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My wife's family used to run a ski area and she has one of the original 2-seater chair lifts when they replaced it with a bigger lift.

I recently refinished it as a gift to her and we we wanted to mount it in our yard similar to the picture I've attached.

I have two questions, any resources around the best size of steel tubing? It looks like the picture maybe uses 3-4 inch, but couldn't find any info on wall thickness.

Also how far to sink it in the ground and how much concrete to use. The lift is about 8 feet and with about 2 foot ground clearance The post itself will be about 10 feet above ground and then offset a couple feet.

I have someone willing to do all the fabrication for me, I just need to figure out how many additional feet the post should be to be stable in the ground.

enter image description here

Nick
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  • That depends on the ground. Bedrock is different than gravel is different than clay... Figure at least to whatever frost line is, and consider putting a leg on the bottom (make the inverted L into a squared off C) to distribute the forces better / improve odds of success (unless you have bedrock, in which case drill a hole and grout that sucker in place.) – Ecnerwal Aug 03 '20 at 14:11
  • The general rule for fence posts is that 1/3 to 1/2 the height above ground should be below ground. If this is 8' above ground that's 30-48" below ground. You'd probably want to ensure your concrete footer goes below the frost line, wherever that happens to be. – FreeMan Aug 03 '20 at 14:37
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    This is a very different scenario from a fence post, though. There will be massive and sustained torque on that post. A substantial concrete base is required. – isherwood Aug 03 '20 at 14:53

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May I suggest a slight alternative? My preference is to avoid tossing the CM (center of gravity) way off from the submerged portion of the support pole. How about fabbing a support like this. Perhaps increase the off-center vertical part's length if you want to "swing" without feet hitting the diagonal stretch.

enter image description here

Carl Witthoft
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  • Clever strategy, but I foresee the inboard person's legs interfering with the angled portion of the post. Would work great with an elevated boardwalk "hill" to replicate an actual lift entrance or exit. There will still be a lot of leverage (and maybe twist) if the chair gets to swinging. – isherwood Aug 03 '20 at 19:28
  • @sherwood you could even go "U-shaped" above ground, I suppose. It does depend on how vigorous the swinging is -- and any mount with a single hang point will risk twisting, so modify the upper horizontal bar to have two eyebolt points. – Carl Witthoft Aug 03 '20 at 21:43
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    the angled portion could actually be horizontal and below the turf, – Jasen Aug 04 '20 at 08:33
  • @Jasen excellent point! – Carl Witthoft Aug 04 '20 at 11:29