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Trireme Rowing Geometry, 6th Century B.C. (Time-Life Books: The Ancient Mariners, Page 71)

Sunday, January 31, 2016

The Oar-to-Boat Connection

What are some of the options for oarlocks, sockets, leathers and buttons?

Oar Locks

Probably the simplest oarlock is a single “thole-pin” with a loose lashing around the loom of the oar and the thole-pin as shown below.


From Small Boats, by Phil Bolger, page 32

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Tom the Rower's (http://drunkrowing.blogspot.com/) large dory has his own variation of a thole pin oarlock. The oar is fastened to the thole pin by a loop of line that goes from the top of the pin, over and around the oar between PVC buttons screwed to the oar and then back around the pin under the oar. He changes ‘gear’, by shifting the loop from button to button. Clever.

Tom the Rower's Custom Thole Pin Oarlock

Tom stated (see Comments in my blog on “gears”,
(http://theoarcruising.blogspot.com/2016/01/change-gears-when-rowing.html) that he could not feather with this arrangements. Since his oar blades are only 3.5” (89mm) wide, he says they don’t present a windage problem.

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The oarlocks below are available through Duckworks and are the locks I use on my Ross Lillistone “Flint”. They are pictured in the ‘gears’ blog mentioned above.


Duckworks “Seadog Premium Brass Ribbed Horn Oarlocks”


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The “Douglas” design oarlocks (below) have two distinct advantages over the ‘horn’ locks above:

1.    The front of the oar is directly over the center of the pivot point and therefore the oar does NOT have the tendency to ‘walk’ as you stroke. (However, I have never felt my oars ‘walking’ (toward the center of the boat) using the ‘horn’ oars above as Bolger talks about in his book, Small Boats, on page 32-33).

2.    To me, the big advantage of the Douglas lock is the 6 degree angle of the forward (pivot) side of the lock. When used with a square or “D” shaped loom, the oar blade is tipped back 6 degrees which is the ideal angle of the blade during the power portion of the stroke… steep enough to keep the oar in the water, but not so steep that the oar dives.

Douglas Oarlock diagram and dimensions


Also see an article reviewing the Douglas Oarlock:
http://www.duckworksbbs.com/hardware/oarlocks/douglas/Ash%20Breeze%20Article%2011-05.pdf

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The oarlocks below are manufactured in Sydney, Australia (http://www.gacooarlocks.com/)


Gaco Oarlocks

Gaco also sells sleeves to enable the locks to fit in either 1/2” or 7/16” sockets. A visit to the site is well worth your time. It contains a series of articles on boats, rowing, oars, etc.

Sockets

Sockets can be top mounted, or side mounted. It is critical that the socket be firmly attached to the boat. I’ve found that (even large) screws are not good enough. The screws will work loose over time. They did for me, and I now use a combination of bolts with cap nuts and washers, along with screws, to attach the sockets. Since doing that, I’ve had no issue of the sockets working loose.

Sockets can be purchased with oversized holes for the oarlock pin, but they include a nylon bushing so that the lock pivots in nylon vs. metal to metal… much smoother and quieter… and replaceable.

Leathers and Buttons

Leathers perform two functions:

1.    Protect the oar from wear at the oarlock

2.    Help to make feathering easier and quieter.

Buttons stop the oar from sliding out (into the water) of the lock. The button can be an integral part of the ‘leather’ or added separately.

Traditionally, leathers have been made of… leather. Shaw and Tenney,
http://www.shawandtenney.com/productdisplay/leather-kit, Duckworks http://www.duckworksbbs.com/hardware/oarlocks/oarleather/index.htm and others sell kits to enable you to apply real leather to your oars.

The photo below is of leathers I applied to a set of oars. The kit came with instructions on how to trim the leather to fit the oar and to sew it on the oar with a ‘herringbone’ stich. The button (supplied in the kit) is cut to the proper length and then, in this case, attached with escutcheon nails (about one inch, brass, with round domed heads).



Leather leathers

But leather is not the only option. On these oars below, I used 1/8” Polyester Solid Braid Line from Duckworks (http://www.duckworksbbs.com/line/polyester/sbraid/index.htm). Jim Michalak (jimsboats.com) suggests making a button by creating a “Turk’s Head” out of bungie cord. No matter how tight I made the Turk’s Head, the button slipped. I finally had to glue it to the loom. Now that I’ve installed the gear changer (See “Change Gears When Rowing”, http://theoarcruising.blogspot.com/2016/01/change-gears-when-rowing.html ), the button is really not necessary.


Oar 'leather' and button made from 1/8" line and bungie cord

There are other alternatives for ‘leather and button’. Consider the Martinoli Oar Sleeves with Buttons from Duckworks
http://www.duckworksbbs.com/hardware/rowing/sleeves-rs/index.htm often paired with Douglas Oarlocks discussed above.

Another option is Seadog Adjustable Oar Collars, http://www.duckworksbbs.com/hardware/oarlocks/sd580101/index.htm My concern with these is that the amount of gearing flexibility is less than 4”.

There are many alternatives for how to connect the oars to your oar cruiser. Make your decision based on the severity of weather conditions you row in, how long you expect your boat/equipment to last and your wallet.

In 'comments' below, let us know what oarlocks, sockets, leathers and buttons you use and what would you change if you were to do it over again.

14 comments:

  1. Here is how I set up the oar to thole pin connection
    https://www.youtube.com/watch?v=qDK6NAHU95Y

    ReplyDelete
  2. Thanks, Tom, for the link. Well done...

    Tom

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  3. Tom,

    Now I'm following your blog I have to comment on this topic. I race with D-shaft Pocock oars in the usual racing gated oarlocks, but for cruising prefer a smoother and easier way to feather.

    My favorite is round loom, rope wrap saturated with varnish, used with oval oarlocks. Thomas Foundry make an oval oarlock for 2" shafts, I make my oars 1.75 diameter and wrap with 1/8" black nylon cord. These have no slop in the locks and feather freely when lubed with lanolin.
    http://www.fisheriessupply.com/thomas-machine-and-foundry-oval-bronze-oar-locks-80415

    These oarlocks also have precision machined 1/2" shafts, when combined with precision oarlock sockets they eliminate slop. I make my own sockets from Oilite bushings, they are a precise fit to the oarlocks and never need lubricating.
    https://www.flickr.com/photos/ricks_boats/albums/72157624205867790

    The Douglas oarlocks are good, I have a set, but don't like the resistance and noise of feathering them on a long cruise. I find shaped grips are just fine for aligning the blade angle when cruising.

    Best - Rick

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    Replies
    1. Rick....I really like the sockets you made shown on your Flickr. Nice job!

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  4. Hi Rick... thanks for the additional information and experience on oarlocks and sockets... As an aside; This is exactly what I hoped to accomplish with this blog... to open up a topic and have others provide their own options and experience so that we can ALL learn from each other... thanks for adding to the body of knowledge... I will now step off my soapbox... Tom

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  5. The nice thing about using thole pins as I have shown in my youtube video is the ease of replacing any part. Thole pin= wood, and then the rope/light cord is used to tie/secure the oar to the thole pin, also easily replaceable with common items you already have. No special orders, no fed ex or UPS. Plus, again, the oars are free trailing. Want to take a break, just let go of the oars.

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    Replies
    1. Point well taken, Tom... I don't do bronze castings...

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  6. I would add one thing further...There are alot of stories from guys who have done a watertribe (watertribe.com) event, only to have an oarlock break mid event. I can't remember all the details, but something like the bronze ones or something about the way some are cast that makes them non dependable over the long haul, such as a long distance event. ( I didn't need to retain all the info, because of my dependable thole pins)

    ReplyDelete
    Replies
    1. I do remember one EC boat (The custom Lightning?) in which the lock didn't break, but the socket came loose... it was only screwed in... that's why I use bolts on mine.

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  7. Tom - I like your thole pins, these certainly have a long history of simple, maintainable functionality.
    Anyone who rows much develops a strong preference for their favorite oars and locks, I've seen (and participated in) many heated discussions over the merits of feathering, spoons, shaft flex, grips, etc. Adirondack Guide Boat types can't live without their fancy captive locks:
    http://vintagecanoeworks.com/restored/92jhr_saranac.html

    ReplyDelete
    Replies
    1. Rick, I rowed a beautiful Adirondack Guide Boat this past Spring, with captive locks... I felt really uncomfortable not being able to feather... different strokes for different folks.

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  8. This comment has been removed by a blog administrator.

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  9. Tom, about attaching oarlock sockets to the boat, the received wisdom seems to be that bolts are better than screws for reliably securing the sockets. I am interested in the details of how the sockets are bolted. For example, what material are the bolts? What size washers are used? Are the bolt holes treated for water intrusion? Is the area around the nuts reinforced? Is a thread locking compound used for the nuts? Justin

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  10. Hi Justin... Definitely bolts!
    On Raven (my Ross Lillistone Flint), I have 3" teak risers mounted on the gunnels... these have about 1/4" x 2" brass bolts (the risers are 'stepped down' at each end) down through the gunnels with washers at the nut end... the bolt is flat head (machine screw?) and countersunk into the teak.
    for the socket, I used two 1" flat head screws on the face, driven into the side of the riser. And two 5.5" stainless steel (1/4") flat head bolts down through the riser and gunnel (found them on Amazon... not available in any local hardware stores) At the bottom are nuts with washers.
    I was a little concerned about electrolysis but no evidence of a problem. These sockets are rock solid for over two years of rowing... Never need tightening...Earlier, before I added the risers, I had used screws on the sockets and they continually came loose... never again.
    To answer your questions:
    bolt/screw material are either brass or stainless steel
    Washers are what I had available.. tightened until they sunk into the gunnel (which is Western Red Cedar)
    Bolt holes NOT treated for immersion, but riser is glued to gunnel and all screws/bolts pulled up really tight.
    Area around nuts is not reinforced...
    No thread compound used.
    Tom

    ReplyDelete