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View Full Version : Captain Pete on locks and thwarts



Kermit
11-07-2002, 01:32 PM
Wayne--and others,

Cap'n Pete gives advice all through the book on measurements, oar type and length, thwart location, and so forth. I don't recall there being a "formula" or even mention of things like "forearm length." He's pretty much clear that leathers should be stitched on and never tacked, and even laments at one point that a herringbone or "baseball" stitch may be a lost art since kids don't make their own baseballs anymore! He says that leathers should be 12 to 14 inches long.

Here are a few paragraphs that may prove useful:

"The height of the thwart is most important, and in craft from 12 to 18 feet in length sometimes cannot be perfect, due to limitations of the boat. I've set thwarts as low as 7 inches from the bottom in very shoal, low-sided craft; this is not the best practice, but, if you have room to stretch your legs nearly straight out, it is quite workable. The height from the thwart to the rail runs 6 inches, more or less, in most boats--when more height is needed, oarlock blocks will work. I find thwarts located at 10 onches from the bottom and 7 inches from the rail a fairly happy medium, though mostly I don't quite make it, due to the design of the boat, so fudge out in various ways.

The standard thwart width when I learned the trade was 8 inches for flat-bottom skiffs, and the oarlock sockets were set 12 inches from the after edge of the thwart. This is a norm to work from, but is by no means ideal. Many fast working yawls and gigs of the past had thwarts only 6 1/2 to 7 inches wide, and I think this has a lot of merit--there is less wood to step over and bark your shins on in getting about in the boat. I also prefer a thwart that is narrow enough so you can hook your butt slightly over the forward edge. Even though there might be a good stretcher for your feet, this hooking over of your butt gives you a firm grip on things, especially when rowing in a seaway, even a slight one. It's quite apparent that the oldtimers who used these craft as a way of life knew what they were doing.

I find that many boats allow the grips of the oars to be too low, almost in your lap, which is awkward in many ways, poor application of your power, and just plain unhandy in any sort o a sea. I like my grips to come just about under my rib cage; if I am in doubt when building a new boat or converting an old one, I simulate a thwart, using a box or some blocking, fake up some oarlock blocks, and sit in her with an oar or even a long stick, taking into account where the water will be and fussing around with the set-up until I think it will work. It may never be perfect, but usually, using this method, I arrive at about the best you can do with a given boat. I'm sure that a person's build has a lot to do with thwart location; a person who is thick in the lower regions is going to crowd things more than the string-bean type. A very short person may not have much reach in his arms, let alone legs, and a really long person always has trouble finding a place for his lower ends. All this has to be taken into consideration--even the stroke the oarsman favors, though this can be altered if you can convince him that a change will make the boat go better. Some people do have bad rowing habits, which they often developed from using poor boats; bad habits can be eliminated, but it's often not easy.

The rough rules of thumb for placing locks and thwarts that I have given are just that--rough guides, somewhere to start. You can work from these, and, with a little trial and common sense, you can make the boat go pretty well and feel right. If, after some use, things don't seem right, try to figure out what's wrong and make the necessary alterations."

Not exactly a pat formula, but a good place to start.

To row is human, to erg divine. :D
Kermit

Osbert
11-11-2014, 09:36 AM
Cap'n Pete gives advice all through the book on measurements, oar type and length, thwart location, and so forth:

<snip>

"The standard thwart width when I learned the trade was 8 inches for flat-bottom skiffs, and the oarlock sockets were set 12 inches from the after edge of the thwart. This is a norm to work from, but is by no means ideal. Many fast working yawls and gigs of the past had thwarts only 6 1/2 to 7 inches wide, and I think this has a lot of merit--there is less wood to step over and bark your shins on in getting about in the boat. I also prefer a thwart that is narrow enough so you can hook your butt slightly over the forward edge. Even though there might be a good stretcher for your feet, this hooking over of your butt gives you a firm grip on things, especially when rowing in a seaway, even a slight one. It's quite apparent that the oldtimers who used these craft as a way of life knew what they were doing."


OK, so this is a bump of an old thread - but I was reading this para in Culler's book the other day, and it got me wondering about the pros and cons of different width of thwart - I'm thinking here of my fixed seat rowboat Drake, which is nearly ready for thwarts.

As the thwarts will be loose, I can experiment, but I'd be interested in other's experience of narrower thwarts.

rbgarr
11-11-2014, 06:13 PM
How big is the part of you that sits on the thwart?

Osbert
11-12-2014, 02:06 AM
How big is the part of you that sits on the thwart?

Pretty skinny and not well padded!

John Welsford specifies wide thwarts in the Walkabout plans, around 12 inches from memory, perhaps a little more. That's how I built them f or my Walkabout and they're fine - I use a bit of closed cell sheet as padding. I wonder if the extra width here though is mainly to make it easier for the thwart, which is loose, to stay in place and not twist sideways.

I'm curious about the 'hook your butt over the thwart' idea, might that mean one isn't siting on (and rocking on) the sinews that run over the bones in ones bum?

slug
11-12-2014, 03:02 AM
Pretty skinny and not well padded!

John Welsford specifies wide thwarts in the Walkabout plans, around 12 inches from memory, perhaps a little more. That's how I built them f or my Walkabout and they're fine - I use a bit of closed cell sheet as padding. I wonder if the extra width here though is mainly to make it easier for the thwart, which is loose, to stay in place and not twist sideways.

I'm curious about the 'hook your butt over the thwart' idea, might that mean one isn't siting on (and rocking on) the sinews that run over the bones in ones bum?


Hook your butt means ....hang over the forward edge of the seat. This keeps you from sliding on the seat and getting blisters on your butt. It also slightly lowers your profile and allows you to get the oars higher off the water in a chop.

Those tractor type seats would be terrible on a rowing boat .....perhaps they work with a sliding seat.

Osbert
11-12-2014, 05:27 AM
Hook your butt means ....hang over the forward edge of the seat. This keeps you from sliding on the seat and getting blisters on your butt. It also slightly lowers your profile and allows you to get the oars higher off the water in a chop.

Those tractor type seats would be terrible on a rowing boat .....perhaps they work with a sliding seat.

Thanks for explanation. But I don't get the second para re tractor type seats :confused:

Ian McColgin
11-12-2014, 07:45 AM
Because of the way the tractor seat comes up in back - most comfortable if you're sitting in one posture and dealing with bumbs - your buttocks muscles get a bit of extra stress from pressure as you reach the end of the power stroke and are really stressing them as they're meant to work. More tiring, significantly.

With a more narrow thwart the weight is inbetween muscles, as it were.

Breakaway
11-12-2014, 08:06 AM
http://secure.ssbtractor.com/graphics/productFTDDSP_fullsize.jpg (http://www.google.com/url?sa=i&source=images&cd=&ved=0CAgQjRw&url=http%3A%2F%2Fwww.ssbtractor.com%2Fcgi-bin%2Ftractor-parts-search.cgi%3Fcategory%3Dall%26keywords%3Dseat&ei=HmljVOv6KYrHsQTAwYKQDw&psig=AFQjCNGmgkNt2pnwwXZugiVTgQ5EHKEPiQ&ust=1415887518795501)

Osbert, this is a "tractor seat."

Kevin

Thorne
11-12-2014, 10:10 AM
The low back padded seat, sorta like a tractor seat, seems to work well for Rick T in the sliding seat rig in his Walkabout. He's posted here several times about it. I suspect it would make fixed seat rowing harder, but don't know for sure.

http://www.luckhardt.com/wr-cs_and_walkaboutdock.jpg

Osbert
11-12-2014, 10:40 AM
Right! It never occurred to me to use a tractor type seat for fixed rowing. I'm curious about the benefits of a narrow thwart though.

Ben Fuller
11-12-2014, 05:37 PM
My Afordsfaering has really narrow thwarts, rowing style has plenty of layback. What it does is the same thing as the cutout sliding seats: provide a place for your coccyx to go. Plus the advantage of some butt hang locking you on the seat. I remember once spending time rowing a St.Lawrence skiff with very wide thwarts: a pain in the butt so to speak. Stroke modification was needed.

Binnacle Bat
11-12-2014, 07:13 PM
It seems to me that if one is going to hang one's butt over the forward side of a narrow thwart, the oarlock socket might need to go forward a tad to compensate, other things being equal.

Allan

Ben Fuller
11-12-2014, 07:27 PM
It seems to me that if one is going to hang one's butt over the forward side of a narrow thwart, the oarlock socket might need to go forward a tad to compensate, other things being equal.

Allan

All depends on the relationship of the two. I'd need to go measure the Afjords, but I bet it's pretty close to standard as the measuremen is from the aft edge of the thwart. Making it narrow is just cutting away the forward edge.

Hwyl
11-12-2014, 08:09 PM
Nice to see Kermit resurrected.

Osbert
11-13-2014, 02:02 AM
My Afordsfaering has really narrow thwarts, rowing style has plenty of layback. What it does is the same thing as the cutout sliding seats: provide a place for your coccyx to go. Plus the advantage of some butt hang locking you on the seat. I remember once spending time rowing a St.Lawrence skiff with very wide thwarts: a pain in the butt so to speak. Stroke modification was needed.

Ben, that's really interesting. Would be helpful to see your measurements if you had time:
- width of thwart
- thwart to oarlock/kabe (horizontal, vertical)

I'd imagine the forward edge of the thwart would need to be nicely shaped to avoid a hard corner.

How is it sitting on the narrow thwart for longer periods?

Also, did you know some faerings had thwarts that rocked/tilted as you rowed:
http://forum.woodenboat.com/showthread.php?171995-My-Strandebarmer-Faering-Project&p=4331579#post4331579 with reply in subsequent post

Any experience, thoughts?

Cheers

slug
11-13-2014, 02:36 AM
Seating position,width, reach are all personal choices.

Dont get all confused thinking about it.

What is important is that you build your boat so that any size seat will work.

wide seats are preferred when they are used to stand on...polling , fishing or coming alongside...

Osbert
11-15-2014, 01:42 AM
Seating position,width, reach are all personal choices. Dont get all confused thinking about it. What is important is that you build your boat so that any size seat will work. wide seats are preferred when they are used to stand on...polling , fishing or coming alongside...

Indeed. I'm nearly at the stage of fitting thwarts and rowlocks and footrests, and I'll be mocking up and adjusting for fit. Apart from the forward one the thwarts will all lift out so easily adapted later, but keen to start off with a good set up.

I hadn't thought about narrower thwarts before, so keen to hear others experience - there's only so much you can learn sitting on a mock up in a cold garage making rowing movements!

Oldad
11-15-2014, 08:03 AM
The low back padded seat, sorta like a tractor seat, seems to work well for Rick T in the sliding seat rig in his Walkabout. He's posted here several times about it. I suspect it would make fixed seat rowing harder, but don't know for sure.

http://www.luckhardt.com/wr-cs_and_walkaboutdock.jpg

Is that a rear view mirror on the port side gunnel?

Ben Fuller
11-15-2014, 12:49 PM
Ben, that's really interesting. Would be helpful to see your measurements if you had time:
- width of thwart
- thwart to oarlock/kabe (horizontal, vertical)

I'd imagine the forward edge of the thwart would need to be nicely shaped to avoid a hard corner.

How is it sitting on the narrow thwart for longer periods?

Also, did you know some faerings had thwarts that rocked/tilted as you rowed:
http://forum.woodenboat.com/showthread.php?171995-My-Strandebarmer-Faering-Project&p=4331579#post4331579 with reply in subsequent post

Any experience, thoughts?

Cheers

Some dimensions: 14-15 inches from the kabe to the aft edge of the seats. (35.5 to 38.5 cm) The seats themselves are 5-5.5 inches (10.3-10.4 cm). They do move a little as they are not structural, but no effort was made to make them rock. Sitting on them, the sit bones are centered on the seat. A bit of foam underneath can provide a bit of padding. When I started this felt odd, but now I'm quite used to it. Seats themselves have small beads and a slightly rounded corner. Bear in mind everything on the boat was done with a blade, no sandpaper.

Osbert
11-15-2014, 03:00 PM
Ben - thanks for taking the time to measure up; all grist to the mill!

By the way, any photos of your faering? Just generally, not the thwarts specifically, I'd be interested to see a Afordsfaering - I've tried searching the forum but it's not turned anything up.

Cheers

Osbert

Thorne
11-16-2014, 09:46 AM
Is that a rear view mirror on the port side gunnel?

Yep, as Rick and our TSCA group tend to row some rather challenging rivers and sloughs. I set up a truck mirror that mounts in stock oarlock bases on both my little boats via a clever method that I came up with meself -
https://scontent-a-lax.xx.fbcdn.net/hphotos-xpa1/t31.0-8/p403x403/10296457_10152465355718646_3738564228787930725_o.j pg


Here's a thread that shows pics of his mirror, but most of my pics have gone missing due to Facebook changing the URLs -- I didn't change any permissions on those albums, so I don't know why.

http://forum.woodenboat.com/showthread.php?176382-Recommended-height-of-gunwale-mounted-rear-view-mirror-on-pulling-boats&highlight=mirror