[TowerTalk] TowerTalk Digest, Vol 165, Issue 11

[Patrick Greenlee]

Careful with the backfill!  I wasn't careful enough with backfill of one 
of my 4 inch PVC conduits and cracked it later after backfill during wet 
weather, most likely a sharp rock.  Ground water infiltrated the conduit 
copiously putting several gal per minute of water onto a metal barn's 
slab floor.  Water came out inside the building over 2 ft above the 
floor.  Barn is down slope from some tower sites. Luckily I hadn't 
pulled any cables yet and just sleeved all the wires in flexible 
irrigation tubing good for 100 PSI at 73F before pulling into the 
conduit.  It won't get that hot underground and the head of pressure is 
significantly less than 100 PSI. The irrigation tubing is quite flexible 
and comes in 100 ft rolls for $12.50 per roll at the big box stores and 
can be spliced for longer runs.

Best wishes for a job well done.

Patrick        NJ5G


On 9/2/2016 2:59 PM, Mitch wrote:
> I'll answer all in one post.
>
> This is a new installation. The feed line exits the radio room on the West
> wall, goes underground, through the house West foundation wall, through a
> little over 70ft of crawl space, out through the  East foundation wall
> again, under the gravel drive way that goes to the back of the property then
> runs approximately 200ft under the driveway along the east side out to where
> the 45 sweep will be, the approximately 80ft to the tower. I thought about
> just direct burying it, but wanted the extra protection of conduit due to
> the driveway traffic. This driveway sees cars, diesel pick up trucks, farm
> tractors, sometimes large trucks and heavy equipment. There is no other
> route the coax can take. I also do not plan on the coax being more than
> about 2ft down due to a large cobble rock layer at about that depth. The
> earth above that is silty sand with some samll rocks. Could the hardline
> survive under these conditions, probably, but I will feel a lot better with
> it in conduit. I can always run smaller conduit for the control lines. These
> conditions and limitations are what they are. Again, no other options for
> the routing to the tower.
>
> If necessary, I can add the two end sweeps after the hardline has been
> pulled. That should alleviate some of the force necessary to get it most of
> the way. Then slip on the end sweeps once its in place. Or just slide the
> conduit sections on one at a time until it is all encased. Would make it
> easier to add the control lines at the same time too. Just a lot more work
> versus pulling through an already buried conduit.
>
> I have a large heavy duty pulling grip that will be used to pull the
> hardline and other cables through the conduit. This should eliminate it
> hanging up on the ends of the conduit.
>
> Mitch KJ7JA
> ------------------------------
>
>
> Message: 7
> Date: Fri, 2 Sep 2016 14:36:45 -0400
> From: "john at kk9a.com" <john at kk9a.com>
> To: towertalk at contesting.com
> Subject: Re: [TowerTalk] Pulling long length of 7/8 hardline in
> 	conduit
> Message-ID: <d16401467cdc58ea6aa7fea9b51c87d7.squirrel at www11.qth.com>
> Content-Type: text/plain;charset=iso-8859-1
>
> This will be very tough. If this is a new installation I would just direct
> bury the Heliax.  If the conduit is already buried I would at least dig up
> the ends and so that they have no bends. I think it is easier to fish
> everything at once but I do not fish Heliax though my conduits.  I would
> fish the new pull line when you run the wires rather than try to get a mouse
> though a partially filled tube.
>
> John KK9A
>
> To:	<towertalk at contesting.com>
> Subject:	[TowerTalk] Pulling long length of 7/8 hardline in conduit
> From:	"Mitch" <mskobier at charter.net>
> Date:	Fri, 2 Sep 2016 10:54:12 -0700
>
>
> All,
>
>                  I'm looking for anyones experience with pulling a long
> (almost 400ft) length of 7/8" hardline in underground  conduit. I have 4"
> conduit which will have a number of sweeps in it. Here's how it will lay
> out. The first 90 degree sweep is where the hardline goes down from the
> junction box into the ground. Then it runs approximately 80ft straight, then
> hits another 90 degree sweep, then runs mostly straight approximately 230ft
> where it hits a 45 degree sweep, then runs approximately 60ft to the final
> 90 degree sweep where it turns vertical up into the junction box at the
> tower. I'm concerned with possible kinking of the hardline making that many
> turns. I can possibly not use the 90 degree sweeps at each end during the
> pulling, but it would be nice to do it all without having to make conduit
> connections after the hardline is in place. I plan on using lots of wire
> pulling lubricant during the pull. I cannot re-route the hardline/conduit.
> This is the only way I can run the hardline to the tower. Has anyone on the
> list ever pulled hardline through a number of sweeps?. There will eventually
> be a number of other coaxes and control cables in the same conduit. I plan
> on pulling the hardline first, so I have the most room, then I will run a
> mouse through the conduit to avoid having the remaining cables trying to
> wrap around the hardline and getting wedged under or stuck by the hardline.
> Thanks in advance for any and all help.
>
>
>
> Mitch KJ7JA
>
> ******************************************
>
>
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