While we’re on stupid questions , what is the purpose of thwarts? Rigidity, to hold the hull closed or open? How about where they are placed?Is there an ideal spot(s)?
"Rigidity, to hold the hull closed or open?" As stated, Yep.
Also to help define the rocker. Play with a mailing envelope to see what I mean here. Widen and narrow the middle. Now just one end. Now do the opposite to the other end. You are now an official canoe designer! ;^)
There is a saying and a formula to help with thwart placement. The saying: "Any good working canoe needs five thwarts." That is of course a tandem canoe. A solo would need four. I found the formula in the Red Cross Canoe book. Be sure to apply common sense when using it.
For a tandem: 1) Place the first thwart dead center. Adjust slightly so it makes a good balanced portage thwart.
2) Measure from the rear of the bow deck plate to the center thwart (C). Divide this measurement by two to get thwart spacing (Ts). C/2=Ts.
3) Mount a thwart forward of the center thwart a distance of Ts. And one to the rear as well. Remember to use common sense and make small adjustments for things.
4) Place small handle type thwarts just aft of the bow and fore of the stern deck plates. These help the deck plates strengthen the bow and stern and take the strain of lifting and carrying off the deck plates.
For a solo: Do basically the same procedure, except after you fine the center line place the first or "middle" thwart approximately 14" aft of the center line. A) Take the "C" measurement from the aft of the bow deck to the off set (to aft) "center" thwart. B) You could also use the actaul "C" measurement to get Ts. This may work better for you. Lay out both and see what looks and works best. And finally; Yes, you do need that center thwart in a solo unless the seat is bolted directly to the gunwales without any drop what so ever, which makes for a very "Tippy Canoe". Tip: Place the solo center thwart so it is at the right place to lean against for those breaks or when arch stretching the back. A seat back can also be attached. A self alining (single gimbaled) one is even better.
Remember to use common sense with all the placements. ie: Do not trap yourself by having a thwart too close in front of a seat, etc ...
Hope this is of help.
I have changed the thwart
placement in two different canoes by a couple of inches without any noticible difference in performance.
Only a couple of inches, mind you!
Holy thwart placement Paddleman!
I’m making the Swamp Girl, and she will be a looker, sort of, as a solo. Does a gunnel mounted seat act as a thwart? The Center thwart in my Voyager solo is just behind my back with the floor mounted seat.
Sorry took so long to finish instruction
Had a lot of interuptions.
My original post with the formulas for both tandem and solo is now complete. See my post above.
Seat normally NOT a thwart!
A gunwale mounted seat acts as a thwart ONLY if it is mounted directly to the gunwale. If it is on any length hanger at all the seat should not be considered a thwart! Repeat: Direct mounted means NO spacers of any kind between the seat and the gunwale for a seat to be considered a thwart.
Many companies cheat in this area to reduce weight and production costs. It is up to you, the consumer to know how you are to use the canoe and if it needs to be brought back into good structural standards before using the canoe. Kinda like “Buyer beware” huh. ;^)
some canoes have no thwarts
Old Town’s Molitor has no thwarts. Poling canoes have no thwarts.
If the gunwales are a continuous arch and are heavy enough there is no need for thwarts. And if a hull were ribbed in conjunction with engineered gunwales there would be no need for thwarts.
In an assymmetric hull the old Red Cross formula would not apply. It was written in the day of wooden canoes, and while useful as a guideline, does not take hull design or usage into much account.
My two cents worth,
My poling canoes, and old Bill Riviere’s
poling canoes have thwarts. I don’t know what Harry Rock and other poling competitors are doing, but I would not want readers to think that a canoe should have no thwarts to be used for poling.
Yes, set up for wooden canoes. BUT
Yes, set up for wooden canoes. BUT still applies to modern canoes. And have you see the newer ultra light canoes (especially Bell and We-NO-nah)? Have you seen their huge ribs and counted the thwarts they have now? Have added?! If the same companies that were leaving out most of the thwarts to lighten the canoes and to save production costs suddenly start putting in all five there is a darn good reason and you had better pay attention or have a very expensive damaged canoe on your hands!!!
There are several experts and authors that still state a good working canoe NEEDS five thwarts. They are not talking wooden canoes. It is obvious they are talking plastics and composites.
I have only seen one set of gunwales that is designed strong enough to carry the whole load as you suggest and that canoe has a single thwart. That canoe also has hull resin that works more in conjunction with the gunwales than others. Have dealt with gunwale manufacturers of late. Not one of their engineers has said their materials will carry the load and hold the shape without thwarts.
I would suggest that the polers canoes you have seen sans thwarts were taking a calculated risk to gain performance much the same as racers do that build their crafts so light they risk collapse during the race just to gain an edge. I do not know the Molitor. Just how small is it? How much weight did they add to the hull to require no thwarts. I am not a fan of Olde Towne mainly due to the fact they do make their hulls so very heavy AND they most always understate the actual weight by a large margin.
It does not matter if the hull were symmetrical or asymmetrical, all but a very few specially designed canoes or greatly under used canoes need thwarts. I do have one canoe that requires no thwarts, BUT it has substantial triangulation in the place of thwarts. Those that tried the same design, but lightened or went without the triangulation have suffered repeated collapse of their hulls.
And with this last post I am outta here for the week, at least through the 4th!
Last I saw Harry Rock and Chip Cochoran’s boats got the same thwart setup as everybody else.
Since poling is the easiest way I know to pin a 16’ canoe I sure wouldn’t want to take any out.
Here is the OT Molitor
For interested parties here is the Molitor with no thwarts:
For what it’s worth, many wood canvas “courting canoes” did not have a center thwart. The concern was you needed space for the young lady and parasol.
I hate being thwarted!
Thwarts on poling canoes
Speaking about the canoes seen at poling competitions in the NE, most, I think, have center thwarts. In fact, Harry Rock’s signature maneuver is the “Rock Hop” in which he hops over the center thwart in the middle of a gate, landing facing the opposite way in the boat. Many have swum trying to master the move.
Some polers install an elongated center thwart to get what they claim are better stability characteristics and more rocker.
Partly for solo paddling (in which the center thwart interferes with decent seat positioning) and partly for poling (for which my age and ineptitude prevent execution of the Rock Hop with or without the half-twist), I replaced the center thwart in my 16’ MRExplorer with two thwarts spread about 50 inches apart. The spacing was taken partly from a factory 15’ (solo) MRCourier and partly from looking at pictures of various factory solo boats.
For tripping, I lash gear down the center of the bilge, leaving me a workable span to move around in.
Most of my paddling life, I’ve dealt with clamp-on or clip-in carry thwarts, so I’m happy with (resigned to?) this setup.
The Molitor can go thwartless, I think, because of 1.) the extreme Ojibeway recurve to stem and stern, and 2.) the long decks. The cockpit just isn’t that long.
I’m pretty sure, though, that the Ojibeway boats had thwarts.
I have two canoes that only have the thin Grab Handles at the ends. I have a Bell Flashfire that only has a kneeling thwart in the center. It’s been that way for 5 years and has thousands of river miles on it with no negative effect. I took the thwarts out when I widened the hull so I could do transverse freestyle maneuvers in it. I never put new wider thwarts in. Never needed them.
I have a 39 pound Mad River Malecite. It has three seats and no thwarts except the grab handles. It’s 13 years old and has been on wilderness trips in wild places like Wabikimi, Lake Superior Provincial Park, BWCA, Algonquin and others. It’s never needed proper thwarts either.
Gee, Tommy, I never pinned my 17 & 18.5
foot canoes. I guess I should have poled a 16 footer to experience the thrill of pinning.
Because one is usually practicing upstream work, when trouble develops, one tends to wash from a more troublesome to a flatter, easier area. Also, frankly, while I used to pole some technically tricky class 1-2 rivers, when the water got heavier, I preferred to kneel and use the paddle.
…and two seats is all that holds my magestic OT Disco together. Took out the second thwart for poling the day I bought it. All I can say is that it works fine for me this way and this ol’ boat has seen a fair amount of action. I did end up putting extra thwarts in my MR Malecite, found that with its extra length it sure made it sturdier.
Well, I’ll be thwarted! who would have
ever guessed the wealth of thwart knowledge available.Swamp girlwill have 3.