southsoundtree
Been here much more than a while
- Location
- Olympia, WA
Re: drop a 75\' tree in a 50\' LZ
[ QUOTE ]
You mentioned the adj. friction saver and srt which reduce the risk but isn't the hip to hip lanyard what crushes you?
[/ QUOTE ]
The Buckingham Ring and Ring False crotch
http://www.sherrilltree.com/Professional-Gear/Friction-Management/std_frc_saver_2, and probably other systems
with the adjustable prussic-ring combo, as used in the little picture on the right side of the web link page, when a tree splits, MAY be able to push the rings apart, into the climber's friction hitch, compressing the hitch, and allowing it to slide, keeping the crush factor out.
I usually have the two carabiners of this system attached to my bridge, with a wire-core lanyard from D-to-D ring.
If I fear a split (and in other situations), I will use a Adjustable False Crotch DdRT, with a lanyard. I will position myself with the AFC with my wire cord flipline clipped back it itself, choking the tree, and keep it on the regular D, or move it to my bridge. The lanyard becomes back up to the climbline.
or
I will use a choked running bowline with a GriGri (or a F8 Revolver system or Unicender, I believe would work as an SRT system).
The split sounds like it could have been operator error/ judgment error, not knocking the climber or anything. That sounded like the textbook situation to have this split, but maybe the hazard was not mitigated by cutting technique. You'll have to correct me if I misunderstood any of the situational factors/ techniques.
I just had to remove a nasty leaning red alder Alnus rubra, known for barberchaining, which had a heavy lean, but no wind.
Wind will act on the tree like a heavier lean, building the internal stresses/ forces.
I used a ratchet strap above the face cut on the alder, to reduce the likelihood of a barber chair and spar split.
I used a small face cut. I don't think really mattered if it was conventional, Humboldt, or open-face/ birdbeak.
Before of after the face cut, preferably before, use Kerf Cuts in the side of the spar, a few inches below the proposed hinge area.
With the face cut and kerf cuts in place, I bore-cut in the holding wood, set up my hinge thickness as I wanted it, continued the bore-cut of the remaining holding wood, cutting toward the BackStrap of holding wood. Pulled out the saw, and nipped the BackStrap, using a Snap-cut technique with my final cut below the bore-cut.
No sign of any splitting it either the top or the spar.
Hope that was clear enough. Different people use different names for the same cuts, so I sorta tried to clarify the names by using capital letters, at times.
[ QUOTE ]
You mentioned the adj. friction saver and srt which reduce the risk but isn't the hip to hip lanyard what crushes you?
[/ QUOTE ]
The Buckingham Ring and Ring False crotch
http://www.sherrilltree.com/Professional-Gear/Friction-Management/std_frc_saver_2, and probably other systems
with the adjustable prussic-ring combo, as used in the little picture on the right side of the web link page, when a tree splits, MAY be able to push the rings apart, into the climber's friction hitch, compressing the hitch, and allowing it to slide, keeping the crush factor out.
I usually have the two carabiners of this system attached to my bridge, with a wire-core lanyard from D-to-D ring.
If I fear a split (and in other situations), I will use a Adjustable False Crotch DdRT, with a lanyard. I will position myself with the AFC with my wire cord flipline clipped back it itself, choking the tree, and keep it on the regular D, or move it to my bridge. The lanyard becomes back up to the climbline.
or
I will use a choked running bowline with a GriGri (or a F8 Revolver system or Unicender, I believe would work as an SRT system).
The split sounds like it could have been operator error/ judgment error, not knocking the climber or anything. That sounded like the textbook situation to have this split, but maybe the hazard was not mitigated by cutting technique. You'll have to correct me if I misunderstood any of the situational factors/ techniques.
I just had to remove a nasty leaning red alder Alnus rubra, known for barberchaining, which had a heavy lean, but no wind.
Wind will act on the tree like a heavier lean, building the internal stresses/ forces.
I used a ratchet strap above the face cut on the alder, to reduce the likelihood of a barber chair and spar split.
I used a small face cut. I don't think really mattered if it was conventional, Humboldt, or open-face/ birdbeak.
Before of after the face cut, preferably before, use Kerf Cuts in the side of the spar, a few inches below the proposed hinge area.
With the face cut and kerf cuts in place, I bore-cut in the holding wood, set up my hinge thickness as I wanted it, continued the bore-cut of the remaining holding wood, cutting toward the BackStrap of holding wood. Pulled out the saw, and nipped the BackStrap, using a Snap-cut technique with my final cut below the bore-cut.
No sign of any splitting it either the top or the spar.
Hope that was clear enough. Different people use different names for the same cuts, so I sorta tried to clarify the names by using capital letters, at times.
