designing a fast rowboat

re-cap

Great photos of the freighter canoes and to know that racing is alive and well up in the Northern Territories. The row-paddle combination does seem to be something that just evolved independently. I'm going ahead with the rebuild of "Nordfiord". The new bottom panel and garboard panels are laminated and rready to go. Last night I started to cut out the old bottom. The plan is to cut out large pieces while leaving webs to hold the shape of the rest of the boat while the new pieces go on. When the new bottom and garboards are firmly in place, I'll flip the boat over and add laminations to the inside to strengthen the panels and firmly bond the whole thing together. The Weir River Race is in late October and I want to have it ready to compete in that race and in the next two or three that follow.

 

progress

All the cuts have been made in the bottom of " Nordfiord" and one side is now in place. The stern went in easily but the bow is a diferent story. To get the bow right, I'm going to have to make a series of radial cuts towards an imaginary point aft and upward near the gunnels. This will result in a very fine hollow entry. The stern has no hollow but is quite fine with no transom at all. The result will be a waterline of about 19' double ended and a reduced waterline beam. Lots of miserable work left tabbing in all the panels, grinding and adding cloth and mat until the structure is solidly bonded with strength enough for the rough use we put it to. Still trying for seaworthy if not finished by the 23thd of October.

 

25th of Sept its the Great River race in London, 316 entries this year, i am just finishing the building of an 18ft skiff,4' 6" beam shes a pretty boat & a fleet of them were used on Hanningfield reservoir in Essex, i acquired the mould 2 months ago & of course had to build one!
GRP Simulated clinker hull & i used a combination of csm & biaxial cloth to save some weight, come out about 120kgs. I could have saved more but the buoyancy tanks add weight, still having been swamped i like the tanks to be there! she is rigged randan style with stroke & bow sweep oared & centre a pair of sculls, looking forward to saturday, once i get her out of the shed i will try & get some pics posted up

 

Did the Great river race yesterday (21miles), 320 entries raced upriver from Millwall to Richmond, a strong incoming spring tide gave everyone a hard time as the wind was NW f5 it in the lower reach below tower bridge & through the city it was very rough indeed & there were several sinkings.
Our new Hanningfield Skiff did well coming in the first 40, with four sister ships finishing within in 10 minutes of each other. Full results should be out shortly.
We might have done better but one of my crew pulled a muscle in his back badly & had to pull up, i took over & we pulled fit to burst, fortunately my back held out.
My son Nick enjoyed it immensely so i reckon he will be up for some more!
Here a link to a photo us going under one of the bridges, http://events.birdmanphotography.com/?Action=VF&id=4934297850&ppwd=nr6706kk,
Note the boat is rigged Randan style with sweep frd & aft & pair of sculls in the middle, thats me on the sculls.
We all ache like hell but it was a great day.

 

Results are out on the Great River race website,http://www.greatriverrace.co.uk/text_files/GRR 2010 Results.htm,
Skiffs from same mould as mine (Hanningfield Skiff) came 8th, 14th & 48th respectively. Our boat came 39th, all in all i am well pleased with that.
And guess what came 1st & third? Two 14ft Cosine wherry's, one of them has been in the trophies for years. Might have to dig those plans out again!

 

Great River Race

Keith, Looks like it was ,in fact, a great race. There seems to be a class for almost everyone. Is there a huge tidal boost there in the Thames River. Times seem to indicate speeds of close to 12 MPH. We don't averge any thing like that in any of our races, and we've got some good crews rowing Cornish piolot gigs. Great pictures also, showing a huge variety of great looking boats. Your photo hasn't been posted yet, but I will look for it tomorrow. My project on the "Nordfiord" is going well. The new bottom and garboard panels are tabbed in place and the new bow and stern profiles are established. There is some trueing up to be done on the bow but all else looks quite acceptable. There will be a lot of bondo work to fair out all the little wrinkles to get things smmoth enough for paint. Looks like she'll be ready for the Head of the Weir River race on Oct. 23thd. Ugly but ready to row and hopefully fast enough to get us back in contention to win or at least place very well

 

At the start the tide is running at about 2.5 knots then as you get up to Tower bridge the river narrows dramatically & with the bridges often set less than half a mile apart, at times it looks as if the water is actually going downhill, something around 4 to 5 knots of tide with you maybe more between some of ther bridge piers. We were clear of the main pack & it must have been hair raising for that lot!
The skiff is back in the shed for a few minor mods to stiffen the gunwales fore & aft where the sweeps go, i made her just a teensy bit light there! The Randan set up does go very well though in rough water you have to be careful not to get tangled up as the oars are quite close together on alternate sides.
Looking forward to getting her back on the water for more trials!

 

rowing down hill

One of our races starts just up river from a bridge. It is always a scramble to get through the arches with out getting snarled up. coming out from under the bridge, you are actually rowing down hill with a strong current. For a brief distance speeds get up around 8 knots. It's a rush getting through and making that kind of speed even for a brief period of time. It's also necessary to really get some speed and keep at the front of the pack or fall back right away and out of contention. Still working on Nordfiord. Weather is the limiting factor. I'm working out side and need 70 degrees for the fiberglass. Still time left, and am hoping to have her ready for the race

 

specs

I did a model of Nordfiord on my Pro Surf program. Admittedly, the boat wasn't a precise model, but very close. Very good numbers: at 5 knots, total resistance of 7.9 pounds C.P .57. All other numbers equally good. Only time and experience will tell if the model holds up. I love working with Pro Surf, seeing the numbers change with just a tweak here or there. Even if I never build any thing I "design" I will have learned a lot about how to build a good rowing boat.

 

I stumbled onto this thread while searching for plans and photos for something along the lines of a Thames River Skiff. I have been building canoes and kayaks for about 15 years, and just recently a few small rowboats. Hve gone fron stictch and glue to glued-lap plywood for my last boat, and have fallen in love with the method, and the looks of lapped planking. My next boat will be a two man rowboat to be used primarily in small lakes, but I plan an occasional short trip down the road to Galveston for a little more serious rowing with my little brother. I have pretty much settled on the Selway Fisher 17' Mandarin Skiff as my next build, and am curious how this hull shape would compare to some of the fast rowboats shown on previous pages of this thread. Are there any designers out there who could take a look at the SF website and give me some input as to how this boat might handle a little chop, and what sort of speed I might be able to get from it, relative to what has already been shown as "fast"?
Also wanted to say thank you to "nordvindcrew" and "Clint Chase" for the inspiring words and photos. Can't wait to "see and hear" the next race.

 

Nice looking rowboat this SF 17' Mandarin. It is quite stable (wide waterline, over 90 cm). I wouldn't expect any problems in a small chop.

Finnish rowboats (approx 21' waterline, similar wetted surface) can easily do over 6.1 knots continuously. With the same energy your 17' can do about 5.5 knots.

Terho

 

Finnish boats

Are there any generic plans for one of those Finnish boats? They are very good looking as well as God-awfull fast. It would be great to get one competing over on this side of the Atlantic. The 17' skiff does look good though the freeboard is a bit low for the nasty stuff we get in some of our races. With careful handling and a good crew it could compete quite well.

 

Just something to remember: terhohalme hasn't tried to design the fastest possible boat yet. He's designed the fastest possible boat within the Finnish class rules. Those class rules include a minimum beam restriction at a certain depth in the boat. If he did not have to comply with that I think the boats would be different and faster. Food for thought.

 

Hello there,

I'm new on this forum, and a complete novice on boat design. I've read (some of) this thread with a great interest, and I'm impressed with the wealth of knowledge and the collaborative spirit shown here.

I have a question regarding the current project of a fast rowboat : do you think that it would be feasible to have an open stern allowing for a self-draining cockpit similar to what we have in a modern dinghy ?

I've started rowing last year on an beamy, stable shell (the "yole" from Virus Boat, sorry for the French only web page : http://www.virusboats.com/aviron-1-Nos_yoles.html). For now, I restrict myself to sheltered areas, but I'd like to extend to more open waters, where I could encounter quite a bit of chop. For right or wrong, I'd feel safer in a boat that can't be filled with water, whatever happens...

 

self bailing

I've seen a couple of Jersey style surf boats with a raised sole and large scuppers to drain the water. The only problem is that either you sit too high to row well or need a footwell to get your heels down low enough to be comfortble. With the foot well comes the need for a battery powere bilge pump. One boat we race against already has ben fitted out that way. Short story- probably no problem to do what you're thinking about. Keep us posted