designing a fast rowboat

http://www.ahoy-boats.info/archives/rowing/000120.html

Nothing new

 

I believe WinTech (Graeme Kings new address?) is selling them as a teaching aid for their racing shells. I believe they are adjusted just above a flat waterline much like Rick's pedal boats. So very little resistance with flat water conditions.

Jim

 

Raggi: that front facing rower looks different from the FrontRower machine that I have seen. Is it from another manufacturer?

 

Sorry, I don't know, I just googled for a picture of outriggers ...

 

Thank you, it was there in the July/August1991 WoodenBoat page 50. I would send the 10 page article to the forum but there is the copyright thing. In the article Mr King says Bart Donohue (mathematician/computer savy friend) came up with a faster but less stable design but they ran with it and Mr King stabilized it with fins: two about 20 feet fom the front (picture is not great, they are short and almost square and maybe a 90 degree included angle, the article says 25 sq in and 5 inches by 5 inches could be about right. The rear fin appears to be much larger is swept and tapered but still very low aspect ratio. A small rectangular rudder is positioned behind the rear fin. The article goes on to say the crew who used the new eight won every race that year. There was no lifting here, it looks like straight displacement. Apparently the increase in wetted area of the fins was justified by a more efficient (and probably lower wetted area) hull. Mr King did mention he had experience doing this a few years earlier with an unstable single with good results.

Jim

 

Correction, I think the front fins have some rake at the leading edge (the black and white library photocopy is not a great reproduction). It does not look like enough rake to shed weeds but the rear fin may be able to and it would protect the rudder and rudder/hull interface from weed build up

Jim

 

progress

The fairing on Nordfiord is coming along well.All the major humps and bumps are gone and I'm working on the smaller dimples now. It will go into my brothers garage where we can get some heat to continue. We are really getting excited to get it in the water. Daves fingers are healing well and the pins come out in two more weeks. He is hoping to be able to pull an oar for the New Years Day Row. It seems like it's pushing things a bit but he is determined to try. The boat will be in an unfinished condition with only a couple of coats of primer as we continue to smooth it out. The bow and stern areas will need one more layer of cloth over the bondo to strengthen and protect it. In some areas it got to be 3/8" thick, so it needs some protection against popping.

 

Hey nordvindcrew! Welcome back! Post a photo when you can so we can see your progress. Glad to hear that your brother is healing well. I am knocking on wood as I write that I have been a cabinet maker for over 35 years, and still have all my finger tips! Not braggin, just lucky I guess. For whatever reason, it always seemed to fall to me to drive whoever got hurt to the hospital. Seeing WAY TOO MANY blunted fingers has made me a very careful cabinetmaker. (Another knock on wood). Just wanted to say thanks for starting this thing. You have inspired me, and I am currently working on a Selway Fisher Mandarin Skiff, Just glued the garboards on today, and was dreaming about my first row in Galveston Bay. Thanks for getting me moving, and good luck with the New Years day row!

 

congrats

Coachwonderfull, congratulations on your build. I'm going to look at theSelway Fisher site to see what you are building. Thank you also for your concern about my brothers fingers. It was a wierd accident. His fingers were pulled into the blade (set at a 20 degree angle and close to the fence) vertically. The cuts go up into his fingers, not across as would be normal. There also was a lot of twisting and pulling going on which broke the fingers as well. The doctors are convinced that he has no nerves what so ever and comment that they've never encountered a higher threshold of pain. He's very determined, and might be able to row on Jan.1st. Right now, he's taping his hand to the rowing machine and pulling for a few minutes. With temps around freezing and windy conditions here, Galveston Bay sounds pretty good to me. RE the Nordfiord: we decided that we need to rebuild the sheerstrake chine line near the bow and stern. It just kind of peters out about 2' from the ends and looks wrong. A little more bondo work will re-establish the lines. Following the final shaping we're going to add one more layer of cloth and resin to protect the soft bondo.

 

selway fisher boats

I went to the SelwayFisher site. The Mandarin skiff is a sweetheart. Are you building the 15' or the 17' version? Both look very good indeed. I'm too cheap to have internet at home and use the computer at work so pictures are out for now, I've got to break down and get high speed internet so I can post some pictures of the fleet and progress on the latest project

 

I had an accident with a small router in the Spring. I wasn't paying attention and put the tip of my thumb into the chip vent, and it got chewed up. The flesh was still connected but the hospital could not stitch it as it was too messy, so they hosed it out and gift-wrapped it for me. Once it had knitted up it looked pretty ugly and there was no feeling. I found some stuff in the local pharmacy called "New Skin, Scar Therapy" which I used, and after a couple of months it looked normal again. The feeling started to return and there was no scar, the fingerprints and sense of touch are just as they were.

Perhaps this stuff would help your brother to a better recovery.

 

thanks

I'll look for that at my local pharmacy. Anything that good should help.

 

Sorry to change the subject guys. I am "planning my fleet" of boats and want to have in it a good solo race boat for fixed seat. That might be an 18' St Lawrence Skiff but more likely will be a finnish rowboat. What I want for feedback is what a good strong rower could pull...the longest waterline that a strong fixed seat rower could reasonably pull at speed, race pace for fairly long races.

I can get you some specs on the boat I have in mind, suffice it is long and lean on the waterline and very, very light. Terho posted pictures of these Finnish boats. The question is how long can I make it as a dedicated single (fixed seat) without it becoming to much boat to pull fast.

I'll post the specs when I get to my shop computer. Terho posted here about these boats post #805, the one mentioned was designed at 6.5m but has been built at 6m. Too long for solo fixed seat rower?

Cheers,
Clint

 

fastest solo?

After reading and re-reading this thread, it seems like the scientist/engineers could (and probably will),come up with the perfect length for your solo boat, including factors like your weight, arm length, hair color and size of your ears. But read the posts by the guys that are out on the water in these races, and it seems like weight is as big a factor in the real world. On flat calm water with no wind the super light boat might have an advantage, but in a chop, with even moderate wind, it seems like 'carry", or momentum of a heavier boat might be a real plus. How much weight would the structure of a water ballast tank add and would that be worth considering? BTW, I have seen photos of 'Drake", she is stunning, I cannot wait to see what you build next. Just got the third plank cut for my Mandarin skiff, but a terrible blue norther has blown in, our current temperture here has fallen to a bone-chilling 65, and we will spend the day huddled around the firplace, waiting for the Houston Texans to come up with another creative way to lose in the last 5 seconds.

 

Thanks for the Drake comment. I am busy with a number of new rowboats, but one I should give more thought to is a stretched out Drake, perhaps 19' LOA which would be about 17' on the waterline.

One rule of thumb I have heard is that 17' LWL is about the right balance for a solo fixed seater.

I agree weight is a biggy and I am in choppy water often, and do find a boat with some carry is a nice thing.