Scribe Ribs-What are they?

There are two pairs of scribe ribs on the Chase guideboat I am reproducing.  Scribe ribs, sometimes called stitched ribs, have no feet.  The reason they have no feet is that they go way forward and aft in the boat.  The bottom board is so narrow there that there is no room for rib feet.  They are called scribe after the geometric technique used to precisely define their shape.  Here is one ready for mounting,

A scribe rib.

When I wrote my book Tale of an Adirondack Guideboat and How to Build One I expected builders would pick up something amiss in the book about my instructions.  After all, building a guideboat is not at all straightforward.  But so far, after 13 years of being in print and a number of boats built using my book, there have been no complaints.

I did have one fellow say to me “I only had one problem using your book.”  On no, I thought, what did I miss? He said, “Oh, it was my omission.  You know when you say to install the scribe rib as soon as the garboard strake is hung?  Well, I waited too long and it was a devil to install it later on when I had nearly finished planking.

Well this time around I was at round 5 of planking when I suddenly remembered the scribe, or stitched, ribs.  So I failed to take my own advice.  Fortunately I installed them without much trouble.  Here they are after installation.

Scribe ribs installed. They are the ones closest to the Pony clamp.

So what’s the use of scribe ribs anyway?  Not all guideboats have them.  One reason, I believe, is to shape the hull nearest the stems to present a more a graceful appearance.  They are also useful in providing a support for the seat cleats.

By the way, I did finish planking the 5th round.  Here it is after round five:

Hull after the fifth round of planking.

Phew! Onward.

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