I picked up a 1976 Old Town Chipewyan 17 last year. It is basically an early Tripper 172.
It has only one thwart/yoke. I plan on replacing the yoke with a molded cofort yoke. I will probably reuse the original one as an additional thwart if it cleans up well.
I do like all of the open space with only one thwart though.
The bottom does oilcan some, especially unloaded. Will an additional thwart help with this?
Some pictures:
I went from 1 center carry yoke in my 147 OT that I removed for a center seat position and I put 5 new thwarts back in. It had an oilcan problem before and it still had it after. So I would say they didn’t help with that. they did give the whole canoe a rugged feel though and yes that many for strength is not required. What I like is I didn’t drill and add loops to the hull and the additional cross thwarts make excellent places to attach and secure gear.
I solved my oilcan problem by adding a foam block that tightly fits between my seat and the flat floor of the keel. It supports the seat and holds hulls slight curve. I even noticed improved tracking after I had it in place.
Of my 5 thwarts there are 3 I would likely never remove. The other two I can remove or replace in a couple minutes depending on what I’m going to be using the boat for that day. If I were just taking a small cooler and a dog or a child for a paddle I would pull the two out for a more open cockpit area. If going camping I would like more compartments and places to lash things to the canoe.
Thanks! I am thinking of probably just one thwart. The newer versions of the Tripper had a yoke and one thwart.
My 17’ Spirit II has 3 thwarts - one behind the bow paddler, one in the center and one in front of the stern paddler. My 16’ Mohawk has 2 thwarts - one in the center and one in front of the stern paddler. My initial thought was to add two new thwarts, but if it has survived all these years with just the one, why bother. Hopefully it will go another 47-years for you with just the one. 
I always put three thwarts in large canoes no matter how many they came with. They add a lot of strength and give you places to lash your gear. It makes a canoe look right.
I would also replace the plastic seats with ash and woven black cloth seats. It will improve the whole look of the canoe.
If a canoe is a tandem to be made a solo and is 15’ long my ideal choice would be a thwart on each end spaced back 3’ from the tip of the deck. Then I would ideally have an air floatation bag that fully fit that triangle on each end flush with the gunwales. That amount of flotation would give me a good minimum feeling of safety for normal all around usage.
That would leave 9’ of opening for gear and person.
Depending on the type of seat used I would then want the third thwart located right behind the seat as there it interferes with nothing. If it is a hanging seat on drops it wouldn’t add much to the hull strength. Some of the molded plastic seats IMO add at least as much as a thwart would to the hull strength and if I was going with that the one behind the seat wouldn’t be needed.
Assuming the front edge of the seat is 8” behind center that leaves 62” open in the front of the seat and 38” space behind seat. You need to think about how cramped you want the cockpit area that will be free of gear if you were to add the 3rd or 4th thwart in the front. I originally made mine a 18” space that was a good fit for my cooler that often rides there. Leaving me 44” of cockpit area that is really way more than enough. That lead me later to adding another 10” back from that for a second smaller cooler.
In my perfect world these two in front would be made telescoping and just clamp to the gunwales wherever I wanted them ether 1 or 2 or none depending on that days need. I can see also adding a small drop in seat for a child in that area where they could face forward and learn to paddle or turn around and face me for fishing or just going for a ride. For taking a good size dog along I would keep the whole 62” open.
I often when just going fishing or a easy paddle use the space behind the seat to toss my dolly wheels and frame and just take a tackle box and small cooler and misc. day gear in front.
It seems like there are as many idea on canoe design and outfitting as there are people. In Europe they outfit canoes way different than we do here. When I read about canoe outfitting in the USA it seems like weight and maneuverability etc are the drivers, but when I talk to people putting in canoes around where I live they are mostly old heavy work canoes they have been hunting and fishing out of for 40-50 years. So much depends on the OPs usage.
Cold deep water, steep banks, little flotation, PFDs stored, can all add up in a hurry for a couple people in a tandem without a back up boat nearby. I always feel ten times better when we have both our boats out together. OT I know.
I agree, a seat upgrade would also be nice.
This is kind of an all around boat. It is used for fishing, canoe in camping, grandkids, and some mild river floats. It is a little heavy, but manageable for short carries.
The first picture is loaded for about a 5 night trip my Son and I took last summer.
Thank you for your suggestions. There are so many options when customizing a canoe.
Adding thwarts won’t reduce oil canning at all. Wedging a foam block between yoke and floor as bud suggests is a great idea. If you do upgrade the seats and seat drops that should stiffen up the boat noticeably. Nice to see a boat being enjoyed.
I didn’t think thwarts would help much with oilcaning. It really isnt too bad. My last canoe was a Wenonah in Tuff-weave so it didnt move much at all.
Here is the foam block I did. don’t even know it is there and it really popped the hull in the right direction.
Great Idea!
Any recommendations for canoe parts?
I am think contoured portage yoke and 1 or 2 thwarts.
Maybe even some new seats!
I have been looking at Ed’s Canoe.
Do you actually carry it overhead on your shoulders much? I had mine up there once when I first got it and didn’t see myself ever doing it again, so I just got rid of the heavy wood yoke.
All my thwarts I made myself from some aluminum poles I had from a house tent that went back to nature many moons ago. Chopped them to length with a hacksaw and smashed the ends flat in the vice. Cleaned them up on the sander and clamped them in place under the gunwale and then drilled the boat and the thwarts together.
I have heard good things about Ed’s and some of the others it just seems all this stuff is pricey but that is true of most hobbies.
I do carry it with the yoke occasionally. It is not pleasant, but doable. It came from the factory back in 1976 at 74lbs.
I dream of kevlar sometimes 
Once I got my wheels for mine 80lbs I have hardly ever moved it alone without them. When we are both going with two boats we do carry them some with one person on each end.
The nice part of having a wheeled dolly for us is we can totally load the boat when we take it off the car and then we set her boat 40lbs on top with coolers and paddles and all we make just one trip to the waters edge and we are in the water and paddling I in just a couple minutes. Others are running back and forth to the car and their boats are blocking others etc. If it is a ramp we go right down the middle often time.
I need a cart. I picked up some wheels a couple of years ago with the intention of building one.
If you shorten the thwarts about 1.5 inches, the oil can issue may disappear, and you probably will notice slightly different handling, turning will be quicker.
That is an interesting idea. 
Hi. My tripper is older than yours, it is the first mold 17 feet 9 inches, I got it while helping its original owner get to the take out, upper Millers,Mass. He said this was the third time it was wrapped around a rock, anyone who could salvage could keep, I sad Sold!, it needed gunnels, (Mad River, Jim Henry), and the bottom was a bit weak, I pulled it in 2 inches, still have it, it paddles well and has seen a lot of NE white water. Good luck with yours
