codz

Good work lads, If I lived in the UK I would probably get the camera out every time I saw blue sky and sunshine too.

I will try and get her to snatch load it.

I will have to come back to this one later, the Missus just went into labor.

I think the strength loss would be similar to our set up or worse. that first bight would reduce the strength dramatically, and what is worse is that it is rope on rope. A good option in this situation is to incorporate a shackle to eliminate rope on rope, I will post a pic shortly. There a much stronger ways of attaching the log if you were to use 2 ropes. 2 splices attached to the shackle and sling we used would be a good option. That 40mm we used was hard enough to handle as it was even with 2 of us in the tree. A 60mm rope would be around double the strength and easier to handle than the doubled 40mm.

Me giving the Cruiser **** to snap the log probably did increase the loads however I dont think it was the straw that broke the camels back. The piece of rope remaining in the tree shows us that the rope broke at the shackle, I believe it snapped when we ran out of elasticity.

We had to make sure the log was not going to topple prior to the climber exiting the tree, you know, safety and all that crap, this meant a pretty fat hinge. We would normally put a scarf cut about 1/2 - 2/3 the depth of the log to allow the weight of the piece to drag it over. There is still enough log and rope left to try another log of similar weight, I have a few ideas.

It was 46 degrees on the first day of that removal!, I might have a bit of footage.

It is a common misconception that the attachment to the piece being lowered needs to be close to the scarf cut. It only needs to be somwhere below the midpoint of the log to prevent it doing a 360. No matter where the log is tied on below the midpoint it will fall the same distance. The scarf cut also would have no bearing on the out come, we could have step cut it for the same result. The hinge is only effective for about 30 degress, probably much less with dead timber. The hinge was completley redundant prior to any load reaching the rope.

The shackle is attached to the log vis an eye to eye sling double wraped, just loke you would if you were setting a cambium saver on a straight stem. This method maintains the integrity of the 2 parts of rope with minimal strangth loss through bend ratios. It also meant the sling did not have to be choked. The dead end of the rope is wrapped around the stub and then wrapped around the log beneath. We were not confident in the structural integrity of the stub so we did this to back it up in case it failed. It was difficult to set the ropes to avopid rope on rope and also not have the ropes lock up.

Again hindsight reveals the "obvious outcome" it would have been great to incorporate a load cell in place of the large shackle and if anyone is willing to loan us one we will repeat the test. As for how far you would need to let it run? More than we did!

When done correctly the wraps will not lock up and can be released gradually. Everyone apart from Joe, myself and the crew that attended the workshop has had the privledge of hindsight from which to draw thier conclusions. It is easy to watch the rope snap then say yeah I knew that was going to happen. As Joe has stated, prior to breaking the piece off the majority off those onsite were confident we had a reasonable chance of success. The scale of the rope compared to the log looked reasonable, taking into consideration we had at least 2 parts of rope supporting the load at all points. The rope was re-directed through a 40 tonne bow shacke attached to the base of an adjacent tree via a cow hitch using 25mm double braid polyester line. The cow hitch became fused together despite the reduction and friction before it in the system when it was loaded. This gives us an indication as to how much force was being dissapated through the system, although that is hard to pick up in the video. It would have been nice to be able to let the log run as we would normaly do in a working situation. The forces involved meant we could not accuratley predict the number of wraps needed which is why we were reliant on the dynamic charateristics of the rope to do the work for us. Thanks for all of the positive feedback that we are recieving both from here and outside.

RC0, I dont doubt that there are plenty of guys on this forum with heaps of experience. That said I will not hold back for a second if I feel it is warranted. .

Yeah its tough when you cant get a crane big enough to get over them.

As always Joe you are the voice of diplomacy and reason, but where is the fun in that.

You need to post a pic of the Redwood from a different angle, I can only see the little one next to the house, the big one is behind it I guess.

I got a heads up from Joe about the banter on this site regarding the video of our snatch, I did not realise that there was such a thing as irresponsible rigging and that people may be offended because we did not use shiny pulleys and double braid rope. I have enjoyed reading through peoples differernt takes on the set up and reasons for it, I have also had a good laugh at the pissing in the wind from the desktop experts who probably have spent most of thier career pollarding plane trees. Big thanks to Mog and Ewan for coming to the rescue of our tattered credibilty. I think Joe has covered why we we did what we did in enough detail. The video does not really do the size of the piece justice so I will attach i pic of it with somthing for scale. Here is another video to show that we dont always break our ropes. Split Eucalypt removal on Vimeo