Introduction: A-Frame Boom for Vehicle - Scavenge Huge Things

About: Tim Anderson is the author of the "Heirloom Technology" column in Make Magazine. He is co-founder of www.zcorp.com, manufacturers of "3D Printer" output devices. His detailed drawings of traditional Pacific I…

Mega Scavenging is made easy with an improvised A-frame boom for your vehicle.
You can put a rig like this on any vehicle that you don't mind scratching.
My old Ford Pinto was great for moving old cinema equipment with such a rig.
I made an A-frame from two beams and lashed them to the rear bumper. The lift cables ran to the car's front bumper.

Question: Why not just use a forklift?
I used forklifts to collect a couple of  these big steel frames for a greenhouse project.
It was a pain in the neck because they were too big to balance on the forks.
The next time a frame got thrown out I happened to have my tree moving A-frame on the truck.
Night and day! So easy and graceful I couldn't believe it.

This A-frame rig is based on boom trucks I saw in the oilfields of Centralia Illinois, my Mom's hometown.
The A-frame boom rig shown here consists of two poles attached to each other at the top forming a triangle.
Hinges at the bottom of the poles are bolted through my truck's bed.
Two winches are attached to the A-frame. One winch raises and lowers the A-frame. The other winch raises the load suspended from the A-frame.

WARNING:
This is big heavily loaded stuff. It's dangerous. Be very careful.
There are lots of ways for this stuff to break, fall, and crush you.
Don't use nylon rope or any material that can stretch.
That could make your rig into spring-loaded giant mousetrap.
Or a deadly whip-gun.

WARNING Warning:
There are lots of warnings in this project. Your rig will be different and there will be lots of ways for things to go wrong that I won't know about. I'm always afraid when moving big stuff.

Step 1: The Other Way: Forklifts

There are forklifts at source and destination ends of the trip, so you'd think that would make everything easy. Unfortunately the forks aren't long enough to reach past the center of mass of these items. So loading these things onto my truck took some figuring, fussing, trial, error, and time.
The A-frame boom is better, quicker, easier, and safer than the clumsy stuff I was doing with the forks.

Question: Why are these giant steel frames being given away?
The people giving them away get paid too much to justify taking them to the scrapyard themselves, and the items are  too big for the local scavengers to collect.

Step 2: Front Anchor Points

The cable that lifts the A-frame attaches to this chain bridle.
I poked holes in the top of my front fenders to run chain down to the frame and bolt it there.
The sheet metal of this truck is amazingly thin and flimsy.
Unlike all the mechanical stuff which is brutally strong.

On other vehicles I've anchored to the following:
front bumper
tow hooks under the bumper
front fenders.
sunroof frame

On a '68 Buick Electra that stuff is solid enough. Don't bet your life on your new car's bumper.
Don't bet your buddy's life on anything. Show her the whole rig and wait for consensus before
proceeding. Yell and make everything stop and step back if you hear any strange sounds.

Step 3: A-Frame and Winches

These pipes came with these come-along winches attached. They were made to lift a work platform for house siding work. Use whatever you have. I've used 4x4 timbers or even 2x4s for smaller stuff.
Laminate a pair of 2x4s together if you can't find any you trust by themselves.

A come-along is a winch with a ratcheting handle that you work back-and-forth instead of cranking it in a circle. Watch out for crank winches, if you free the ratchet dog the handle can spin and hit you really hard. It's a little harder to do that with a come-along.

If you don't have come-alongs use pulleys, deadeyes, or even a trucker's hitch.


Step 4: Position for Loading Up

Be careful and spend the right amount of time getting positioned. If your load swings into one of those yachts you won't be glad about how you spent your day.

Back up to the thing you want to load. I want to snug this up to my tailgate, so I position my truck just a hair in front of it.
Lower the boom until it's over the center of mass of the item you want to lift. That way it won't swing or drag. Be careful walking under the boom. If it falls all your projects are over.
Lower the lift cable and attach it to your load.

Step 5: Rig and Lift

I used heavy POLYESTER rope to rig to the frame. It doesn't stretch as much as nylon so it's not as dangerous. I cleated it to the truck box, down under the front of the frame, threaded through aft of the center of mass to the lift cable.
Every rig is different.
I winched it up and it worked as planned. The front got lifted also and rested against the rear of my truck.

Backing out was a pain in the neck. I hadn't lined up perfectly and the load was too close to the fence.

Step 6: Stop and Check the Load

I drove a block and stopped to walk around and check the load.
It was riding up in the front so I lashed it down to my trailer hitch.
One of my tires was low but I wasn't going very far.

The front wheels are lightly loaded. I step on the rear of the frame but they don't come off the ground.
The boom trucks in the oilfields had welded junk boxes on the front bumper. They'd throw scrap metal in there whenever they did a heavy lift.
When moving cinema equipment with my Pinto back in the day, the load lifted the car's front wheels off the ground, so my uncle rode on the hood. You can't do that any more. It's called "car surfing" and there are laws against it in many places.

A police car cruised by and admired my work while I was taking pictures.
Sometimes when I'm scavenging they think I'm dumping stuff and I have to explain that I'm doing the opposite.
Local towns have huge expenses from cleaning up illegal trash and junk dumping.

Happy scavenging!
Be careful!