UK Caving

TECHNICAL FORUMS => Digging => Topic started by: The Old Ruminator on October 08, 2019, 08:14:06 pm

Title: Almost a Capping Calamity
Post by: The Old Ruminator on October 08, 2019, 08:14:06 pm
Some cavers were capping a dig and had a hosepipe 5 to 10m away. The hosepipe stopped working so they went to have a look. They cut this bit out. Yes. It is a cap. It had fired out of the hole passing the rod and mat and somehow missing the diggers. A friend had similar. Went to hospital and the X ray showed the cap embedded in his finger bone.

(https://live.staticflickr.com/65535/48866652526_c45b276b94_z.jpg) (https://flic.kr/p/2hsbniQ)PA080014 (https://flic.kr/p/2hsbniQ) by Nicholas Chipchase (https://www.flickr.com/photos/96466079@N05/), on Flickr
Title: Re: Almost a Capping Calamity
Post by: Wolfo on October 08, 2019, 08:16:59 pm
Unfitting mat, bad procedure.
Title: Re: Almost a Capping Calamity
Post by: Cap'n Chris on October 08, 2019, 08:32:31 pm
Unwise technique, bad idea. Shall consider the post a report of a near miss, as BCA request those routinely.
Title: Re: Almost a Capping Calamity
Post by: Fishes on October 08, 2019, 09:16:27 pm
Its a widely technique used by many including me but anyone who thinks it is safe is ready to have an accident. You can reduce risks by taking appropriate precautions but the reduce rather than eliminate the risk.
Title: Re: Almost a Capping Calamity
Post by: thomasr on October 08, 2019, 09:23:27 pm
I think some of the comments a little unfair Not knowing the full facts . Thank you for sharing this with us and hope you are not put off  [from posting ]
Title: Re: Almost a Capping Calamity
Post by: SamT on October 08, 2019, 09:35:53 pm
It had fired out of the hole passing the rod and mat and somehow missing the diggers.

Is it more likely that as the rock fractured, it passed through the new 'crack' in the rock thence onwards to its final destination.  Perhaps in a more sideways direction.

I had a friend who ended up in hospital the day after a digging session with sore ribs and a strange red lump.   Xray showed that a small fragment of brass was wedged between his ribs.  Very very lucky it didn't pass between and puncture his lung!

All things are dangerous, and all things in life come with a certain level of risk.  Use best practice to reduce the risk as much as possible.
Title: Re: Almost a Capping Calamity
Post by: The Old Ruminator on October 08, 2019, 11:00:39 pm
No names of course but for once I was not even there.
Apparently, the procedures followed were the usual ones. Good fitting mat etc. If any clever clogs knows a safer way please advise.
Title: Re: Almost a Capping Calamity
Post by: Leclused on October 09, 2019, 08:06:31 am
If any clever clogs knows a safer way please advise.

Safer = remote capping/blasting via the straw method.

We use both methods but we prefer the straw method (95% of the time). Only in some rare occasions we switch to capping with a rod. However, we also know friends who prefer rod capping :-)

This said, the straw method has other "problems" with the air. So it is a trade off that you have to make for yourself

Title: Re: Almost a Capping Calamity
Post by: mrodoc on October 09, 2019, 09:10:43 am
I have now done some capping and see one of the issues as having the ability to  adequately cover the area to be capped . Draping a mat over the top of the rock being capped certainly reduces the likelihood of material flying out vertically but unless the material is folded adequately around the area being capped then problems can occur. I tend to fold the mat over the rock carefully and pin it down if possible. I also lean to the side or away when driving the slide hammer.  A tougher but foldable mat would help or one thing that occurred to me was to attach small weights such as fishing weights around the edges to keep a stiff folded mat in place. For the afore mentioned reasons  I have avoided capping up against a roof or horizontally against a wall unless someobody can come up with a way of pinning the mat against such a surface.
Title: Re: Almost a Capping Calamity
Post by: christopher on October 09, 2019, 09:56:05 am
Quote
Is it more likely that as the rock fractured, it passed through the new 'crack' in the rock thence onwards to its final destination.  Perhaps in a more sideways direction.

I'm in agreement and  thinking that this must have been the case, if you have an  8mm hole, 8mm rod and a good fitting mat etc etc

Well, What ever happened it's a sobering reminder not to get  complacent whilst capping , 
Title: Re: Almost a Capping Calamity
Post by: rhychydwr1 on October 09, 2019, 10:24:31 am
snip
 If any clever clogs knows a safer way please advise.

Call in Dr Nobel with a long length of wire.
Title: Re: Almost a Capping Calamity
Post by: SamT on October 09, 2019, 12:12:13 pm
I'm sure OR is aware of this technique Rhychydwr
Title: Re: Almost a Capping Calamity
Post by: Maj on October 09, 2019, 12:16:00 pm
Is this the right place for this discussion.   :-\

Bear in mind this is a public forum.   
 

Maj.
Title: Re: Almost a Capping Calamity
Post by: Alex on October 09, 2019, 12:56:54 pm
Quote
Is this the right place for this discussion.   :-\

Bear in mind this is a public forum.   
 

Maj.

Why we are merely talking about loose fitting head gear, that can sometimes fall off at alarming speed. But in all seriousness I don't think capping needs any licences so why not speak about it?

As for getting complacent, this can happen any time even when not doffing ones cap. I genuinely had/have a hole on my head from a flying spanner a few weeks back which still has not fully healed. I bled quite a lot. All that was involved was a rock or two, an elastic cord and a 13mm spanner. I have renamed Magnotometer the "Cave of the flying spanners" I hope you guys are okay with that new name :)
Title: Re: Almost a Capping Calamity
Post by: Rob on October 09, 2019, 01:30:02 pm
...If any clever clogs knows a safer way please advise.
I tend to have a small metal plate (with an 8mm clearance hole through the middle) which sits between the rock and the mat, which the rod goes through. This avoids fragments shooting up and out of the hole, and also protects the hole in the mat to make it last longer.

However i agree that whole cap did not fly up the hole whilst the rod was in there.
Title: Re: Almost a Capping Calamity
Post by: The Old Ruminator on October 09, 2019, 01:57:14 pm
Possibly an unwise post from the start. Perhaps the mods should consider removing it.
Title: Re: Almost a Capping Calamity
Post by: SamT on October 09, 2019, 05:16:44 pm

The mods are having a chat.  Its been discussed before but perhaps a specific policy on subject matter may be put in place.

For now, I'll lock the thread.  OR posted the photo as a quick sobering reminder of the risks involved in exploratory caving, to which its served its porpoise.