Sunday, February 28, 2016

Rowing in Rough Water

Rough water can happen to any of us: The wind gains strength while we’ve been easily rowing downwind… A sudden thunder storm comes up… A wind shift causes a ‘confused sea’, waves from multiple directions. Regardless of how much we love nice calm rowing conditions, stuff happens… Here are ideas on how to deal with unexpected rough water.

Dale McKinnon, in an article in Small Boats Monthly, Rowing Rough Water , identified three keys for rowing in rough water:

1. Shorten your stroke by a quarter to a half.

 
Birgit Skarstein, of the Lidchhardt Rowing Club agrees:
“When the water is very rough, you need shorter, more frequent strokes and steady, smooth power.”
 The author also states:
“In extremely rough water, stop your hands about 3 or 4 inches away from your ribcage at the finish of the stroke. This will allow more room to drop your hands [lifting the blades higher to avoid hitting waves] and release the blades from the water.”

 

2. Relax.


Dale says: 
“Concentrate on softening your grip… you will calm the rest of your body. Stay balanced and relaxed, and let the boat do its wild hokey-pokey beneath you…”
Shirwin Smith, Founder of Open Water Rowing Center in Sausalito, California, states:

“Don’t fight the water. The biggest problem for scullers on rough water is their tendency to stiffen their upper body, arms and hands. “

 

3. Zigzag to deal with a ‘beam’ sea.


Dale recommends, rather than rowing parallel to the waves (with first one oar and then the other oar digging in and water possibly pouring over the gunnel), we angle (30 to 45 degrees) into the wind. The boat will not roll so much and it will be easier to keep both oars in the water. Turning into the wind will also offset the distance the boat is being blown down wind.


An excerpt from Dale’s article:

“Halfway across the entrance to McKay Reach [in the 3rd week of an 800 mile row from Ketchikan, Alaska, to Bellingham, Washington in a 20’ Sam Devlin designed dory] I encountered swirling gale-force winds and waves coming at me from all directions. As my fear increased, my grip on the oars grew tighter. I was tiring quickly and my hands, forearms, and back ached. I knew that if I didn’t regain my composure and relax, fatigue would add exponentially to the danger I was in. To reach the safety of even the nearest lee I would have to conserve energy. I kept pulling and calmed myself. I loosened my grip and soon felt my body begin to relax. As my spine became less stiff, my hips could adjust to the wild gyrations of the hull. My head no longer swayed with every wave, and my growing dizziness subsided. My blades stopped getting slapped skyward off the tops of waves, and my tendency to “catch a crab” disappeared. I could feel the water on each blade and adjust more quickly to the waves’ erratic shapes.”

Sunday, February 21, 2016

Feathering Without Pain

To feather an oar is to spin it forward approximately 90 degrees so that the blade, during recovery, is almost level (keep the leading edge of the blade slightly above horizontal) to the water. Why feather? Two reasons:
  1. Wind resistance is reduced, especially when rowing upwind. When rowing upwind and I don’t feather, I can definitely feel the resistance.

  2. In rough water, sometimes we don’t raise the blade high enough. If the oar is feathered, then the blade will cut through the wave… if not feathered, it’s called “catching a crab”, which not only slows the boat down but can be dangerous if only one oar catches.
In private correspondence with Christopher Cunningham, Editor of Small Boats Monthly, we discussed feathering and why people find it uncomfortable after just a couple of minutes. I mentioned to him that I feather by rolling my fingers, rather than cocking my wrist. He told me that his father, a rowing coach for many years taught his rowing students this technique to feather.

Hand and Wrist During the Pull Portion of the Stroke
This photo shows the hand position during the power portion of the stroke. Notice the blade is almost vertical and the wrist is straight.



Hand and Wrist When Feathering by 'Cocking' the Wrist







Here, the oar has been feathered (blade is horizontal) by cocking the wrist. I found, after a couple of minutes of feathering this way, my wrist starts to feel uncomfortable… soon leading to pain.



Hand and Wrist When Feathering by 'Unrolling' Your Fingers





And here the oar is feathered the same amount, but the wrist is straight. Just ‘unroll’ your fingers and loosen the thumb (exaggerated here). When the oar is all the way forward, raise your hand and ‘re-roll’ your fingers at the same time for the ‘catch’. Your hand will look like that in the first photo above.




If you don’t feel the need to feather your oars, you may want to practice feathering in case you are in a situation (high wind, rough water) when it will be essential that you do. 



Sunday, February 7, 2016

What are Common Oar Dimensions?


How various designers dimension their oars.

Length


Koti uses the following table:


Oar Length as a Function Oar Lock Spread

























He suggests selecting an oar length between the light blue and red lines if you are strong or rowing in smooth and low wind conditions. If you’re not that strong, or wind/wave conditions are more difficult, then select an oar length between the yellow and black lines. Note that “Beam” is the beam at the oarlocks.

Does this mean you need to have two sets of oars? Not necessarily… you can adjust the effective length of the oar by using ‘gearing’.

 Oar Designs


Following are a sample of oar designs created by small boat designers:

Jim Michalak

Jim, in his book (Boat Building for Beginners (and Beyond)) diagrams an oar made from a single 8 foot "2 by 6" (1½” by 5½”) (38 mm by 140 mm):

Jim Michalak Oar from a "Two by Six"









If we placed the pivot point (oarlock position) 3 inches outboard of where the loom changes from square to round, the gear ratio would be 2.5. If this point were to be the center of 6” (152mm) leathers, we could adjust gear from a ‘high’ gear of 3.0 to a ‘low’ gear of 2.1.

Gear = outboard length (tip of blade to oarlock) divided by inboard length (oarlock to end of handle). 
See this post for more information on 'gear' for oars.


R.D. Culler, in his book, Boats, Oars, and Rowing, page 44 gives dimensions for 8’ (2,44 m) oars.
R.D. Culler's 8' Oar











And on page 61, he diagrams an 8.5’ (2,6 m) spoon-blade oar. If we place the oarlock 3” from the handle end of the 13” leather, then the gear would be 3.5. If we placed the oarlock 6” from the handle end of the leather, gear would be 3.0.


Culler's Design for an 8' 6" Spoon-blade Oar



















Phil Bolger
(Small Boats by Phillip C. Bolger, page 30) provides a diagram of a 7’ (2,1m) spoon-blade oar from “Old Town Canoe Company”. According to their site, these are no longer made.

Old Town Canoe Spoon-blade Oar Dimensions












On this oar, placing the lock 3 inches outboard of the button would produce a gear of 2.7, the same as the oar below.

Bolger's Suggested Changes to a Mass Produced Oar













The diagram above shows how Bolger would modify a “mass produced oar” to make it lighter and more efficient.


John DeLapp

John, in the Winter 1990 issue of Ash Breeze (http://www.tsca.net/puget/resources/oars/)published a diagram (below) for how to make a spoon blade oar. I followed his instructions to make the spoon blade oars I currently use on my Ross Lillistone Flint. See this post for the process I went through to make these oars.


Diagram for Making DeLapp Oars

























Assume lock is 2.5 inches from button, gear is 2.3



Concept2 (www.concept2.com)

“Hatchet” (aka “Cleaver”) bladed oars were first designed in 1991 by Dick and Pete Dreissigacker (https://en.wikipedia.org/wiki/Oar_(sport_rowing)). The advantages of the hatchet blade are that the blade has more surface area for a given oar length (thus oars can be shorter) and that the amount of shaft in the water is reduced compared to a more traditional blade shape.

Pictured below is a Concept2 Fat2 sculling blade:
Concept2 "Fat2" Blade














Blade length is 18.1" (46 cm), width at tip 6.5" (16.5 cm) and width at widest point is 9" (23 cm). Overall oar length is measured from the end of the handle to the point on the blade at the arrow, an extension of the center line of the shaft.

Recreational rowers are beginning to use hatchet bladed oars because of their higher efficiency.