"Alex" wrote in message
...
"Dan Listermann" wrote in message
...

"Andrew Erickson" wrote in message
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In article ,
"Dan Listermann" wrote:

I have built a floating dock from treated 1/2" 4 x 8 plywood, skirted
with
treated 2x4s and supported by 9 cable restrained 15 gallon plastic
barrels.
Currently I have two of these tied together with 8' 2 x 4s using lag
bolts.
The resulting dock is 8' x 8'. I want to double the size with two more
sections for a total size of 8' x 16'.

The river floods occasionally so I will want to be able to take the
docks
out. This will involve dragging them up about 12' of bank. I want to
disassemble the four sections to do this. I am looking for a way to
connect
the four so that they can be easily disassembled and reassembled
without me
getting too wet in the winter. So far, I have bought hanger bolts and
wing
nuts that I intend to use with 16' 2x6 boards on either side. This
will
work, but it will be very tricky to get all the holes aligned at once.

Any suggestions?

I'd be tempted to use eyebolts and something to join them with--such as
"quick links" or a vertical pin of some sort. Both of these assume that
the sections don't have to be absolutely rigidly attached to each other
(although the ring-and-pin approach could be made nearly rigid).

If you wanted to go with the 2x6 approach, you could at least split the
16' length into sections that only cover one joint, so it's only
necessary to line up two sections at any time. That may, of course,
force you to keep track of more wing nuts and washers and whatnot, and
that (if you're like me) means more fishing around the bottom of the
water for nuts and bolts.

--
Andrew Erickson

"He is no fool who gives what he cannot keep to gain that which he
cannot
lose." -- Jim Elliot

I would like to keep the whole assembly as rigid as possible. I am
leaning toward the short section method, but I need to work out how to do
it without needing to keep close tract of individual sections. In other
words, I would like all sections to be able to work anywhere.
You might think a two-layer approach, first joining the sections one by
one with (say) 3-foot lengths of 2 by 6, drilled to accept bolts
projecting sideways from the floats. Then, when the entire dock is in the
water, the pre-drilled 16-foot length of 2-by-6 could be placed on those
same bolts (which of course would have to be long enough) and fastened
into place. This would add full-length rigidity, and should be easier to
put in place once the short pieces are holding the dock fairly still.
When the long piece is removed, the short pieces would act as a hinge,
allowing you to pull one part up on the shore at a time.
This is purely a hypothetical solution, and may be totally impractical.

_____
|| | bolt (plus spacer lumber)
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| | (open space behind long board, good for tying up to dock.)
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|| | bolt
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|| |
_____|| | bolt (holding both the short "hinge" board and the long
"rigidity" board.)
_____ | |
|| | bolt
|| |
| |
|| | bolt
| |
| |
| |
_____|| | bolt







I think I will try the short sections and see how rigid it is, then consider
a longer stiffener system. At least the longer system should only need a
single bolt per section.