Results 1 to 21 of 21

Thread: Wooden Hatchet-Blade Oars

  1. #1
    Join Date
    Oct 2009
    Location
    Dallas, TX
    Posts
    71

    Question Wooden Hatchet-Blade Oars

    Here I've lifted a CAD drawing from the Dreher website just to clarify what shape I mean:



    I'd like to know if anyone in this forum has attempted and/or succeeded in making a wooden hatchet blade.

    Even if no one has I'd like to discuss the possibility of finding/making a plan for a pair. I have doodled out some drawings making some guesses at the dimensions, but having no oar making experience myself I don't even know how this build would compare with building a traditional spoon blade (which, again, I only have theoretical knowledge of.)

  2. #2
    Join Date
    Apr 1999
    Location
    West Boothbay Harbor, Maine
    Posts
    21,552

    Default Re: Wooden Hatchet-Blade Oars

    They are designed for rowing shells, as you know. Those oarlocks are very low to the water so the blade angle to the loom on another kind of boat would have to be altered quite a bit especially if the oars are short. I doubt there would be much advantage to rowing a non-competition boat with them (and they might be a vulnerable shape in wood) but it certainly would be a woodworking challenge. Show pics if you do it!
    "Now and then we had a hope that if we lived and were good, God would permit us to be pirates." ~ Mark Twain


  3. #3
    Join Date
    Oct 2000
    Location
    Wellesley, MA USA
    Posts
    8,858

    Default Re: Wooden Hatchet-Blade Oars

    The shape of a hatchet blade is complex enough that its construction will be a composite of some material. Given the value of lightness in an oar blade, wood would not be my preferred material.

  4. #4
    Join Date
    Oct 2009
    Location
    Dallas, TX
    Posts
    71

    Default Re: Wooden Hatchet-Blade Oars

    rbgarr,

    I'm assuming in this daydream that the oars will be lengthy..say 9' or more, for use in protected waters only, and only for home-built rowing shells or wherries. Now that you mention it, my primary reason for desiring a hatchet blade is because that is what I am familiar with. I realize the spoon-blade is more versatile but for someone who wants to have a home-built rowing shell or wherry for use on protected waters, hatchets could be a valid choice.

    Jim,

    The oar weight doesn't bother me. A wooden hatchet blade would be no more heavy than a wooden spoon blade-which have been made from for over a century and used to be the competition standard. However if there has to be any funny reinforcement of the wooden hatchet, carbon lay up...aluminum core...I think I'd give up on the whole thing and just do a spoon.

    The strength of the oar is my biggest question mark, one that might only be answered by building one and trying to use it. Hatchet blades will transfer more torque to the loom than spoon blades, but the difference in force wont matter much to the loom I think. As for the blade shape itself being vulnerable in wood-that would be where the money is in the design so to speak.

    The more I think about it, the more I think its doable. But I've never built an oar before.

    So no one else has ever tried this? That surprises me. Hatchet blades shouldn't only be in the competition realm. I should think they aren't married to carbon fiber.

  5. #5
    Join Date
    Aug 2005
    Location
    SF Bay Area- Richmond
    Posts
    13,424

    Default Re: Wooden Hatchet-Blade Oars

    Quote Originally Posted by Jayhawk View Post
    So no one else has ever tried this? That surprises me. Hatchet blades shouldn't only be in the competition realm. I should think they aren't married to carbon fiber.
    As you mentioned, I suspect torque is a major issue, as to avoid it the oar would have to be pinned or use a flatside hard sleeve like the ones used for Douglas locks. But that means it could not be feathered or used with the dory stroke.

    If you don't see the blade design used for paddles or most oars, there will be a number of good reasons for that lack. Those old guys weren't fools, y'know...
    "The enemies of reason have a certain blind look."
    Doctor Jacquin to Lieutenant D'Hubert, in Ridley Scott's first major film _The Duellists_.

  6. #6
    Join Date
    Mar 2000
    Location
    Plainfield, Massachusetts
    Posts
    14,678

    Default Re: Wooden Hatchet-Blade Oars

    I've never built oars like this but looking at that oar blade shape, it looks to me like something you would want to shape out of plywood, or maybe using cold-molding techniques to effectively make your own plywood. That deep "belly" in the blade, if made out of solid wood, would be very vulnerable to splitting unless it was made quite thick, in which case it would be hard to make an oar that was at all balanced. An oar that is not balanced (i.e., it does not balance at the oarlock) would be very tiring to use. Made out of plywood or laminated wood it could be made light but fairly strong, especially if you overlaid it with epoxy and glass cloth.

    Making an oar like this with a solid (or better yet hollow, birds-mouth) loom and a laminated blade does not strike me as especially difficult, just a bit time consuming. The trickiest part would be connecting the loom to the blade since ideally the loom might curve a bit to wrap around the back of the blade, which would be a bit tricky to do.

    As Thorne noted, if the blade shape is such that stroking creates torque on the oar then you either need pinned oars (which I find very annoying) or oarlocks and oars with flat faces that match up when the oar is at the right angle to take a stroke.

  7. #7
    Join Date
    Apr 1999
    Location
    West Boothbay Harbor, Maine
    Posts
    21,552

    Default Re: Wooden Hatchet-Blade Oars

    For a home-built shell or wherry spoon and hatchet blades are fine. I think they aren't used so much by 'normal' rowers because sometimes an oar blade is used for fending off or poling.
    Last edited by rbgarr; 12-12-2009 at 01:04 PM.
    "Now and then we had a hope that if we lived and were good, God would permit us to be pirates." ~ Mark Twain


  8. #8
    Join Date
    Mar 2005
    Location
    Iowa
    Posts
    644

    Default Re: Wooden Hatchet-Blade Oars

    JayHawk, If you would like to make a pair for experiments sake, I have an article that will show you how to make an Octagonal, Hollow Core, Birds mouth, Spoon Blade oar. You would just have to change the blade design. The link will show you pictures of the oar construction process and a finished oar.

    If you would like the article, email me direct. I made two pair for my wife and myself for my Whitehall for less than $30.00 total.

    http://sports.webshots.com/album/366127989OQvvXQ

    Any one else who wants the article email as well.

    Tom...
    "Lord, please keep your arm around my shoulders and your hand over my mouth."

  9. #9
    Join Date
    Mar 2003
    Location
    Philadelphia, PA
    Posts
    433

    Default Re: Wooden Hatchet-Blade Oars

    I love mine, they were a lot of fun to make and they are beautiful. I also just copied shapes from different manufacturers off the internet. One thing I didn't know before using them was when you row, the larger blade area under the loom balances the pull of your fingers on the top of the loom - you do not have to compensate as much for rolling the oar as you pull it towards you. I always feather when I row. The shafts do have some flex but not an issue for me as a recreational rower. They work really well in the melonseed which is low to the water - it rows very well. I originally made them 10' long - 1 piece, 3-1/2 lbs each from clear doug fir with fiberglass reinforcing on 3 edges of the blade. I then cut them down to 8' 10-1/2 " to fit in my melonseed.

  10. #10
    Join Date
    May 2004
    Location
    Cuyahoga Falls, Ohio
    Posts
    2,737

    Default Re: Wooden Hatchet-Blade Oars

    I should think that if the area of the blade above the line of the loom extended equals the area below it, torque on the handle would approach zero unless you didn't get the whole blade into the water.
    Nicely done, Phil. Are those blades carved solid wood or ply or what?

  11. #11
    Join Date
    Mar 2003
    Location
    Philadelphia, PA
    Posts
    433

    Default Re: Wooden Hatchet-Blade Oars

    Tom, as far as the areas being equal, you would think so until you try them. When you pull with your hand with fingers wrapping over the top of the shaft, that tends to roll the top of the shaft towards you, so you stiffen your wrist to prevent that rotation, with the hatchets with unequal area/greater area below the shaft, these torques tend to cancel eath other and I end up rowing with a lighter grip on the shaft. Both oars are cut from a single 2X10" X 10' blank , nested - single piece - the curved blade is using the full 1-1/2" thickness of the stock. It's very much hand, eye, ruler work, make them together - taking care that they match each other mirrored left and right.

  12. #12
    Join Date
    Mar 2003
    Location
    Philadelphia, PA
    Posts
    433

    Default Re: Wooden Hatchet-Blade Oars

    I've published these before, here are the dimensions I used. The blades are 14-1/4" on the bottom edge by 6-3/4" on the outside edge. The projected line of the loom intersects the blade 4-1/2" at it's inside edge and 3-3/4" from it's outside edge measuring up from the bottom. I curved the blade the full 1-1/2" thickness of the stock. 1-1/2" dia loom at the oarlock tapering to 1-1/2" x 1-1/4" at the blade. I used circular, jig saw, hand and power plane, spokeshave, disk, belt, pad sanders. Something like that CAD drawing will just throw you off, you cannot get too technical, the hardest part is keeping both oars the same and power tools are not left and right hand - they are only single handed and this comes up as your trying to shape the the loom melting into the blade. You just have to keep a clear vision of what you want to leave, figure out how to do that with the tools at hand and then go for it.

  13. #13
    Join Date
    Mar 2005
    Location
    Biddeford, ME
    Posts
    1,987

    Default Re: Wooden Hatchet-Blade Oars

    Quote Originally Posted by JimConlin View Post
    The shape of a hatchet blade is complex enough that its construction will be a composite of some material. Given the value of lightness in an oar blade, wood would not be my preferred material.
    The reason they are composite usually is what Jim touches on, that the shape needs to be reproduced often and therefore a mold is best and wood hanging all the way down at the outboard end of a loom makes the oar blade heavy.

    We solve these issues by making the blade material very light, so it's going to be Carbon Fiber or Fiberglass (don't get fooled...they make 'glass black so it mimics carbon) with a core material to build stiffness in the thin laminate with hardly any weight added. See more on wood and carbon blade oars in the link at the bottom of the post.



    Wood is wonderful to use in blades and a joy to make and look at but we need to fix the issue of blade heaviness by counterbalancing the oars with lead. One way is to pour lead into a form -- such as copper pipe -- or by taking lead flashing or lead shot and sticking it into the oar handle or the upper most part of the inner loom. Below you can see the lead filled pipe just sticking out of one handle while the other handle is bored out. These 'slugs' were a little more than a pound a piece.



    Whether wood or composite blade, the right balance happens when the blade sits on the water like a feather with hands off the grips. It is a wonderful feeling. Over-counterbalancing results in the inner loom feeling too heavy and the inertia that produces can actually be fatiguing as can an oar that is too blade heavy.

    I called my brother-in-law who happens to be a hall-of-fame rowing coach to ask him for some info on the hatchet style blades, specifically, why did competitive rowers switch from Macon to the 'hatchet'. It probably has something to do with what folks have said about the oar feel during the pull. I'll report out again.

    Cheers,
    Clint
    Clinton B. Chase
    Portland, Maine

    http://tinyurl.com/myboats

  14. #14
    Join Date
    Oct 2009
    Location
    Dallas, TX
    Posts
    71

    Default Re: Wooden Hatchet-Blade Oars

    Quote Originally Posted by Philip Maynard View Post
    I love mine, they were a lot of fun to make and they are beautiful. I also just copied shapes from different manufacturers off the internet. One thing I didn't know before using them was when you row, the larger blade area under the loom balances the pull of your fingers on the top of the loom - you do not have to compensate as much for rolling the oar as you pull it towards you. I always feather when I row. The shafts do have some flex but not an issue for me as a recreational rower. They work really well in the melonseed which is low to the water - it rows very well. I originally made them 10' long - 1 piece, 3-1/2 lbs each from clear doug fir with fiberglass reinforcing on 3 edges of the blade. I then cut them down to 8' 10-1/2 " to fit in my melonseed.
    Spectacular blades Phil!

    How old are they? Any observations on how they wear over time/use?

    -do you think they could be made with a square collar section, to accept a collar/rigger system?

    Thank you for showing!

  15. #15
    Join Date
    Mar 2003
    Location
    Philadelphia, PA
    Posts
    433

    Default Re: Wooden Hatchet-Blade Oars

    Thanks, I guess these are 5 years old and I have had no problems but honestly I do not use them alot as they only live with the melonseed and I have about 4 boats and I use them all so it will be hard to wear them out. I made the blades thin because I wanted them light and the FG reinforcing on the edges is absolutly essential. They certainly would be easy to break on a rock or break off if you get then stuck between dock planks or in mud, etc so they are not bang around oars but I'm sure not going to break them against water. I should add that if I had to repair them - as long as I have all the pieces it should not be hard, but if I lost half the blade obviously that could be a tricky repair/matching job. Funny you should mention square collars. I see no reason you could not use square collars. I made these originally for my wife for the merry wherry I made her. She had joined a crew and she said the oars turn and "click". I had never rowed outriggers or even seen the hardware used and I did not know what she meant by the "click" - which is of course the square collars. Incidently she did not like these, and got carbon fibre hatchet oars (with square collars) for the merry wherry and I had no problem with that as I like these much more than the CF oars (although the CF oars are lighter and stiffer) and then cut them shorter to fit under the side decks of the melonseed. But now I know about square collars (from rowing her pair of CF oars). I realize the square collar "sets" the angle of the oar for you and to some extent locks it at that angle during your stroke and that is probably how most if not all hatchet oars are used. My case of using them with round collars reveals more of that torque effect I was trying to explain - because they are floating and not "locked" during the stroke. I've got nothing against square collars and I see why they are used especailly in a competive team setting where getting everyone to row in sync is really important but I personally prefer round for recreational rowing.

  16. #16
    Join Date
    Aug 2005
    Location
    SF Bay Area- Richmond
    Posts
    13,424

    Default Re: Wooden Hatchet-Blade Oars

    If you like the Douglas-style oarlocks that hold the oar at a specific angle, you can either go with the commercial plastic sleeves with one flat side, or make your own from leather to avoid the click.



    "The enemies of reason have a certain blind look."
    Doctor Jacquin to Lieutenant D'Hubert, in Ridley Scott's first major film _The Duellists_.

  17. #17
    Join Date
    Mar 2005
    Location
    Biddeford, ME
    Posts
    1,987

    Default Re: Wooden Hatchet-Blade Oars

    Firstly, Philip, those oars are gorgeous...sorry not to have said that in my last post. They look really functional. Did you counterweight the looms? This is where I think the square section collars (pictured below) would be great.

    I like the Douglas oarlocks and would use them with the collars I used for the customer whose oars are pictured here, the spruce with CF blades. The collars are these:



    They are easy to install and the oarlock (C2) sets the 6 degree pitch angle as does the Douglas Oarlock. The trick with make square loom oars is that you need to be darn sure that you get the flat planed onto the loom right such that they pitch angle is correct...that would be a challenge to say the least. The nice thing about the black oarlocks I used or Thorne's is that the collar can be rotated if the angle is not right. This dig angle in actual use of oars is totally key.

    I spoke with my brother in law/rower/coach guru, while I was bathing the kids, and he quickly explained that the Dreissigackers and C2 did a lot of research and figured out that the hatchet shape does the most work (i.e., the least slip through the water) in the rowing stroke as compared to the Macons. Additionally, when the top of the blade is parallel to the water surface efficiency is much improves so that is why the oar loom/shaft comes in at the top of the blade so that it can establish the correct angle with the water. Therefore using these type of oars in anything but a scull needs to take that angle to the water from the boat into account. The oars can be shorter because of the increased efficiency and shorter oars makes for better stroke ratings in competitive rowing.

    But us fixed seat, recreational folks can stick with nice symmetrical blades and not lose any efficiency...it is only in sculling type of boats that these higher-evolved blades start to really matter.

    http://tinyurl.com/customoars
    Last edited by Clinton B Chase; 12-10-2009 at 08:46 PM.
    Clinton B. Chase
    Portland, Maine

    http://tinyurl.com/myboats

  18. #18
    Join Date
    Mar 2003
    Location
    Philadelphia, PA
    Posts
    433

    Default Re: Wooden Hatchet-Blade Oars

    Thanks Clinton, Actually I've never thought of counter weighting them - I was pleased they were as light as they are and stopped there. I guess making square looms would be tricky although if you already had the boat/riggers set up that should make it possible to set the angles without to much trouble but once you are getting into that type of hardware I would guess you would want everything to be adjustable anyway so round looms with the square collars may make the most sense. I was just trying to do something fun - I had never even used a pair of hatchets before I made mine and ended up very happy with the results.
    Last edited by Philip Maynard; 12-10-2009 at 09:43 PM.

  19. #19
    Join Date
    Mar 2005
    Location
    Biddeford, ME
    Posts
    1,987

    Default Re: Wooden Hatchet-Blade Oars

    I am trying to imagine how much it would cost to have these custom made...they'd be expensive. Perhaps the approach I would take -- and might when I make a new pair of sculls for Drake -- is to laminate the blades out of plywood (suggested by Bruce already), cut to the hatchet shape, and the spruce looms would glue to the back of these blades like they do on my line of CF blades like this....



    One could adjust flexibility this way too by altering the amount of wood on the back of the blade. This glue joint has to be bombproof, or dock proof, or stuck-between a rock and a hard place-proof.

    A lot of folks worry about making their oars stiff...this is the last thing you want in oars unless you are rowing sprints on the Charles River in a CF shell! Oars that flex are less harsh on the body, so for rowing endurance and when a softer workout is desired, flex is desirable. How much and where the oar flexes is the art of this business.
    Last edited by Clinton B Chase; 12-12-2009 at 07:15 AM. Reason: clarification
    Clinton B. Chase
    Portland, Maine

    http://tinyurl.com/myboats

  20. #20
    Join Date
    Oct 2009
    Location
    Dallas, TX
    Posts
    71

    Default Re: Wooden Hatchet-Blade Oars

    Thank you guys for the discussion.

    I've decided not to try making hatchets on my first oar-making attempt, though I'm still intrigued by the idea.

    I'll be doing a set of 9'6" oars for a CLC boat I want to build this spring. Since there are some very good plans and patterns out there for "spoons," I'll be conservative the first go around.

    So I went out to source lumber for these. I live in Texas Horse country...no spruce....no yellow cedar... BUT, I have found some nice quarter-sawn Douglas Fir in large pieces.

    So the next question is: has anyone made Doug Fir oars? Are they too heavy?

    I can also get a hold of White Oak and Southern Yellow Pine but according to wood books these are even heavier than the Doug Fir.

    Any thoughts?

  21. #21
    Join Date
    May 2004
    Location
    Cuyahoga Falls, Ohio
    Posts
    2,737

    Default Re: Wooden Hatchet-Blade Oars

    More weight = more inertia. For rec. use does that mater?
    Bird's mouth the loom, if that bothers you, to lose some of that weight.
    Oars aren't such a major job that litttle is lost if you don't like the result - hang them on the wall of the shop and try another scheme.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •