THIS WAS MY PRELIMINARY PLAN
FOR A DECKED BOAT PADDLING FIXTURE
AND FOLLOWING ARE PHOTOS OF
THE FIRST ONE THAT WAS MADE
BY A CONTRACTOR (KYLE) IN MAINE
FOR HIS CLIENT - CAROLINE
Because Caroline has good use and grip with her right hand
the builder chose to incorporate an eyelet style "oar-lock"
to allow the paddle to be slid left and right as needed to
maneuver in close proximity to a shoreline or dock.
The square holes in the left plate provided for use of
carriage bolts which allows the wing nuts on the right
side to be tightened with one hand - brilliant idea Kyle!
REFERRING TO THE FIRST DRAWING AT THE TOP OF THE PAGE...
The "L" channel pieces, one of which is shown at the very bottom of the drawing,
are the only pieces that are attached directly to the kayak.
Only 4 holes would need to be drilled through the upper deck.
The L-Channels can be situated for "Inside" or "Outside" mounting.
Then, there are 2 or 3 more pieces of aluminum shown in this design.
One is the large plate that crosses from one L-Channel piece to the other.
The vertical pieces that hold the boom could be fabricated as a single piece
with 2 90-degree bends. It is easier to make the bends if this is done
in 2 pieces, as shown in the drawing.
Note: The creative craftsman could build the entire fixture with less individual
pieces; possibly as few as two, if longitudinal placement was worked out.
Through these vertical pieces, there are 3 bolts.
-A- supports the boom as it rests in the operating position.
This could also be used to snug the plates against the boom.
-B- actually goes through the boom at the forward-most end
and is the pivot point for the boom.
-C- is a pin for the boom to rest against when the boom is
in the raised position for boarding and exiting.
Extra holes are shown in the vertical pieces to provide height adjustment
for the boom. The distance from the paddler to the paddle is adjustable by
placement of the larger plate on the L-Channels, and by boom length.
To hold the boom down when paddling, in case you cannot tighten the rear-most screw,
a bungee cord from an eyelet on the deck up and over the boom and back down to the
deck would work well. If you installed an eyelet for each end of the bungee,
you would either have two ends that could be released quickly, or you could permanently
secure one end of the bungee to the deck and leave the hook on the other end.
A rope tied to the rear end of the boom could be helpful for pulling
the boom down from the tilted up position.
Here's my very latest (as of March 23, 2007) design
for these vertical aluminum mounting plates.
Click on the drawing for a full size version.
A bolt through Hole A provides a place for the boom to rest in the up position
during boarding and exiting the kayak. The holes at B and C provide a pivot
point for the forward end of the boom. The holes at D are where the boom rests
in the operating position, and the bolt through D can be used to snug the boom
in place. The holes at E are for mounting to the Deck Plate.
These will also work for the sit-on-top fixture! Click on the drawing for a larger version.
PRELIMINARY PLANS FOR A CLAMP-ON FIXTURE
You will need to reference the original design drawing above to get the
whole picture of how it comes together with the boom and paddle-lock.
The screws holding the boom support (black) to the flat plate (green) are
countersunk so they are flush on the underside of that plate. You would
assemble that part before attaching to the main adjustable cross-members (yellow).
Loosely mount the flat plate to the cross-members, tighten the clamp to your kayak,
then snug up the bolts through the flat plate and cross-members.
I would plan to make the main cross-members (yellow) 12" wide,
as viewed from the side, for rigidity.
This drawing shows my thoughts for an "open" paddle-lock design that
would allow the paddle to move around and side to side, but still keep
it in the lock under normal operating conditions. The black buttons are
rubber feet that you could find at a hardware store. They already have the
recessed hole for the mounting screw. A "release-pin" (like that used in
marine applications) could be used in place of the cotter-pin for easy disconnect.
This would be more applicable to a paddle-lock that was not open at the top.
Please keep in mind that this is Very early in the design stage!
This drawing just shows the rivets you will want to use
and a simple way for making bolts watertight.
Q & A
Q: The "L" channel pieces, one of which is shown at the very bottom of the drawing, are the only pieces that are attached directly to the kayak. Only 4 holes would need to be drilled through the upper deck. Excellent. I like that. What about the little round hatch? Where would the L channel pieces go in relation to the hatch, and would the hatch still be useable?
**** That main aluminum piece that connects from one L-channel piece to the other is basically arched, providing room to reach under it and access that small hatch should the fixture actaully be mounted over top of it. Some experimentation with the degree of arch might be needed to provide sufficient clearance. It could be fairly high, then the boom could be adjusted more downward to bring the paddle height back down.
Q: Another question would be what the shape of the deck is. It's not flat. So the L-channels would have to be somehow adapted to a curved surface. I'll try to take some photos of the deck and cockpit for you.
**** Over say 14-18 inches lengthwise on the deck, I'd guess the deck should be flat enough to mount the L channels relatively flat to the surface. If not, some spacers could be added to make up the difference. You might want to add plastic or rubber spacers anyway just to keep the L-channel pieces from rubbing on the deck.
**** Crosswise the deck is quite rounded, and so the "vertical" edges of the L channel pieces will not be truly vertical. Bends in the large plate that spans them will be adjusted to accommodate the outward tilt of the L-channel pieces.
Q: Then, there are 2 or 3 more pieces of aluminum shown in this design. One is the large plate that crosses from one L-Channel piece to the other. The vertical pieces that hold the boom could be fabricated as a single piece with 2 90-degree bends. It is easier to make the bends if this is done in 2 pieces as shown. I don't understand: First you write "as a single piece" and then "done in 2 pieces."
**** The drawing shows this section made in two pieces. It would be possible to make it as a single piece, but... Some benders have trouble making 90 degree bends down inside what is essentially a deep channel, and, the boom would then have to be made as an exact fit to that "channel".
Q: Through these vertical pieces, there are 3 bolts.
-A- supports the boom as it rests in the operating position. This could also be used to snug the plates against the boom. So the boom just rests on this bolt, correct?
**** That is correct. And, that bolt could be tightened with a Wing-nut to snug that end of the boom as well.
Q: -B- actually goes through the boom at the forward-most end and is the pivot point for the boom. I assume it has some washers to allow it to pivot? And is that a butterfly nut on the end of the bolt?
**** Washers are not required. In fact, I would prefer to let the aluminum plates snug directly against the boom. This will help keep the boom down AND from moving side-to-side.
Q: So somewhere at the end of the boom there is a hole for the shaft of the oarlock, correct?
**** Yes, you could add something similar to the block for the oarlock as shown in the attached photo: PaddleLock.jpg, or you could use my original paddle-lock design.
Q: Extra holes are shown in the vertical pieces to provide height adjustment for the boom. How much height adjustment do you think there would be? An initial question is whether the top of the deck is approximately at chest height already. I'll sit in the boat and check that tomorrow.
**** The height will depend on how much height the "arched" aluminum plate and other components of the boom mount give the paddle, and on how much height the oar-lock" provides. A "closed" oarlock" could be mounted Under the boom! This part of the design really needs to be finalized on the kayak itself, but my design should accommodate whatever the requirements end up at. The mounting will be high enough to allow the boom to be ajusted in a downward (from horizontal) position.
Q: The distance from the paddler to the paddle is adjustable by placement of the larger plate on the L-Channels. You're a genius! Beautiful. Again, how much adjustment would there be? I'm assuming a few inches, since arm length varies by a few inches.
**** Again, kinda' need to figure this part out on the kayak. A longer boom would allow the mount to be placed further forward on the deck. A second hole drilled in the end of the boom would allow the same boom to be mounted further forward. A larger block at the paddle end of the boom could have more than one hole drilled through it for the oarlock to fit into (this would be the best solution for adjusting while underway), etc...
Q: Ideally, the plate could be easily moved back and forth to adjust while in the boat for variation in position when the kayaker tires. How would this plate be attached to the L channel? Any ideas for making it easily adjustable?
**** See above. And... If you really want to get fancy, the L-Channels could be sliding rails with some sort of a spring loaded catch pin that would allow adjustment. Picture the slide track used for stationing the main sheet or jib lines in a sailboat.
Q: To hold the boom down when paddling, in case you cannot tighten the rear-most screw,a bungee cord from an eyelet on the deck up and over the boom and back down to the deck would work well. If you installed an eyelet for each end of the bungee, you would either have two ends that could be released quickly, or you could permanently secure one end of the bungee to the deck and leave the hook on the other end.
A rope tied to the rear end of the boom could be helpful for pulling the boom down from the tilted up position.
I suspect that the kayaker will easily be able to reach the boom and bolt B just by leaning forward. I can easily reach the small hatch and beyond. Also, it seems like the boom wouldn't have to be extremely tight, because the paddle will provide downward pressure on it. So the boom can be raised without loosening bolt B, right?
**** Yes, but some upward pressure occurs while paddling. I am thinking that some rubber "bumps' could be postioned inside the plates above the boom, past which the boom would "pop" into position.
Q: PaddleLock.jpg shows my thoughts for an "open" paddle-lock design that would allow the paddle to move around and side to side, but still keep it in the lock under normal operating conditions. Doesn't a regular closed oarlock provide rotation in all directions? The oarlock pin turns 360 degrees in the hole (which by the way might need a metal sleeve to prevent the pin from wearing the wood?).
**** YES. And the sleeve is a good ides too!
Q: The black buttons are rubber feet that you could find at a hardware store. They already have the recessed hole for the mounting screw. Are those buttons to prevent the paddle from popping out of the oarlock? If so, how do you get the paddle in the oarlock? Break it apart, slide it in, and put it together?
*** The paddle shaft would simply "pop" down past the rubber feet. The feet would resist the paddle shaft trying to rise up and out of the open end of the oarlock, but would allow it to come out if the paddler so intended.
Q: Do you think it's desirable for the paddle to come out quickly in an emergency? I would say yes, because there could be, for example, a high-wave situation (passing motor boat) where I would want to have full control over the paddle by holding it in the regular manner, free of the oarlock.
**** Good reason to have an open oarlock from which the paddle could be removed with intentional effort.
Q: Two possibilities: either the paddle comes out of the lock freely (open lock), or the oarlock comes out of the boom easily, while still attached to the paddle (closed lock). Which do you think is better?
**** I kinda' like the idea of the paddle being able to be "popped" out of the oarlock.
Q: Can you please give me an idea of the dimensions of this whole device? Then I guess the last question would be to adjust the dimensions to my kayak and my body, right?
**** Starting with the L-Channel pieces: I'd imagine they would be 14-18 inches long. They would be spaced 14-16, maybe 18 inches apart. I'd like to see the pieces that snug against the boom be at least 12 inches long. Their height would depend on how much height adjustability you need. Just make them large enough at the start to provide a good range. The other dimensions will simply fall into place to accommodate the primary mounting. The boom length can be adjusted to allow the mount to be placed just about anywhere on the front deck.