Negative rigging big wood

[Scheffa]

Hi all.
Just looked at a job today, removing 3 45m mountain ash that are threatening a concrete dam spillway for a remote located hydro plant in the hills.
Trees have to come down to ground level or very close, not allowed to fell then as this will create too much disturbance to bush land around dam.
All logs and debris to be left onsite and stacked somewhat in the bush, no access for anything other than a Ute and possibly small excavator.

thinking of possibly negatively rigging the whole thing down or preferably running a slack near vertical speed line anchored to a nearby tree away from the buildings and dam wall.

thinking the speeding will probably be the safest and quickest way of doing it, less shock loading of the spar, less chance of a piece slipping from the rigging due to reduced shock loading of the angled vertical line.

chasing feedback and suggestions on the method and gear used from more seasoned pros than myself.

middle two trees of photo attached

 

[Scheffa]

 

[Reach]

If you’re not worried about the pounding the ground will take from the vertical speed line, that sounds like a good plan to me. If crashing heavy logs repeatedly into the soil is a problem, I would suggest negative rigging the logs with a double block system to reduce the loads on your rigging lines.

 

[Steve Connally]

As long as the speed line anchors can take those peak forces!

 

[Treetopflyer]

I'll leave that one alone

 

[Scheffa]

Why you going to leave it alone @Treetopflyer?

for connecting large heavy pieces to the almost vertical speed line would you still comfortable using steel biners or opt for a steel pulley

 

[Treetopflyer]

Sheffa, I was just playing around.. your down under and I'm not, so unless the constitution of physics have opposite effect with vertical speedline on steel biner rated in kn zone you'll be rigging in, hard for me to see a problem with that. I prefer xrings or the similar for that specific rigging and avoid pulleys for the obvious impact reasons ... as long as the root zone is not a worry for impact ..which on a healthy tree you can mostly deduct it is( like when the logs smashes you dont take a long ass puckering ride)..I'd assume that's fine..but your a long ways away from me! Are those trees massive or linguini noodles.. I can't tell lol! How tall ? Dbh?

 

[Scheffa]

Sheffa, I was just playing around.. your down under and I'm not, so unless the constitution of physics have opposite effect with vertical speedline on steel biner rated in kn zone you'll be rigging in, hard for me to see a problem with that. I prefer xrings or the similar for that specific rigging and avoid pulleys for the obvious impact reasons ... as long as the root zone is not a worry for impact ..which on a healthy tree you can mostly deduct it is( like when the logs smashes you dont take a long ass puckering ride)..I'd assume that's fine..but your a long ways away from me! Are those trees massive or linguini noodles.. I can't tell lol! How tall ? Dbh?

Was thinking of maybe rings to help reduce glazing on the rope, rope will most likely be retired after this job.
Trees lasered between 40-45m tall and approx 1-1.2m dbh

 

[Chaplain242]

Maybe missing something but looks like there’s a drop zone, can’t a brush pile be established to drop the speedlined pieces onto?

 

[KevinS]

If you’re not worried about the pounding the ground will take from the vertical speed line, that sounds like a good plan to me. If crashing heavy logs repeatedly into the soil is a problem, I would suggest negative rigging the logs with a double block system to reduce the loads on your rigging lines.

If the ground beating is an issue negative rig 3-4 blocks out to make a crash pad then vertical zip your heart out

 

[Scheffa]

Maybe missing something but looks like there’s a drop zone, can’t a brush pile be established to drop the speedlined pieces onto?

there is really the room at the base of the tree to rig pieces straight down, also not much room to move debris around in to keep a clear work area. Photo below with arrow pointing to the tree kinda shows a little bit better the location of one of the trees.
Because of the tick hush it’s hard to get a decent photo.

 

[Chaplain242]

If there is room to fell I would be tempted to speed line the branches down to a pile where the trunk would strike if felled, probably the lowest impact method one could use. If the slope risks the trunk sliding down hill just tie a tether above the scarf tied to another trunk nearby. Almost no ground contact at all, and secondary damage very minimal - if a corridor wide enough to fell exists. Can even land the trunk in three sections over two piles if tight length wise. Sounds like there’s little room to play on ground so may be the best option...

 

[JeffGu]

I'm not sure that I understand why you need to do any "negative rigging big wood", other than blowing the tops out if you don't like climbing skinny stems. There's so many other, equally tall trees there that the two you're after could be span rigged to the nearest convenient spot. With all the rigging on neighboring trees, you'd hardly feel a wiggle on the spar you're tied into.

Any way that you do it, the grade is going to be a pain for the ground crew, and it's going to be a long day. Taking smaller pieces takes more time, for sure. Can you spread the work over two or three days? Pack in a nice lunch, maybe do some drop bear hunting to keep it interesting?

 

[Scheffa]

The job will be spread over a couple days camping on site, the photos definitely don’t any justice to the scale of the job and the infrastructure directly below that isn’t visible in the photos,
Span rigging may be an option, I haven’t really done any of it though. Climbing tall skinny tops isn’t an issue. The next part of this job is to remove 100 trees of similar size along and over a 16km long aqueduct through the bush with the only access being by quad bike

 

[Chaplain242]

The job will be spread over a couple days camping on site, the photos definitely don’t any justice to the scale of the job and the infrastructure directly below that isn’t visible in the photos,
Span rigging may be an option, I haven’t really done any of it though. Climbing tall skinny tops isn’t an issue. The next part of this job is to remove 100 trees of similar size along and over a 16km long aqueduct through the bush with the only access being by quad bike

With span rigging be sure to check forces and use back ties if necessary. I know one job near me that was similar height but DBH was about 5ft, they used speed line to a small drop zone with crash pad, but to keep forces down because of underground services nearby they installed eye bolts into each of the blocks and cut smaller.... if have the time may be an option...

 

[Sfoppema]

Damn, sounds like some fun work! Take some pictures

 

[*useless info*]

If can equitably, putt rigging forces, even speed line pulls on other tree.
>>i think best if it is balanced in opposing direction of pull.
.
If need to pull uphill to lose pieces would try to get them aligned to that target
>>then use high pulley redirect for winch, truck or even hand pull
>>holding redirected tail/control leg and leaning back and grabbing load leg as a pull
Giving abut 2xEffort + whatever bodyweight against load.
.
Any speed line more than 45degrees, i try to have the low anchor past the delivery point
>>so as not to screech everything to limit if bow in line to very end
Allowing softer fail away and away from low anchor congestion
.
L-earn al that can, aligning to the next 100 with this trial!

 

[rico]

Obviously armchair quarterbacking here, but it looks like I would be brushing those things, blocking a few logs to itself, then putting a big butt-hitch on those fuckers and pulling over some big spars...Quicker and safer.....

Otherwise why not just brush em out, negative rig the upper wood, then move onto a near vertical speed line set-up for the bigger wood, and then a butt hitch and pulll over the spar as soon as you can.... We use that routine a lot when needed.

It also appear that swinging 1 or 2 of the trees to another treee is a very real option. If the swing is too big simply employ a holdback on the tree your working down. like butter......Loooks like a fun gig with lots of viable option... Have fun and enjoy it.... Pics or vids are mandatory...

 

[JeffGu]

Allowing softer fail away and away from low anchor congestion...

I'm going to talk to the coders at Google Translate about a new module for converting your posts into a human-readable format. It may require hooking your brain up to some analyzers and waveform monitors. I hope you don't mind. It's for the good of mankind and will allow more people to benefit from your analytical talents.

 

[rico]

Yep... I know there is super useful info in there. Sadly I am just too daft to understand it any of it? Its comforting to know I am not alone...