lowering BIG blocks.

treestyle · 4th October 2007, 03:41 AM

hi,

Got a big job coming up. 35m plus (approx. 1m dbh) stringybark leaning towards a house and growing in between 2 driveways to take down (no where to fell) far enough away from the house to easy lower off the branches and top. the option is then to either block down the trunk in small enough pieces to chuck into the tight dropzone or lower off some big sections. it's a big tree and doesn't have much taper, more like a big cylinder.

any thoughts would be appreciated.

Thanks

Sean Freeman · 4th October 2007, 04:01 AM

Whats your crew like? Taking down big blocks rigging off the stem relies on the abilities of more than just the climber, you need experienced ground crew, and of course the right gear.

For the job you describe I would want at least 3/4 static line a block and a porty, with those basic elements and confidence in the groundies it should go well, physically wearing but manageable.

Pace yourself (if you're the climber ensure you have 2 tips its less strain on your body as much as anything else) trying to turn a 4hr job into a 3hr job can often result in 6hrs of struggle and exhaustion.

treestyle · 4th October 2007, 04:09 AM

thanks, i've got a nice 3/4 inch double braid line saved for occasions such as this, will be getting a block and using the porty.

my intended method would be:

block cow hitched to trunk, cut an open skarf with sloping bottom and top cuts (1/3 of trunk deep) pull rope on top of section. lowering rope attacthed to section using multiple half hitches finished off with a running bowline. do the back cut hang my saw and brace, then the crew can do the rest.

how important do you think it is to have my 2 "tip's" between the block attachment and the skarf?

thanks.

Ekka · 4th October 2007, 04:10 AM

Did you quote it, if so, how did you determine the time/price and using what method?

If you didn't quote it then how did the person who quoted it determine the price/time/method?

If it's in between 2 driveways my preferred method is crane.

treestyle · 4th October 2007, 04:19 AM

I quoted it, the job will take all day, 7am till 5am on site. based on these hours and my rate for 3 men plus the additional for the nature of the job and that's how i came up with the price.

the methods i contemplated from the start were blocking down or lowering.

i like the idea of a crane, i've never worked with a crane or even seen one in action. i'm a bit weary of using one to remove large sections without having had any experience with them. i have heard of them being being very effecient though, would be something i'd like to involved with in the future.

how much would a 35m crane be worth per hour?

Sean Freeman · 4th October 2007, 04:48 AM

Ekka's right of course a crane is the way to go, a favourite method for me too, love working with cranes.

Presuming you meant how much for a crane with a reach of 35m? That would be a 120Ton since an all terrain 80T has only really useful reach of 24m. 120T crane is expensive (but great fun to work with!!

) You're right to be careful about your first crane job, perhaps if you could help out with another crew on one of their crane jobs? (I don't know your circumstances work wise) Not all crane companies are equal (see Ekka and Jim's post on the Queen palm removals) only experience will tell you which ones to go with.
If and when you do move into working with cranes a bit of advice....get the rep to come out to the job site and assess your work plan, use this time to suss out the crane company...how long has the rep worked for them...what tree experience do they have....who will be the crane operator...how long has he/she been working for them, and what tree experience. If the rep can't answer your questions to your satisfaction give them the flick.

As for the 2 tips see attachment..for me of course the safety aspect of having an escape route in case of emergency is critical, but the 2nd tip being attached to your front D's is far more comfortable than the side D's, it allows you to have a more comfortable position both working and resting...less fatigue=greater safety and efficiency.

Ekka · 4th October 2007, 04:57 AM

Cranes work on weight not boom length.

It's the lower sections that will test you, the closer you get to ground. Even a 25t franna has near 30m of stick.

If you have a CSI Yellow block rated 2000kg SWL you'll be cutting off 250kg chunks max to stay within the SWL.

That tree is good for around 1000kg/m3.

So you want to be cutting off 0.25m3 which is 250kg

So at 800mm dia what length block can you cut to get the 250kg?

To get volume of a cylinder formula is

Quote:

π is symbol for pie (3.1416)
r is symbol for radius (use m not mm)

πr2 x h but we need to know what length to cut the log so

h=.25/(πr2 )

Answer is 0.5m (close enough)

Want to test me

(3.1416 x (0.4 x 0.4))x0.5= 0.251m3 which is 250kg

But now it's 1100mm dia so how high, lets try it

h=.25/π x (0.55 x 0.55)
h=0.263m long

Hope you get it, just shows how a small increase in dia of 300mm halved your length.

It's murder on your gear and a porty sucks at lower log like that, the capstan winch is way superior as you can pull in slack when the piece gets pushed off.

Every block you cut means resetting the pulley and tying everything up ... you'll be up there a while and that's after lowering out the branches. This is where people straighten out 50kn biners coz they dont do the math.

That block will go 7x it's own weight at the pulley if you let it run and are pretty good, it can go 10x or more easily if too many wraps lock it up.

As you get closer to the ground it gets worse as there is less rope out. Also, how do you tie up an 1100mm dia piece that's only 263mm long? How do you push off a 250kg block?

You asked the cost of a crane, I ask you the cost of what you are doing to your gear and yourself? Also, the customer pays for the crane but who pays for your back, broken gear, injuries, damage etc?

Lets say we have only 20m of 1m dia, that makes that whole barrel weigh in at 15,700kg

Tree Machine · 4th October 2007, 05:35 AM

Listen to the wisdom of Ekka. A lot was said right there.

Lowering BIG blocks has got to be one of the slowest and most agonizing parts of treework that I can think of. By the time you get the third block rigged, you realize that if you could have just cut and pushed em off, you'd be done already. Especially if you're tying timber hitches. Men standing around, waiting...... Aughhhh! The pain!

However, damage to the driveways will cost ya far more time and money.

Leaners are tricky, but they don't require the conventional face-cut of any sort, just lop firewood length blocks, or whatever. A handful of round, bamboo chop sticks (not the squared-off wooden ones) can aid really well when it comes to the slide-off.

If using the conventional face cut you are generally to 'tip' the block off, like on smaller or taller big blocks. Shorter or more massive ones, they don't 'tip'. They slide and often need to be persuaded. Have Chinese for lunch is what I say. Round chopsticks (pencils don't work nearly as well).

Personally, I think the crane would be cheaper. Ever hear the expression that the last 10% of a tree job takes 90% of the time? Big logs will do that. Crane, and you'll be glad you did because any time you can take the last 10% of the job and make it take 10% of the time, go for it.

Get your standing log rigged, cut from the compression side through to the tension side, straight through, as low as possible. Your saw will clearly pinch, but that's the beauty of the crane. Now he starts his tension to get the leaning log vertical, saw no longer pinched, keep cutting. Crane guy should be moving things very slowly now, gentle lift, men clear well away, this giant log will hover and float, then fly up and out of there. Dice it up next to, or on the trailer out front.

I would explore the option of plywood, tires or foams for conventional push-offs. ANYTHING but rigging big, single blocks. Anything.

Ekka · 4th October 2007, 06:16 AM

Hey, get the crane and I'll come over show you how to do it, I love cranes!

Then also, what do you have on the ground to move 20,000kgs of blocks around?

What's the impact force of a 250kg log dropped from 20m high when it hits the ground?

Hey, here's an online calculator Energy of falling object

Sean Freeman · 4th October 2007, 06:51 AM

The reason why if I were to use a crane on the job described I would use one of larger capacity (and more expensive) is the loss in lifting capacity at greater distances. A franna does have a radius of around 30m but at that distance can only lift around 300-400kg.
An 80T crane can lift around 3T at 24m....the 100/120T crane could take the whole stick in one at 35m.

JohN Dee · 5th October 2007, 04:29 AM

Indeed the crane sounds like the best option for you TreeStyle.

You could be doing the best take down in the world and have the cutomer cheering, but put one crack in their driveway and that is all they will remember, you cracking their driveway.

If you do still attempt to rig down the big sections, I would suggest a series of half hitches to a timber hitch oposed to a running bow. When putting in the final back cut, make sure your two TIPS are above your sling/topping strop, so in the event that the strop went sliding, it's only gunna gaff you out(where your second TIP will grab and save you).

Tree Machine, love the chopstick idea, I'm going to use this from now on... I was only recently thinking about this too... :P

Quintrex · 5th October 2007, 02:59 PM

All very good advice above!
A crane operator experienced in tree work will talk you through the job and show you where to sling each lift.
Have you considered a contract climber for with crane experience for this job as a training execise for yourself?
Lowering big blocks is a bitch, we only do it when absolutely necessary.. As ekka said, tieing off the fat mothers so they don't slip out is very hard.
Good luck with it whichever way you go.

RC1 · 6th October 2007, 01:28 AM

Treestyle

If you do decide to rope the trunk down then try to make sure you have a dry day for it. Thick, wet ropes can be far more difficult to work with. Also, right after you take each section off, try to get into the habit if placing your saw on top of the trunk while you're undoing the rigging ect rather than having that weight contantly hanging on your belt. Over time this will come as a welcome relief to your feet. Take your time and keep cool.

Oh, and here's a handy tool for blocking-down big stems. Although we were just horsing around on the floor in this particular video, you should still get the jist of its potential usefulness on a job like the one you've described.

BLOCKDRIVER: A quick demo.

Good luck with which ever strategy you decide upon and make sure you get some pictures for us!

Reg

treestyle · 11th October 2007, 03:20 AM

thanks for your replies.
Much appreciated. i'[m gonna give it a go, lowering the blocks off. HOWEVER, in future if i'm faced with a similar job i WILL be considering a crane. I think i have to do a job like this once in my life so i know not to do it again.

Thanks, i'll try to get some pics!

Ekka · 11th October 2007, 03:37 AM

I thought you'd done it last weekend, oops, pic and video ....

.... hey, can I come and video?

treestyle · 11th October 2007, 03:41 AM

next Saturday (20th), i'll think bout the video part......You might expose too many flaws in my technique? Honesty i'll give it some thought, might do me good to get some constructive criticism.

I'll be in touch.

That's what i might try, thinking if the lower branches allow for it, i might lower the top out first? will see what happens.

Ekka · 11th October 2007, 03:46 AM

Have you heard of "editing"?

4th October 2007, 03:41 AM	#1 (permalink)
treestyle Semi-mature vigorous tree Join Date: Jun 2007 Location: North Brisbane Posts: 128	lowering BIG blocks. hi, Got a big job coming up. 35m plus (approx. 1m dbh) stringybark leaning towards a house and growing in between 2 driveways to take down (no where to fell) far enough away from the house to easy lower off the branches and top. the option is then to either block down the trunk in small enough pieces to chuck into the tight dropzone or lower off some big sections. it's a big tree and doesn't have much taper, more like a big cylinder. any thoughts would be appreciated. Thanks

4th October 2007, 04:01 AM	#2 (permalink)
Sean Freeman PDF King & Arborist Extrodinaire Join Date: Feb 2007 Location: Townsville Nth Queensland & Gold Coast Sth Queensland Posts: 1,638	Re: lowering BIG blocks. Whats your crew like? Taking down big blocks rigging off the stem relies on the abilities of more than just the climber, you need experienced ground crew, and of course the right gear. For the job you describe I would want at least 3/4 static line a block and a porty, with those basic elements and confidence in the groundies it should go well, physically wearing but manageable. Pace yourself (if you're the climber ensure you have 2 tips its less strain on your body as much as anything else) trying to turn a 4hr job into a 3hr job can often result in 6hrs of struggle and exhaustion. __________________ Sean Trees are poems that earth writes upon the sky, We fell them down and turn them into paper, That we may record our emptiness. - Kahlil Gibran

4th October 2007, 04:09 AM	#3 (permalink)
treestyle Semi-mature vigorous tree Join Date: Jun 2007 Location: North Brisbane Posts: 128	Re: lowering BIG blocks. thanks, i've got a nice 3/4 inch double braid line saved for occasions such as this, will be getting a block and using the porty. my intended method would be: block cow hitched to trunk, cut an open skarf with sloping bottom and top cuts (1/3 of trunk deep) pull rope on top of section. lowering rope attacthed to section using multiple half hitches finished off with a running bowline. do the back cut hang my saw and brace, then the crew can do the rest. how important do you think it is to have my 2 "tip's" between the block attachment and the skarf? thanks.

4th October 2007, 04:10 AM	#4 (permalink)
Ekka Eric Frei Administrator - Brisbane L5 (Dip) Hort Cert III Arb + some Join Date: Jan 2007 Location: Brisbane Posts: 6,815	Re: lowering BIG blocks. Did you quote it, if so, how did you determine the time/price and using what method? If you didn't quote it then how did the person who quoted it determine the price/time/method? If it's in between 2 driveways my preferred method is crane. __________________ Remember to use the "search" function, if you have answers/questions post them so everyone can benefit. Free Tree and Green Industry Link Directory Qualified Brisbane Tree Lopping Brisbane Tree Care, Consultations and Arborist Reports Forum Sponsors

4th October 2007, 04:19 AM	#5 (permalink)
treestyle Semi-mature vigorous tree Join Date: Jun 2007 Location: North Brisbane Posts: 128	Re: lowering BIG blocks. I quoted it, the job will take all day, 7am till 5am on site. based on these hours and my rate for 3 men plus the additional for the nature of the job and that's how i came up with the price. the methods i contemplated from the start were blocking down or lowering. i like the idea of a crane, i've never worked with a crane or even seen one in action. i'm a bit weary of using one to remove large sections without having had any experience with them. i have heard of them being being very effecient though, would be something i'd like to involved with in the future. how much would a 35m crane be worth per hour?

4th October 2007, 05:35 AM	#8 (permalink)
Tree Machine Over mature heritage tree Join Date: Mar 2007 Location: Indianapolis Posts: 569	Listen to the wisdom of Ekka. A lot was said right there. Lowering BIG blocks has got to be one of the slowest and most agonizing parts of treework that I can think of. By the time you get the third block rigged, you realize that if you could have just cut and pushed em off, you'd be done already. Especially if you're tying timber hitches. Men standing around, waiting...... Aughhhh! The pain! However, damage to the driveways will cost ya far more time and money. Leaners are tricky, but they don't require the conventional face-cut of any sort, just lop firewood length blocks, or whatever. A handful of round, bamboo chop sticks (not the squared-off wooden ones) can aid really well when it comes to the slide-off. If using the conventional face cut you are generally to 'tip' the block off, like on smaller or taller big blocks. Shorter or more massive ones, they don't 'tip'. They slide and often need to be persuaded. Have Chinese for lunch is what I say. Round chopsticks (pencils don't work nearly as well). Personally, I think the crane would be cheaper. Ever hear the expression that the last 10% of a tree job takes 90% of the time? Big logs will do that. Crane, and you'll be glad you did because any time you can take the last 10% of the job and make it take 10% of the time, go for it. Get your standing log rigged, cut from the compression side through to the tension side, straight through, as low as possible. Your saw will clearly pinch, but that's the beauty of the crane. Now he starts his tension to get the leaning log vertical, saw no longer pinched, keep cutting. Crane guy should be moving things very slowly now, gentle lift, men clear well away, this giant log will hover and float, then fly up and out of there. Dice it up next to, or on the trailer out front. I would explore the option of plywood, tires or foams for conventional push-offs. ANYTHING but rigging big, single blocks. Anything.

4th October 2007, 06:16 AM	#9 (permalink)
Ekka Eric Frei Administrator - Brisbane L5 (Dip) Hort Cert III Arb + some Join Date: Jan 2007 Location: Brisbane Posts: 6,815	Re: lowering BIG blocks. Hey, get the crane and I'll come over show you how to do it, I love cranes! Then also, what do you have on the ground to move 20,000kgs of blocks around? What's the impact force of a 250kg log dropped from 20m high when it hits the ground? Hey, here's an online calculator Energy of falling object __________________ Remember to use the "search" function, if you have answers/questions post them so everyone can benefit. Free Tree and Green Industry Link Directory Qualified Brisbane Tree Lopping Brisbane Tree Care, Consultations and Arborist Reports Forum Sponsors

4th October 2007, 06:51 AM	#10 (permalink)
Sean Freeman PDF King & Arborist Extrodinaire Join Date: Feb 2007 Location: Townsville Nth Queensland & Gold Coast Sth Queensland Posts: 1,638	Re: lowering BIG blocks. The reason why if I were to use a crane on the job described I would use one of larger capacity (and more expensive) is the loss in lifting capacity at greater distances. A franna does have a radius of around 30m but at that distance can only lift around 300-400kg. An 80T crane can lift around 3T at 24m....the 100/120T crane could take the whole stick in one at 35m. __________________ Sean Trees are poems that earth writes upon the sky, We fell them down and turn them into paper, That we may record our emptiness. - Kahlil Gibran

5th October 2007, 04:29 AM	#11 (permalink)
JohN Dee Over mature heritage tree Join Date: Feb 2007 Location: Sydney, Australia Posts: 728	Re: lowering BIG blocks. Indeed the crane sounds like the best option for you TreeStyle. You could be doing the best take down in the world and have the cutomer cheering, but put one crack in their driveway and that is all they will remember, you cracking their driveway. If you do still attempt to rig down the big sections, I would suggest a series of half hitches to a timber hitch oposed to a running bow. When putting in the final back cut, make sure your two TIPS are above your sling/topping strop, so in the event that the strop went sliding, it's only gunna gaff you out(where your second TIP will grab and save you). Tree Machine, love the chopstick idea, I'm going to use this from now on... I was only recently thinking about this too... :P __________________ Climber with slow climbing speed, must make up with mighty chainsaw roar. Free Tree and Green Industry Link Directory Red : Green : Blue

5th October 2007, 02:59 PM	#12 (permalink)
Quintrex Mature tree Join Date: Jun 2007 Location: Sydney Posts: 437	Re: lowering BIG blocks. All very good advice above! A crane operator experienced in tree work will talk you through the job and show you where to sling each lift. Have you considered a contract climber for with crane experience for this job as a training execise for yourself? Lowering big blocks is a bitch, we only do it when absolutely necessary.. As ekka said, tieing off the fat mothers so they don't slip out is very hard. Good luck with it whichever way you go.

6th October 2007, 01:28 AM	#13 (permalink)
RC1 Semi-mature vigorous tree Join Date: Jan 2007 Location: Macclesfield England Posts: 138	Re: lowering BIG blocks. Treestyle If you do decide to rope the trunk down then try to make sure you have a dry day for it. Thick, wet ropes can be far more difficult to work with. Also, right after you take each section off, try to get into the habit if placing your saw on top of the trunk while you're undoing the rigging ect rather than having that weight contantly hanging on your belt. Over time this will come as a welcome relief to your feet. Take your time and keep cool. Oh, and here's a handy tool for blocking-down big stems. Although we were just horsing around on the floor in this particular video, you should still get the jist of its potential usefulness on a job like the one you've described. BLOCKDRIVER: A quick demo. Good luck with which ever strategy you decide upon and make sure you get some pictures for us! Reg

11th October 2007, 03:20 AM	#14 (permalink)
treestyle Semi-mature vigorous tree Join Date: Jun 2007 Location: North Brisbane Posts: 128	Re: lowering BIG blocks. thanks for your replies. Much appreciated. i'[m gonna give it a go, lowering the blocks off. HOWEVER, in future if i'm faced with a similar job i WILL be considering a crane. I think i have to do a job like this once in my life so i know not to do it again. Thanks, i'll try to get some pics!

11th October 2007, 03:37 AM	#15 (permalink)
Ekka Eric Frei Administrator - Brisbane L5 (Dip) Hort Cert III Arb + some Join Date: Jan 2007 Location: Brisbane Posts: 6,815	Re: lowering BIG blocks. I thought you'd done it last weekend, oops, pic and video .... .... hey, can I come and video? __________________ Remember to use the "search" function, if you have answers/questions post them so everyone can benefit. Free Tree and Green Industry Link Directory Qualified Brisbane Tree Lopping Brisbane Tree Care, Consultations and Arborist Reports Forum Sponsors

11th October 2007, 03:41 AM	#16 (permalink)
treestyle Semi-mature vigorous tree Join Date: Jun 2007 Location: North Brisbane Posts: 128	Re: lowering BIG blocks. next Saturday (20th), i'll think bout the video part......You might expose too many flaws in my technique? Honesty i'll give it some thought, might do me good to get some constructive criticism. I'll be in touch. That's what i might try, thinking if the lower branches allow for it, i might lower the top out first? will see what happens.

11th October 2007, 03:46 AM	#17 (permalink)
Ekka Eric Frei Administrator - Brisbane L5 (Dip) Hort Cert III Arb + some Join Date: Jan 2007 Location: Brisbane Posts: 6,815	Re: lowering BIG blocks. Have you heard of "editing"?