designing a fast rowboat

help

Keith IMMEDIATLY go to a S.S.A. meeting (sliding seats anonomous) They will you have you back in a proper fixed seat and happy to be there

 

Keith if you think the BP is a joy you need to try the Finnish Rowboats. This is the Savo 21


Finnish Rowboat by Clint Chase Boatbuilder, on Flickr


The Savo 21 by Clint Chase Boatbuilder, on Flickr

 

congrats

Clint, a beauty. Is it built to Finnish rules? I've read them and thety are pretty strict to ensure uniformity of design. How long are your oars? Ours on the Nordfiord are 8' 9" which everyone seems to think is very long. yours look even longer yet. What kind of speed are you seeing on a GPS, it's got to be upwards of 7 knots.

 

almost done

work continues on the Nordfiord. corrected some bad geometry in the oarlocks, working on changes to the foot stretchers to allow fulll foot support and added a small rudder to offset the drift to starboard we seem to have. the rudder will also help in the river races where there are dozens of turns. being in the right place in the river to avoid back-currents and to stay in the strongest current that helps speed you up wins or loses the race. Right now, the rudder is operated with a pull cord and bungie. Later it will be foot operated so that rowing doesn't have to be interupted to steer. Weir River Race is this Saturday, starting time is 1:30 which should be the windiest part of the day and make for a tough race. Time will tell, could be beautiful and calm (I can wish, can't I?)

 

sissified

Looks as if tomorrows' race will be cancelled. There is a North-East storm brewing. Short of disasterous conditions, let us race. The politically correct are so worried about their collective legal rear ends that we can't be trusted to decide if individually we think it is too dangerous. Oh well, it will give me one practice with the rudder on the boat and a little ballast in the stern to find out how the boat behaves. We've never had her out in any really rough going but I don't anticipate any problems. A few weeks ago we got out in the mouth of the North River and did a little mild surf work. Going out was ok; a little pounding and a little water into the boat but still OK. Coming in was a bit hairier. She wants to broach a bit and even with a lot of work on the oars she still wants to go sideways. Speed seems to be the answer. Keep it slow and control is good; too fast and it goes to hell. Maybe the rudder will help. It is located on the bottom of the boat and about 3' forward of the stern. The total area of the rudder is about 35 square inches and it is a balanced design with just a bit of aft bias. No idea at all how much it will help. Time will tell.

 

race day

The Head of the Weir River race goes off at 10 AM tomorrow. Forecast is for sunny and temps in the low 50's. Haven't heard anything about wind. Today they're calling for 15-25 mph. I hope for a little less tomorrow. Not much chance for a win. Daves' hand is still no-where like 100% and we're not rowing as much as we need to to be competitive. Just go out and try our best is all we can do. This winter I WILL spend more time on the rowing machine.

 

Best of luck & let us know how the rudder works out!

 

rudder

I am really hopefull that the rudder will help the boat track better. It is set up with a bungie cord to port and a pull cord and jam cleat on the starboard sideof the tiller. The cord is marked to indicate dead ahead. Adjustments to our course should only take a second or two and if all works as hoped won't be changed during the race unless weathercocking gets too bad. The next scheme is to rig foot pedals at the aft station so we can really steer on the river race where there are turn after endless turn. In that situation, being in the right place on the river, through the turns, wins or loses the race. Our 16' boat is quite nimble, but this 20' boat turns a bit hard. With almost 19' on the water and with little rocker in the keel to get that waterline it's to be expected. for results, check out Hull Lifesaving Museum, there will be results and pictures by Monday or Tuesday. Otherwise Google Weir River Race for pictures.

 

rudder

Well, The Weir river Race is history. We came in a poor third; almost 9 minutes behind the leader. Sad thing is that our time was competitive a few years ago. The competition is just getting much better. The Last Chance, A weird looking boat with extreme reverse chines won in 56 minutes and change. A Herreshoff Althelas was about 3 minutes behind them. We were at 1:05. The rudder really helped. The wind was bloewing us to Port and a slight change allowed us to row with out compensating for the wind. We are out of shape and our oars are too long to pull effectivley. I've got some cedar oars I made that I'm going to cut down to 8'-4". we row with 8'-9" now and just can't get them moving fast enough. As Jon Aborn commented after the race "Maybe we're just getting too old". Can't give up that easily, have to try harder to at least be a threat. Next on the rudder is to get it to be foot operated so it can be set without having to take your hands off the oars. All in all, it looks like the boat is a lot better than we are.

 

Handicapping !

Well what were there ages ? It makes a difference even if we dont want to admit it. In the sliding seat world they handicap the masters. I cant remember what it is but it can be a significant amount of time.To the point where younger masters really have to work hard if they are going to beat the more mature rowers. There should be some reward for putting in all those hard years right ?

 

handicapping

It sounds good. I wonder how it is done. In this case, I'm 67, my brother is 61 and the crew of the "Last Chance" are maybe 50 and 63. The pool is so small that it might not work. there have been ideas floated about handicapping boats by a combination of weight, waterline length and waterline beam. Nothing has come of it yet. I am kind of partial to handicapping the boats if anyone can come up with a good method that people can agree on. Right now, bieng in good shape is the problem. Lots of us colder guys just don't row enough to be in top shape.

 

As soon as the handicapping rule is announced someone will be working on a design which gives the best combination of performance and rating.

 

The Great River race use a handicapping system where the length, beam, depth & approx midship section, weight number of thwarts, sweep or sculling plus length of oars etc are all fed into a computer programme that gives a start time ie slowest boat away first. It takes no account of the crew whatsoever.
With three hundred boats many of wildly different designs it seems to work fairly well though some always moan about being stitched up.
The arcane handicap rule is not published so no one knows how to exploit it!

 

oars and oarlock beam

I just came through this great thread by accident today. I honestly know nothing about rowing except what I read during the last few months when I decided to build a small row boat. I built a white spruce lattice male mold and built a carbon fiber boat from that plug. I quickly found out that good oars, rig and sliding seat came out pretty expensive, so I built a carbon/kevlar/corecell sandwich wing rig and the oars and sliding rig as well based on measurements that I gathered here and there on the net.
From your post quoted above I wonder if I am completely out of whack: the sculling span for the wing rig is 65", the oars are 9'8", I placed the collars at
34½" for a 4" overlap. The boat has not hit the water yet and the rigging is not installed and if necessary or useful I could make changes to the rig or oar lenght.
The boat measurements (subject to correction when mesured in water with/without weight) are: LOA 18'4", Beam 40", draft 4", weight 65 lbs. waterline lenght 17' 10", waterline width 23", depth at center 14½".
Your recommendations will be appreciated.

 

oars and oarlock beam

I just came through this great thread by accident today. I honestly know nothing about rowing except what I read during the last few months when I decided to build a small row boat. I built a white spruce lattice male mold and built a carbon fiber boat from that plug. I quickly found out that good oars, rig and sliding seat came out pretty expensive, so I built a carbon/kevlar/corecell sandwich wing rig and the oars and sliding rig as well based on measurements that I gathered here and there on the net.
From your post quoted above I wonder if I am completely out of whack: the sculling span for the wing rig is 65", the oars are 9'8", I placed the collars at
34½" for a 4" overlap. The boat has not hit the water yet and the rigging is not installed and if necessary or useful I could make changes to the rig or oar lenght.
The boat measurements (subject to correction when mesured in water with/without weight) are: LOA 18'4", Beam 40", draft 4", weight 65 lbs. waterline lenght 17' 10", waterline width 23", depth at center 14½".
Your recommendations will be appreciated.