Safe way to remove chock stones/rubble from a narrow rift?

[Smithers]

Hi all,

At one of our digging sites we've established a vocal connection between two sets of passage, one directly above the other.  In the upper passage there is a pit which has a false floor of rubble and chock stones, but due to the width of the pit we cannot bed down to remove this rubble without doing a lot of extra capping.  However, in the passage below we can look directly up at the bottom of the pit from the underside and see the rubble and debris which is preventing a visual connection.

Removing the rubble from the underside is preferable, as it is an easier location to get to and won't require so many return trips to the other passage to make the connection.  However, trying to provoke this material to come crashing down on my head isn't such a great idea.

Does anyone have any suggestions for how we could tackle this?  I was thinking it might be possible to use a scaffold bar to try and knock the rubble down, but this still means that we're pretty close to where things would be falling.  Alternatively, would placing snappers in amongst the wedged debris and setting them off be likely to cause the material to become dislodged?

Any other ideas would be welcome.

Regards,

Smithers

 

[SamT]

gingerly tie a rope round crucial chockstone, retreat and pull rope.

tie a rope to end of crowbar. place crow bar in suitable 'neutral' position, retreat and pull to 'activate' crowbar.

snappers need to be contained really to get any useful 'power' out of them. they tend to just 'fizz' if not contained in a shot hole.

scaff the hole void out and work on the choke up close.

 

[Paz Vale]

Scaffold bar with one end fixed to pneumatic car jack.  Extend pump handle with scaff to suit.  Keep pumping jack till the whole lot comes crashing down.

A video demonstration of this technique to clear a mineshaft from beneath was  shown by Buster at Hidden Earth some years back.

 

[Maisie Syntax]

Safest way is to contact the eldon and see if they'll lend you the Pembertons.

 

[Smithers]

I'm probably showing my ignorance here, but who or what are the Pembertons?

 

[SamT]

in the words of Jeremy Clarkson -  "Some say that they can move boulders merely by glancing at them, others, that their fingernails are harder than a hilti drill bit....all we know, is they are The Pembertons"

 

[Pitlamp]

I'll PM you.

 

[Roger W]

This thread might help....

http://ukcaving.com/board/index.php/topic,8440.0.html

 

[Maisie Syntax]

All joking apart (eh?) in answer to your original post, Paz's method of poke and run is tried and tested as well as fun.

 

[Smithers]

So would either of the Pemberton's be willing to come to our dig and roundhouse the chock-stone out of the way (from on top or underneath - it doesn't matter)?

 

[andychapm]

Where's the dig then?

 

[Smithers]

Ah well, that's the million dollar question.  It's going to be announced via MMMMC in the next couple of days (the trip report is still being written) and then it will probably be made public knowledge after the connection has been made.

What I can say now, is that it will create a dry connection between two caves, bypassing a miserable wet crawl.  I can't really say much more than that right now.

 

[Pie Muncher]

I can have a length of Aluminium Scaffold bar, light weight and excellent for upward proddling, deposited at a certain caving emporium if you want to give it a go.

 

[Maisie Syntax]

I'd have thought that if it's owt to do with MMMMC then they wouldn't have needed to ask how to shift the problem in the first place?
I take it that a certain (former?) member of MMMMC has not been and pirated it already?

 

[DAN]

Snappers wont do anything. You need somthing with a bit more power. Earth leakage was a bit like that up hill digging through a boulder choke not nice!