If anyone has photos or information on center-rib construction (Wenonah) I’d love to see/hear from you. I’ve been panning the web for information and there is very little out there, especially in terms of photos of canoes > 16 feet long with center-rib.
I have an old fiberglass Wenonah Jensen WWC1 in center rib construction. It is a 16’ long solo canoe designed as a downriver racer.
Wenonah discontinued the center rib construction years ago, but when they used it they marketed it as a robust construction intended for river use.
The center rib is basically a rectangular channel that runs down the centerline of the boat on the inside of the hull bottom. My understanding is that the Wenonah tandems had shock absorbing struts that extended from the center rib up to the thwart bottoms. The solo center rib canoe do not have the struts.
I didn’t realize that what the OP is
looking for was the triangular center core with the side ribs attached.
If that is the case; I have two Wenonah Jensen 17’s in ultralight and that is how they are constructed.
If that is what the OP is looking for, I would be glad to email you pictures,
Just e-mail me and I’ll attach some.
(Incidently; if you crack one of those side ribs, it is a snap to repair them)
Wenonah center rib canoes
The construction method that Wenonah called "Center-rib" did not involve a foam bottom core or side ribs.
A single foam rib, roughly rectangular in cross section and covered with fabric, extended down nearly the full length of the bottom mid-line somewhat like a keelson. On the tandem boats shock absorbers extended from this center rib up to the middle of the thwarts.
Here is what Wenonah said about their center rib construction in a 1992 catalog:
"One full-length foam rib stiffens the bilge. We mount shock absorbers from the rib to the thwarts. Extra fabric is added into areas prone to impact.
This method is also unique to us. It flexes and will deform to take severe impact, yet it holds shape in normal use. As the very toughest type of composite canoe, Center-rib is ideal for treacherous waters.
These hulls weigh and cost the same as Cross-rib. A Center-rib hull is more durable but, due to its greater flexibility, it doesn't paddle quite as efficiently.
We offer Center-rib on all solo pleasure hulls and tandems that are made for whitewater use. Many of these can also have our special "Expedition" option that adds an extra full layer of Kevlar to the hull."
I had a Sundowner 17
with center rib. I took the struts out because I didn’t like the sound of the squeaky springs. Didn’t notice any problem with them out. Perfectly fine design. The fiberglass/polyester cloth was coarser than now which took up a bit more resin. Unfortunately the term “flex core” was utilized later which is kind of a misnomer as there is nothing flexible about the cored bottom.
It would be neat to see an Innegra/s-glass coweave with clear coat in the center rib layup.
To add to what has already been said, Wenonah made both Kevlar and Fiberglass hulls in center rib construction. Both had gelcoated exterior and can be ID’d by the interior which was painted in the fiberglass hulls and natural Kevlar in the Kevlar hulls. Compared to the flexcore which replaced both center-rib and cross-rib, the weights of all three are very close, more variation in day to day weights within a type of construction than between the layups.
Under normal paddling there is no noticeable oilcanning in a center-rib tandem hull. In fact they never oil-can. The entire bottom rises and falls. The sidewalls of the canoe flex as the whole bottom moves together. Much like the newer flex-core reacts to going over an obstacle in the water. The cross-rib layup gives between the cross ribs as a rock or log passes along the bottom of the hull. It also flexes at the bilge area as the sidewall gives under load. If you are looking at a center-rib canoe check the bilge area for cracks. Small spider cracks in the gel-coat are normal and harmless. Deeper cracks with cloth showing are evidence of hard usage. Check the attachment points of the thwarts bearing the shock absorbers in tandem hulls
For sale, “Wenonah Kevlar canoe”. There is a white solo currently listed with center rib. No spring loaded struts though because the seats on the floor.