Industry Forums > Wireless Service Providers > Stand offs for a water tower question...

Stand offs for a water tower question...

Without a railing at the top you are pressed for mounting methods. The optimal method (and really the only accepted method for tanks that are currently in use) is a special method of welding known as capacitive discharge stud welding.

»www.wirelessestimator.com/indust···egid=293

An experienced welder using this method can effectively and safely attach any type of array mount to an in-use tank. Special thanks to our local resident engineer John Galt for pointing me in this direction.

Should you be able to coordinate with the water utility/company to perform the installation during the time that they are inspecting/resealing the inside of the tank, normal methods of welding (such as MIG) can be used.

A lot of installers will use epoxy-based adhesives to secure mounts and waveguide to the tank, but those are ineffective. The link above points to that as well. Over the summer, I was engineer and project manager for a two-site job for a local utility on some large water tanks. There was a co-located cellular carrier on one of the tanks. Upon reaching the top of the tank during my pre-install engineering, I found that the cell carriers waveguide cushion mounts (unistrut epoxied to the tank) had come loose. This is completely unacceptable for a long-term installation, and furthermore unprofessional and dangerous. There were at least 8 pairs of 1-5/8" feeders tied to this unistrut channel, and obviously it was not secure. This not only violates installation standards setforth by the manufacturers of coaxial feeds, but even violates installation standards by many companies and vendors of cellular gear.
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"No job is so important, and no service is so urgent that we cannot take the time to perform our work safely."
-- AT&T, Your World, Destroyed.
--Safety One Tower Rescue Certified
--LLigetfa:"Wimax is like teenage sex. Everyone talks about doing it."

Here is a pic of the tower, »stlbroadband.com/h20.html
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»StLouisBroadband.com

reply to Air WAV
Yeah those types of tanks are a pain. The ones I have worked on have a railing up top.

I'd highly suggest coordination with the department in charge to see if you can schedule a time during maintenance to install your mounting hardware. You should perhaps look for a installer that can do the capacitive discharge welding method I mentioned above, if at all possible should you not be able to have the welds re-sealed on the inside.

Do you need waveguide for ethernet? Also any ballpark figures to have this welded?

Thanks again!
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»StLouisBroadband.com

reply to Air WAV
You are welcome. Be sure to point the water dept guys to the links. They mention AWWA, which is the who's who in the water world. I worked with a global-wide utility for the project I mentioned, and they were highly interested in the methods discussed in the links. Unfortunately, the job I was working on forced me to place antennas in a different location, so we never had to route feeds over the top of the tank. Should I had to have done that, it would have been done using capacitive discharge welding methods, or securing the lines down to a custom-fabricated mount that attached to the ladder stand-off's.
--
"No job is so important, and no service is so urgent that we cannot take the time to perform our work safely."
-- AT&T, Your World, Destroyed.
--Safety One Tower Rescue Certified
--LLigetfa:"Wimax is like teenage sex. Everyone talks about doing it."

reply to Air WAV
Waveguide is not required for radios that use PoE to the ODU.

You will however need to fabricate a method of securing the cabling as it runs up the inside of the tank (where you climb).

How many runs of CAT5 do you need to run to the top?

Any idea on costs? And how the heck to they get welding equipment up there?
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»StLouisBroadband.com

reply to Air WAV
8 cat5 runs? I would assume there is a ladder running up the tube.

There are two ways you can do this.....

1) zip tie the runs to the ladder standoffs. Cheap, easy, and IMO all around lazy and potentially illegal.

2) Run a conduit up the ladder standoffs. Secure the conduit to the standoffs using angle adapters, and then bolt another angle adapter to the one that is attached to the standoff. This second angle adapter should be capable of accepting a round member adapter (hose clamp for those that don't work with tower hardware regularly!!!) so that you can hose clamp down the conduit to the assembly. Run the conduit up the ladder using this method and then ziptie your cables to this conduit every 3 feet. This does two things: First, allows attachment to the structure that is secure, and won't rot off or rust, and second keeps the cabling away from where the climbers must put their hands and any possible fall restraints. The second half really trumps the first reason, because strapping the cabling properly would mean every 3 feet and you can't very well do this because the ladder stand-offs are placed every 10-15 feet typically. Everyone I have seen straps it directly to the ladder, which means that the climbers may possibly have to put their hands where the cable feeds are, or have to snap on a snap-hook for their fall restraints. this would impede them which is a violation of OSHA standards, and possibly (most likely) cause damage to your CAT cables.

I speak from experience when I say it is dangerous to ziptie the cable to the ladder. I was doing an estimate one day (different job than I mentioned before) and a competing WISP was on the tower. They ziptied their runs up the side of the ladder. It was very hard to work around their feeds to get my pelican hook for my fall restraint secured to the ladder (no safety climb) and when I was at the top their feeds criss-crossed the ladder and railing which further made it difficult to cross over from the ladder to the railing. Totally unacceptable and unsafe. Side note: When I reached the top I found they had sealed their N-connectors with silicone sealant from a caulking tube....... this further sealed their grave in proving to me that they have no business doing ANY type of tank or tower work. LAZY LAZY LAZY LAZY.....
--
"No job is so important, and no service is so urgent that we cannot take the time to perform our work safely."
-- AT&T, Your World, Destroyed.
--Safety One Tower Rescue Certified
--LLigetfa:"Wimax is like teenage sex. Everyone talks about doing it."

reply to Air WAV
As to price I have no idea...... I never got to the point where I needed to RFQ that part!

I would assume they haul the gear up with them, or run a utility feed to the top and then go from there.

reply to Air WAV
Go with magnet mounts. By the time you mess around with welding and repainting you're going to end up spending a lot of money. If you go with a magnet mount you can take it with you when you leave.

Check these out: »www.metal-cable.com/page13.html

reply to Air WAV
Fascinating!!! I never knew those existed!

Have you used those magmounts before? I have a job where I might be able to use them actually.

Of course, it won't be for equipment like that cheesy Harris radio..... That's childs play.

reply to Air WAV
Another thing you could do is "help" the city find a cell carrier to go up on the water tower. Let them cover the cost of installing a safety ring and antennae mounts and then mount your equipment somewhere else on the ring. We did that in one city and it worked well.

reply to Air WAV
I personally haven't used them but I know people who have and they love them. Apparently one has to be extremely careful with these magnets because they are so incredibly strong. One false move and someone could loose an arm.

Cool. I'll call them first thing Monday and get my estimate worked up. I need one that can hold a pair of 2.5 footers for an 11GHz link.

I would assume they are done using earth magnets, like the type in your hard drive.

Edit:

Nice, I was just poking around their site and it looks like the guy does all of his engineering and production in the USA. And to boot, he is a ham operator!

reply to keefe007

reply to AMD Phreak

reply to keefe007
WOW

Very kewl. What kind of costs?
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»StLouisBroadband.com