Why are some caves called vertical caves?

Answer 1

Vertical Caves either have entrances which you must go down using a rope (instead of going in horizontally) and for safety reasons specialized equipment like a harness, rappel rack or "figure 8", (although if you absolutely had to you could go down using a body rappel technique) or most of the sections in the cave are similar in which you have to use the same equipment to go down safely. These cave entrances or sections are called pits if you are touching the wall or pretty close to it, within a couple of feet to the wall. If you are in free fall the entire distance, which is to say the cave walls are nowhere near you and the only thing you can touch is the rope and your equipment, it is called a dome cave, both of which are vertical caves as well.

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To which I would add it's handy to be able to come back out, and most caves do not have convenient lower exits! That's done by a technique called "prusiking" - often spelt "prussiking" but the former is correct as it's from the inventor's name.

This entails climbing back up the rope you rappelled down, using "ascenders" (cam devices) attached to the harness and to foot-loops, and which slide up the rope but grip it when loaded. The effect is that of a ratchet. There are various different arrangements of rope-rigging, harnesses & ascenders, and other types of [rappel] descender as well as the rack, but the principles are the same.

Dr. Karl Prusik, the Austrian mountaineer who invented the method originally for rescuing oneself from crevasses, initially used a loop of cord tied in a special knot (the Prusik Knot) giving the same effect.

A point on terms: I stuck to the US term "rappel" above, but it's "abseil" here in the UK, and looks German / Austrian in origin, presumably from Alpine climbing.

We use the term "vertical caves / caving" but not "pit" and "domes". The vertical drop is called a "pitch" or a "shaft" irrespective of its dimensions and the caver's distance from the wall - I hadn't realised there is a distinction between "pit" and "dome" in US caving terminology.

Another difference is that the Fig-8 descender is not now used in UK and European "Single Rope Techniques" - it would not work very well! We use a rack or a "bobbin" descender, which works fairly similarly to a rack.

Answer 2

Vertical caves are so named because their entrance or main passage descends vertically from the surface, as opposed to horizontal caves where the main passage goes horizontally into the ground. Vertical caves require specialized equipment and techniques for descending and ascending safely due to their vertical nature.