[TowerTalk] Schedule 40 or 80 PVC Conduit Underground

[john at kk9a.com]

I lived in the Chicago area for most of my life and it definitely gets cold
in the winter.  My 350' tower runs were only a foot or so deep and well
under the frost line. Perhaps I was just lucky as it never obtained any
damage. Telephone and cable TV wires are buried just below the surface and
they also seemed to suffer no ill effects from the harsh winters. Electrical
runs are buried very deep, but I assumed it is to protect them from shovel
damage. There was no frost line at my home in Aruba, My tower cables were
buried only a few inches deep and the water pipes were run outside the
house!  Here in Charlotte NC, there is a minimal frost line and my cables
are well below it.  Perhaps in some areas with certain deep freeze thaw
cycles this could be a problem but I have never seen it happen.

John KK9A - W4AAA 


To:	towertalk at contesting.com
Subject:	Re: [TowerTalk] Schedule 40 or 80 PVC Conduit Underground
From:	Jim Lux <jimlux at earthlink.net>
Date:	Wed, 12 Nov 2014 10:03:44 -0800
List-post:	<towertalk at contesting.com">mailto:towertalk at contesting.com>
On 11/12/14, 7:57 AM, john at kk9a.com wrote:
Why would tower/antenna control lines and coax need to be buried below the
frost line?


to avoid mechanical disruption of the conduits.. Things like frost heaves
and the generally mushy condition of the soil during thaw.

Mind you, I'm a California boy and have no practical experience with this
(thankfully), but my friends who live in Maine tell me that there is about a
month in the spring when trucks are not allowed on many roads. I can say
from personal experience that many of the roads are spectacularly wavy and
bumpy, which they attribute to the effect of uneven freeze thaw. They also
have horror stories about broken sprinkler pipes and such in the yard.



John KK9A

To:     "'Allen Brier N5XZ'" <n5xz at earthlink.net>,      
<towertalk at contesting.com>
Subject:        Re: [TowerTalk] Schedule 40 or 80 PVC Conduit Underground
From:   "Dick Green WC1M" <wc1m73 at gmail.com>
Reply-to:       wc1m73 at gmail.com
Date:   Wed, 12 Nov 2014 07:02:29 -0500

<snip> Where I live, Schedule 80 is
always used for buried conduit runs, but that's probably because the frost
line goes down four feet and the conduit has to be buried at least that
deep. Could be a different story in your area.

73, Dick WC1M