designing a fast rowboat

[nordvindcrew]

I printed the equations for general hull form, and it's a great help to have them in one easy to access place. It is good to see the thread re- energisedvand many of the old contributers again signing in. Clint, It's too bad about your wifes' injury. i have been thinking about a mixed doubles class. Not life or death competition but more a fun thing. Could have some possibilities. Team Saquish from Plymouth is talking about something big fot November but there is no information about what they are planning. Their fall race is 4 1/2 miles and is a bit tough because navigation is difficult and almos always two legs are into the wind on one quarter or another. I'm going to New Bedford on the 13th for the row for Buzzards Bay to see if I can better my performance up in Essex last month. Short race, only 3 1/2 miles.

[JotM]

Originally Posted by terhohalme

Swede, I found two second hand markets for row boats:

[1]http://www.soutuliitto.fi/suomen_sou...kalustoporssi/

[2]http://www.kalevankierros.fi/phpbb/v...221e136d76ecfe

Yes, Finnish

Thanks to Google we can nowadays all "read" these pages:
1: http://translate.google.nl/translate?prev=hp&hl=nl&js=n&u=http%3A%2F%2Fwww.soutuliitto.fi%2Fsuomen_soutuliitto_ry%2Fkalustoporssi%2F&...
2: http://translate.google.nl/translate?prev=hp&hl=nl&js=n&u=http%3A%2F%2Fwww.kalevankierros.fi%2Fphpbb%2Fviewforum.php%3Ff%3D5%26sid%3D7493af6805dcab54b6221e136d76ecfe&...

[nordvindcrew]

I went to New Bedford Saturday for their race. It was very poorly attended which was a shame because it is well run and is in a great location. There were only two fixed-seat singles, and I came in 20 seconds behind the other boat. Shaun is from Conecticut and rowed a Gloucester gull. I am still sorting out the Nordlys and trying to get back in shape. I find that from rowing double that I am being lazy with my right arm ( left-handed ) and in the last part of the race my right arm just plain gave out. The wind was about 15 degrees off my port stern quarter as were the waves. Every time a wave would pass under me it would pick the stern high enough to get the skeg out of the water and allow the wind to kick the stern to port. It meant constant correcting with my weak right arm and it finished me off. I need to work on a soultion. The skeg seems adequate in most situations and I hate to make it much larger. Maybe a kick-down rudder such as the kayakers have might work. For now though, I just need a lot more time at the oars. My time for 3.5miles was 40:27 not great but OK for the conditions.

[Clinton B Chase]

Jeff that is too bad about race attendance. What was the weather like? Wasn't it a gorgeous day?

My friend Ben Fuller is a very experienced small boater and loves the idea of an adjustable skeg built into a boat like a small daggerboard or swing centerboard. He swears by it.

Today my students launched a fast rowboat, hull #1 of the MSD Rowboat, a fast rowing skiff designed by Michael Storer from Austrailia. Great boat.

Cheers,
Clint

[ancient kayaker]

Hinged (retractable) skegs and rudders are common on Kayaks, less so for canoes and rowboats.

My home built canoe had a significant tendency to weathercock as initially built and heavy wind had a severe effect on my efforts to maintain a heading. I installed an oversized skeg which I trimmed down until it retained a slight tendency to head into the wind, which is convenient as it allowed me to concentrate on power paddling. Downwind is less hard work so I can spare more effort to control the heading. The skeg also eliminated the boat's tendency to yaw when gliding, but a retractable skeg would have been better for exploring narrow streams and inlets when manouverability is needed.

I can feel the slight extra drag and hear the turbulence when my kayak's rudder is lowered into the water, but it is not very much. The canoe may have been affected by the skeg but it is still noticeably easier to paddle than factory boats of the same length.

[nordvindcrew]

Clint, how about a photo of the boat your students ( ? ) just launched? The weather for the race was beautiful. sunny and just warm enough to be comfortable. Light wind out of the N.E. ( ? ) maybe 15 MPH. Only good day we've had for weeks. I'm going to take a good look at a kayak rudder and start to fabricate one. It won't be a rudder as such, simply an easily retracted daggerboard to be used only when necessary. Ancient Kayaker described what is going on with my boat exactly and his observations and fixes fit the problem.

[KJL38]

Clint has posted some photos at http://www.woodworkforums.com/showth...t=94441&page=4

Kelvin

[Clinton B Chase]

I am building up for the Blackburn. Did 10mi this morning. Averaged 4 kts. I am wicked tired. This is gonna be a hard race!

The MSD rowboat is a great boat but certainly not an open water boat by any means. Kids loved it. Did people see the link. That is forum for Michael Storer's baots. I follow the forum a lot. I may be kitting out his MSD skiff and his Goat Island Skiff, maybe offer components for the boats too.

On another note, the students finished the prototype for our carbon bladed spruce oar. Came out great. You can see it in the forum pictures. I'm doing a set for a local using Sitka Spruce and carbon fiber blades. The big question here is blade shape! He like the narrow blades like I have on Drake (4 3/4" wide, 36" long) but most carbon blades we see are quite wide. Any thoughts?

Clint

[terhohalme]

For short courses concept 2 type oars:

http://www.concept2.com/us/oars/default.asp

or for longer courses like this (FinRace K):

http://www.lahnakoski.fi/english/airot.html

[Clinton B Chase]

I need to design a blade that I will be making out of carbon for a guy's 18' sliding seat wherry. He doesn't want to have to feather, so a very wide blade won't be good. I like narrow for open water so the blades clear the chop, but he wants something inbetween.

My oars look like the ones in the picture. My blades are 4 3/4" wide by 36" long. We just did carbon oars pictured in the link to my students' project. One student is holding an oar, the blade is pretty wide, about 180mm x 680 mm long. So something between the two. I am putting time and money into a mold and want it to be a mold that could do a variety of blade lengths and widths. So, I need to look at a certain range of blade lengths that I'd need and establish my curvature.

I am not presently making oars but a friend of mine does a fine job in which you may be interested. The reason I bring this up is that I feel that oars, in general, are too heavy for non-workboat use and carbon fiber oars won't fit wood boats.

http://www.grapeviewpointboatworks.c...snpaddles.html

[nordvindcrew]

Clint, I saw pictures of the boats your students built in Points East. They look like a good value, particularly the kayak. a possible addition to your projects might be Seth Pressons' Atlantic 17. I think he has a special licensing for schools, and, I know, it's a good boat. It rows well and keeps up in the local races. Good job with the kids! Jeff

[nordvindcrew]

Terho, I was watching the video of the race boat you designed. It moves beautifully through the water but I noticed that yhere is some turbulance at the stern. Is the stern a requirement of your rules? Double ended in the water would seem to offer a slight reduction of the drag there. Clint, about your students building oars, how about Pete Cullers' design? I'm working on a couple and will see how they work. The ones I'm working on are 8'11" for one of our doubles. It isn't too hard to make them but they are a good exercise in woodworking. Next up is a couple of 8'2" for Nordlys to see if they lower the resistance at the grips to a more reasonable level.

[Clinton B Chase]

Jeff, Our students do basic flat blade spruce oars. Actually, one group did a prototype carbon blade-spruce loom oar. Pretty cool.

I like Culler's oars a lot and think they are great. I will build a couple pair for my dory I am working on, drawing that is. A couple people at COmpass Project are going to build the boat. I think Culler's long narrow blades make a lot of sense for open water boats.

Drake and I were at the wooden boat show in Mystic and we won 1st place in man-powered division! A lot of people asked about my oars and why the blades were so long and narrow. I explained that getting the blades to clear the chop was what it is all about. Also long, narrow blades can be efficient if the blade area is correct. You also don't need to feather them so much.

Here is the Wooden Boat Forum link for the Show discussion. I'm in there somewhere.
http://www.woodenboat.com/forum/showthread.php?t=98884

Cheers,
Clint

[keith66]

I also like long narrow blades if its rough, our club currently uses modern cleaver blades and they are great in smooth water but you have to watch it if its choppy. The admiralty whaler oars had great long blades nearly 5ft long,
Gigs often use a needle blade which is a longish narrow blade with curved spoon end.
The narrowest i have seen are the oars used on the Irish Curraghs no blade at all just a square tapering loom, effective "blade" width about 2-2 1/2" .
When you see these its hard to see how they can work but those boats can really move.