"mmc" wrote in message
ng.com...

"Tom G" wrote in message
...

"mmc" wrote in message
g.com...

"Dan Listermann" wrote in message
...
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?

The 55 gallon drums filled with dirt may float because of the air
trapped in the dirt. If soaked after positioning and filling, they still
won't weigh much. Concrete blocks are something like 30-40% thier (in
air) weight when submerged.
You can "jet" pilings in with a trash pump. Last time I rented one was a
couple years ago and it cost me $25/day. In a day you can jet around a
bazillion pilings. Four of us non-professional jetted in 40 pilings in a
couple of hours.
I use an old pontoon platform for my dock but I'm interested in the
details of how you "jet" a piling in and exactly what a "trash pump" is.
I have need to put in a permanent short pier at the edge of the bank to
support the land side of my ramps to the dock. I had piers supported by
2 inch pipes driven into the shore bottom but last years flood lifted the
pier and the pipes right out of the ground and bent everything to hell.
I figure 4 inch well pipe would hold up but the only contractor on the
river with the equipment capable of driving them is apparently not
interested in any new business. I tried for 3 years to get him to give
me a quote on some rip rap or vinyl wall (his advertised business) but he
doesn't seem interested. I had $26,000 in my budget but I didn't really
want to tell him that up front.

Tom G.

Tom,
Check this link:
http://www.wikihow.com/Install-Posts...a-Dock-or-Pier
Good description and saved me the time of writing it.
The dock work I've helped with has been in Florida's Indian River with
sand bottom. I don't know how well this will work in other environments.
We used a rule of thumb of 1/3 the piling length and a minimum of 4 feet
buried. One of the docks I helped with got destroyed by a big storm fetch,
but the pilings were still standing.
The rental places here have pumps set up just for this with the pipe
already set up and pinched. All we did was plunge the pipe length (6')
(1-3" water depth) all the way down a couple of times, then stand the
piling up and let it sink in the hole. One guy holds it plumb while the
other jets around it a little, guy one keeps holding it plumb for a few
minutes until the sand settles. Doesn't take long.
Thanks...answers my questions. I think it just might work. River bottom is
mostly sand with some small gravel mixed in. Pilings would be above the
edge of the water's edge except at flood level and then no ice involved.
Intend to set an aluminum pier section on top that can be lifted off during
the off season. I had a heavy wooden pier section but the water was
unusually high this last year and it floated it and the steel pipes up and
twisted everything beyond saving.

Tom G.