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speed lining query


munkymadman
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i haven't had much experience on heavy duty speed lining, so the last two days has been completely experimental(i had so much fun).:rock:

 

i was asked to remove a 25 metre gum in the middle of two sheds. front limbs simple clip on, cut, zip. for the side laterals and back limbs. i would attach a slack speed line 20mm. make a gob on the top side of the limb, get the patrol to apply tension on the line until the limb starts to crank up. apply the back cut and watch it pop off and whizz down. for the back limbs more slack was required, and the patrol just kept going once the cut was made to get the clearance. the lower bigger wood i applied a second lowering line which held the piece in place while the line was tightened and controlled its decent.

 

worked really bloody well(top was a bit of a muck around) and came down surprisingly quick(thought it was better than standard rigging), but am i applying far too many forces on the speedlline/tree?:dontknow:

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I'd advise against using a vehicle as a means of holding one end of a zip line.Well,a vehicle with windows,headlights,or panels that could get damaged.

You can use a pully to re-direct the zip-line and have it parked out of the way if possible.remember that the distance the pulley is off the ground will be roughly the distance the zipline will fall when the load is about mid point,plus ofcourse any stretch in the rope.

When it comes to chunks,you might need a "Tail rope",this is usually attached to the block and provides breaking to the chunk on its desent down the zipline,it also is a means of returning the block back to the climber.

Somitimes it is also nesesary to have additional breaking on the zipline,getting a lenght of old fire hose,cutting a hole through it and threadding it on the zipline before you tension it.attach bags of sand/earth to each end of the hose still on the ground and when the pulley hits the hose,it cannot "eat" the hose,ie get stuck in the pulley,so it draggs the bags of sand and takes it to a steady stop.if the bags are to light you can tie previous chunks of wood to the hose also.hanging bags off the zipline can also work for the smaller bits.

I prefer using a tirfor winch to tightnen a steel cable and use blocks that are designed to run on cable,they are generally steel and have "swing cheeks so they can to attached on the cable while its tensioned.

Somtimes hanging a block off a hi ab is a great way,as the peice approaches the truck,the opperator dips the arm and the peice "runs out of steam".

Zip lines can be most efficient in the right circumstances,they can take a long time to set up.I really don't like snatching blocks onto a zipline,it ¨shockloads the system and can cause all sorts of problems.Best have the zipline into a tree or two,or three behind the one you are dismantling if possible.Thats my prefered method,but it dosn't always work that way.:santaclaus:

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cheers for that,

there was no point of attachment for a redirect pulley. so we just put a prussik knot with a rope attached (to help direct it slightly, and stop it from smashing the back lights). we were using the hiab earlier that day to speed line cocunuts over a roof into the back of the truck, good for getting height and tension. but the hiab isn't any good for giving you loads of slack, or tensioning quickly. thats why we chose the patrol.

for snatching i was wondering if you could attach the speedline to the same sling as the lowering pulley. so you don't have to move two setups down the tree as you section. or have you got more chance of rope on rope action.

but what i was asking was is it a good idea cranking branches up by applying tension to the speed line

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for snatching i was wondering if you could attach the speedline to the same sling as the lowering pulley. so you don't have to move two setups down the tree as you section. or have you got more chance of rope on rope action.

but what i was asking was is it a good idea cranking branches up by applying tension to the speed line

 

I'm having a hard time following you on that sentence about the sling and the lowering pulley?

 

I can't see why cranking up the speedline would cause problems,unless the tenison of the line plus the weight of the branch over loaded the system?

 

I wish we had coconuts here in Norway.I get excited when I see them in the supermarket!

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alright tree bogan,

here's the scenario normally when snatching on a speed line, you have a whoopee sling/timber hitch with a carabiner/pulley on it which the speed line runs through, below this you have a similiar setup but with a lowering block which you snatch the pieces onto before letting them run down the speedline. as both setups are similiar in components could you therefore have both setups on the one sling to help save setup time, as you move down the trunk. e.g two pulleys on the one sling.

with regards to tensioning branch pieces on the speedline. if the speed line is at 120 degrees the force at both points of attachment, is equal to the force your applying to the point of attachment of the piece your tensioning. if you tension more than 120 degrees the forces increase exponentially. and as the branch hasn't been cut you really have no idea how much this applied force is. bringing yourself into a very grey area. so is it advised to cut the piece first hold it in place somehow, then tension it?

 

off the track i like doing coconuts, feels real tropical. visa's up in three months, norway was one of my places of interest for next port of call, complete opposite end of the spectrum. is the money as good as they say it is?

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alright tree bogan,

here's the scenario normally when snatching on a speed line, you have a whoopee sling/timber hitch with a carabiner/pulley on it which the speed line runs through, below this you have a similiar setup but with a lowering block which you snatch the pieces onto before letting them run down the speedline. as both setups are similiar in components could you therefore have both setups on the one sling to help save setup time, as you move down the trunk. e.g two pulleys on the one sling.

with regards to tensioning branch pieces on the speedline. if the speed line is at 120 degrees the force at both points of attachment, is equal to the force your applying to the point of attachment of the piece your tensioning. if you tension more than 120 degrees the forces increase exponentially. and as the branch hasn't been cut you really have no idea how much this applied force is. bringing yourself into a very grey area. so is it advised to cut the piece first hold it in place somehow, then tension it?

 

off the track i like doing coconuts, feels real tropical. visa's up in three months, norway was one of my places of interest for next port of call, complete opposite end of the spectrum. is the money as good as they say it is?

 

No after you've subtracted the 61% tax you pay,no.

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