I am looking at a used Wenonah Cascade. It is 10 years old, kevlar expedition lay-up. The gentleman I talked to said it has a center rib that is 2" high x 3" wide elevated above the floor of the hull running down the center. I didn’t think the new ones had this, but I haven’t seen one. I’m not real excited about a rib down the center, but was hoping someone would know more about this. Another thing it supposedly has are “shock struts”, which I wasn’t familiar with either. Any information on this would be appreciated. thanks.
From the 1990 Wenonah catalog:
“A structural foam rib is laminated bow-to-stern with shock absorbers mounted from it to the thwarts. Hulls are thicker where prone to impact or abrasion. Only we use this lay-up and it gives the toughest laminated hulls. it flexes to absorb severe punishment yet holds its shape otherwise. It is lighter than all-cloth and ideal for dangerous rapids or big waves. It’s available on most all pleasure canoes. Tuf-weave hulls have a full layer of that material plus Kevlar reinforcing. Kevlar hulls have Kevlar seats. Tripping hulls can have an additional Kevlar layer (at extra cost) for even more durability.”
My old Moore Voyageur has a center
rib, and I have the shock struts Moore supplied to keep the keel from oil canning. It DID oil can if struts were not used.
The struts were concentric aluminum tubes with auto valve springs in them. They were strong enough to keep the bottom from pooching in, but would allow some hull flex if we ran over something.
To save portage weight, I substituted spruce struts, and later I added an ethafoam pedestal running most of the length of the hull.
Wenonah is dealing with a design where, if the layup is light, the bottom is going to pooch upward. I think that for a whitewater boat, it would be more appropriate to use minicell pedestal seats, bow, stern, and center, between the thwarts and the bottom, to keep the bottom down.