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Jib crane mounted next to a retaining wall

Bill D

Diamond
Joined
Apr 1, 2004
Location
Modesto, CA USA
I know I will need to talk to an engineer but I wanted to see if anyone has seen one. And if it worth the money to pay one to look into it. I would like to mount a job crane, may two ton, at ground level but set it up so it can swing over a sunken patio walkout basement. If the foundation was down in the patio level the post would need to be over 18 feet tall.
So I was thinking mount it near or even make the foundation part of the retaining wall. I am not real clear on the foundation is it just a counterweight or is the soil part of the opposing forces to prevent it from tipping over. I have seen recommendations here to bore a deep hole in the middle of the foundation and fill that with rebar and concrete to act as a lever.
I am sure they must mount them next to a loading dock which is a similar situation
Bill D.

PS: it will be 8 feet down to the patio from the ground level.
I saw a foundation plan for a similar crane with a normal flat area. 6 foot across by 4 feet deep
 
Look at store bought solutions, then decide if you want to roll your own. Look at sleeve mount pillars, that way the base doesn't take up any room. The size of the base is to spread out the area so the soil can resist the forces imposed by the crane. There isn't enough mass in the base to be useful as a counterweight.
 
Interesting, I had never seen or heard of a sleeve mount. Looks similar to how a volleyball net is mounted. I suppose the sleeve can be made as long and deep as needed. It would have to be thicker wall as it got longer with uneven side support.
 
The top of the sleeve is flush with the top of the concrete. In your situation, I think of the base being flush with the surface of your sunken patio.

For more details, there is a rat slab under the sleeve. The sleeve is then bolted to the rat slab and set plumb. The concrete is then poured around the sleeve. Make sure the sleeve is well bolted to the rat slab, as it will become rather buoyant when surrounded by wet concrete. Weld a metal cover over the sleeve to prevent concrete intrusion. After the concrete is sufficiently set the pillar is installed. The pillar has a bulkhead in the bottom with a center hole, and the sleeve has a center spud to locate the bottom of the pillar. The pillar will have some play in the top of the sleeve, maybe 1/2" per side. The pillar is set for final plumb and a collar is welded to the sleeve and piller.

Sleeve mount or flange mount, the concrete reaction block will need to be the same size.

Sleeve mount aren't as common, as you must have head room to install them.
 
Are you building a new retaining wall? If so the crane foundation could be part of it, most likely a box section, and actually serve to reinforce the wall. This needs an engineer but certainly sounds doable.
Dennis
 
If it is all new construction the retaining wall can be designed to support the jib crane. The structural engineer for the retaining wall can easily incorporate the base for the jib into the wall. Consider mounting the jib crane at the top of the retaining wall to minimize the height of the column.
 
Yes, all new construction on a flat property. I figure 99% of the time it can hold a umbrella or a bird feeder. I may decide on some kind of four legged crane rail design.

You are "correct", VERY! in giving it proper attention.

Similar situation but existing FOUR foot max retaining wall, tapering over 35 feet at the garage/shop wall to two feet at the street.

And option only seafarers - or sappers - might consider, I WAS looking at a lay-down gin pole or modular stiff-leg derrick executed in steel, not wood.

Both depend on guy wires to deadman anchors. BTDTGTTS. No sweat lifting a battle-damaged 5T LWB truck or even a M113 APC.

"Plan A" was to erect only when needed, lay-down concealed under a long, rain-sloped "lid" in a trough, top rear of the wall when NOT needed. About as out of sight as can be.

Decided to change the landscape (done) and demo the wall (to-do) instead. Periodic forklift rental was easier "in MY case".

May yet acquire a decent used, POWERED, straddle-stacker or a mobile "quadruped" to reduce need of FL rental. I'm not a big fan of gantries.

A "quadruped" can be lower as to heignt, is easier to store over or around other goods, or store OTHER stuff in and under between taskings.

MEANWHILE.. "along those lines"... I may not bother..

I have BEEN using a modified general-purpose adjustable construction scaffold as a mobile "loading dock" and to lift goods hung under it off the deck and onto skates. H-F, Northern, others sell those as commodity priced goods, and run a "big sale" about once or twice a year.

Shed the shitty plywood, do a bit of other mods and clean-up, rather small money spent for the handiness.

An ignorant 2-Ton folding engine hoist, ratchet chain falls, 120 V electric hoist, hydraulic "die carts" & aluminium ramps are the associated "enablers".

Gots more machinery skates, in more types, than I own boots and shoes! It is simply harder to break stuff or drop it on anything when it is kept only a few inches off the deck!

I LIKE "harder to break", and the skates don't eat any battery, hydraulic juice, cable corrosion, nor even very much storage space in between jobs.

"YMMV" but a jib crane collapsing the embankment it was meant to live a peaceful life in is a very real - and rather nasty - possibility.

Good move to research it thoroughly. Then STILL hire an expert if you go that way.
 
A new thought...get An old forklift mast and a hydraulic pump. Tie it to the wall so you can step onto the forks as an elevator. It could be down out of site. I am liking this idea. Only need 8-9 feet of motion. Would like the ability to lift one ton of lathe or milling machine max.
Bill D
 
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A new thought...get An old forklift mast and a hydraulic pump. Tie it to the wall so you can step onto the forks as an elevator. It could down out of site. I am liking this idea. only need 8-9 feet of motion. Would like the ability to lift one ton of lathe or milling machine max.
Bill D

Been done many times. See with a platform to stand on.

Buy a hydraulic power pack (motor, pump & tank) made for a vehicle lift, surplus center has them.

However, not secondary braking system like a human xporting elevator has.
 
A new thought...get An old forklift mast and a hydraulic pump. Tie it to the wall so you can step onto the forks as an elevator. It could be down out of site. I am liking this idea. Only need 8-9 feet of motion. Would like the ability to lift one ton of lathe or milling machine max.
Bill D

"One ton" is only 2,000 lbs, Avoir. 2200 Metric or "long" ton. Decent engine hoist can do two or even three times that, max, lift 1,000 at medium extension.

Where TF do you FIND either of a lathe or mill as weighs that LITTLE that is even worth the BOTHER of lifting?

Even a lowly BeePee is heavier, is it not? The Quartet has about the same work-envelope and book sez 5,205 Avoir IIRC.

12" Sheldon/Vernon shaper is a small one as shapers go, Very. And that's over 1800 Avoir.

3 Ton rated or stick with portable rigging gear?

Somebody aluminium gantry also fold or take-apart?

Gantry, Cranes, Hoist, Gantry Crane, Tripod Cranes

What used to be "Knock-Down" AKA "K-D Bluebird" is under new ownership, long-since and still making usefuller ones than Horror-Fright, including some neat towable units often found at the rental agencies:

Engine Lifts – ICF Industries

A(ny) fixed-position rig is going to be in the wrong place easily half the time you need it.
 
The main function of the foundation is to act as a big solid monolith that transmits the crane forces to the soil, and obviously overkill as you don't want to be right on the ragged edge of that.

The issue I see with mounting right on top of the retaining wall is that then you don't have the foundation's "foot" buried on the arm side of the crane to transmit the downforce. Its all going to be transmitted behind the arm where you only have counterweight. Also important is to make sure the monolith is heavily steel reinforced so that the forces get transmitted where they need to go. In your case I would consider making a steel weldment that actually transmits the forces and is counterweighted by the monolith, rather than relying on the monolith itself to resist bending.

Not sure I'm explaining that last point but envision a classic engine hoist with the arm turned 180 degrees. You'd be reliant on the total amount of counterweight you could stack on the Y-shaped base. Same concept here except that the counterweight is buried concrete and diagonal braces are allowed to the plate where the column mounts.

I excavated this hole/poured/leveled/grouted/assembled this crane, 500 lbs @ 12' arm into my shop this year. The cube is roughly 4' square x 36" deep plus my depressed pocket of roughly 1ft. Crane sits in a depressed pocket so I don't have to deal with the gussets and large round "foot", the difference is made up by 3/4" steel plate trimmed to fit around the base. The 1-1/8" rods are 36" deep with 6" dia steel "washers" to prevent pullout. With the floor arrangement the goal is to pack stuff tighter around the column :D





 
That looks very similar to a socket mount design but only one piece not two. Of course you do loose one foot under the beam.
I do see what you mean about a counter weight in the foundation. I would only need about 180 degrees of motion so counter weight could be on one side not all around, saving concrete. I have only seen giant tower cranes that use a counterweight. Of course forklifts all have a counterweight.
 
I think you could do the same job as you are proposing a lot easier for 2T working capacity with 4 posts and a monorail I-beam that runs between the posts. I don't know the entire design of your area but from an engineering standpoint so much easier.

The moments on the bases are so much smaller...All of your work would be steelwork/weldments/bolting and some anchors for the columns.

The jib crane column sucks to erect in that its significantly more work . Must be grouted to get contact with the concrete or a poorer job is to simply shim it. Then you get to mount the shoulder and arm which probably takes a mobile crane....
 
Monorail I beam sounds like the ticket. I was thinking bridge crane which eats up too much vertical space. thanks for the vocabulary lesson.
Bil lD
 
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