"A" Frame

[Norm_Hall]

\"A\" Frame

The most recent storm produced alot of downed and fallen trees. Most of which were very common. Lots of broken white ash and honey locust. The ground was already saturated, so there were alot of uprooted trees as well. Ironically, we had a crew on site and had just finished pruning this tree. They witnessed this tree falling on the clients home. A red oak 26" DBH. Fortunately for the client, it only broke an upstairs window, and damaged the roof and gutter. I'm posting this cause I've only had to do this 5 times in 35+ years. We had to construct an "A" frame using dimensional lumber to avoid the spar falling on a wooden deck and 'fixed' gas grill. We used (2) 2" X 6" X 12' nailed and screwed together as the A frame. The crossmembers are also 2" X 6" lumber. The hardware is 5/8" hex head bolts. The footing is 3/4" plywood and 2" X 6" lumber.

 

[Norm_Hall]

Re: \"A\" Frame

This pic shows the footing and how we built up the lumber at the end of each 'foot'.

 

[Norm_Hall]

Re: \"A\" Frame

This pic shows the spar resting on the "A" frame after the brush has been removed. Notice we added a piece of metal angle iron at the base. I just didn't trust the 2" X 6" crossmembers.

 

[Norm_Hall]

Re: \"A\" Frame

This is the video of the section resting on the roof to the "A" frame being removed. We had a 40 ton Terex crane doing the hoisting. We had the cutter stay with the section to be on the safe side. We didn't want him coming down to the ground "just in case". The crane was good for 6,000 lbs. The piece weighed 1,800 lbs.

49 seconds

www.youtube.com/v/FzwRg7g577k

 

[Jamin_Mayer]

Re: \"A\" Frame

Nice Norm! I'm going to remember that technique. That could come in handy.

 

[TheTreeSpyder]

Re: \"A\" Frame

We've done similar; but certainly not so polished; im-pro-vised a lot to make a folding 'table leg' from an existing branch. This doesn't need to be over something either to be useful; can stabilize against storm fallen tree twisting etc. while sawyer is mounted on it; or near it in bucket.

1 way is to take a branch and make a small face in the underside; that allows just enough sweep to make branch vertical leg. Then tie it so it can move back towards original position. At first, don't cut it to fit to ground; but rather use the extra length to give leverage to force a thicker hinge. Then just before vertical support position, trim it to fit. The extra thick hinge will give more support; and protect from side to side movement. The closed face protects against further movement closed; while the rope protects against re-opening. Real strong leg can also be formed by suing a 3:1 etc. line to pull leg to vertical and then lock.

 

[RemovalWizzard]

Re: \"A\" Frame

right on Norm!!! I like

 

[TreeCo]

Re: \"A\" Frame

Great work Norm! Fell over after it was trimmed???? Now that's got to have some pucker factor involved!

I have a suggestion for building the support that would be stronger. I believe the forces developed in your design don't take into account some of the natural strengths and weaknesses of building with lumber.

For more strength the center X braces in my design could be replaced with a full sheet (uncut)of plywood that could be reusable with nail pulling after the job. The plywood 'truss' would also extend up to and be nailed to the horizontal support under the log

 

[nailer]

Re: \"A\" Frame

Sweet work, Norm.

 

[tockmal]

Re: \"A\" Frame

Norm,

Why is the climber riding the ball with the timber in this video? is it because there was no other anchor point for the climber to work from?

What about the tree to the left? too far away?

Basically......was it absolutely necessary for the climber to be riding the ball with the timber?

Video of storm damage

Good A-frame.

 

[TheTreeSpyder]

Re: \"A\" Frame

Nice additional bracing with plywood!

Bill'em Dano!

 

[Reg]

Re: \"A\" Frame

Very good work Norm. Ive used props for felling short side-leaners on occasion, but have never really considered your application. Thanks for sharing.

 

[WPArborist]

Re: \"A\" Frame

Norm,

Have you thought of also bracing the A-frame to prevent it from tipping due to any horizontal pushing that may occur?

Nice job!


WP

 

[Kevin]

Re: \"A\" Frame

This attachment is what I would consider building.
The inner structure with the header could be bolted into the legs and be adjustable for height.
The tree could be strapped to the header.
Guys could also be added near the top for added support if needed.

 

[Tree_Frog]

Re: \"A\" Frame

Nice work.

 

[MikePoor]

Re: \"A\" Frame

Great work Norm! That worked well and w/ minimal expense too! I have only used this once: Craned a tree out for a friend who made a similar set up. He went the expensive route & used 6x6's (It felt like moving logs to get it set up!)

 

[No_Bivy]

Re: \"A\" Frame

[ QUOTE ]
Norm,

Why is the climber riding the ball with the timber in this video? is it because there was no other anchor point for the climber to work from?

What about the tree to the left? too far away?

Basically......was it absolutely necessary for the climber to be riding the ball with the timber?

Video of storm damage

Good A-frame.

[/ QUOTE ]
Iwas wondering too. Nice Idea on A frame....How much weight was it holding? any idea.

 

[Phil]

Re: \"A\" Frame

if you read the whole thread, Norm mentioned why the climber stayed with the piece.




[ QUOTE ]
This is the video of the section resting on the roof to the "A" frame being removed. We had a 40 ton Terex crane doing the hoisting. We had the cutter stay with the section to be on the safe side. We didn't want him coming down to the ground "just in case". The crane was good for 6,000 lbs. The piece weighed 1,800 lbs.

49 seconds

www.youtube.com/v/FzwRg7g577k

[/ QUOTE ]

 

[Norm_Hall]

Re: \"A\" Frame

[ QUOTE ]

1. Why is the climber riding the ball with the timber in this video? is it because there was no other anchor point for the climber to work from?

2. What about the tree to the left? too far away?

3. ......was it absolutely necessary for the climber to be riding the ball with the timber?

4. Good A-frame.

[/ QUOTE ]

1) In my opinion, it was the safest option. The ANSI Z133 says the climber may stay attached to the load line when a load is hoisted if the load being hoisted does not exceed 1/2 of the capacity of the crane. (the crane was good for 6,000 lbs, the log weighed in at 1,800 lbs.)

2) The tree to the left was surrounded by standing water.

3) In my opinion, yes.

4) Thank you.

 

[Norm_Hall]

Re: \"A\" Frame

[ QUOTE ]
Norm,Have you thought of also bracing the A-frame to prevent it from tipping due to any horizontal pushing that may occur? Nice job! WP

[/ QUOTE ]

If you look close, you can see it secured with a 1/4" rope to prevent from shifting.
Thanks for the compliment.