Thwart Install on 1980 OT Tripper

I recently bought a 1980 OT Tripper as a first project canoe (it was priced as such…).

The thwarts/yoke were missing, so I replaced them.

Need advice on installing new thwarts properly. Here’s the full story (sorry this got really long for a first post):

I bought two 36" thwarts from Ed’s Canoe, but then realized that I didn’t know the proper beam width of the canoe (either Old Town’s exact specs on this old canoe or from my own measurement, due to fact that seats, thwarts, yoke, and deck plates were off).

[Side notes/background: I’ve switched out the deck plates w/ perfect new replacements I found on Craigslist–thanks, Steve in Asheville. The molded seats were all blown out, so put in webbed ones for now. Gunwales and skid plates seem to be in good shape. We’ll see what shape the Royalex is in (no holes, gashes or patches, still flexible and bouncy)–I removed [brutal] some old epoxied tie-downs and foam knee pads and have been G-Flexing and painting the resultant exposed ABS areas. Gave her a good 303 bath too. Seems to have been kept inside until the guy i bought it from bought it in an estate sale.]

ANYWAY, I went ahead and installed the 36" thwart at the beam, but I think I may need to get a longer one and cut to 37" or so.

With the thwart installed, the beam now measures 37" from the OUTSIDE of the gunwales. However, i think (from what I’ve gatehred online) the old Tripper is supposed to have a 37" beam measured from INSIDE the gunwales.

Should seats, thwarts and yokes be cut at such a length that the canoe is in its “natural” position? I guess even the deck plates pull the sides in a little bit.

I’m afraid I “squeezed” the canoe by an inch to make the beam thwart fit.

Thwart was only $11 so not a huge deal to get another one (or a yoke). But in the meantime, is this bad for the canoe (I mean, it’s a beater anyway)? No big Class IV’s in the super near future.

Another issue: this may have screwed up my webbed seat installation also, but not overly concerned, as I can move them around/drop them down a bit (they’re just installed directly on the gunwales for the time-being).

I suppose I could go take everything off, put the old crap, now convex, plastic seats back on, and see where the beam thwart ends up, but any advice is appreciated.

The trial and errorS method is probably not the cheapest route, but having fun.


I would
sight down the keel line and make sure it was not hogged. If it was still slightly rockered or straight I personally would leave it be. If it was reversed rockered(hogged) I would put in longer thwarts.

A tripper is a longboat so if it is hogged it will be about impossible to manuever(sp?)

don’t worry about it

– Last Updated: Jul-19-12 8:48 AM EST –

I have removed the thwarts and seats from many canoes, both Royalex and composite. My experience has been that most boats will collapse inward (become a bit narrower) when the thwarts are removed, but typically not very much and sometimes the opposite is true.

Manufacturers also seem to vary in how they measure gunwale width. Most seem to go by the molded width of the hull but some seem to measure from outside of one outwale to the outside of the other.

It is extremely unlikely that changing the beam of this boat by one inch will have any measurable affect on either the cross-sectional configuration of the hull bottom or the rocker. I have pulled in the gunwales on a number of smaller canoes up to a couple of inches (which generally requires using pipe clamps to narrow the boat) and seen no measurable affect on rocker or visible affect on cross-sectional shape.

Thanks bald and pblanc!
Maiden voyage is this evening in the lagoons at grayton beach. If my dog gets eaten by an alligator, then we’ll know what went wrong…

I don’t know anyone that measures beam
inside the gunwales. Anyway, we owned a Tripper, and I “pushed” the beam a bit with a wider center thwart, and it ended up 37" across the outside of the gunwales. Ours also was braced between the center thwart and the bottom with foam, so the boat ended up with a splendid center rocker zone. More maneuverable, but probably a tiny bit slower.

I’d go ahead and use your 36" thwart. If you observe any upward flexing of the bottom when you get it on the water, you can add a substantial minicel pillar between the thwart and the bottom. If you’re clever as you sound, you might find a way to make that pillar serve as a portage yoke, too. (Unh! Trippers are hell to portage.)

on the light chop
W 50 lb 1.5 yo active shepherd mix (Muddy), we had some oil canning. Not a shocker.

I love trippers
but they oil can big time. Comes with the territory. I recently purchased an old (1978-80) or so tripper. It has the sea foam interior color. I could take some measurements if you need them.

mine is sea foam int
With the tan gunwales and decks (now new black decks). That would be awesome. Thx. I guess it’s time for a foam party.