On Feb 13, 6:33 am, "Dan Listermann" wrote:
"Two meter troll" wrote in ...
On Feb 12, 10:54 am, "Dan Listermann" wrote:

I want to build two docks, one permanent and a floating one. The floating
one will be supported by 15 gallon plastic drums. I can get 55 gallon, but
for a 4 x 8 dock, I worry about center of gravity issues.

The permanent one will be built of 55 gallon drums filled with dirt. Any
issues to look out for?

and again build it so the barrels can fall out when they get full of
water or your dock will sink lower and lower.
those plastic barrels will eventually fill all you need them to do is
push up so it costs you nothing to make the darn thing safer

Can you expand on this? I am not sure that I follow you here.

when you build the floating dock you are going to have a bit of free
board. when plastic barrels fill with water they just barely clear the
surface. if you fix them to your floating dock they will pull the dock
down as they fill. so you make the dock in such a way that the barrels
can sink without pulling the dock down.

Anecdote: here in oregon we get spring floods that bring root balls,
sunken trees, and other stuff down the river. floating docks made with
plastic barrels are popular here. if the barrels on the edge of the
dock get hit by a submerged root ball it can put a hole in the barrel
causing it to fill with water and sink. if the barrel is fixed to the
dock this will pull down the edge of the dock a bit. then the intact
barrels are closer to the stuff rolling down the river and more likely
to get punctured.

if you do not strap the barrels to the dock then the punctured barrel
sinks out from under the dock. this may cut down on the flotation of
the dock but it wont have the effect of pulling your dock down.