designing a fast rowboat

[ancient kayaker]

Originally Posted by NoEyeDeer

... If I wasn't using epoxy I'd use a polyurethane glue ...

It's great stuff but I don't think it is right for strippers. Just MHO, but it foams and will push the joint open given a half chance. It's also expensive.

[KJL38]

When I built my guideboat I used bead and cove strips with titebond III, I began by clamping the strips but later switched to a staple gun which I found much quicker and more accurate.

When I build another boat I think I will use the method advocated by Bjorn Thomasson at http://www.thomassondesign.com/build...ng_manual.aspx He uses square cut strips and staples them all to the moulds before epoxying them afterwards. He claims it is much faster and equally functional.

[ancient kayaker]

Are the strips assembled to the mold dry and then the epoxy injected into the gaps? A slight reverse bevel on the strip edges would make that easier. Like NoEyeDear says, it might need a few extra forms, but it sounds like a nice, clean and fast way to do the job. Neat!

[jackson.daniel6]

Originally Posted by terhohalme

I made this rowboat last spring. She took Finnish wooden row boat champion this summer at 2000 m.

Hi!! I'm Daniel. Your wooden boat is looking very nice.

[KJL38]

Yes, it's assembled dry and glued afterwards. No matter how tight the seams the epoxy still seeps in as it's designed to reach into the wood cells. A detailed explanation is at http://www.thomassondesign.com/build..._and_deck.aspx

[mike1]

Hi , In th book Rip Strip and row,, the cosine wherrry use a simler fixing style,, I bult ona while back and use battery clapms to holg the strips to frames, . but glue each frame with hot meltglu,, quick,, then filld in th "gappas with a nice epoxy glass bubble mixture prior to glassing,
mike

[NoEyeDeer]

Originally Posted by KJL38

When I built my guideboat I used bead and cove strips with titebond III, I began by clamping the strips but later switched to a staple gun which I found much quicker and more accurate.

When I build another boat I think I will use the method advocated by Bjorn Thomasson at http://www.thomassondesign.com/build...ng_manual.aspx He uses square cut strips and staples them all to the moulds before epoxying them afterwards. He claims it is much faster and equally functional.

Yeah I really like that idea of his. I think I'd be trying that one next time. Sounds like the best of all worlds to me.

[mike1]

Gee this Thormasson design is really clude up,, this is about the best i've seen.

[nordvindcrew]

On bead and cove, what is the proper radius? Using 3/8" strips, I would guess about a 5/8" or 3/4" would work. any one have any thoughts. I'm trying to get my brother back into rowing again, he's been through hell with his health and the resulting depression that follows for a person who has always been a strong physical worker. He has a talent for boat design that comes naturally to him and I hope that he will get to work on a plan and lofting up a deign that we can build. Maybe that will get him back on the water and rowing competively again.

[ancient kayaker]

If you make the bead and cove diameter about 50% more than the thickness of the strips, you’ll get a cove with an angle of 67 deg which is about right. For 3/8 thickness a ½ or 5/8 diameter cutter should be fine. There’s a picture of what you are trying to achieve at http://www.noahsmarine.com/United_St...ilding-us.html

Note that the strips shown are quarter sawn, it looks nicer that way. There’s some more information on cutting strips at http://www.greenval.com/FAQstrips.html

I hope your brother feels better soon. Paddling and boatbuilding help me fight of the debilitating effects of old age and keep my brain and hands busy since retirement.

[Douglas Ingram]

Hi everybody!

I'm a little late to this party but have read (slogged!) my way through pretty much every post in the thread.

I discovered this forum through the typical "fast rowboat" search. While I'm a paddler not a rower (not much rowing done around here...) I have a particular interest in the subject at hand. Let me lead you through the story of how I came to be here and what I have found, its actually quite interesting!

I am a professional canoe builder of 20 years experience, most of that full time and specializing in building and repairing wood & canvas canoes, as well as making paddles.

A few years ago I began getting inquiries from people in the northern Manitoba communities of Norway House and Cross Lake about building 18'+ freighter canoes (long, deep, and having a "Y" stern) to be used in some races that are quite popular there. They have been taking old freighter canoes and "adjusting" their shape to make them faster. I have one in the shop now that I am taking the lines off of, that's the old one in the photos below. Anyway, the supply of old canoes is getting thin and they have begun to look for new canoes for the purpose, which is how they have found me.

I have repaired several of their boats, and and have built two. I used my 17'6" mold, setting the stem and transom out 6" at either end, as well as setting the gunnel depth much deeper. The result was good, but the quest is on to build a faster boat. They all want a faster boat!

A little about the race. First, the intention is to keep the equipment in the range of "readily available" in a remote community. They set the bow paddler up to row using an outrigger made up of 2 x 4's and a single thole pin with the oar held with a leather strap. The stern is a paddler.

After reading through this thread I was fascinated and surprised, shocked almost, to read about the Finnish "Vuorosoutuvene", the Shift Boat. The dimensions and use are pretty much exactly the same! And from such different parts of the world! It is also interesting that the shape adjustments that are made to the freighter canoes result in something that resembles the shift boat.

I look forward to seeing what all becomes of this!

[HJS]

A rowboat for pleasure, designed for testing new lines.

Length on waterline 5,64
Length over all 6,00
Beam on waterline 0.66
Beam over all 0,95
Displacement on wl 0,14
Draft 0,095
Prismatic coefficient 0,574
Metacentric height 0,45 over cb

js

[ancient kayaker]

Thanks Douglas for an interesting post and nice images. And welcome to the forum!

As you will know, the traditional freighter canoes were designed for capacity, portaging, ability to survive and be repaired in white water and wilderness conditions, leading to buoyant ends and broad beams. They were still fast, but largely because of their size and the power of large professional crews. It is not surprising to see convergence in the lines of modern “freighters” and racing rowboats and canoes, as the long hulls are adapted to speed and efficient use of limited human power.

Narrower beam, finer entry and exit are all seen in profusion, and elimination of the overhanging sterns of the older fast passenger wherries, to save weight without reducing waterline length leads naturally to the Y-stern or transom, although uncommon in canoes.

My designs are all open solo canoes with a double paddle. A convergence of canoe and kayak I suppose; they were dubbed “lost pond boats” some time ago. As an older paddler, the emphasis in my designs is slightly different, as I find reducing the length and weight leads to a boat that makes best use of the small amount of power available and is actually faster for me than a narrower, longer race-bred factory-built kayak of mine. For sheer speed that is not the way to go, but for long distance I suspect a lot of human-powered boats tend to be longer than they need be. Of course, once one factors in heavy sea conditions (my boats are intended for flat water) it introduces a new set of requirements.

The use of a rower and a paddler is something I haven’t seen. It makes a lot of sense, combining the increased power from rowing with the steering ability of a rear paddler. Again, harking back to the traditional freighter, if one or more of the crew had been rowing it would have reduced their ability to fend off threats such as tree trunks and rocks and paddles were cheaper and more durable than oars. It either introduces a new class of human-powered boat, or perhaps it allows paddlers and rowers to compete together: I'm not sure which ...

[KJL38]

The rower paddler combination is also used with Adirondack Guideboats in races such as the 90 miler. http://www.youtube.com/watch?v=RIeZq...eature=related

[Douglas Ingram]

Originally Posted by KJL38

The rower paddler combination is also used with Adirondack Guideboats in races such as the 90 miler. http://www.youtube.com/watch?v=RIeZq...eature=related

Fascinating to see that. Thanks!

How common is this arrangement for Guideboats? I always thought that they were usually operated by just one set of oars, rowed by the guide with the Sport being treated with an easy ride.

Finding this rower/paddler combination from at least three distinct sources makes me wonder if there is some common root to the practice.