Airplane777
join:2004-06-20
4 edits | 10' to 15' mast guyed to NPRM sled ?
Here is a picture of a NPRM sled. I believe they can come in 3 to 4 feet square...even longer to hold short towers.
Have any of you used one of these sleds with a 10 to 15 foot mast (maybe a 1 1/4" tv mast), and with four guy wires, to each of the four corners, to hold a light CPE?
I have only seen it used at one place, which is near where I live. Never seen it done elsewhere. But it seems like a good way to easily and quickly mount a small CPE onto a 10 to 15 foot tv mast.
The one near my home looks to have a 10 or 15 foot tv mast, with a guy wire collar at the top. It has four guy wires, each going down to each of the four corners. I believe there are eye hooks at each of the four corners. And it uses turnbuckles to tighten up the guy wire.
Have any of you used this method? Do you like it?
Thanks for the info. |
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viperm
Carpe Diem
Premium
join:2002-07-09
Winchester, CA
| Not sure if we used the "same model" but we have use siler with masts 10 ft without guys and it worked just fine. Granted we were in an area of the roof without any real exposure to winds. If it were out in the elements to direct wind action I might think of using guy wires.
Usually 10 ft and under we dont as long as we use at min 6-8 cinder blocks on the base.
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ComTrain Certified Tower Climber. American Tower Certified approved contractor |
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Airplane777
join:2004-06-20
| Hi viperm:
Maybe this guyed tv mast I saw was even longer then 10 feet. I wasn't able to get real close to it.
It was guyed. Maybe it was 15 feet tall, rather then 10 feet. I don't think it was 20 feet. That may be too tall for guying to the four corners of a 4 foot square sled.
Is "siler" the trade name of your sleds? |
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viperm
Carpe Diem
Premium
join:2002-07-09
Winchester, CA
| reply to Airplane777
First I would never attach the guy wires to the edge of the sled??? basic law of physics your guy wires would not be far enough out to do any help and they are not attached to any solid part of the building..
Thats the whole point of guy wires I dont think you will find anyone here that will tell you they tie them to the edge of the sled that is just plain wrong in my opinion.
We order ours thru talley so I am sure they are made by Andrews or MTS wireless
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ComTrain Certified Tower Climber. American Tower Certified approved contractor |
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Airplane777
join:2004-06-20
1 edit | I realize the angle of the guy wires wouldn't be the best angle for guying, but I thought if the cinder blocks on the sled were heavy enough to keep the mast & CPE from tipping over, and 4 guy wires were used, that it might be able to support a light CPE at 15 feet?
The CPE might be 4 or 5 pounds, and maybe 14 inches square. So that shouldn't put too much wind load on it.
You think it might work? |
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LLigetfa
join:2006-05-15
Fort Frances, ON
| An NPRM can hold a 10 foot mast without guys but personally, I would not use 1 1/4" TV mast. I would use heavier 2 1/2" pipe. If you intend to use that spaghetti crap then yes, I would guy it out. If going 15 feet, I would use maxi-blocks or smaller blocks and 4 bags of sacrete. |
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Keithb
join:2003-09-16
US | reply to Airplane777
You could always mount some angle iron to the NPRM to extend the base out and guy to that. |
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Airplane777
join:2004-06-20
| reply to LLigetfa
said by LLigetfa  : If you intend to use that spaghetti crap then yes, I would guy it out. If going 15 feet, I would use maxi-blocks or smaller blocks and 4 bags of sacrete. When you say "guy it out", do you mean, not to guy it to the 4 corners of the sled, but out further away from the sled, by having the guy wires go to the maxi-blocks, which are sitting on the roof? And a bag of sand would be on each of the maxi-blocks? So the 4 corners of the sled are just too close to guy to?
Only reason I asked, was I see a competitor is guying about a 15 foot pipe to the four corners of a sled, near by where I live. It seems pretty stable, even in wind. I can't see how many cinder blocks he is using, but it must be enough to keep the thing upright in a wind.
I thought if a 3 or 4 foot square base might be wide enough to hold a fairly light CPE at around 15 feet. That kind of setup could come in useful in the future for me. |
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LLigetfa
join:2006-05-15
Fort Frances, ON
| If you use the Wade NPRM I spec'd for you, it has a 4' X 4' base that takes 12 maxi-blocks. It has a mast clamp height of 51" so it can accept a 2 1/2" mast 10 feet long without guys. What I meant was that if you wanted to use that thin-walled spaghetti mast, you would need to guy it to the 4 corners of the sled.
The picture you show is nothing like the Wade NPRM. |
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Airplane777
join:2004-06-20
1 edit | Do you think the Wade NPRM can go to 15 feet, if I guy it to the four corners, and if I use a 2 1/2" mast?
Or, if a 15 foot, 2 1/2" mast is sturdy enough, maybe I won't have to guy that either?
I wonder if they make 2 1/2" masts up to 15 feet? |
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LLigetfa
join:2006-05-15
Fort Frances, ON
| 15 feet might be pushing it a bit, depending on region. Is the area prone to very high winds? I don't recall how much those maxi blocks weigh. We used to hoist them up scaffolding with one hand so they can't be all that heavy. I'm talking about concrete blocks, not cinder blocks, 12" X 8" X 16" nominal. You may want to put a bag of sacrete on each corner. You can use galvanized posts made for chainlink fences. Ever do time?  |
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