At 10:25 AM 2/28/96 -0500, you wrote:
>In a message dated 96-02-27 22:01:11 EST, you write:
>
>>How deep would you have to go in the swamp-like condx Charlie's talking
>about ?
Somewhat related is the way they set utility poles in the swamps. They
bring in a utility pole using a helicopter. The pole has a charge of dynamite
on the bottom, which is detonated and before the goo rushes back into the
resulting hole the pole is dropped into the hole.
Not sure I would want to be the first guy trying this--experimenting with
just how much dynamite is enough. Might require splinter removal
and new uses for Preparation H.
Caisson drilling is pretty common but requires special equipment. It may be
possible to use a caisson technique while pumping out the insides and
settling the caisson as you go. The real question remains about what are
the details of the soil--how far down before you hit anything solid and just
how liquid is the swamp.
I once had a 4ft long 12 inch diameter concrete pipe that was mounted vertically
to provide access to a water valve. Over the years the thing had completely
filled up with soil and sand. Kept thinking that this would be a real pain
to dig out with a little shovel. Finally "excavated" the inside of the pipe
with a Sears heavy duty Shop Vac. Didn't take very long at all. The
technique won't challenge a back-hoe in normal circumstances but may
be the only answer in some cases.
The ionospheric heater array at Arecibo consists of about 100 towers that are
100ft tall, supporting a large phased array of log periodics. It is built on
vegetation floating on a swamp (done deliberately to enhance the ground
conductivity for a vertical beam). When you jump up and down on the
"ground" everything shakes. You can drive a car on it but it has just enough
bounce to be un-nerving. Once, I was driving 3ft long rebar pieces to act as
temporary guy anchors for a little array of receive antennas. At the last
tap of
the hammer the rebar just kept on going--penetrating the "soil" and falling
on down through the water, completely lost. These towers were built on
some kind of surface platform of pressure treated logs and were
guyed to dead-men of more pressure treated logs. Not sure of the exact
details of Arecibo but the situation of towers in a swamp is an interesting
problem and I think I will call my friends at Arecibo and find out the exact
details.
73 John W0UN
John Brosnahan
La Salle Research Corp 24115 WCR 40 La Salle, CO 80645 USA
voice 970-284-6602 fax 970-284-0979 email broz@csn.net
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