Oarlock spacing?

[Ocean Spray]

In a rowboat with fixed seats what is the typical demension from the edge of the seat to the center of the oarlock?

[Thad]

12 inches

[Ron Carter]

My personal choice is 13". Shaw and Tenney says 8" minimum which is way short for my tastes.

[Graham Knight]

I went with 11" for my Acorn Skiff, which is what's shown on the plan. But surely this must be partly down to the type of boat and the size of the rower, and maybe some other factors too? There can't be a "one size fits all" for something like this can there, any more than positioning of stretchers, for instance, which usually have several positions to suit different size rowers?

[htom]

I don't think that there is a universal dimension; it's going to depend on both some of the dimensions of the rower and things like the depth of the thwart from the gunwale and the inboard length of the oar. Eleven or twelve inches from the edge of the thwart seems to be the "normal" recommendation.

[Ian McColgin]

We fuller figured gents go for 14" or so.

Try just hanging a couple of C clamps on each gunnel and experiment. If you tangle belly and oar handles on the return, give it a bit more space.

G'luck

[Osborne Russel]

Do you mean the vertical distance from the outboard edge of the seat to the lower edge of the oar where it rests in the lock?

[Tom Robb]

How long are your arms?

[Ron Carter]

Ian, I resemble that remark, explains the 13".

Edit for fat fingers.

[ 02-28-2006, 06:07 PM: Message edited by: Ron Carter ]

[Ian McColgin]

It's usual to measure from the aft edge of thwart. The reason for a bit of experiment, besides that people differ in size, is that differences can occur depending on the height of the seat above the sole or bottom, and the height of the gunnel above the seat. In general, the lesser either of those two, the more distance you'll want.

Unless the boat is very high sided, I don't personally favor a thwart any higher than absolutely needed as, if you've good foot rests, youcan get more power the lower your seat.

The less the distance between thart and gunnel, the more difficulty the rower may have in clearing first the knees and then the belly.

Finally, remember that this is not a scull where long long strokes are a good thing. If you swing from 30 - 45 degrees ahead to the same aft, 60 - 90 degree total arc, you're in a good place. Much more arc and you're pushing water away at the start of the stroke and pulling it in at the end.

It's nice to achieve comfort where you mostly use your big back and torso muscles more than your puny arm muscles.

G'luck

G'luck

[JimConlin]

So, to state it simply, typical distances from the aft edge of the thwart to the rowlock socket are:
Vertically- at least 6" .
Fore & aft- 12" (14" for Ian and me)

[htom]

There is no rule, either, that says you can have only one pair installed, especially at the primary rowing station. Depending on the sockets and your budget, you could have them at 11" and 13", or 10", 12", and 14", or some other combination.

[LazyJack]

The drawings that John Gardner developed from a 16 foot Lewis Grant Adirondack Guideboat placed the oarlock sockets 16 and 15/16 inches from the after edge of the foward rowing station. I built accordingly...and it is way too far! I moved the seat aft about 2 inches and dropped it down about one for a much more comfortable position. That was about as close as I could move it without my gut ubstructing the oar handles towards the end of the stroke. The oar handles overlap on a guideboat so there is considerable length inboard of the locks. Constructing a mock-up with c-clamps etc as suggested above is well worth the effort. Ya gotta be comfortable!

[Ocean Spray]

The boat in question is a 15'00" Ducktrap Wherry. It has two rowing stations and the plans call for a distance of 12" from the seat to the oarlock. The Nutshell Prams that I built have 10" so I just wanted to here what kind of input I'd get from the forum . . . . and it has been excellant!

[Ian McColgin]

Part of the difference is that the pram is rowed with shortish strokes, especially if loaded with two people plus gear. There's not much room between the rowing thwart and the stern sheets.

On little boats like this, by the way, a fore-and-aft thwart with two stations is nice if you need to balance just one passenger and not much gear.

On the wherry, you can swing through 90 degrees as she'll carry a good ways and you thus need more space butt to oarlock.

[BrianY]

In his book on skiffs, Karl Stambaugh says that the olde fashioned Chesepeake way to determine the distance betweent the edge of the thwart and the oar locks is to place your elbow on the gunwale right above the center of the thwart, lay your forearm down on the gunwale and straighten out your hand. The oarlock goes right where the middle of your hand lies.

Haven't tried it myself (yet) but as this method automatically accounts for variations in the dimensions of the rower's arm length, it seems to make a lot of sense.

[ 03-01-2006, 02:18 PM: Message edited by: BrianY ]

[Graham Knight]

Interesting formula Brian, I just laid my arm on the desk and measured as you describe, measuring from my elbow to the centre of the palm (I assume that's what's meant by the middle of the hand?) that would be 15 inches, minus half the 7" wide thwart equals 11 1/2". So the 11" called for in my Acorn plans is pretty close, if I shuffle forward 1/2" I should be spot on!

[Steve Lansdowne]

The height of the seat in relationship to that of the oarlocks and the bottom of the boat must be considered also. If the position of your legs gets in the way of the oars because your legs can't stretch far enough out to be avoided when you row, things don't work out well.