A pencil, a friend and a tape measurer.

Have a friend stand at the base of the tree with the tape measure in hand. Then you stand back from the tree 50 feet or so holding the pencil in your outstretched hand until the pencil is the same height as the tree.

Then turn the pencil horizontally to the ground keeping the eraser (either) end at the base of the tree. Have your buddy walk out to the tip of the pencil.

Then you go over to your buddy and grab the tape and walk back to the tree and your buddy can look at the tape measure to get a very close answer.

Hope I wrote that in a way to be understandable.

tell me you've done this before, please

quote:

Originally posted by old rugged cross:
The stick and shadow method

This ^^^^

Know anyone with a good drone? (Not a toy.) Their GPS altitude indicator would be more than accurate enough.

Some of you guys have a great sense of humor as well as providing good advice and I appreciate both. This isn't the first tree I've had to cut down but it is the tallest. As someone else already mentioned I will cut the limbs from the bottom up and then cut the trunk from the top down. To be safe I'll cut the trunk down in 6' sections which requires more work but will be safer. The manlift provides enough stand off distance that it's safe to cut without worrying about something falling on you.

Sunbelt Rentals only charges you for one day if you rent their equipment Friday through Monday so I'll have plenty of time.

quote:

Originally posted by jhe888:
Know anyone with a good drone? (Not a toy.) Their GPS altitude indicator would be more than accurate enough.

Unfortunately I don't know anyone with a drone :-(

quote:

Originally posted by bendable:
tell me you've done this before, please

If it’s me your talking about I’ve for sure done it.

Should have mentioned calugo by name. Felling tree's is fun to watch and the people who do it for a living make it look easy. But what the audiences rarely see are the mistakes , the miscalculations and the loss of limbs and sometimes life.

Take a 45 degree triangle and walk away from the tree. Keep the horizontal side as level to the ground as you can and use the vertical side as a sight, walk until the vertical side just covers the tree. Then measure your distance from the tree. It’s the same as the pencil method above but we always had a triangle around.

My dad is a logger and that’s the easiest method he taught me. There are a lot of tools you can use to get a more accurate number but for your purpose it should be close enough.

If you have a smart phone, you can download an app called “theodolite” and it will do the trig calculations for you based on the angle you measure visually on the phone from base to top and your estimate or measurement of the horizontal distance from phone to tree.

We used it for our century plant and it seemed quite accurate.

You might as well get the bigger one. It will allow you to keep the lift further away from the tree. This will prevent damage to the lift. Another option is to get a price from a tree service to just cut the tree down to a height that you can drop it and not include any cleanup. Make sure you have a rope that they can tie to the top of the spar so you can pull it in the direction you desire.

quote:

Originally posted by bendable:
Should have mentioned calugo by name. Felling tree's is fun to watch and the people who do it for a living make it look easy. But what the audiences rarely see are the mistakes , the miscalculations and the loss of limbs and sometimes life.

This is the exact reason I'm renting a lift, makes the job safe for an amateur to perform.

From GardenGuides:

One method uses the height of a stake, the length of its shadow and the length of the tree's shadow. This shadow method relies on the fact that the ratio of an object's shadow and its height is the same for all objects in a given place and time.

Place a stake in the ground next to the tree so that the tree's shadow does not obscure the stake's shadow. Ensure the stake is far enough into the ground that it does not move easily.

Measure the exposed length of the stake with a tape measure. Assume for this example that the exposed stake measures 4 feet in height.

Measure the length of the stake's shadow from the base of the stake to the tip of the shadow. Assume for this example the stake's shadow is 3 feet in length.

Measure the length of the tree's shadow from the base of the tree to the tip of the shadow. Assume for this example the tree's shadow is 27 feet in length.

Divide the length of the stake's shadow by the height of the stake to find the ratio between an object's shadow and its height. The shadow of the stake is 3 feet and its height is 4 feet long in this example, so the ratio between the stake's height and its shadow is 3 divided by 4, or 0.75.

Divide the length of the tree's shadow by the ratio between an object's shadow and its height to obtain the height of the tree. The tree's shadow is 27 feet long in this example and the ratio between the length of its shadow to its height is 0.75. The height of the tree is therefore 27 divided by 0.75, or 36 feet.

quote:

Originally posted by calugo:
I need to cut down a tree in my backyard that's half dead but first need to figure out how tall the tree is so I can rent appropriate height manlift. The 60' manlift is 400+ bucks cheaper than the 80' manlift. I don't mind spending the extra money for the 80' manlift but if I can save 400 bucks I'd rather get the 60'. Looking for a reliable way to estimate the height of the tree to help me decide which manlift to rent.

I honestly don't think a man lift adjacent to a tree is really a good idea; you're going to be limbing on the way up then dropping trunk back down. That shit can get very heavy and go exactly where you DON'T want it to go on the way down.

Knocked down my share of timber; climbed, roped off and roped down chunks. It's not a breeze even if you can just tip wood over. Shit happens. Be safe.

Look up Bunyan's number.

Don't laugh, but I have used this method to measure the height of scaffolding needed to clerestory windows from the floor when making stained glass for a couple of older churches where no blueprints were available.

I used a helium balloon and a ball of kite string. I floated the balloon to the base of the windows, marked the string where it hit the floor, retrieved the balloon and then measured the string. I repeated this for the top of the windows.

Of course, you would have to do this on a windless days, but it is a lot more fun the figuring it out with math and will really impress any kid.

.

42

A little story here, if I may, from my schooldays in London. I'll be honest, I sucked at math, I loathed the subject deeply, although I later knuckled down to it and while not exactly learning to love it, I cam to accommodation with the subjerct.

Our principle math master was a very inventive kind of guy. He served in the RCAF during WW2 and earned a DFM as a Flight Sergeant pilot of a Stirling, got commissioned, and earned TWO DFCs, retiring at the end of hostilities as a Squadron Leader with 82 missions behind him.

He was a hard taskmaster, but fair, and this particular day he gave us our task for the session. Just along Millbank on the River Thames, upstream from Lambeth Bridge, was a large-scale contruction project - the Millbank Tower AKA Vickers Building. He gave each of us a piece of string about fifteen feet long, a three-foot rule, and a stopwatch. Our task was to use the items to calculate the height of the new structure to the nearest five feet. We had to use our spare time, and produce the answer on by Friday morning prep.

Later on that same afternoon, we did a recce, and we got to the location, and like all seventeen y/o's, began to argue before engaging brain. Some wanted to use the shadow factor/known height method, except that had one element that we didn't know - namely, the height. Hmmm. One bright spark said Let's measure the shadow of some of the other buildings around, or, better yet, compare it at a distance with a London bus [14ft 6in] as it passes in front of the building on the embankment. We can do THAT from Lambeth Bridge, right?

Good plan, Batman!!

I had other ideas.

Fast forward to Friday - last lessons in the afternoon - Math.

Well, said Dickie [he was also our house master, so we could call him Dickie for the last lesson of the day, besides, we were all big boys.]

We have some VERY interesting figures here, he quoth, some are pretty much near the figure, some are waaaaay out, but one is exact. Amazingly, tac has achieved the almost impossible, and given me an answer that exactly tallies with the planned height of this building. Perhaps you;ll share your method with the rest of us?

Well, Sir, you know full well how I struggle with math - especially trigonometry of the kind that might have gotten me some kind of an answer here. So I figured that although I wasn't much good at math, I AM very good at talking to people. So I walked onto the site and asked to see the principal architect. Having gotten in to his office I explained what the task that I'd been given - he agreed that given the location it was never going to be easy using the tools we had been given.

So I explained that I had been given a MUCH better tool to use, namely my brain and the mind inside it.

I gave him the stopwatch for a five-minute look at the building plans.

quote:

Originally posted by tacfoley:
A little story here, ...<snip>

So I explained that I had been given a MUCH better tool to use, namely my brain and the mind inside it.

I gave him the stopwatch for a five-minute look at the building plans.

The Kobayashi Maru test!

positive thoughts and a prayer for you

Be sure to post pictures...