[TowerTalk] Crank-up base

[Bryan Swadener via TowerTalk]

Hi Mike,

I had a water table issue as well. I solved it with a sump pump.
I backfilled the hole a bit with some round rock and created a
small "dimple" in the bottom of the hole for the pump to set in.
At first, the pump clogged with pebbles between the impeller
and housing.  Some aluminum window screen wrapped around
the pump solved that issue.

Since the pumped didn't have a float-operated switch, I pumped
the water out daily (or as-needed).  The last pumping came just
before the concrete arrived. The only wood used was above ground.

Photo story: http://www.tinyurl.com/wa7prc-tower

vy 73,
Bryan WA7PRC


________________________________
Date: Wed, 30 Apr 2014 20:20:41 -0400
From: Mike Reublin NF4L
To: towertalk reflector
Subject: [TowerTalk] Crank-up base

I'm negotiating to get the base for my HG70-HD dug and poured. I have a high water table, soil tends toward sandy, and an engineer said he would be happier if the hole were 10' deep rather than the 7.5' called for in the manual.

The concrete guys I'm talking to want to line the hole with plywood to prevent collapse. One guy who does a lot of big sign installations says he does it regularly, and there would be no stability issues.

I've read several times the pour needs to be into undisturbed soil, no backfill, altho that's not in the manual.

What are the facts?

73, Mike NF4L