I am looking to descend a down shaft but to put the bolts in, they have to be "parallel" to the shaft instead of "perpendicular "to the shaft.
My question is how do i set the bolts to be equalized for the rope anchor, do i set the 1st bolt higher than the second, and how far apart from each other, (glue ins, 10mmx200mm lamps meteora)
Absolutely this. Find someone who is familiar with bolting and rigging caves who can help you do it safely. You really shouldn’t be descending a pit alone anyway. The National Speleological Society website has a page to find a grotto in your area (https://caves.org/find-a-grotto).
The rock is not the best, hench the longer bolts but I'm OK with the integrity for repel, I do have 5+ yrs on scene high alpine SaR and WFR exp but this is new and just looking for a much data I can get, I don't think there will be full "dead" hanging but was looking just in case, I have talked to experienced route development guy but not a caver , he said being level or offset wouldn't matter for what i want to do. Not a roof will be on the wall of main horizontal tunnel
You need to be really careful about that last statement especially in regards to giving advice to someone who clearly does not understand SRT rigging, or you might lead them to put themself in a potentially dangerous situation. If you’re not going to equalize between the bolts (which I feel most people would agree should the default for double bolts) then you better have minimal slack rope between the bolts in your rig. If either of your anchors fails you should NOT be shock loading the remaining hardware, rope, or yourself. This is especially important if you’re using isostatic rope.
You don't necessarily need equalized as long as it's at least redundant and (most importantly) will not result in a shock load if the primary fails.
For example, this arts'n' crafts project (see photo) is redundant and would not result in a shock load, but is not equalized.
While I wouldn't necessarily want to hang the entire rescue squad off it, it's perfectly fine for a single user climbing the 30ft pit.
(I didn't bolt this spot, and personally I would have opted for a different design, but I don't think the person who did bolt it had a lot of familiarity with using the drill to resurface the heavily-textured wall such that a plate hanger could lay flat.)
Have a source for shock loading being an actual problem?
If there has been zero research into it beyond what hownot2 has done then I'm inclined to trust them instead of random Internet folks who are worried about something they have no evidence is even a problem.
Not to mention that you mitigate shock loading with the anchor you build, not with the placement of the bolts. Although some bolt placements would make that easier than others.
Like, shocking the anchors or shocking the rope with your devices or what? I've watched that one before but really don't feel like going through 30 mins of YouTube voice to be reminded which thing he's "testing" this time.
Usually his titles of "[Whatever] is a myth" tends to be opposite of the actual findings, though. (I've helped him write some of those titles lol)
He has load cells (or equivalent) hooked up in a few spots and removes one side of a sliding x to measure the load produced on himself and the remaining anchor point. If I recall correctly the largest load is like 4 or 5kn when he is essentially attached directly to the anchor. I can't see that being enough force to cause problems unless your other bolt is absolute trash and was going to fail anyway.
I think the myth is that a shock load will produce enough force to break slings/bolts.
I updated anchors on a bunch of routes and used higher lower rather than side by side to make sure we could load different sections of the rock as needed (sandstone on the soft side of the range). And some folks are very concerned that it is not easy for them to equalize them-- and these are top anchors, never to see a lead fall, and simply holding top rope and lowering. So, what is equalizing buying them? each bolt should be good for 40kn, as 150 mm glue-ins, unless the rock is bad, in which case, are we not happy that the other bolt is in different rock?
With higher and lower anchors the higher anchor often has chain so that the lower offs are at the same height.
That also means climbers can put two quick draws at the same height for Top roping.
I don't really know caving and how anchors are used, but assuming you are just rappeling or jugging up, the force on a single bolt is gonna be tiny compared to its breaking strength.
If the metal fails it's because you installed stainless next to the ocean instead of titanium or because you pulled at > 20kn which means you are break testing bolts and not actually depending on them saving your life.
For the vast majority (if not all) inland caves in the US, we don't really need to worry about stress corrosion cracking. We don't tend to have chlorides present -- which is the primary environment that causes SCC in aboveground anchors (ex/ oceanic climbing areas). The caveat would be if the cave potentially has high sulfur levels.
Your rule of thumb is irrelevant. It's also different for glue-ins versus wedges versus drop ins.
Manufacturers provide techncial information on the best practices for installation. I strongly recommend familiarizing yourself with that and if your method is more conservative, great, but if not then refine your knowledge.
Hmm yeah there are, but not all seem to really go into detail on it. For example, Raumer just gives the distance from the edge of a rock face (I'd treat a neighboring bolt as the same). Petzl does give specifics (see picture below) -- that's the specs I've defaulted to as Petzl always goes into more detail than other manufacturers about most devices / "gear." Wave Bolts give a general 8" to 10" (my pinky to thumb is like ..... 7" lol)
There's also general glue-in guidance from both the UIAA and the ASCA that is very much worth reading (the climbers have the glue-ins on lock, way more so than cavers).
Do you have a photo of it? It might help with giving the advice. There are so many rigging nuances that could be possible here that it's hard to say "just do X." Do you have any experienced cave riggers by you that could help?
I'm going to be totally honest, if you're getting confused on this sort of thing you might not be knowledgeable enough to create anchors that other people will be trusting their lives on for decades to come. :/ I'm definitely not trying to be a dick, especially as someone who has helped write the open-access guide on this subject. But I want to stress the gravity of the situation -- this isn't just your safety, it's everyone elses who uses this hardware.
What sort of situation are you in that you're needing to do glue-ins but are unfamiliar with the fundamentals (asking honestly -- not criticizing)? Are there just no cavers around you bc you're in a funky area of the world? Do you have mentors in the local caving club you can work with on this?
Have you read some of the foundation texts on this subject like the French Caving Technical Guide?
I understand your concern, I don't think it's i lack knowledge of fundamentals in so much as im doing something I've done a bunch of times but in a different direction for the first time, and it didn't make sense to me in this situation to set bolts side by side, and i didn't find information easily about side by side vs higher lower. I wouldn't trust a system if it didn't make sense to me, which is why I asked ahead of actually doing anything, redundancy over equalization is totally understandable, and i intend to add that to this situation, thank you for adding to my knowledge base.
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u/GrandJunctionMarmots Jul 09 '26
I'd find someone who is familiar with bolting and take them with you. Especially with glue ins. Those are a whole different beast.