[TowerTalk] guy posts math

[Jim Thomson]

Date: Mon, 20 Jul 2015 02:32:54 -0500
From: "W5GN" <w5gn at mxg.com>
To: "'Jim Thomson'" <jim.thom at telus.net>, <towertalk at contesting.com>
Subject: Re: [TowerTalk] guy posts math

My dad ran Bartlett Tree who serviced all of the AEP lines in
SW Virginia and their engineer said they put 7 feet of a 35 foot
pole in the ground in the late 50s. Sounds like your TELCO poles
had lighter loads and thus put less in the ground than power poles.

73

Barry, W5GN

##  IF only telco + cable are on the pole, the poles are usually shorter..like 35 feet.
IF it’s a joint use pole..and also has commercial AC power  with the usual 12.5 kv  or 
14.4 kv HV on top, with lower voltage 240/120 down below plus telco and cable etc,
then the poles are typ 40 ft tall.   The HV sits another 18 inches above the 40 ft pole...
via an insulator on top of steel.   What diam are ur poles ?   What kind of wood ?
Joint use pole applications  typ makes up 95% of pole applications.   You rarely see
telco +  cable co only poles, but they do exist. 

## They all have a metal plate on em..exactly 12  foot up from the bottom.  The plate 
if u know how to read it, will have info on it which also gives the exact co-ordinates
of the pole location.   When u see that the plate is  6 ft above the grnd, u know the
pole  is exactly 6 ft into the ground.   If the plate was 5 ft above grnd, the pole is 7 ft
into the grnd.   This is the case for a 40 ft pole. 

##  Those 50 kva /75 /kva /100 kva /125 kva xfmrs weigh one helluva lot....and if u have 
ever seen em on the grnd, they are a lot bigger than u think.   The most I have seen on one pole
is  3 x 100 kva xfmrs.      The place u see guy wires, typ at two levels  is where stuff Ts  off to one side,
placing  a huge side load on the pole.  or where a pole line does a right angle.   Typ guy strand is either
.3125  or .375 inch for the bottom level.....and   either  .375  or .4375  for the top level. 

##  If u ever see a new pole or poles laying on the ground in  residential neighbourhoods etc, get out
and measure the distance  between the plate and the bottom end.   Then compare that to the total
end to end length of the pole.   30 ft poles will have the plate  10 ft from the end.  40 ft poles will
have the plate 12 ft from the end etc. 

##  concrete pole have gone out of vogue.   They had a lot of re-bars in them, running the length of the
pole. I don’t know how deep they put concrete poles into the grnd.  Only saw em used for joint use
applications.

Jim   VE7RF