Base anchor

[Marc]

Drew, not a fan of the knotted line, just think it might get caught up?

 

I use this.

 

I actually thought Drews looked well thought out and simple, the problem with yours DeerMan is you have no real back-up other than the lock, Drew is backing his prussik up with a further lock behind the disc.

 

The only downside is the extra kit needed not everyone has that much bling lying around although I appreciate you could adapt other bits to do same job.

 

Drew have you tried that system out?

 

What I've always wanted to try in an SRT set-up is the ability to slip something on to the the line at the base or say you had a suitable midline knot pre tied, then for another climber whilst on the ground clip his climbing system into that and either cut below the midline knot or have some system that could be untied under weight? There by belaying the climber on your system/aerial rescue kit.

 

The srt line going through a crotch should give enough friction to counter any weight discrepencies between rescuer and rescuee. Always been curious to the fesabilty of the idea just never got round to giving it a go.

[Paul Smith]

I used to back it up with a prusik but I don't bother now.

[DrewB]

Hey old mill, I don't actually think its complicated. There's no knots to tie around the base of the tree, the ring loop cinchs it tight and the hub is just cinched through a big spliced eye. The hub is used mainly cus I've got one!! The vt is massive as it was some spare cord I spliced up. All I have to do to set up is put the large eye around the tree and through the ring loop, then cinch the hub on the big eye. All the rest is on the rope so I just clip the vt onto the hub and feed the rope through the hub. But there are many many ways of doing this so will be good seeing all the other variations.

[DrewB]

Hey marc, we normally lower the climber at some point everyday or so to make sure people on site know how to use it and can see/ get to feel how it works. Even with 2 climbers on it it's smooth to lower on.

[Al Baker]

Drew, not a fan of the knotted line, just think it might get caught up?

 

I use this.

 

That's a nice clean one. You can also lose the figure 8 and tie directly into the carabiner with a Munter hitch followed by two half hitches to lock it off.

[softbankhawks]

Peter from arbtalk suggested splicing directly onto a friction device.

I think it is important to take away the karabiner from a trunk anchor in case of cross loading.

Paul, your gate is rubbing on the trunk!

It is a cautionary idea but I use a small aluminium ring (28mm) when tieing off the trunk anchor. I will post pictures tomorrow.

I have added a 6m length of small diameter hitch cord. This means that as well as using a cow hitch like deerman we can tie off using a klemheist and load releasing hitch on to the aluminium ring. The 6m hitch can be applied to a climbing line that has been trunk wrapped enabling ease of second line attachment for a long 'trunk belay' lower.

There is a good reason not to add a hitch above a friction device. Firstly, the soft and hard locked figure eight will not come undone. Secondly, the aerial rescue aware groundsman should have a friction hitch to hand if one need be applied and thirdly, a climber will be inverted if unconcious and there is a possibility of neck injuries if the groundsman can not walk out from the trunk to manhandle said climber.

Drew didnt have enough line for his tree and so accomodated this to his trunk anchor. Very good thinking.

[DrewB]

and heres the cheaper option.

to lower in an emergency, put a second climbing system through the ring, tension it up and cut the rope below the alpine. simple.

[atree]

Nice and simple

[Old Mill Tree Care]

Sorry Drew, at first I assumed you had to assemble the whole thing every day. I see the simplicity now.

 

I like the simple one with the ring loop and alpine b. excellent.

[Al Baker]

and heres the cheaper option.

to lower in an emergency, put a second climbing system through the ring, tension it up and cut the rope below the alpine. simple.

 

Very nice. Especially if the existing rope isn't long enough to make a lower off.

You can also build that sort of "bypass" for lower off in a flash from nothing. Even if you have no existing method in situ.

 

If you build such a system from scratch then best tie an "On the bight" knot in rope bellow the hitch after tensioning new anchor and make your cut below that.