Speed Line

I agree it does seem like fun, personally I would have cut all that into the water and then handed the guys an axe so they could make a canoe out of the trunk and be onto the next one.

Its hard to put a price in the beginning on a job like that, it takes alot time to set up and if the ground help is medioker it can really slow you. It is almost faster for them to swim out and grab a piece of brush than it is for them to figure out how tension and lower the system and send it back. Besides our guys are from Mexico they'd have no problem crossing that little Rio Grande.
 
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well hey, we did think about just dropping them into the lake, but our customers said that this was not an option.... oh well, they had to pull their checkbook out for this one /forum/images/graemlins/bling.gif
 
Nothing wrong with that, it's hard to get some people to put the up the money for safe productive work. Most rather save a few dollars and risk and someones safety.
 
Glad I went back and read the thread b4 I second guessed you. Very Tough to see the big picture from pics even video. Nice job, Time and Material Job? -- 100 man hours @ $75 + disposal I guess the line in there checkbook says
8200? If you bid it, did you make out? Bling bling says you did. Great Video and commentary and tenacity to work in that rain. I Love Zip/speedline jobs.
 
not really sure what the price was, but i think that it more than doubled your guess.... there was 140 man hours... and it was not time and mat.

They bid the job for 5 days, and we did it in three (there was also two other removals on the other side of the building), and we had to figure our cost for the extra gear... we bought a 700' spool of 5/8" static line, 600' spool of true blue for a control line, and that handy dandy SL-ing double pully kit (thank you Charley)

over all i'm sure that arborguard did alright, my paycheck was not effected by it though /forum/images/graemlins/icon1.gif


Rob
 
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i did try the link before posting, it worked fine for me.

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There's a difference between seeing if anything's there and seeing if what's there is complete and good. I was keying on your statement that you'd not downloaded it yet. Until you download it and compare it to the original you cannot know that what others are getting is what you want them to get (unless you have shell access to the server and can run a checksum on the file and compare that to one generated from your local file). How many times do you see an attachment posted to a forum such as this and the attachment isn't quite all there? Not often, but it does happen.
 
lekjrlskjf lksdflksd jkd cvkdwo ekjfdks /forum/images/graemlins/damnmate.gif Hey it's all Greek to me.... my brother just said "here is the link, use it!" and i did.... i just left click on it and it works, never have downloaded it (that i know of) I click on it and it shows up fine, maybe it's because i have cable? i don't know, but sorry to the guys that it has not worked for.
 
If you watched it as a result of following the link then you downloaded it just fine. There's no way to watch it without downloading it. Maybe what you're referring to is the fact that you didn't save it to your drive (well, in fact you did -- it was or still is in your browser cache).
 
Yeah, great video.

Funny to see rain ... and autumn leaves on trees and deciduous trees ...

... what a great job and lots of "friggin with the riggin".

I'm sure Spydie will correct me if I'm wrong but the load at the anchor point of a tensioned speed line is 5x the weight of the load. So 750lb load will put around 3750lb of load at the anchor point ontop of the pretensioned load ... that's of course a static load and why people who dump onto speed lines do so at great risk, not that you guys did that.

So lets say that you pretensioned as tight as a guitar string with 4500lbs of force from a truck etc ... now that's already there and on the rope. Then you lift that 750lb piece with the block and tackle or lower it on from above ... it adds another 3750lb to the rope andchor point ... thus the total is now 4500 + 3750 = 8250lb of force on the anchor point. Now 5/8 samson double braid is rated at 16000 lbs so infact the rope has come up to 50% of it's breaking strength and in appearance no abuse has been going on.

Of course some comsideration has to be placed on the angle of the line as well but these numbers gives an idea of how easy it is to over do good rope. ANother factor is stretch in the rope, even at 1% for a good rope over 500 feet of rope means 5' of stretch ... stretch can be your friend in loading though.

The spars used for the speed line should always be guyed off by a seperate rope and if possible at the height or higher than the speed lines block for redirection on the spar. Using the speed line tail thru a block to another anchor behind the spar isn't really ideal as forces will act to move the spar to a point of equilibrium in the tensioning. The diagram shows the green back up ...

Nice one again guys and I suppose now you're looking for the next job to use all that rope. /forum/images/graemlins/grin.gif
 

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Glen, Joe etc. are better number hackers than me; i go more for conceptual models as thumbrules for judgemeant calls and to maximize and minimize forces in sytem etc.

Any way ya cut this, it is a lot of immediate force; and i'm with Dan; any even potential shifting of root plate with hu-man on board/ in tree should be dis-allowed IMLHO. Let alone the potential rigging disasters and any implications there. Especially once pulled and shifted then subsequent pulls on compromised support.

The force on the line would be in relationship to the angle of the line run; how perpendicular it was to the downward pull of gravity. Then the bend in that line all calculated X the impact force + tag line pulls. The bend could be relieved/ not as sharp a multiplier by give/ elasticity in line and tree support; to include shifting of root plate to assume minimal force positition overall. Then the calculated pull on that line would be X height from ground anchor of tree roots; so climber is on a long lever with this high leveraged impact of line pull on it + downward force of tagline pulls...

In Ekka's drawing, green would brace more; especially if well tightend or even over tightened before use to more fight proposed pull. Though i would choose seperate anchors for SL and green line. The pull oacross support spar as a direction would be more in the vortex of the line angle at pulley rather than straight across though i think. The angle at pulley increases the force on the top of support, but lessens the total leveraged angle of the pull at top of spar. If Line terminated at top, there would be less force, but at a more perpendicualr angle to spar. If root plate shift was up on Left side and down on right, i'd especially, surely not attatch pull line shown for SL to the left side; in fact it should be brought the opposite direction i think(unless figured some advantage to coming around and connecting to SL side of trunk. Of curse my green line might run like that, over limb and tie off to SL side of trunk!




Bent Line Calculator allows you to filll in own values. The load does have 2 support lines; just that each half of the load is carried on a line not inline with the downward pull, but more perpendicular to it. The more the line is pretightened and static, the more it will resist the bending of the line, thereby raising the leveraging of the line.


It is a great movie and very polished effort; but personally i'd want more of the force, on my side, rather than standing so much against'me.
 
oh yeah!

Good stuff Ekka. and right you are about guys dropping loads into SLs..... i do stress to my guys that loads are not ever to be shock loaded into SLs, also i do want to stress that if you are ever using a static line(which we were in this case), shock loading will result in breaking a static line far before it will break the lines that we typically use.... so the moral of this story is: Know your forces AND your equipment.


I agree with the spars always being guyed, but in some cases(if you have enough rope and the right points to tie to) you can simplify your setup. meaning, if the spar is in the direct middle of your two points, then no worries.... I know that these would be rare cases, but i think that it worked out OK for this job.... moving this system was very fast, and i hate to think of all the trouble of re-tentioning the spar tie off!


Rob
 
Because vectors and angles are inconsistant from tree to tree, sometimes even changing through a single job, the rule of thumb I live by is that forces can be magnified 7-10x on a speedline's anchor points.
 
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