Ian A
  • Ian A
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9 years ago
Hi,

There was a trip through CRTT on Saturday last and the visiting club have reported a problem which is going to become an issue. Here is the report (copied & pasted);


Hi Ian,

I was one of the party that you met on Saturday afternoon, in Rhosydd mine. We experienced a problem on the first Tyrolean that we need to make others aware of. Hopefully you're well connected with local miner explorers and will therefore be able to pass this on to those who need to know.

When we arrived at the side of the 1st lake we tried to retrieve the fixed pulley, using the return cord. However, about 40% of the way across there was a 30cm strand of cable pointing directly upward. This completely prevented the pulley from returning. Luckily one of the two fixed cheek pulleys we were carrying, was wide enough to fit over this wider gauge wire. We also had a roll of blue insulation tape with us. I went out to the blockage and used tape at 10cm intervals to tie the strand down to the main wire. When I say strand, it was actually more like 4mm in diameter. Whilst the end was taped down, it was possible for the fixed pulley to travel carefully in both directions, across the breakage. We obviously weighted the pulley so that it return more smoothly.

We were lucky that we had a suitable pulley and had some tape. Otherwise we would have had to abort the through trip and prusik back up the pitches. Obviously the insulation tape is a very temporary fix and will not last for many more crossings.

I'm not sure who we should tell about this, but we need to make some effort to inform those involved in managing the fixed aids, so as to minimise the impact on the next explorers.

A door, once opened, may be stepped through in either direction.
Wormster
9 years ago
Saw this on UKC and was going to cross post, but you beat me to it!!

Better to regret something you have done - than to regret something you have not done.
Morrisey
9 years ago
Just to confirm that the Zip line is on it's way out. As stated one of the wire braids on the cable has rusted through, i taped it down again but tbh the cables days are numbered.

Best way over at the moment is to use a steel carabiner and drag yourself across - soon be time to get the dinghy out early.:)
tegwin
  • tegwin
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9 years ago
Worth noting that the suspended ladder bridge after the first zipline is also in poor condition. One of the bolts for the suspension wire has popped out and another is loose! Keep meaning to go through with a bolting drill and replace it but not had time 😞
Llion
  • Llion
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9 years ago
"tegwin" wrote:

Worth noting that the suspended ladder bridge after the first zipline is also in poor condition. One of the bolts for the suspension wire has popped out and another is loose! Keep meaning to go through with a bolting drill and replace it but not had time :(



Is this where you get on or off the bridge ?? A few of us dragged it out of the water years ago and rebolted it on the wall, the side you get on.
🅱Me... Back n Boogying ag wrth n modd
tegwin
  • tegwin
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9 years ago
The side you get on... The side furthest from you has lost a bolt and the other is on its way out!

The stringers from the wire to the ladder have snapped in places causing an uneven loading which probably hasn't helped.... I suspect when the other bolt Pops out the entire thing will collapse as the cable isn't held amazingly well on the other side 😮
owd git
9 years ago
Just an open question, what length / Dia' steel cable is needed for replacement? O.G.
Pete K
  • Pete K
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9 years ago
I'm yet to actually do the CRTT myself but have experience bolting in slate and all the equipment to install and test resin bolts. I'm not volunteering to pay for all the anchors but if there was a collaboration / whip round to cover the cost of resin and anchors then I'd be prepared to do the work. I can get supplies at trade prices.
I'd not bother with any more expansion anchors, personal experience has shown a 50% failure rate in slate when proof tested to approx 600kg. A zip wire / tyrolean can easily generate 500kg in normal use.
Not seen the sun for months. Now evolving to see in the dark.
owd git
9 years ago
"owd git" wrote:

Just an open question, what length / Dia' steel cable is needed for replacement? O.G.


Bump;
I have a turfer cable / no charge!
will measure the length.
O.G.
Moorebooks
9 years ago
"Pete K" wrote:

I'm yet to actually do the CRTT myself but have experience bolting in slate and all the equipment to install and test resin bolts. I'm not volunteering to pay for all the anchors but if there was a collaboration / whip round to cover the cost of resin and anchors then I'd be prepared to do the work. I can get supplies at trade prices.
I'd not bother with any more expansion anchors, personal experience has shown a 50% failure rate in slate when proof tested to approx 600kg. A zip wire / tyrolean can easily generate 500kg in normal use.



Isn't this where a grant from Cambrian Caving Council could be sought. There's an excellent article and photos of the through trip in the latest Descent

Mike
dtyson
  • dtyson
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9 years ago
"Moorebooks" wrote:



Isn't this where a grant from Cambrian Caving Council could be sought. There's an excellent article and photos of the through trip in the latest Descent

Mike


The council can and does fund equipment installation. We funded the new chain ladders in Darren Cilau last year which were a significant cost. We do have a limited amount of money available and try to recover the cost from the BCA or Sport Wales (which we get a grant for training and safety), otherwise our reserves would dwindle quite rapidly.

I think the major concern with the Croesor-Rhosydd rigging is that it is used by a lot of people who are relatively inexperienced and some have a 'devil may care attitude'. The fixed aids have been installed by many different people over a long period of time and so there is no central 'authority' to report problems. This is partly because no-one in their right mind would want to take on the liability - I am amazed that there hasn't been a serious accident or drowning yet.

If a group wanted to replace the zip line or re-bolt other fixed lines then the CCC committee would be happy to look at a costed proposal for funding. We would want to try to recover the money off the BCA or SW so we don't have to dip into our reserves.

We may need to talk to Nick Williams about liability issues.

Dave

CCC Secretary

darkside
9 years ago
Its been 4 years since I did the CRTT and I have to say someone has done a lot of work in there, new looking rope and some good rigging. It has tamed the trip down considerable compared with before which is I guess why it is being abused as it is so easy to do. We took a boat and 2 ropes 1 to sacrifice if needed but didnt use any of it. What we did not have was a new zip wire cable to take in but we did retape the old one so the trolley would run. How about everyone from the mine explorer forum who has ever done this trip for free and used other peoples rigging all give a £5 towards a new wire?
Pete Monkhouse
9 years ago
We went through on Saturday - replacement wire needs to be approx 30m. Looking at some prices it's not too bad :

We thank you for your valued enquiry and offer as follows:
1 off 14mm dia. 6x36 IWRC RHOrd galv. x 30mt. long, fused and tapered one end, thimble eye other end
MBL 13.97t Price: £76.50 + V.A.T.
1 off As above but in AISI316 s/steel, thimble by copper ferrule MBL 11.11t Price: £211.50 + V.A.T.
Availability – currently 2 to 3 working days from receipt of order.

I'd be happy to chuck some money in for this. Any thoughts, galvanised or stainless?
BertyBasset
9 years ago
Are the bendy rails of doom and the nail encrusted beam of death still there? I presume zipwire bypasses these? There wasn't any point lining up on these as you were probably better just falling into the water rather than falling into the water roped around a nail encrusted beam. Mind, one of our party who was carrying the dinghy did fall through a rotten bridge into the water, rather inconveniently leaving the dinghy intact on the bridge above as well as knocking his lamp switch off on the way down.
Pete Monkhouse
9 years ago
The bendy rail of doom seems to have descended to the bottom of the sea. What's left is a bit of aluminium ladder resting on about 30 feet of rotten, half on it's side beam. It's an interesting balancing task....

The zipwire is earlier on - after the two pitches, before the suspension bridge. Currently it's not very zippy, more two half-zips with strenuous gymnastics in the middle.

The canoe in the final lake is the most splendid thing I've seen underground. Huge respect to the taker-in of that!
nickwilliams
9 years ago
How much flexing does the zip wire get? It may be that a galvanised cable will actually last longer since s/s (especially 316) may work harden and snap. (It's not that the whole rope will break - individual strands will fail first - but by the time that starts happening, the rope needs to be replaced.)

It's very difficult to predict whether this will be a problem or not. The main thing is that it will need regular inspection no matter what is used.

The over-riding consideration will be ensuring that there is a system of bomb proof anchors to which a replacement rope can easily be attached.
Willy Eckerslyke
9 years ago
Was the canoe retrieval system working smoothly? There had been rather a tangle of rope making its progress a little uncertain.
"The true crimefighter always carries everything he needs in his utility belt, Robin"
Pete Monkhouse
9 years ago
I think the canoe retrevial may need a bit of new rope soon, and the blue ployprop probably isn't ideal. I think what's needed is some 6mm cord which won't twist up so much. the other issue is that the top pulley on the Croesor side wants replacing - the rope runs between the sheeve and the fork holding the sheeve and frays. I think the polyprop will probably break soon....

Rather agree that galvanised may be the better bet for the zipwire, and much cheaper!
NouveauRiche
9 years ago
Although obviously quite new to this since Nov 2015, and don't really know anyone outside the Thursday nighters... but, could I make a suggestion - it definitely looks like a through trip I would love to do if the youtube videos are anything to go by:

My suggestion would be to set up a GoFundMe page for the project of replacing whatever needs replacing to make this a tough, but safe and enjoyable trip and help prevent what I've heard from most as an inevitable nasty accident or drowning. The stipulations would be that anyone who has used, is using or will use this equipment in the future needs to provide some money. Even if we have 30 people who give something like £15 pounds each - that's an immense £450 which may be able to cover the cost of most of the materials and perhaps some costs for time for Mile's two Pete's to do some of the bolting or other jobs seeing as they have the tools?

Just a suggestion - please don't get the :guns: out!
"Who dares nothing, need hope for nothing." - Johann Friedrich Von Schiller
owd git
9 years ago
"owd git" wrote:

"owd git" wrote:

Just an open question, what length / Dia' steel cable is needed for replacement? O.G.


Bump;
I have a turfer cable / no charge!
will measure the length.
O.G.


another bump. :thumbup:

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