Rigging Lava Tubes and Pits

[Aaron Addison]

Does anyone have any experience in rigging lava tubes and more specifically cinder cone pits? Are there any resources on the topic?

Thanks-

AA

[Caverdale]

Does anyone have any experience in rigging lava tubes and more specifically cinder cone pits? Are there any resources on the topic?

Thanks-

AA

I have been down a few lava tube pits and cinder cones. They are rigged just like any other vertical drop. The only possible two things that I can think of that might be different: Lava can be as sharp as broken glass. If there is even the slightest chance that the rope will rub use adequate padding. Also, often it is impossible to find a natural anchor. Drilling a hole for a hanger can sometimes be a bit more time consuming and energy-intensive than drilling in limestone. Take a battery-powered hammer drill. I've never seen anything specifically written about rigging vertical drops in lava.

[Aaron Addison]

Thanks Dale-

The latter is definitely the problem. The rigging situation is that there are no natural anchors for 100s of meters in every direction. It's like rigging in a gravel pile of cinders.

AA

[Scott McCrea]

Would stemming (is that the right word?) be an option? A length of treated 4x4 wedged in somewhere? How about a line of stakes in the floor? There's always a bubba anchor--a big boy or three planted solidly with the rope tied around them.

[Aaron Addison]

See the image below for an example of the rigging problem.





AA

[Stridergdm]

Would stemming (is that the right word?) be an option? A length of treated 4x4 wedged in somewhere? How about a line of stakes in the floor? There's always a bubba anchor--a big boy or three planted solidly with the rope tied around them.

Stemple is the word I think you're looking for.

[Stridergdm]

See the image below for an example of the rigging problem.





AA

Lots of stakes driven far from the pit at an angle.. then LOTS of padding to protect the rope.

Problem isn't rigging so much as no really easy way to do high-help w/o making the rigging problem worse.

[Ralph E. Powers]

If you can get your vehicle close enough you might try making an A-Frame by whipping and frapping two 8-10 foot redwood logs together and using your vehicle as the stability anchor. The apex of the A-frame can be leaned out a bit over the edge to keep the rope off the rocks. If vehicle access is a problem then your want of a bomb-proof anchor is definitely a sticky. Know how deep the pit is? How far is the pit's edge from the road... too far (over 100 feet)? Hmm, definitely a sticky one.
I dunno, what else to tell ya. Sorry.

[Tim White]

4x4 mono-pod for high-help with pickets for anchors. Back-tie...back-tie..back-tie...then back-tie some more.

[Stridergdm]

4x4 mono-pod for high-help with pickets for anchors. Back-tie...back-tie..back-tie...then back-tie some more.

Exactly.

(Actually I was thinking a bipod may work a bit easier, but same basic idea.

Lot's and lot's of pickets and back-ties.

Where's that order form for PMI now?

[Wormster]

Could you not construct some type of 3 legged A frame over the hole?

or maybe something of here might help:

http://www.gemtor.com/retrieval.htm

[RichBCAG]

The other thing to be mindful of is rockfall from the lip. Because lava tubes are so close to the surface, the lip area is almost always unstable.

Be super-careful about how the rope lies in the landing zone. I'd go so far as to minimize the amount of rope on the ground so the rope is just touching down (if you can see the bottom of the pit). I've ropes cut almost all the way through with Basalt rockfall.

Leading the rope out of the fall zone isn't enough if the first person in kicks something loose. All the edges of basalt are sharp enough to slice through a rope from a height of just 15'.

[Ralph E. Powers]

The other thing to be mindful of is rockfall from the lip. Because lava tubes are so close to the surface, the lip area is almost always unstable.

Be super-careful about how the rope lies in the landing zone. I'd go so far as to minimize the amount of rope on the ground so the rope is just touching down (if you can see the bottom of the pit). I've ropes cut almost all the way through with Basalt rockfall.

Leading the rope out of the fall zone isn't enough if the first person in kicks something loose. All the edges of basalt are sharp enough to slice through a rope from a height of just 15'.

If that is a real concern... (and it really is a good one) then stuffing the rope into a rope bag and having the first person dangle the bag off their harness where the top of the bag just barely reaches the bottom of their boot(s), then garden the ledge well so that problem shouldn't occur.

[RichBCAG]

I guess I had bad luck. My rope got split in half as the next-to-last guy was climbing out. The rock (a 5-pounder) came out of the middle of the thin lip (gardening from the top wouldn't have been possible) and happened to land on the rope as it was snaking away out of the fall zone to its protected overhang.

Watching from well out of the fall zone, I was astonished with the rock's ability to target my rope. When the festivities were over and I got close enough to inspect the damage, I discovered it had split 2/3 of the core. I'd never seen a rock do that to a rope before. Basalt vs. limestone.

Then I was happy that the bit of rope between the ground and the top was still OK.

:)

[NZcaver]

Does anyone have any experience in rigging lava tubes and more specifically cinder cone pits? Are there any resources on the topic?

Rig a highline, then drop a rope from the middle of it. You will need to construct some really bomber anchor systems on each side, and be fully aware of the mechanics of highlines and of negotiating horizontal/sloping tyrolean traverses.

This is the type of rigging used to drop the deepest open-air pit in the US - an 862-foot cinder cone on Hawai`i's Big Island.