Pic

Pic
CLC's Chester Yawl

Sunday, December 17, 2017

Yawls

"Yawl" – from the Dutch “jol”
"Yawl" – a two-masted sailboat in which the rearmost mast (mizzenmast) is aft of the rudder post… a classic example is Olin Stephens' Dorade

Olin Stevens' Yawl Dorade (52' [15.9m] by 10' 3" [3.2m])

(Canoe) "Yawl" – a two-masted large canoe-shaped sailboat popular in the late 19th century such as the Iris


Yawl Canoe Iris...

Iris lines...

...and Specs.

(Source for Iris information above -- scroll to bottom of this linked page.)


"Yawl" – a four or six oared small boat used as a tender for large sailing vessels (A small ships boat, usually rowed by four or six oars. (Webster's dictionary 1828))

HMS Victory Yawl Boat



The term “yawl” (in rowing craft) is rather loose in modern usage, often interchanged with Wherries  and Whitehalls. Rowing versions of “yawls” are typically characterized by ‘round’ bottom lapstrake hulls with ‘wine-glass’ transoms and vertical stems. Given the wide meaning of the term “yawl”, following are some examples of various yawls that could be oar cruisers.

Modern Adaptations:


CLC’s Chester Yawl
"Boats like the Chester Yawl were used as working craft in 19th-century.  Efficiency was critical in these human powered craft, so they evolved easily driven hull shapes.  Working watermen weren’t immune to good looks, either, so these “livery boats” were often beautiful.  The most famous of the type, the “Whitehall” boats of New England, are still considered a touchstone of small craft elegance.  The Chester Yawl is based on the Whitehall and adopts its distinctive plumb bow and “wineglass” transom." (From CLC writeup)

Chester Yawl from CLC: 15' (4.6m) by 42" (1067mm)

This would be a very effective and beautiful kit-boat oar cruiser… I’d add SOF decks fore and aft and provide for temporary shelter such as these.

Selway-Fisher's Dronheim Yawl

This is a large ‘yawl’ for at least two rowers.

Selway-Fisher's Drontheim Yawl Lines

Specifications...

  • LOA 21'8" (6.6m)
  • Beam 6' (1.8m)
  • Hull Mid Depth 2'1" (0.64m)

Commentary from the write-up...
The Drontheim Yawl was designed for the Causeway Coast Kayak Assoc. - this is a traditional Irish open yawl and we have been asked to model her on the computer and develop the 9 hull planks for stitch and tape construction plus frame shapes only - guidance is available for those who need construction details, or we can draw up plans to suit.



The following are not true 'oar cruisers', but rather sail boats using oars as auxiliary power. (For purposes of this blog, we define an 'oar cruiser' an oar powered boat with (optional) sails as auxiliary power.)

Selway-Fisher Canoe Yawls


Selway-Fisher has two ‘canoe yawl’designs. The first is the 15’ (4.6m) Lillie  The second is an 18’4” (5.6m) version of Lillie called Jim Canoe Yawl.

Description of Lillie from Selway-Fisher
This lovely craft was commissioned by Tom Dunderdale after reading the series of articles in the Classic Boat magazine on the 13’ strip planked canoe yawl Ethel. The idea was to produce a canoe yawl of similar style to those of the last century used by Baden Powell and MacGregor and which formed the basis of modern canoeing today but using modern ply/epoxy construction methods with computer generated plank shapes. Her length is based upon the maximum length of plank that you can get out of 2 sheets of ply and we have increased the beam a little over the original Ethel design which allows more extensive cruising and even the ability to sleep on board. She uses 6 sheets of 6mm and one of 9mm ply in her construction. The standard set of plans show details for stitch and epoxy construction using 7 planks per side to give a beautiful round bottom hull shape and details are given for her to be fitted out in classic style with a lug yawl rig. The plans include mould shapes and construction details for her to be made using the strip plank method. Tom reports that up to a force 2 she will sail herself both before and into the wind hands off allowing the helmsman to drink his beer  in comfort. Above that, she handles herself with grace and she rows very well with excellent tracking.

Specifications...

LOA 14'11" 4.53m
Beam 4'8" 1.43m
Hull Mid Depth 1' 5" 0.43m
Draft 8"/2'1" 0.2/0.63m
Sail Area 106 sq.ft 9.84 sq.m
Approx. Dry Weight 353 lbs 160 kg

Selway-Fisher's Lillie lines...

...and Sailing

Iain Oughtred’s Caledonia Yawl 

(Click on Catalog>>Double Ended Beachboats>>Caledonia)

Specifications...

  • LOA:        19' 6" (5.95m)
  • Beam:       6' 2" (1.88m)
  • Sail Area: 170.01 sqf (15.8 sq m)
  • Weight:     330 lbs (150Kg)


Description of Caledonia Yawl from Iain’s website…
I first saw one of these sailing with the gunter yawl rig in Tasmania about 8 years ago. It was a very cold, windy day, white topped waves whipping down the Derwent toward Constitution Dock. The Caledonian Yawl, with it's crew of five, looked very at ease in the unwelcoming Derwent, and I had the feeling that they could have taken much more. 

Iain Oughred's Caledonia Yawl...

...and Profile.



Yawls are beautiful boats and in smaller sizes, make outstanding row boats that are fast and seaworthy.


Monday, December 11, 2017

Feathering Without Pain

(Note: This is a series of posts originally published 2016 each focused on a different aspect of powering small boats with oars. So far, we have re-posted the following topics:
  • Designs for various oars, including how to determine oar length... Sept 24
  • How to make a set of spoon-blade oars... Oct 1
  • The various ways to connect the oars to the boat... Oct 8
  • Alternative outriggers... moving the oar locks to a proper 'span' on a narrow hull...Oct 15
  • Various foot braces... Oct 22
  • Rowing geometry... Oct 29
  • Sliding seat/rigger options... Nov 5
  • Changing 'gear' when rowing...Nov 12
  • Rowing in Wind...Nov 26
  • Rowing in Rough Waters...Dec 3
  • Today: Feathering without Pain
=================================================

(This post was originally published February 21, 2016)


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 (see http://www.usrowing.org/news/details/13-03-07/In_Memory_Frank_Cunningham.aspx for a write-up about his late father) 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 
at the same time ‘reroll’ your fingers 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. Try it and let us know your experience.




Sunday, December 3, 2017

Rowing in Rough Water

(Note: This is a series of posts originally published 2016 each focused on a different aspect of powering small boats with oars. So far, we have re-posted the following topics:
  • Designs for various oars, including how to determine oar length... Sept 24
  • How to make a set of spoon-blade oars... Oct 1
  • The various ways to connect the oars to the boat... Oct 8
  • Alternative outriggers... moving the oar locks to a proper 'span' on a narrow hull...Oct 15
  • Various foot braces... Oct 22
  • Rowing geometry... Oct 29
  • Sliding seat/rigger options... Nov 5
  • Changing 'gear' when rowing...Nov 12
  • Rowing in Wind...Nov 26
  • This week... Rowing in Rough Waters
=================================================

(This post was originally published February 28, 2016)

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.”
 In another article Rough Water Technique, the author 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.

My personal ‘learnings’ from rowing in rough water:

  • Stop the ‘death grip’ on handles
  • Stop trying to power through wind and waves… Use steady pressure with shorter, more frequent, strokes
  • Stop smashing into the waves with the oars… Make the stroke recovery higher and feather the oars so they either skim over waves or ‘cut’ through them
  • Think “Relax, firm and steady… I can do this.” Repeat.

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.”
Tell us about your experience rowing in rough waters.

Sunday, November 26, 2017

Rowing in Wind

(Note: This is a series of posts originally published 2016 each focused on a different aspect of powering small boats with oars. So far, we have re-posted the following topics:
  • Designs for various oars, including how to determine oar length... Sept 24
  • How to make a set of spoon-blade oars... Oct 1
  • The various ways to connect the oars to the boat... Oct 8
  • Alternative outriggers... moving the oar locks to a proper 'span' on a narrow hull...Oct 15
  • Various foot braces... Oct 22
  • Rowing geometry... Oct 29
  • Sliding seat/rigger options... Nov 5
  • Changing 'gear' when rowing...Nov 12
  • This week, Rowing in Wind...Nov 26
  • Next, Rowing in Rough Waters
=================================================
“While not pleasant, rain has little adverse effect on rowers. Heat stress can be a problem for athletes, but the major impact is wind speed and direction.”
BBC July 28, 2012 in discussion about rowing events at London Olympics 
“Sailing would be great if it wasn’t for the calms…
Rowing would be great if it wasn’t for the winds.”

                                                                          T. Clarke 2016

Impact of Wind on Rowing


Klaus Filter of the DDR (Deutsche Demokratische Republik), in 1970s, using a wind tunnel, measured the impact of wind (strength and direction) on rowing racing shells of 1-, 2-, 4- and 8-person crews. It is summarized below, extrapolated from his data posted in the Rowing Biomechanics Newsletter.

I combined the data for the four different racing shells since the differences among the 4 were all less than 5%, in most cases only 1% or 2%. Wind direction is relative to course… 0° is a head wind and 180° is wind directly from the stern. Wind speed is given in meters/second and miles per hour. The tabular data is the percent impact on speed.

Per Cent Impact on Speed as a Function of Wind Speed and Direction

The key ‘takeaway’ from this chart, for me, is not so much the percent cost, or benefit, from the wind, but rather it is how the course relative to the wind direction impacts speed… rowing against the wind costs a lot more than the benefit of rowing with a wind of the same speed.

And rowing at an angle to a headwind (tacking, in effect) eases the drag (slightly), but increases the distance to be rowed. See Small Boats Monthly article on Tacking for Rowing.

For the oar cruiser, the percent impact would be greater than in the table above, since the oar cruiser has much more aero drag than the racing shell. How do we calculate the aero drag of an oar cruiser?

The formula for determining aero drag is:
Aero drag (pounds) = .0034 x S x C x V x V where:
.0034 is a constant
 S is the square feet of frontal area exposed to the wind
C is the “drag coefficient”… for simplicity we’ll use “1”
V is the velocity of the wind over the boat.
What is the square feet of frontal area exposed to the wind for a typical oar cruiser?

It’s the frontal area of the boat itself (let’s assume 4’ wide and 18” high for 6 sq. ft.) plus the exposed portion of the rower (assume 2’ wide by 2.5’ above the gunnel for 5 sq. ft.) for a total frontal area of 11 sq. ft.

“V”, velocity of the wind is the wind speed in miles per hour plus the speed of the boat (if a headwind… minus boat speed if heading downwind). Let’s assume a 10 mph head wind and a boat speed of 3 mph for a V of 13.

Plugging these numbers into the formula, we get:
Boat aero drag = .0034 x 11 x 1 x 13 x 13 = 6.3 lbs of aero drag from a 10 mph head wind.
There is another aero drag component that Klaus Filter mentions in his article. And it is a component that we can control… to feather the oars or not.

Lets assume I’m using a set of oars 94.5 inches (a little less than 8 feet [2.4m]) long, with a gear ratio of 2.5 (end of blade to oar lock [67.5 inches] divided by oar lock to end of handle [27 inches]). Let’s further assume the blade is 5” by 24”, which is .83 sq. ft.

When I’m rowing, the handles will move through an arc let’s say 2 feet long. This means the blades will be moving through an arc 2.5 times as long… 5 feet. If I’m rowing at 3 mph at a stroke rate of 20/minute, the blades are moving 5’ under water (no windage), but during recovery they are moving 5 feet in 1.5 seconds (2.3 mph) added to the boat speed of 3 mph for a total of 5.3 mph. If the wind is blowing at 10 mph, then V (velocity of wind over the oars) is 15.3 mph. Plugging these numbers into the formula, we get…
Oars aero drag = .0034 x 1.66 x 1 x 15.32 = 1.32 pounds. 
But since the oars are moving against the wind only half the time, the actual aero drag from this set of oars under the given conditions is 0.66 pounds.

To put this into the context of the real world, we need to add yet another drag component… let’s call it ‘water drag’, which is made up of skin resistance, form resistance and wave resistance.  A complex calculation, but Jim Michalak comes to the rescue.

Jim used his Roar2, which is 14’LOA and 42” wide, as his ‘test boat’. He found that the water drag was (slightly less than) 5 pounds at 3 knots. This figure came from a Hullform derived analysis of Roar2 which he then confirmed by measuring the force on the oars in his own Roar2.

Putting all this information together, we can come up with the following summary:

  • Rowing a 14’ nicely shaped row boat at 3 knots in calm conditions (no wind, no waves) requires 5 pounds of force by the rower (to overcome the 5 pounds of water drag).
      
  • Rowing a 14’ nicely shaped row boat at 3 knots against a 10 mph headwind requires 5 + 6.3 (=11.3) foot pounds of force by the rower, if the oars are feathered during recovery.
      
  • Rowing a 14’ nicely shaped row boat at 3 knots against a 10 mph headwind requires 5 + 6.3 + 0.66 (=12) pounds of force by the rower, if the oars are NOT feathered during recovery.

Rowing in the Wind


As we calculated above, rowing against a 10 knot wind takes more than twice the energy than rowing in a calm. But what if it’s blowing 20 knots?

With a 20 knot headwind, rowing at 3 mph requires 24.8 pounds of force on the (feathered) oars, five (5) times the energy required for rowing in a calm…not a pretty picture.


Rowing in a beam wind (90° to the wind direction) presents its own set of problems. In my Lillistone Flint, a beam wind causes the boat to turn into the wind…this, in spite of more windage from the bow vs. stern.

Rob Fisher and his son rowed a Welsford Mollyhawk in the 2016 Texas 200. He relates that at one point, when rowing in a beam wind of 20+ knots, they rowed for miles using only the starboard oars in order to maintain course. He felt that a rudder would have helped.

My own thinking is that the ends of the boat should be low (with fore and aft decks added) in order to reduce windage in beam winds. For me, rowing into a headwind is just ‘grunt’ work. But rowing with a strong beam wind is more difficult because the impact on rowing varies and I’m always pulling harder with one oar or the other to keep on course.

Sunday, November 12, 2017

Change Gear when Rowing

(Note: This is a series of posts originally published 2016 each focused on a different aspect of powering small boats with oars. So far, we have re-posted the following topics:
  • Designs for various oars, including how to determine oar length... Sept 24
  • How to make a set of spoon-blade oars... Oct 1
  • The various ways to connect the oars to the boat... Oct 8
  • Alternative outriggers... moving the oar locks to a proper 'span' on a narrow hull...Oct 15
  • Various foot braces... Oct 22
  • Rowing geometry... Oct 29
  • Sliding seat/rigger options... Nov 5
  • This week, Changing 'gear' when rowing
  • Next week, Rowing in Wind

=================================================

Note: First published Jan 20, 2016

Change Gears When Rowing?

Yes, you can.

Why would I want to change gears? If you were riding a bicycle, you would want to shift to a 'lower' gear when going uphill, and a 'higher' gear going downhill.

When rowing, going against the wind (or current) and/or rowing a heavy displacement boat (thanks to Brian M. for suggestion to add 'displacement' factor) is 'uphill' (use a lower gear) and rowing with the wind or current with a light boat is 'downhill' (use a higher gear).

Let's define "gear" as it's used in rowing: Gear is the ratio of the outboard length of the oar to the inboard length of the oar.

The outboard length is measured from the tip of the blade to the pivot point on the oar at the oar lock and the inboard length is from the pivot point to the end of the handle.

My current set of oars are 8' (244cm) with an outboard length of 67.5" (171cm) and inboard length of 28.5" (72cm), resulting in a gear ratio of approximately 2.4 (171/72 = 2.375).

Koti, in the site referenced below, suggests the 'optimum' gear ratio is 2.5 to 2.7. If I moved the location of the pivot point closer to the handle by 1.75" (4.5cm), the gear ratio would be 2.6, right in the middle of Koti's optimum gear ratio.

So how do we change gears? Six ways:

1. Have two (or more) sets of oars with different gear ratios for different conditions. Long distance 'ocean' rowers carry multiple sets of oars, not only for safety, but also to deal with different conditions.

2. Move the locks. I've never seen this, but it certainly is feasible to have the oar locks mounted on blocks which could slide in or out and lock into position.

3. Move the collars -- the issue is that collars typically are permanently attached to the oar and can't be moved, although in competition rowing, the collar, also called the 'button', is moved to change gear ratio.

4. Slide the oar in or out on the lock. This works for a few minutes, but soon the oar slides out (butting up against the collar and thus to a higher gear).

5. Make oars with longer handles and move your hands out (toward the oar blade) for higher gear and in for lower gear. My oars have handles 5.5" (14cm) long. I can definitely feel the difference  in 'gear' with the approximately 1.5 (3.8cm) inches of hand movement available on these handles.

6. Add a small jam cleat (Duckworks Jam Cleat 'SD-002040') and 3 feet of 1/8 non-stretch line as shown the photo below. Tie a tight loop around the oar loom just outboard of the cleat, wrap the standing part of the line around the oar lock and back to the jam cleat. This provides infinite and quick adjustment.


Two other advantages of this 'gear shifter':

1. You can let go of the oars and they will stay in the oar locks while you take a photo or drink some water.

2. You really don't need collars (unless you are a "belt and suspenders" person).

Measure your own current gear ratio and add the 'jam cleat' adjuster to increase your rowing efficiency.

Comment below with your experience in using 'gears' when you row. I'd love to hear from you.

For a detailed discussion on oar length and gear ratios, see "Optimum Sculling Oar Length" http://koti.kapsi.fi/hvartial/oarlength/oarlen.htm#top

For more on the "Physics of Rowing", see http://www.atm.ox.ac.uk/rowing/physics/index.html

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Note: First published May 13, 2016


CATCH: Another Way to Change Gears


In the January post "Change Gears When Rowing?", six alternatives for how to adjust 'gear' (ratio of outboard to inboard length of oar) were presented. Chris Cunningham, in the April issue of Small Boats Monthly presented yet another way to control 'gear' when rowing.

"Thumb Buttons" to Control Gear on Oars
He put three of these buttons on each oar. The buttons are on the bottom of the leather when the oar is in the 'power' portion of the stroke. Included in the article is a video that shows how he changes gears while rowing without missing a 'stroke'.


(Text and photo used with permission from Chris Cunningham.)

Sunday, November 5, 2017

Sliding Seat/Riggers

(Note: This is a series of posts originally published 2016 each focused on a different aspect of powering small boats with oars. So far, we have re-posted the following topics:
  • Designs for various oars, including how to determine oar length... Sept 24
  • How to make a set of spoon-blade oars... Oct 1
  • The various ways to connect the oars to the boat... Oct 8
  • Alternative outriggers... moving the oar locks to a proper 'span' on a narrow hull...Oct 15
  • Various foot braces... Oct 22
  • Rowing geometry... Oct 29
  • This week, sliding seat/rigger options
  • And next week, changing 'gear' when rowing

============================================

(Previously posted May 20, 2016)

Introduction


Sliding seat/riggers enable you to use your leg muscles to row, as well as your back and arms, increasing the power of your stroke. This post is about various alternative systems that can be used.

Sliding SEAT systems enable the rower to move while the oarlocks are stationary.

Sliding RIGGER systems enable the rower to be stationary (in his/her location in the hull) while the oarlocks move. The advantage of the sliding rigger systems is that the weight of the rower is not shifting fore and aft with each stroke which can cause the hull to pitch. Sliding rigger systems are banned in formal races.

Sliding seat/rigger systems that include, in one unit, the seat, outriggers to hold the oar locks, rails for either the seat or the outriggers to roll on and foot braces are typically called “DROP-IN UNITS”. The unit can be detached from the boat, and the boat ‘converted’ to fixed seat rowing.

Sliding seat/rigger COMPONENT systems are custom made such that the various separate components (seat, outriggers, rails and foot braces) are independent and are stored in the boat.

If you intend to sleep in the boat AND you are considering a drop-in system, where will you store the drop-in unit while you are sleeping? The only solutions I’ve seen are to 1) design a custom component system in which the pieces can be separately stored and/or are a built-in part of the boat, OR 2) only use fixed seat rowing.😊

If you are looking for parts to make your own system, then one source is Latanzo.

Following is a wide variety of sliding seat/rigger options, divided into three categories:
1) Plans and Kits
2) Commercial systems
3) Custom made systems, both component and drop-in

Plans and Kits


Glen-L
Glen-L Sliding Seat System

 Glen-L has both plans and a hardware (only) kit for this system.

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Colin Angus sells both plans and a kit for this sliding seat unit that he uses in his boats.

Colon Angus Sliding Seat System

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Platt Monfort’s article contains plans for a  home-made drop-in sliding seat system based on a 1947 design, with ‘upgrades’ provided by Platt.

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Kudzu Craft sells (only) the plans for this drop-in unit which can be customized to fit most boats.

Kudzu Craft Sliding Seat from Plans

Commercial Systems


Drop-in Sliding Rigger

Drop-in Sliding Rigger Unit from "Sliding Rigger"

Shown above is the end view and side view of their system. Note the very low profile, which would require the whole system to be raised in order to clear the gunnels of a typical oar cruiser.

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Adirondack Rowing has a review of seven commercial drop-in sliding seat units which they sell.

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Wayland Marine

RowWing by Piantedosi sold by Wayland Marine

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Poseidon sliding seat system

Double Seat version showing only Foot Rests for the Forward Seat

Both a single and double version are available, and either system can be fully adjusted to fit rowers up to 6’ 6”.

The system can be mounted in virtually any boat because it is supported by two crossbars attached to ribs

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Salt Pond Rowing


Wood Drop-in Sliding Seat Unit from "Salt Pond Rowing"

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FrontRower(TM) is not a sliding seat nor sliding rigger system, but a rowing system that enables legs and/or arms to be used to row, while facing forward.

Custom Made Systems


Gig Harbor custom component system they use in their boats.

Example of a Wood Sliding Seat System from "Gig Harbor"

They sell units with both wood (as here) as well as fiberglass seats. Eight wheels keep the seat located properly (See Rick Thompson's comments below.)

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Clovelly Sculls


Custom Component Sliding Rigger System for Their Boat

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Home Made Sliding Seat System

I found this photo of a home-made, drop-in, sliding seat (only) unit.  The dowel under the seat runs through a piece of PVC pipe to limit movement only to fore and aft. There was no ‘builder’ information.

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Custom (?) Drop-in Sliding Seat System

No builder information available.

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Rick Thompson, (Welsford custom Walkabout, shown here) wrote to me describing his custom designed component sliding seat system. He included many pictures. Following is the text and pictures he sent me:

"1) Many slide seats use 4 wheels held in tracks. The problem with those is that the wheel edges rub on the sides of the tracks, that's how they stay in the tracks. The wheels need to be a hard material, sometimes metal, which can cause a rough and noisy ride. 
2) My first open water rowing boat (that got me started on this activity) was a Gig Harbor Whitehall. Gig Harbor [See Gig Harbor link earlier in this post] has a seat system that uses 8 wheels - 4 supporting the seat and 4 keeping it on the flat top track. I like this system, mine is copied and revised from that. The GH wheels are soft urethane, making for a very smooth slide. The seat is securely held, it would have to jump up above the side wheels to come off track. The 4 wheel systems can jump track easier, unless there is also an upper retaining track. 
3) My GH boat and the Walkabout have side seats, making a convenient place to run the tracks. The Walkabout side seats curve upward at bow and stern, I just made my tracks to follow the curve and the slide seat works fine. The seat can easily be lifted out to make the center of the boat clear. The drop in seat units like Piantedosi or Angus can be added to boats with no side seat, but they are not quick to remove. 
4) If you look at the "Wheel Detail" tab on the GH page, you can see that they make their own wheel bearings from plastic parts. I have heard that these work well and have crossed oceans. I used standard skate board wheels and bearings which are readily available. The bearings can be found in stainless and even in ceramic. I used stainless, but re-packed them with heavy waterproof marine grade wheel bearing grease. They have not needed any service in over 2000 saltwater miles so far. 
5) My gray rafting seat is a little unusual. I have it angled backward by 12 degrees to better accommodate slide rowing geometry. It is very comfortable, even for a week of extended cruising. The low back part could interfere with layback, but I don't use much layback [for the ‘catch’] so it is not a problem.

[I asked Rick for the source of the seat he uses.]

This is what he uses.

Seat Rick Thompson Uses 

Underside of the Seat Showing the Eight Rollers to Keep it Aligned

Foot Rests of the Custom Component System

And a Close-up View

The Hinged 'Stop' Quickly Converts His Rig to a Fixed Seat Rig (Genius!)

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(Previously posted May 27, 2016)
Earlier this week, we posted a number of alternative sliding seat/rigger systems. Here are five more.

Fyne Boat Kits in UK offers this sliding seat system:

Sliding Seat System from Fyne Boat Kits

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Denman Marine in Tasmania offers this sliding seat system:

Denman Marine Sliding Seat System

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RowSurfer, located in Amsterdam, offers this sliding RIGGER system (seat is stationary and oar locks slide):


RowSurfer's Sliding Rigger System

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X-Cat , located in Austria, offers in interesting forward-facing, sliding seat system with automatic feathering. Shown is the rowing system (which can be purchased separately) mounted on their catamaran rower. See a video of the X-Cat in action.

X-Cat Forward Facing Sliding Seat System

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OarBoard, from Victoria, offer a sliding rigger system designed for SUPs (Stand-Up-Paddle). It could be adapted to oar cruisers.

OarBoard's Sliding Rigger System


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Thanks to Justin Miller and Rick Thompson for identifying these additional commercial sliding seat systems.

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(Previously posted June 23, 2016)

In the May 20 and May 27, 2016 posts, we presented a number of sliding seat/rigger systems. Here's another sliding rigger (seat is stationary while the locks and outriggers slide) that a reader sent me. No details except the photo.

 

Sunday, October 29, 2017

Rowing Geometry

(Note: This is a series of posts originally published 2016 each focused on a different aspect of powering small boats with oars. So far, we have re-posted the following topics:
  • Designs for various oars, including how to determine oar length... Sept 24
  • How to make a set of spoon-blade oars... Oct 1
  • The various ways to connect the oars to the boat... Oct 8
  • Alternative outriggers... moving the oar locks to a proper 'span' on a narrow hull...Oct 15
  • Various foot braces... Oct 22
  • This week, rowing geometry
  • And next week, sliding seat options

This post is about rowing geometry for fixed seat rowing.

Colin Angus has a very complete description, with detailed measurements, of rowing geometry for sliding seat rowing.

John Welsford, in an article for Duckworks Magizine titled "Some Thoughts on Rowing" includes the following information for rowing geometry for fixed seat rowing (as well as much more excellent advice):
  • Distance between oar locks: Minimum of 3’ 10” (117cm), and an average of 4’ (122cm) to 4’ 4” (132cm)
  • Oar lock to back edge of seat: Minimum of 13” (33cm)
  • Bottom of oar lock height above seat: 8” (20cm) to as high as 11” (28cm)
  • Seat height above ‘heel rest’ on foot brace: 6” to 8” (15cm to 20cm)

Paul Truszkowski’s rowing geometry for his Michalak Vireo is:
  • Distance between oar locks: 49.5:, 126cm
  • Oar lock to back edge of seat: 13”, 33cm
  • Bottom of oar lock height above seat: 12.5”, 32cm
  • Seat height above ‘heel rest’ on foot brace: 8”, 20cm
  • Bottom of oar lock to waterline: 13.5”, 34cm
  • Length of oars: 96”, 244cm
  • Overlap when oars are level: 4”, 10cm
  • Paul's height with shoes he normally wears when rowing. 6’ 1”, 185cm

Rowing Geometry for my own Ross Lillistone Flint is: (Note: this link works as of October 2017 but may change as Duckworks site is upgraded)
  • Distance between oar locks: 53”, 134cm
  • Oar lock to back edge of seat: 10”, 25cm. The oar locks are closer to the seat because I like to make a deeper recovery (forward angle of oars at the catch: 50 degrees) and shorten the end of the power stroke (35-40 degrees aft)
  • Bottom of oar lock height above seat: 10”, 25cm
  • Seat height above ‘heel rest’ on foot brace: 10”, 25cm
  • Bottom of oar lock to waterline: 14.5”, 37cm
  • Length of oars: 96”, 244cm
  • Overlap when oars are level: 3”, 76mm
  • My height with shoes I normally wear when rowing: 6’ 1”, 185cm

An effective ‘rule of thumb’ for adjusting the foot brace is to sit on the seat in your normal rowing position, extend your legs until your thighs are level, then position the foot brace against the bottom of your feet.


Pictured below is a Rowing Geometry Worksheet you can download from Dropbox and then ‘model’ your own rowing geometry based on you, the size of your boat and the length of the oars.

A Rowing Geometry Worksheet you can Download and Use

Sunday, October 22, 2017

Foot Braces

(Note: This is a series of posts originally published 2016 focused on a different aspect of powering small boats with oars. So far, we have re-posted the following topics:
  • Designs for various oars, including how to determine oar length... Sept 24
  • How to make a set of spoon-blade oars... Oct 1
  • The various ways to connect the oars to the boat... Oct 8
  • Alternative outriggers... moving the oar locks to a proper 'span' on a narrow hull...Oct 15
  • This week, various foot braces... Oct 22
  • And next week, rowing geometry...The relationship of seat, oar locks and foot braces.
"Foot braces", aka “Foot stretchers”, “Foot risers”, and “Piggy pedestals” are used by both sliding seat and fixed seat rowers. They are the braces that keep you from sliding aft when you row. 

In terms of design, there are probably as many designs as there are rowers. Following are seven examples, in no particular order. 

 

Steve Chambers' SOF British Columbia Hubert Evans Handliner

Detail of the Foot Brace and Box Seat
1. Steve Chambers built a SOF British Columbia Hubert Evans 14’ 6” Handliner (4.4m), using a plywood floorboard with a center stiffener strip. Both the box seat and foot brace are grooved to sit over the stiffener strip. Steve says the rope loop (around the back of the box seat and threaded through the foot brace) works well as long as you put equal pressure on the two ends of the foot brace. Distance between the foot brace and the box seat is adjusted by the sliding knot (tautline hitch or rolling hitch?... latter is less likely to slip).

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Close up of the Foot Rest and Straps

Rick Thompson's Foot Braces

2. Rick Thomson made these foot braces for his Walkabout (Rick's Walkabout). As with all of Rick’s work, these are elegant and superbly made. Note that Rick uses these for both sliding seat (for racing) and fixed seat rowing. 

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3. John Welsford's design for the Walkabout specified a series of about 6 paired ribs (about 12mm square) attached to the side of the air boxes at the same location as Rick placed the notched supports for his foot braces. John’s ribs are angled back from the vertical about 30 degrees and are spaced about 12 to 14mm apart. The actual foot brace is a plank that slides into the slot between ribs. 


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Paul Truszkowski's Drop-in Rowing Unit, Integrating Seat, Foot Rest and Outriggers

The Rowing Unit in a Custom 15' 6" Kayak/Rowboat

4. Paul Truszkowski built a drop-in unit that combines foot brace, outriggers and a seat.   

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Adjustable Foot Brace Attached to Seat in a Michalak Verio

5. In Paul’s Vireo (referenced in this blog), the foot brace is attached to the seat by adjustable chains. I’ve used this and it works well. 

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6. In the model Vireo (pictured at the link above), another adjustable foot brace is shown. It is hooked into the slats of the floor boards, as is the box seat, to allow both to be adjusted for leg length and fore/aft weight distribution. 

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Adjustable Foot Brace for a Ross Lillistone Flint

Forward End of the Brace Held in Place by a Wedge

Underside of the Foot Brace

After End of the Brace Showing One of the Wing Nuts

7. For Ross Lillistone’s Flint, I made this adjustable foot brace. The forward end is held down by a wedge jammed under the block screwed to the bulkhead. Two wing nuts anchor the sliding foot brace on the slotted beam, providing a wide range of adjustment. (Note that the only fasteners used are the two wing nuts. All the other joints are held only by Titebond 3 which has held up for two seasons.)


What would I do differently in making this foot brace? 


a. Make the actual brace much taller. I find it more comfortable to have the ball of my foot supported by the brace in addition to the heel. In addition, I’d make the brace wider so that I could brace my feet better (wider) in rough conditions.  
b. Create a better way to secure the front end of the slotted beam. The wedge is just okay, but has a tendency to work loose. 
In the March 2016 issue of Small Boat Monthly, Ben Fuller wrote an article on foot braces, in which he shows 10 different designs of foot braces. With a total of 17 different designs, there should be a style that is suitable for your oar cruiser. 


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(Following was first posted May 2016)

In an earlier post on foot braces, we presented 7 different styles. Chris Partridge, in his blog, Rowing for Pleasure, introduces us to Jubilee, a 18' lapstrake Langstone Cutter.

18' Langstone Cutter Jubilee

Jubilee uses yet another style of foot brace.
Foot Brace in Jubilee

The line leads to the yoke on the rudder. Note also the beautiful, knot-free floor boards, riveted lapstrake planks and keelson.

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(Following was first posted February 2017)

In a July 2016 post, we presented Floorboard Alternatives. And frequently, for oar cruisers, we’ve recommended in this blog that floorboards be made from ‘slats’ arranged crosswise in order to provide adjustable anchor points for foot rests and a seat, and a dry sleeping platform.

This post is a description of floor boards and foot rests I made for my Ross Lillistone Flint.

My Ross Lillistone Flint, Raven

The slats in the floorboards are 1” by ½” (25mm by 13mm) Western Red Cedar. The two longitudinal struts (glued and screwed to every slat) are oak, ¾” x ¾” (19mm x 19mm).

The slats are spaced exactly ½” (13mm) apart to allow the cleats to hook under a slat.  The ends of every slat are tapered to the slope of the bottom. The floor boards (and foot rests) are finished in Exterior Watco Oil. Since there is a permanent rowing thwart, there was no need to make a separate, movable, rowing seat.


Floorboards Installed in Raven

I added a wedge to hold down the forward end of the floorboards to prevent them from lifting when pressure was applied to the foot rests. The wedge is jammed under a cleat used for the main sheet when sailing Flint.

Wedge to Hold Down Forward End of Floorboards

The footrests are made from 6mm Ocume, a single oak base (3/4” x 1.5” x 14” long: 19mm x 38mm x 356mm) and three aluminum cleats 3.5” (89mm) inches long, ¾” (19mm) high and ½” (13mm) deep. The three cleats are spaced so that they fit between and on either side of the longitudinal struts.


3 Aluminum Cleats to Hold the Foot Rests to the Floorboards

Foot Rests Locked to Floorboards

Back of the Foot Rests

The footrests and floorboards have worked very well. The footrests can be moved to any slat to accommodate different rowers or to adjust rowing geometry.

If I were to do it again, I’d make the struts (to which the slats are attached) bigger (deeper) to prevent the floorboards from bending up (slightly) when pressure is put on the foot rests. Other than that one change, I would use this arrangement in future rowing boats.

Questions and/or comments are welcome.