Apologies for the lack of editing. These short videos were taken with a cell phone while the job was underway.

It took two people setting lines/hardware 45 minutes to set this rigging system up.

This was the first time we have used this device, after owning it for several months. It was an opportunistic use, not premeditated.

The "high line" used was a 300 foot 13mm static line. We terminated one end at the base the tree being pruned, and terminated the other on the base of the anchor tree used near the road/chipper. All natural crotch, and the line was tensioned by hand (4 men pulling) ie, it was not very tight. In a situation where additional tension would be necessary, at least one block aloft would be required.
The rigging line was a 200 foot line, which was not long enough (a 250' rope would have been enough for this use). An additional rope was tied nearer the tree being pruned, and the rope was terminated at the base of the tree. The other end was set through a block aloft in the anchor tree near the street down to a porta wrap.

The limbs were cut into sections small enough that most ropes were tensioned/pulled by hand. (belly of Keanu trolley generates 2:1 lifting/lowering) For larger sections, a winch or ideally bollard on mini skid grapple would be ideal. Lots of pulling. GRCS would work, but that's a lot of rope to crank every cut....

The anchor tree we pulled the limbs up to was uphill from the tree being pruned. The haul line would have ideally been pulled by mini skid with bollard as well. the closer the trolley gets to the anchor point, the steeper the high line angle and harder the pull required. Also, if little limbs interfere with the high line, it becomes very difficult or impossible to advance the trolly passed them. Consider this when installing system.

The high line was oriented in the anchor trees to provide at least some type of guying effect to reduce forces on anchor points. An anchor point for a high line like this will experience a force roughly equal to 6x the weight of the load in the direction of the high line (laterally). Because of the 2:1 belly from the Keanu, plan for 12x the weight of the limbs. If pretensioning or pulling, these forces would be even more. Very important to consider. If planning to take larger sections than shown in video, guy lines to the anchor point would be a must. Also, this device has a working load limit of 10kn. Because of the 2:1, that means you are really limited to pieces 1000lbs or lighter. (1000lbs x 12=12,000 pounds lateral force on anchor point.... that is a lot!)

When installing this device, remember that it is not mid line attachable for the high line or rigging line.

This job could not really be performed in a convenient way. No bucket or lift access. Small pieces could have been rigged and fumbled down, cut up small, and walked out. Or a crane could have set up in the driveway. It was all just kind of dumb, but got paid pretty good, and got to play with cool toys, so all good. Enjoy.

свернуть