Turning a Canoe into a Row Boat

For a canoe, which I find tippy, and facing forward, which I find smart, I propose adapting a paddle boat drive. It should be simple to fiberglass the impeller housing in the center of the boat(even two!). Steering can be with the paddle, which can help with the propulsion and workout. We have more leg muscles than arm muscles, and a canoe has good hull shape. This thing just might go good, especially with two people.

It would not be extremely complicated to build such a mechanism but it may be more than your friend wants to spend. The best material to use for this would be aluminum because of it light weight but aluminum fabrication is expensive. If I were going to do it I would also install a couple of small outrigger pontoons just big enough to add some stability to the rig. Your friend might try to use wood to build the thing from. It would be affordable and fairly easy to work with. If it works well later on when he could afford it have it re-made from aluminum. The problem I see is attaching the thing to the bottom of the canoe. I would suggest him not try and attach anything to the hull to avoid having a ruined canoe. The canoe I had was built with support ribs that would hold something well attached to them but the fasteners would be prone to stripping out of the soft aluminum. The best way I think would be to weld brackets and then through bolt the rowing rig to them and avoid threading the aluminum.

Years ago me and some friends rigged two canoes together with about 2 ft gap in between them and attached a 10 HP outboard centered in the gap to propel the contraption. It work very well and we used it all that summer for our river trips. The problem we had was if the person operating the motor gunned it all of a sudden. The front of both canoes would stand up as much as 4' like they were having a wheelie competition and this would scare the crap out of anyone in them especially the guys in front. All we had back in those days as far as materials goes was wood and all though it worked pretty good I don't consider wood to be the best material for that type of construction.

Thank you for your reply. I gave GA (1 vote). He was not planning to attach anything to the hull but good point. Everything will be clamped in and easy to remove. He has purchased two oar clamps that swivel in two directions ($10) and plans to mount those in PVC pipe clamped to the struts (no drilling, tapping or gluing). Clamps can be screwed together, back to back. We'll see how it goes. Nothing planned for feathering yet. He is planning to use PVC for seat as well. Say, 2" (2x) for short runners and 2 1/4" pieces (2x) attached to the bottom of the seat. The 2 1/4" pieces would slide over the 2" runners. The runners would be mounted to a wooden base with clamps. Not the best for avoiding friction but worth experimenting with as far as cost goes. Will post pictures whenever possible. He is still open to suggestions though, so keep 'em coming.

Thanks,

Keywalker

he might be able to use pvc 90 degree ells glued on the end of each runner and maybe a couple tees in the middle or some 2x4's across the under side wired or U-bolted to the runners to give them enough strength to hold his weight. When you mentioned swivel clamps I thought about the swivel pole scaffolding clamps. If you all know a scaffold builder he might "loan" a couple to try out. If he has support ribs in the canoe he could make the runners just long enough that the ribs could act as stops on each end. I would also try to make the height of the seat as low as possible to help stability. Anyone who ever got a newbie in a canoe with them understands how tippy they can be when they suddenly stand up or makes some other wrong move. With all the motion/movement your friend will make when using the rig he may have to add some sort of outrigger and pontoon that could easily be added as well. A few foot of 6-8" PVC with caps glued on the end would probably have enough buoyancy to do the trick.

Thanks for the ideas. I will pass them on. I had thought about the ells and mount plates but thought clamps would be easier to line up and still provide a small space between pipe and wood. The clamps I have in mind are Minerlak clamps (may be very old terminology as I haven't done electrician work in years) used to mount pipes to walls and the like in electrical installation. I'm not really following you on the "Ts" in the middle? Thanks again!

What is the point of having the seat move to and fro? In addition to wasting "oar energy" to move the seats... Seems counterproductive if the canoe is to be reverse rowed to move forward (as if paddled) instead of backward (as if rowed). Why not use the legs to pivot the oars (using hands only to control, dip, feather...); then use back muscles to recover the system to "legs retracted- ready-to-push/power-thrust-again position. (We are talking about a simple, cable/pulley actuated system wherein locomotion occurs in two stages: a leg push stage (via cables and pulleys to the oar) to propel the vessel; a back (and arm) pull-and-leg relax phase in preparation for the next leg thrust.

The idea of a sliding seat/thwart goes against the the notion that canoes are best trimmed with rider weight (or riders weights center of balance) fixed amidship; with rider sliding the prow will be rising-dipping causing extra drag--the more so if constructive oscillation gets started.

A cable pull system would also, is seems, entail the least added weight.

On obstacle to any system would be interference by thwarts (and still keeping rider and drive equipment low as possible in the boat). Again, cables (placed beneath the gunwales) and pulleys (mounted to thwarts?) seem most easy to accomplish this.

Any thoughts?

The only thing I can think of as far as the seat being able to slide back and forth is so that the legs can be utilized to aid the rowing process. As the body is pushed back the length of stroke will be increased. This seems to be a natural motion. However, I do see a need for the seat to have some sort of spring loading to move the body forward again (or at least assist in this). What do you think?

For one, the springing needed for "rower recovery" repositioning after thrust (whether it be his system or my original conception) must entail added weight--the more so considering the "moving seat rider's weight"; and more weight to be propelled in the water. Your notion of a spring-back system recognizes the essential aspect of rowing (or any man-powered paddling...):

• That rowing (pull or push rowing) entails both dorsal and ventral trunk and limb muscles contracting/relaxing in alternation
• That to replace (mechanically substitute for) either muscle group (say, to substitute a springing system for abdominals' exertion) must impose a penalty that will eliminate most conceivable advantages, for example:
• The added muscle exertion (at thrust) needed to propel the extra weight of the spring, etc.
• The muscle exertion needed to compress/expand/flex the springing mechanism each time after spring kinetic energy is expended.

Now, while a sliding seat arrangement is not inconceivable (if oars are long enough and properly shaped to still dip into water given a canoe's shallow draft and low gunwales; or if oarlocks can be made to also slide to and fro along the gunwales (perhaps a ratcheting setup)), your friend would do well to remember that there must be a trade off: in this case, a sacrifice in attainable speed (no matter the payload)...so if the idea is simply to make the canoeing experience somehow more leisurely, then leisure must be enjoyed at a very slow pace. In this regard, it is not unlike the suggestion for a paddle boat setup made previously. What a paddle boat (like a bike) tends to do is focus exertion on large (fatigue resistant) muscles (and relieve other muscles (just like the sliding seat canoe). But, paddle boats are intrinsically slow...limited in speed by the limit of the foot paddlers ability to increase muscle exertion in order to increase paddle speed.

If, on the other hand, your friend's objective is speed, I believe he will soon come to realize:

• Had such a thing been possible it long since would have been invented.
• That there is bit of rube goldberg aspect to his imaginings.

As to inventions that have given rise to enhancement of speed, they all seem to invariably consist in adding mechanical advantage (think leverage) to the rowing process itself, but not a saving in terms of muscle exertion...nay, quite the opposite. Whether it be the very long oars (and oar sweep) of a whale boat, or the extended oar (sweep) in a racing shell, the gain in leverage (speed at the oar tip) is at the cost of added, not reduced, exertion by the rower's muscles...because the fulcrum oarlock is closer to rower's hand than to oar tip.

I am thinking (in view of your latest post - whoever you are [and that is not to say that all guests are one person]) that maybe the spring loading of the seat (however fleeting the notion may have been) was not a good idea. Perhaps some method of hooking one's feet and using the legs and abs for forward pulling of the free wheeling seat would be preferred. I don't know (just throwing out ideas here). I don't think "leisurely" is what he has in mind here. After all, he is planning on rowing 100 miles in some sort of a sports endurance event. As far as the invention of a device for speed, I think it already has been invented. Check out the link to the video Canoe Oarlocks & Sliding Seat for Rowing The problem here is that he is facing backward and my friend wants to face forward (not a minor problem, I'll admit).

Thanks for the all the suggestions! I am the guy trying to build the contraption. The reason for having the sliding seat is to use the larger muscles of the legs. I don't really need this to add speed to the canoe, but I do want to employ the larger muscles to raise my heart rate and engage the entire body. I am working as a personal trainer while in school and I agree with the earlier poster that it is much more useful to engage the larger muscles of the legs for exercise purposes, but I want to use the arms and back muscles as well. I am not opposed to a pulley system if it is easy to build and cheap. I only want to spend about $75 if I can. A system like the one in the video Keywalker posted would be great if it engaged the all the same muscles. That would eliminate the potential rocking of the boat, although I'm not sure this is going to be a huge problem. The boat is 15.5 feet and it doesn't seem like other people who have put sliding seats in canoes that size have had major problems with it. There is another rig like the one in the previous video that someone built and posted plans to, but I can't get my head around it (not too much experience with this kind of thing), and it looks expensive. Here is the link: http://www.econologica.org/rowrig.html

At first I thought of making a track out of aluminum but it seems like it will be hard to work with. I don't have a lot of tools at my disposal and I want to avoid paying for fabrication. Here is an example of this: http://www.youtube.com/watch?v=qdohfn5-R8s

The way I am leaning at the moment if the PVC thing doesn't work is a wooden track with skateboard wheels like this one, but not as fancy: http://members.shaw.ca/bawalker/roar2.htm

I'm not particularly worried about performance, but it does have to work somewhat proficiently. I am planning on taking trips of more than 100 miles with this rig. I will be doing some of them as endurance sports outings that I will do for time, but I'm not racing anyone so it doesn't have to break any world records, although that might be cool...

Here is the canoe he is going to use.

Here is a closer shot of the center struts.