Longer oars, blade length and width?

[Toxophilite]

So I laminated up the looms for oars with epoxy

Now I'm going to make the blades .


I wonder if people have insight/opinions on blade shape and width?
I was going to copy my Barkely sound oars as I enjoyed them when I used them (albeit I had no comparision except the open water oars my boat came with Long narrow but thick blades)
Then I was ogling Shaw and Tenney straight bladed oars and was curious about longer slightly thinner blades which they reccommend for oars over 8.5'
Their wide blade oars are 5' 3/8" while their longer ones are 4 5/8"

Any insight as to performance? The Barley sound 8' oars I had had blades 5'1/8" wide about 25" long
Culler oars , including a long taper have blades somewhat similar to Shaw and Tenny's long narrow blades
36' long(including 12' of taper) 4.5" wide at the tips
Shaw and Tenny's calculations would have my oars being 9' long (current oars are 9'1")
My boat has a lowish freeboard of about 12"

For rowing as an auxilliary, 1-3 hours, maybe longer as needed when camping.

[Peerie Maa]

N.B. Oars or sculls made of fir exceed the dimensions in the above tables one-eighth of an inch. The price of fir oars is seven shillings less than ash oars, and fir sculls three shillings and sixpence less than ash sculls.

http://www.thebigrow.com/wp-content/...3/05/oars2.jpg

[Ian McColgin]

I like long (10') narrow bladed oars with a bit of spine down the centerline of each side. The spine gives the blade almost as much grip on the water, is symmetrical to hold, and sculls better than a spoon shape. I can't actually feel a power difference between spoon and flat with spines. As I study the oar eddies they look similar. I can't imagine that crew teams and single sculls would keep using spoons if they were not good but I think the spoon makes more sense in a very light craft. I row traditional craft using the "doryman's stroke" which really lends itself to straight oar blades.

[Peerie Maa]

I like long (10') narrow bladed oars with a bit of spine down the centerline of each side. The spine gives the blade almost as much grip on the water, is symmetrical to hold, and sculls better than a spoon shape.

Like these.
finished 008.jpg
They measure 10 foot.
Handle 7 "
Loom 22", by 2" square
Shank 57", 2" by 1 1/4 at the wrist.
Blade 34" by 4" wide.

[johngsandusky]

I have Shaw and Tenney long oars with the wider blades. I plan to shave them down.

[Toxophilite]

12' clinker dinghy
I used Shaw and Tenny's length calculations. The space between my locks is 56" the actual beam is 5'
So 9'. If I went off the beam it would be 9.5 If I used the double the beam method it would be 10'

Don't longer oars give you more outboard weight?

[Nicholas Scheuer]

If you're going to scull much, taper the edges of the blades a bit and then round them, but don't taper them to a fine edge. They will move to and fro laterally more effectively than the squared-off edges often seen on commercial oars. for sculling you want the oar blade to sort of resemble a propeller blade. Propellers don't have squared-off edges.

[stromborg]

Don't longer oars give you more outboard weight?

Yes, the portion of the oars inboard of the locks is often left pretty hefty to balance out the outboard weight. Some folks will drill out the handles so they can add or subtract weight to get the balance just right.

[Toxophilite]

I like long (10') narrow bladed oars with a bit of spine down the centerline of each side. The spine gives the blade almost as much grip on the water, is symmetrical to hold, and sculls better than a spoon shape. I can't actually feel a power difference between spoon and flat with spines. As I study the oar eddies they look similar. I can't imagine that crew teams and single sculls would keep using spoons if they were not good but I think the spoon makes more sense in a very light craft. I row traditional craft using the "doryman's stroke" which really lends itself to straight oar blades.

Out of curiousity what us the length , beam and type of your craft?

[robm]

If you're going to scull much, taper the edges of the blades a bit and then round them, but don't taper them to a fine edge. They will move to and fro laterally more effectively than the squared-off edges often seen on commercial oars. for sculling you want the oar blade to sort of resemble a propeller blade. Propellers don't have squared-off edges.

I believe regular rowing oars also benefit from being shaped this way. Long narrow oars are foils, they are not just shovels that push the water around.