Truck Gin Pole tube size

AKwelder · Oct 4, 2008

We had a truck for small iron erection, it used 2 inch sch 80 pipe but had a strap that was held about 4 inches away from the pipe in the center. In effect it made a truss. then we had a hand winch that allowed us to raise and lower the boom, and change the distance off the tail board.

if we wanted to load the truck we moved the pins to the center of the bed. this allowed the hook to just reach the tail of the bed. Be careful of where you have your winch and pivot your poles. if you pull from behind your poles pivot point they can tilt back on you. most oil field rig up here have a pulley in the tail of bedvery intense when the poles move back with a load.

AKwelder · Oct 4, 2008

I should have added this, the 2 inch poles were only about 12 feet long, and I am not sure how much they would lift. But we routinely set 20 foot steel beams with this unit. 12 feet of pole at a angle and a bed almost 4 feet in the air is more that 2/3 the length of a 20 foot beam.

RonMar · Oct 4, 2008

Some pretty tricky engineering involved with weights lifted from the end of a lightweight structure. Can you sketch out what you are contemplating exactly, then we can more accurately pick it apart er... I mean make suggestions

Even a simple .BMP like the one attached so we can get a better idea of what you have in mind. Also some more info about exactly how high and how much weight you have to lift.

There was a gentelman on here a few years back who took a lot of trouble to build a boom pole extension that went on in place of his loader bucket. I think he was planning on lifting roof trusses. With the length he built and the supporting structure involved with the FEL, it was IMO an accident waiting to happen, and a small bounce with a light load at that long moment arm would have most likley pretzeled the lift cylinders or worse... That is the issue with these things. Lifting a static load is one thing, the real fun begins when you start trying to motor that weight around while hung out on that long moment arm.

Basic Design Guidelines:
1. Most all structures/structural members are strongest in tension.
2. Make structural members that MUST be in compression as short as possible and as large
a diameter as possible.
3. Avoid shear loading like the plague, or do everything possible to transfer shear loads to
tension or compression loads.
4. And last but not least, triangles are your friend. The larger the better...

davo727 · Oct 5, 2008

Hello Gentlemen!

Thanks for the comments. I will take some measurements on the truck and since Im not worth a darn with any kind of autocad, I will do some scale drawings on graph paper HA!! I will be able to see how the angles look and figure how high I need. I have a friend who is super with CAD and one of his programs will figure strength on welded structures so I will get him to put it on the computer and see how it comes out. I will get the files from him and post the drawings here for us all to check out.

The truck is very heavy already - it is a 1 1/4 ton K30. Empty is listed at 6300 lb and 10,000 lb gross on the Department of Defense data tag. And im also contemplating a generator and welder mounted ahead of the front bumper and work platform to stand on over the hood and the welder-gen unit. All that will add prob 900 pounds to the front of the truck for additional counterbalance for the hoist rig. The front of my property where im going to build is flat as a board and I certainly wont be moving more that 1/2 mi per hour with anything hanging off the boom.

Give me four of five days to get something drawn up and consult with my bud and i will get back with yall and see what we can come up with.

Thanks, Dave

davo727 · Oct 5, 2008

Well I cant get to sleep and in 2 1/2 hrs I have to go to work for 16 hours- darn. Bet I sleep good sunday night after I get home after working from 6am to 10pm.

Anyway: Hey AKwelder- That idea for a hand winch to set the boom angle is great, then lock the hanger chains in place.

Also sounds like a good thing to do would be have a couple chains or straps from the rear bumper area to the boom that would prevent it from swinging back up towards the truck cab. I wont be trying to self load anything onto the bed of this truck, it will be used to unload my other trucks and or trailer and setting poles in the ground and setting trusses and other pieces of structure.

Thanks Ronmar for the guidance.

And that stupid hurricane cost me about $800 that I would rather have spent on steel or equipment or cool stuff!!!!!!!!

Later, Dave