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 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 that he could not feather with this arrangements. Since his oar blades are only 3.5” (89 mm) 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. (Note, I have since switched to the "Douglas" design oar locks below.)

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

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The oarlocks below are manufactured by Gaco in Sydney, Australia. (Note, the site is well worthwhile to visit... lots of information on rowing.)

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 over-sized holes for the oarlock pin that include a nylon bushing so 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 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 Shaw and Tenney kit came with instructions on how to trim the leather to fit the oar and to sew it on the oar with a ‘herringbone’ stitch. 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. Jim Michalak (jimsboats.com) suggests making a button by creating a “Turk’s Head” out of bungee 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, the button is really not necessary.

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

There are other alternatives for ‘leather and button’. Consider the Martinoli Oar Sleeves with Buttons from Duckworks often paired with Douglas Oarlocks discussed above.

Another option is Seadog Adjustable Oar Collars. My concern with these is that the amount of gearing flexibility is less than 4” (102 mm).

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.

Is "Measure Twice, Cut Once" Enough?

Most of us who have made things from wood have used the adage, "Measure twice, cut once". Once in a while, I have forgotten and had to redo the work. Most recently, I did measure twice and cut once, and still had to redo the work. (Sat in my 'crying chair')...

That was when I created a new adage that included the building step I missed... be it boats, models, furniture, hanging pictures, whatever.

Here's the four-step process I now use... It's called "4M".

• Measure; using metric, Imperial, or two tick marks on a stick.
• Mark; use a sharp pencil, or if absolute accuracy is needed, I use a small utility knife (pictured below) to make the mark.
• Mock-up; this is the new step I added. Mock-up means put the pieces together as best I can (for example, using tape to hold them together) to make sure that the result will really work. When I was making a folding table for my son, I discovered in the mock-up that the legs would not fold properly. My drawing didn't show the problem. Mock-up saved the day.
• Machine; this is when I finally put drill, or saw, or chisel to wood.

My 'marking' knife

Since using 4M, I use my crying chair much less.

John Welsford's Walkabout

Walkabout is lap-strake sail- and row-boat designed by John Welsford for single-handed cruising.

Walkabout profile

Cross section about mid-ships, with tent

Profile with sails furled and tent cabin

Specifications:

• Length: 16' 2"(4.9 m)
• Beam: 5' 0"(1524 mm)
• Weight: 200 pounds (92 kg)
• Water Line Length: 14' 7" (4.4 m)
• Water Line Width: 4' 3" (1285 mm)
• WLL/WLW Ratio: 3.5:1
• Hull Speed: 5.1 knots, 9.5 kph, 5.9 mph
  
  

Rick Thompson's Custom Walkabout

Rick Thompson's Modified Walkabout:

• Stretched LOA by 8% to 17' 10" (5.44 m) to accommodate two rowers. Rick said that using two rowers did not significantly increase speed and says that for long distances, it is better for the two rowers to take turns rather than both rowing together.
• Used a single lug rig (designed by John Welsford) rather than the original yawl rig.
• Replaced the fixed seat rowing with a sliding seat.
• Eliminated the dagger board and dagger board case.
• Replaced the tiller with rope steering (Rick only uses the sail for downwind sailing).
• Changed the shape of the cockpit coaming to make the build easier.
• Modified the stern compartment to provide more storage space and added a large access hatch, plus top hatches to access the side compartments.
• Redesigned the tent shelter in order to use laminated bows rather than removable bent rods.
• Added a bowsprit to hold the anchor.

Summary-Pros:

• Traditional lapstrake hull with decking and coamings makes Walkabout very seaworthy.
• Lots of room for storage of supplies and equipment.
• Cockpit is large enough to move around.
• Rows comfortably at a cruising speed of 3.5 knots (6.5 kph, 4.0 mph) according to Rick Thompson.
• Plans include details of a shelter.
• A perfect oar cruiser... no need for modifications.

Summary-Cons:

• Windage on the hull makes her a little more difficult to row in cross-winds.
• Boat is too heavy to car-top.
  
  

Preparing for the Next Day's Cruise:

The watch alarm buzzed her awake at 4:00 am so she could be rowing by sunup on one of the longest days of the year… opened the insulated canister of oatmeal, nuts and dried fruit she had covered with boiling water the evening before… water was starting to heat for the green tea… ate breakfast along with a banana… retrieved a half-dozen energy bars, an orange, apple and 4 bottles of water from the aft compartment for the day’s fuel she’ll need, and stored all in ‘ready-nets’ hanging under the side decks. Unhooked the tent, stored it in the forward compartment along with her sleeping pad, light blanket and luxurious feather pillow she always brought… washed out the canister, cup and spoon… While a fresh cup of water was coming to boil, she added a mix of beans, bacon bits and bit of cayenne pepper to the insulated canister, added the boiling water, shook it to mix the ingredients and put it aside for tonight’s hot dinner… put away the ‘soda-can’ alcohol stove in the utensil box and stored the box in the aft compartment…pulled the anchor in, and after washing off the mud, stored it on the bowsprit…Untied the oars and set out in perfectly calm, windless waters, easy strokes initially, just as the sun came up. She thought; “Oh my God… thank You… it’s perfect.”

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).

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

Why Do Many People Hate to Row?

I hear these comments... "I can't see where I'm going when I row."... "My neck hurts when I row"... "I almost ran into a fisherman yesterday."

There are at least 3 solutions:

1. Row facing forward by pushing on the oars, often standing up. Maine Coast fisherman used to do that at times so they could safely navigate the rocks as they came close to the shore.
2. Use the FrontRower(TM) System (http://www.frontrower.com/). Not only do you face forward, but you can use your legs and/or arms to row.
3. Use a mirror. I use a Yamaha motorcycle mirror with an 8" stem: (http://www.jpcycles.com/product/7600075)

This is what I see when I'm rowing:

This is a close-up of the image in the mirror, It's difficult to see in this photo, but you can see about 10 degrees past the center line of the boat... sufficient to keep from running into another boat.

The mirror is bolted to a piece of oak held by a wing nut with lock washer on a stud coming up through the gunnel. Easy to remove... weather proof and effective.

If you haven't already done so, attach a mirror to your oar cruiser. It is definitely worth the effort.

3 Scarfing Techniques and Jigs

If you are going to build a boat, you'll probably have to scarf wood. There are a number of ways to 'lengthen' wood.

Here are three ways to scarf or taper that I've used.

Scarfing Plywood

I used this when I needed to make two 4' (1220mm) by 16' (4877mm) plywood sheets when I built Ross Lillistone's Flint.

The general idea is that we put an 8:1 wedge shaped slope on the end of two sheets, turn the top sheet over, then glue (typically epoxy) the two wedges together, resulting in a 4' by 15'10" (4826mm) sheet. Note the loss of 2", due to the overlap in the scarf.

For Flint, I needed two sheets approximately 16'. This first picture shows the stack of 4 sheets of 1/4 inch Ocume, each sheet stepped back two inches (1/4 inch times 8 is 2 inches resulting in an 8:1 scarf. In this picture, about half of the wood has been removed to make the 'wedges').

Stack of 4 sheets, each offset by 2"

Once all four sheets were perfectly aligned, each sheet stepped back 2" (51mm) from it's neighbor below, I drove two screws through the stack to ensure they did not move. I aligned the edge of the bottom sheet with the edge of the supporting bench. I also drew a line across the top sheet exactly 2" back from the edge of that sheet to use as a guide for making the 'wedge' on the top sheet.

Using a sharp (SHARP!) plane, create, on all four sheets, the wedges. The plywood layers provide a perfect guide to make sure the wedges are straight in all directions. I continued to plane and sand until all four wedges ended in a 'feather' edge, shown in the second picture below.

Final view after planning and sanding

Note the chip out in the red outline. This was because the plane became dull and I didn't sharpen it. Now I was ready to create the two full-sized sheets I needed.

Glueing up the full sized planks (4' by 15'10") involved the following steps:

1) I used a 2' by 4' bench to support the forthcoming joint and two supports for the ends of the plywood so they wouldn't sag.

2) Placed a piece of (minimum) 12" (305mm) wide wax paper under the forthcoming joint (center of the bench).

3) Laid one sheet on the supports, wedge slope up, wedge centered on the wax paper. I screwed this sheet down so that it would not slip.

4) Laid the matching sheet (slope down) on top so that the two slopes exactly matched. Ensured that the sides of the two sheets make a perfectly straight line for the full 15'10". Marked the edges of the two sheets at the center of the wedge where they overlapped to act as an alignment guide in preparation for the next step.

5) Slid the top sheet back a couple of inches and slathered epoxy on the bottom sheet slope. Then slid the top sheet back so the alignment guide was accurate. Verified that the sides of the two sheets made a straight line. I then screwed the second bottom sheet to the underlying bench so that it wouldn't move.

6) Repeated steps 2) through 5) for the second two sheets (I used clamps rather than screws to hold these in place).

7) Put a third layer of wax paper over the joint and weighed down the two joints with concrete blocks and bricks. Let epoxy set for at least 24 hours.

That's it, I now had two sheets 4' wide and 15'10" long.

Scarfing Long Narrow Wood 

The first picture below shows a jig made of plywood with a 1/2" by 3/8" (13mm by 9.5mm) runner to fit in the table saw groove. Screwed to the top is a 3/4" by 1 1/2" (19mm by 38mm) fence set at 8:1 angle.

Jig for cutting 8:1 scarfs

Jig with stock clamped in place

This jig will produce a slope of 8:1 on any long piece of wood that is clamped to the fence as shown in the second picture. Make absolutely sure the blade is perfectly vertical. I always check this with a square because the supplied tilt index on the table saw is not accurate enough. Also make sure the front clamp is far enough back that the saw blade clears it. Ask me how I learned this...

Frame to be used for tapering stock at any angle

The picture at the left shows a frame that can be used for any angle, such as cutting a taper in a spar.

The cross braces should be as low (and thin) as possible, yet still enable two clamps to be used to hold the stock without hitting the table. The limiting factor in using this frame is the height of the table saw blade compared to the thickness of the stock plus the height of the frame.

Frame with stock clamped in place