Subscriber Discussion

Mounting Security Cameras On 4"X4" Timber Poles?

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James Talmage
May 27, 2015
IPVMU Certified

A client is proposing 20 foot long poles, buried 5 feet, for a camera mounting height of 15 feet.

This is for analytic cameras with long zooms (22mm), so bouncing is going to be an issue.

Is a 4"x4" too small? Has anybody ever tried this before?

U
Undisclosed #1
May 27, 2015

I'd say that will cause problems...

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James Talmage
May 27, 2015
IPVMU Certified

Undisclosed A, is that a guess or from experience?

U
Undisclosed #1
May 27, 2015

It's from experience.

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Brian Rhodes
May 27, 2015
IPVMU Certified

Is it possible to stabilize the poles with guy wires or stiffeners?

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James Talmage
May 27, 2015
IPVMU Certified

At that point, it would probably be better to just go with a sturdier pole.

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Brian Rhodes
May 27, 2015
IPVMU Certified

A freestanding 4x4 timber pole would move pretty significantly even in modest winds. That focal length is not going to do you any favors, either. :(

You might consider something like galvanized steel in a tapered hex profile, or even extruded aluminum poles to cut down on movement at 15' mounting heights.

Will the analytics provider give you any guidelines or tips here?

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James Talmage
May 27, 2015
IPVMU Certified

Any guidelines on how to figure out what size pole is needed?

Each pole will have 3x cameras and a 20" x 20" x 6" box electronics and batteries.

JS
Jason Spielfogel
May 27, 2015

22mm really isn't that a super high zoom, but I need A LOT more information.

1) What type of analytics? - if it's simple tripwire/motion type stuff, you probably will be okay. If you're trying to capture license plates or do more advanced object identification, and there's a lot of sway on the poles, it could be a problem.

2) Is this a windy environment? The more wind, the more sway.

3) What are you sinking the poles into? Dirt, Cement? That's going to affect sway

4) Does it have to be wood posts? Can you use steel poles or something with more rigidity?

5) Do you have the opportunity to install one as a test and see if it'll work as designed?

These are questions I would ask. 15' high really isn't that high off the ground, so depending on the factors above, you might not have as much sway as you think.

DW
Dennis Widdows
May 27, 2015

4 x 4 Wooden TImbers will weather and will warp over time as well...Been there...

Good Luck!!

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James Talmage
May 27, 2015
IPVMU Certified

Cameras will be temporary. As long as it makes it 20 months, we would be fine.

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Mark Jones
May 28, 2015

For 20 months you should be fine unless it is significantly windy. Even though they are temporary I would still put cement in that hole. Just cut them off even with the ground when finished.

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James Talmage
May 28, 2015
IPVMU Certified

Have you installed on 4" x 4" pole before? At what height? How did it perform?

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Mark Jones
May 28, 2015

Yes. It was a lumber yard so they had poles a plenty and they were insistent. As the yard grew, they could move the cameras as needed. Ours were for a longer period and over the course of 2 southern summers they will warp, especially if the wood is green, but the customer knew that too. We were at just over 12' and I insisted on concrete. Heavy winds can play a large factor. They actually performed quite well. The poles never really wavered as much as they would "shudder". I still think if they had been round instead of square some of that shudder would have been mitigated. We did not use analytics, but did use motion detection. Everyone had clear expectations. This same customer mounted a camera on the front of a tree chipper with a monitor inside the cab so the operator could see what was going on in the throat of the chipper. It vibrated something awful when in use but they expected that and actually thought it was a vast improvement over what they did have which was nothing. I am sure you have seen large limb chippers. It was like that but on steriods. This thing was as big as a combine. It was much safer than having someone nearby watching, and allowed that second guy to go do something else. The operator really became quite dependant on it.

TC
Trisha (Chris' wife) Dearing
May 28, 2015
IPVMU Certified

From a video in Installing Timber Poles For Surveillance, posted by Brian.

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James Talmage
May 28, 2015
IPVMU Certified

Thanks for the link. However, the question here is not how deep to bury the pole, but whether a 4" x 4" pole is appropriate.

U
Undisclosed #1
May 28, 2015

To give you a little more definitive info.

I'd rate a 4x4" pole as "good" up to about 8' above ground with 2 smaller cameras mounted on it (bullet-style cams ranging from the little Dahua's up to about the size/weight of an Avigilon bullet). I agree that 4x4's can warp and twist and you need to watch out for that. We have a couple of 4x4's with cameras at our marina that do OK enough (IMO) for decent analytics performance, but the cameras are not very high up (I had nothing to do with the install...)

A 6x6" post is good for the same scenario up to about 10' above ground.

The profile of the camera or equipment and average wind speed will play a big part here. If you are in an area where the winds are mostly blocked off you may have fewer issues. If you're also mounting an equipment box on the poles that is going to increase the profile that catches wind and also add weight higher up on the pole, causing more sway.

If there is lots of heavy construction equipment moving around near the site that can also cause smaller diameter poles to vibrate and move around more.

I've seen several sites use ~4" diamter steel poles with good success, sometimes filling them with concrete. That is more permanent solution though and I think you wanted something that could be removed after a couple of years.

KL
Keefe Lovgren
May 28, 2015
IPVMU Certified

James,

I would recommend a larger dimension of lumber or a different material all together. I have never used 4x4 post before but have used 8x6 with cameras mounted at 10' on a 12' post. Even with 8x6 small winds would create shakey video.

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James Talmage
May 28, 2015
IPVMU Certified
Keefe, Thank you. That is the quote that will convince the client.
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Jon Dillabaugh
May 28, 2015
Pro Focus LLC

What you haven't mentioned is the type of wood you are planning to use. Different species have very different strengths. My gut feeling (not experience) tells me that 4x4 #2 pine from Home Depot wouldn't be well suited for this application. I have a similar setup as a test rig with the 4x4 cemented into a bucket. Obviously this is much different than one buried in the ground. But on a flat cement surface with a single box cam, it still catches the wind pretty easily. Add in another camera and an outdoor box and my guess is that you will have more drag than your post can support without movement.

TU
Tony Uhl
May 31, 2015
We always use 4"x4" aluminum powder coated posts for 10' high to the top of the post. If it were to be 15' I would use 6"x6" aluminum post. You should be able to get them from an aluminum fabricator pretty reasonably. This would be way better than using wood...
UE
Undisclosed End User #2
Jun 02, 2015

Any pole at a certian height will have some type of movement.

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LM
Luke Maslen
Jun 04, 2015
IPVMU Certified

Out of curiosity, why do the poles have to be timber? Is it a cost issue due to the temporary nature of the poles?

If timber must be used and you're worried about camera shake, would the client consider a tripod?

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