for those terms.

[Chadd Hamilton]

I have to bring this post back to life to ask a question in regards to riveting schedule: Is there a point of reference that I should follow when starting to drill my pilot holes? ie start at bow and work back, start at mid ship and proceed for and aft?

Thanks for the help.

[nedL]

I understand terminology can be different depending on where you are geographically, but I must say that on the Jersey Shore they've been 'putt'n ribs inta boats' for well over a hundered years. New Jersey was famous for its lapstrake shiffs, up to about 50', and you may not have been showing ignorance, but you sure were not local if you talked about putting in frames. -- For what its worth [img]smile.gif[/img]