How to add an electrical cabinet to an exisiting pole?

[nolanola]

Hey Everyone -
We recently had a request to replace the top part of a pylon sign.
Client claims there is working electrical to the pole.

There is a photo attached of the pole.

What is the best method to attach a new cabinet a top the pole so it is sturdy enough to withstand wind and weather? We thought maybe 45 degree angle supports? steel plate along the bottom of the cabinet?

Any info or ideas would be really helpful.
Thank you!

 

[Billct2]

Looks like it was designed for a plate mount. So the original sign probably had an angle iron frame. But it also looks like it was raised at some point, those other two plates look suspicious. I'm always leery of messing around with existing poles without getting an engineer to sign off on it, and that is almost impossible without the original plans/permits. They want to know what the footing is and that is pretty hard to do without the original drawings or digging it up.

 

[Bradley Signs]

How long you been in the trade?

 

[Gino]

I agree with Bill. Without an existing cabinet up there, you have no idea of what kinda pad, footings or anything else about how that was originally planted. If you do that around here, you'd hafta have engineers sign off on it and the only way that can be done is to dig a buncha holes around that existing pad and hopefully get enough information to put something up there...... legally. It'll be cheaper to put up a new standard and use a saddle mount. Flanges aren't used as much anymore, anyway not around here.

 

[kcollinsdesign]

Looks like a plate mount. Easy enough to fabricate a sign that can attach to the existing plate (the sign will either be made of steel angles and/or have an internal steel pole with a match plate welded on the bottom).
The problem, as others have pointed out, is that you will not get an engineer to sign off on it unless they know the specifications of the footing, and the section modulus of the existing pole (determined by size and wall thickness). The plate size, weld quality, and that troublesome joint in the middle will also present engineering problems.
Sometimes, the municipality will have records of the original installation and modifications (might require a FOIA). You may also consult with the people that did the work originally. Usually, in these cases, a new installation is recommended.

 

[nolanola]

Thanks for the replies & advice on this! Unfortunately in our area paperwork & records are not well kept by local gov so we've recommended going all new fab.

 

[MikePro]

was going to chime-in, that its definitely matchplate-mounted BUT doubtful that the sign was raised..... that extention was most likely the center of the structure of the sign cabinet itself and whomever removed the sign just carved everything away from it.

not knowing what the footing is that set that pole in the first place, or what it was designed to handle, would make me worried about simply unbolting the top section and fabbing a new sign around it to bolt back-up. all-new is the safest-approach, as you will be to blame if the sign comes down, but would be hell of a lot easier/economical to make use of existing if you had some proper info to hang your hat on.

 

[Texas_Signmaker]

You can do a Google street view and look back in time by clicking the icon with a clock and arrow going around it. Then you could see what was on there before.

 

[Gino]

Will that show you Xrays of the pad underneath ground level ?? Will it show if rebar was used ?? Will it show what grade concrete was used ?? Will it even show the actual width, length and depth of the slab ?? Last, but best for last...... was the pole built to today's specs for installing such signs ?? Years ago, none of this sh!t was needed or discussed. Only for building foundations and bridges..... and even that, they had all wrong. How much input was there on simple sign installations like this one ??

 

[netsol]

Thanks for the replies & advice on this! Unfortunately in our area paperwork & records are not well kept by local gov so we've recommended going all new fab.

Thanks for the replies & advice on this! Unfortunately in our area paperwork & records are not well kept by local gov so we've recommended going all new fab.

no paperwork and records? unobtrusive local government? can I be your new neighbor?

about 10 years ago, one of our local towns got on a tangent, where a business was not supposed to change the 9v battery in their own smoke detector.
you were ordered to call an electrician.

you will all swear I am making this up. (if only that were true)

 

[unclebun]

As small as the pole, driveway, and surrounding buildings look, that looks like it originally had maybe a 4'x4' or 3'x3' on it. The pole probably went through the sign and the top of the sign sat on the top plate. Double face with pan faces. Something like the FedEx sign behind it.

Regardless of what current engineering standards say, if it's been there since the 1970s or 80s, it is probably sufficient.

Of course you could try removing it and report back how easy that was...

 

[Jester]

Regardless of what current engineering standards say, if it's been there since the 1970s or 80s, it is probably sufficient.

Funny story: I once purchased a place in the mountains. The house had a two-foot thick river rock foundation loosely chinked with cement. To me it looked really rough and suspect. (Kinda like your sign pole does, lol.) This was in earthquake country so I called a good friend who is a very conscientious structural engineer to inspect it prior to closing the purchase. When i told him the house was built before 1914 he declined to visit, saying if it was still standing after all those years I had nothing to worry about!

Just an anecdote and of course YMMV.