Items of Caving Equipment

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Items of Caving Equipment

This topic has 11 replies, 8 voices, and was last updated 31 July 2019 at 10:45 by SillyOldDuffer.

Viewing 12 posts - 1 through 12 (of 12 total)

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5 June 2019 at 21:54 #412829
Nigel Graham 2
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@nigelgraham2
I made first, a " Figure-of-8 Descender ", a friction-brake for abseiling. It is a fig-8 shaped aluminium plate with all edges rounded, and a fairly narrow waist. In use you reeve the rope through the large eye and round the device's waist, then clip the small eye to your harness. It has long been obsolete for caving and industrial / arboricultural rope access techniques but still used for charity abseils and the like. I keep mine out of sentiment.

A fellow caving and model-engineering friend gave me the blank band-sawn from 3/4" aluminium-alloy plate; I bored out the two eyes on a large lathe* our model-engineering club owned at the time, in a rented workshop. Then filed and emery-strip polished the profiles. Took hours!

I used quite a bit for a few years, before replacing it as techniques developed.

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A battery-case to be worn on a belt (miner's lamp style), out of thin steel sheet, holding 4 large cylindrical Ni-Cad cells. I made the case ends semi-circular both to conform to the cells and so it was less likely to catch on rough cave walls in narrow passages. The headset was second-hand to me but made from what I later found was an ex-Admiralty torch.

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Replacing the Fig-8 descender, as methods improved, a simple " bobbin " type descender. In this the rope passes in a crossed pattern, round two pulley-like but non-rotating bobbins between two aluminium-alloy sheet side-plates.

Luckily I spotted its fatal design flaw before proving the point…. I'd missed the point that the top end should be bent over the bobbin to prevent the rope coming off the side and turning the braked abseil into a free-fall. I scrapped it and bought a commercially-made one with that guard built in.

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An acetylene lamp. A curious effect of developing modern caving techniques was the return for a decade or so to acetylene lighting, because the only alternatives available then were ex-mining lamps. They used corrosive liquid electrolyte that could leak in the harsher conditions of a cave, and attack plastic-fibre ropes and harnesses.

So a sheet brass generator, waist-hung on a belt, with plastic hose to the jet and reflector on a clip on the front of the helmet. I added extras not on the commercial versions, included a dished top so the water reservoir could be refilled easily from a thin film trickling down a cave wall.

These were superseded by the commercial development of powerful headlamps using l.e.d. luminaries and small alkaline or rechargeable cells. These are similar to, though more rugged than, the ones some cyclists use for dazzling other road users…

I have seen a commercially-available acetylene caving lamp generator and jest used in model-engineering to give the particular, large model appropriate lighting. The builder concealed the plastic modern generator in a sheet-metal facsimile of the 19C original.

[For those unfamiliar with this, water is dripped through a controlling needle-valve onto calcium carbide in a vessel sealed except for its outlet. The two react to produce acetylene which flows unimpeded to the lamp jet, though its pressure exerts a slight regulating effect on the water. The by-product is quicklime slaked by the water.]

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* The large lathe… was an IXL-badged, fully-fitted, Erhlich, 6" x I think 30" or even 36" BGSC with powered cross and long feeds, T-slotted saddle and comprehensive accessory set. I owned it for many years after we lost the workshop, then donated it to the Lynton & Barnstaple Railway for its maintenance workshop. I like to think, indeed trust, whether still there or in other caring hands, it's still in use.
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5 June 2019 at 21:54 #34407
Nigel Graham 2
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@nigelgraham2
5 June 2019 at 22:50 #412835
David George 1
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@davidgeorge1
Hi I still use my figure of 8 decender which I first used 50 years ogo. I was lowering some branches from one of our trees which I trimmed off from about 50 to 60 foot off the ground. I don't know how many potholes it was used in over the years as well as bridges etc I used training students to abseil. I still have various chocks and wedges which were milled at work just replaced the rope work from time to time.

Ps you can still buy figure of 8 decenders.

David
5 June 2019 at 23:17 #412838
Peter Spink
Participant
@peterspink21088
I made one of these: **LINK**I during my caving days.

Advantage was to be able to take a bar out if the descent was too slow . . . .

Figure of eight descenders had a bad reputation for twisting the rope.

Bit of a leap of faith abseiling off a 200 foot drop for the first time but still here to tell the tale 😄
5 June 2019 at 23:47 #412841
duncan webster 1
Participant
@duncanwebster1
My acetylene lamp was self contained affair that clipped on the helmet. The water lasted about 30 minutes I think (it's long time ago). If it ran out in a dry stretch you had to pee in it, then clip it back on your helmet. Very unpleasant. Even worse was if the lid came off the tin of carbide in a wet bit, started producing acetylene big time. I swapped to batteries as soon as I could afford it, then you'd have the joys of turning the light off to save batteries in a long crawl, you don't need to see much so if your mate had his on one would do. I must say being somewhere in sound of running water but totally dark is a very restful experience.

Edited By duncan webster on 05/06/2019 23:50:59
13 July 2019 at 23:55 #418734
Nigel Graham 2
Participant
@nigelgraham2
I think Figure-of-Eight Descenders are still used by climbers and events like charity abseils, but are obsolete in caving partly over fear of them kinking the rope (I've never seen a definitive verdict) but more importantly, they don't work with modern single-rope techniques.

I still have one or two of my acetylene cap-lamps as Duncan describes, made by Premier. I can vouch for the water charge lasting much more than 30 minutes though, with a reasonably-sized flame (up to about an inch long). And generally carried the carbide in a screw-topped plastic jar, not its original tin!

I think the longest trip I've done on them lasted about 8 hours, reaching the practical end of the stream-way in the Grotte de Gournier, in the Vercors, of SE France. We were all using Premier carbide lamps on that trip; we refilled them completely before starting back out, but topped up the water as and when necessary or precautionary. So one charge of calcium carbide for about 4 hours – generally these lamps' limit. That was a while ago… 1975 in fact.

These lamps were originally made for miners in the methane-free conditions of metal-ore and ball-clay mines, and underground stone quarries.

When Steve Baldock built his (third-scale?) Ruston steam crawler-tractor some years ago, (sold since I believe) he fitted it with proper acetylene lighting, but using as gas generator a modern caving one inside a replica of the original.

'

It's a curious experience sitting alone in total darkness, and many cavers find it rather unsettling and soon put at least a pilot lamp back on. I've found if I hold my hand up in front of my face, I can "see" a vague image of it as a sort of silhouette even darker than reality. Strange I know but I assume it's the brain expecting the hand and trying to form the image from non-existent optic-nerve signals.

Water is one thing, but sitting in the dark in somewhere like Sand Cavern in Gaping Gill is even more intense because it is a very dry chamber and there is no sound from anything around you.
14 July 2019 at 07:37 #418754
not done it yet
Participant
@notdoneityet
I doubt the sound of running water,in complete darkness, is particularly restful if one knows that the water level is rising …. and there is no easy exit!
14 July 2019 at 10:18 #418784
Nick Clarke 3
Participant
@nickclarke3
Thanks guys for bringing back two memories –

Peter – Only went caving a couple of times but on mountains, being how shall I put it?? more economy sized or family sized shall we say – I always felt more confident abseiling with the multiple bars of the Rappel Rack to slow me down

and

Duncan – Never personally used an acetylene lamp, but they were used to light up the steaming bays and hut at the old Nottingham SMEE track at Valley Road 50+ years ago for the annual night run. I can stlll remember the distinctive smell!

Nick
14 July 2019 at 11:39 #418814
ChrisB
Participant
@chrisb35596
During my time as a volunteer with the local cliff rescue division we mostly used figure of 8s for rapelling, belaying etc. To recover someone from the bottom of a cliff we would use a Larkin frame and pulley systems combined with ascenders, quite an exertion if the drop was high! If the place was vehicle accessible we would use the capstain on the land rover, much better.

The issues we found with the 8s was they got very hot if you went down fast over a long drop especially if free rapelling, and sometimes this damaged the rope sheat. After training with the Merseyside FRS we were introduced to better equipment and procedures…miss those days!
31 July 2019 at 09:14 #421806
Nigel Graham 2
Participant
@nigelgraham2
In Nick Clarke's post:

Peter – I used a rack for a time but found it awkward because I am short; making passing re-belays more difficult. I recall one particular pitch (Slit Pot in Simpson's Hole) whose take-off was so tight I had to remove my wet-suit jacket to gain about half an inch clearance, then ooze through the squeeze with the rack bars nestling in the valleys between my ribs. Once out, I retrieved the jacket and abseiled down.

Duncan – your club (Nottingham) played a part in introducing me to model-engineering; along with an exhibition by Weymouth & District MES of which I am still a member.

My first attempt at driving a miniature steam locomotive was a lap or two of the Valley Road track when, during a family holiday visiting relatives in my ancestral town, my uncle took me there for an afternoon. He was the Society's Hon. Sec. for many years.

I don't know who owned the loco, but it's remarkable that he was generous enough to entrust it for a solo drive to a complete novice in early teens and whom he'd not previously met! I have been invited to drive other's engines, both rail and road, plenty of times over the years since; but it's not a common practice and I feel it rather a compliment.
31 July 2019 at 09:58 #421821
duncan webster 1
Participant
@duncanwebster1
Posted by Nigel Graham 2 on 31/07/2019 09:14:36:

In Nick Clarke's post:

…….

Duncan – your club (Nottingham) played a part in introducing me to model-engineering; along with an exhibition by Weymouth & District MES of which I am still a member.

………

Must be someone else, I've never even been to Nottingham!
31 July 2019 at 10:45 #421828
SillyOldDuffer
Moderator
@sillyoldduffer
Posted by duncan webster on 05/06/2019 23:47:41:

My acetylene lamp … If it ran out in a dry stretch you had to pee in it, then clip it back on your helmet. … I must say being somewhere in sound of running water but totally dark is a very restful experience.

Thatks Duncan, next time I need a wee I'll draw the curtains and turn the lights out. What could possibly go wrong?

Dave
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