Author: nwmines

Radon Monitors

Radon Monitors

nwmines

Radon monitors have arrived and will be placed over the next few days. Please do get in touch if you’re around and fancy getting out of the sun for a few hours to place them!

Monitors are to be placed in designated sites, below is a list of whats going where. They will be in place for 4 weeks then sent off for analysis. Once they’re back the reports will be added to the mine inspection reports folders online.

If you spot any of the monitors when underground over the next few weeks please do not fiddle with them. They are sealed in plastic bags and should not be opened or moved. May be worth briefing your groups…

Gethin

Radon Tests Sites for North Wales Mines

  • Rhiwbach slate mine (6 test kits)
    1. Ventilation door/Head of incline (Floor H, Head of incline)
    2. Tyrolean start (floor I, Ch3East)
    3. Large Chamber on first floor (Floor H, Ch2East)
    4. Museum on first floor (Floor H, Ch8West)
    5. Museum on floor 4 (Floor G, Ch8West)
    6. Base of waterfall climb (Floor F, Ch1East)
  • Wrysgan (2 tet kits)
  1. Pitch head/Air Shaft between floors 1 & 2
  2. Top of roped climb (Floor 2)

  • Fish Caves (2 test kits)
    1. Head of main pitch
    2. Far end of floor 1 workings
  • Bwlch y Plwm (3 test kits)
    1. Bridge
    2. Crossroads on floor 1
    3. Far end of floor 1, 5th adit West
  • Cwmorthin (5 test kits)
    1. G Floor Chamber Z38
    2. Caban 1934, Floor DE, Ch34
    3. Compressor Chamber, Floor DE
    4. Stripey Vein, far chamber
    5. Top of freefall pitch
  • Cwmorthin Floor 4 (1 test kit)
    1. Wire ladder junction
  • Gaewern (2 test kits)
    1. Top of fixed ladder climb
    2. Top of “hole in floor” pitch

 

Useful images from previous inspections

nwmines

Here’s a few images/warnings issued over the years that still stand for some sites. These images have dropped down to the bottom of the news feed on the site so I thought I’d add them again and stick them to the top of the updates feed.

Rhiwbach Brow

Here’s a photo of the brow taken after the cracks were originally painted, this image can be used to compare any changes


Rhiwbach Entrance Adit

Picture of the entrance which has seen some vegetation’s slippage over the Winter of 2015-16

Rhiwbach Top Entrance

Photo following clearing some loose rock at the exit of the mine

22 MineReports2013 Rhiwbach Top Exit Picture

Wrysgan Slab

Route passed the fallen (eased) block between floors 4 & 5 in Wrysgan

WrysganSlab2013

Wrysgan Roof

Section of roof which pealed away in 2014. Photo can be used to compare changes

WrysganRockFall 2014

Rhiwbach Anchor Testing Report

Rhiwbach Anchor Testing Report

nwmines

On the 18th of March 2016 the majority of the anchors in Rhiwbach mine were inspected and tested. This work was requested and funded by Go Below Underground Adventures Ltd who engaged Pete Knight to undertake the testing.

The anchors were tested to 6kN for 15 seconds using a Hilti HAT-28 anchor tester with a current calibration certificate. All anchors that passed (showed no movement, deformation or rock failure) were marked with a green cable tie. Anchors that were deemed to have failed (moved, deformed or detached from the rock) and could not be removed from the mine were marked with several red cable ties. No failed anchors remain attached to fixed rigging. Unmarked anchors were installed after the 18th March and remain untested.

There are no plans to retest any anchors on a regular basis as it is a concern that the resin bond may be damaged by regular high load testing. No Petzl P38 Longlife anchors were tested in Rhiwbach.

Tyrolean Area

All anchors were tested in this area. One Petzl Collinox anchor was removed from the wall under the test load. It detached with a section of slate that showed a hidden area of quartz weakness. This anchor was not replaced as it was immediately adjacent to another which passed the test.

Pool Traverse in next chamber

The final anchor in the chain appeared to have been hammered into the rock to prevent use. It could not be tested or removed but was tagged as a failure. All remaining anchors passed.

Climb and Traverse to Abseils

All anchors passed.

Waterfall Climb

The lowest of the Collinox anchors had a small amount of spalling under test. It was tested to 10kN as a precaution and passed. This anchor should be checked regularly by users to identify any further rock degradation.

Airshaft

3 Collinox anchors failed in this section of the mine. One was removed completely but the other 2 are awaiting removal/destruction but have been tagged as failures and removed from the rigging.
1 Collinox was removed from the rock along with its resin. The hole appeared to have not been cleaned prior to installation. A second Collinox was removed because the section of rock it was in split apart. The third anchor was another Collinox, which began extracting with its resin. Replacement anchors have been installed already but will not have been tested.

Summary

The testing does not diminish or remove the important requirement for all users to inspect the anchor and overall safety system on each and every use. The nature of the rock and the type of use these anchors receive may mean that an anchor can become suspect or even fail in the future. This can happen without warning and cannot be predicted by this testing. All fixed rigging attached to the tested anchors remains the responsibility of the installing organisation and all users are reminded to inspect for safety prior to each and every use.

Peter Knight 3/5/2016

Rhiwbach

nwmines

There is a loose rock high on the right side wall of the rising traverse climb chamber on floor 1 in Rhiwbach.

(as you are looking at the climb towards the window, look high and right half way along the chamber wall to your right)

I have raised a maintenance ticket to have it removed. However, it is very high on the wall, and whilst not very big, will be difficult to remove safely.

I will send another mail out when the work is complete.

Thank you.

Chris Phillips
Operations Manager
Go Below Underground Adventures Ltd.

Inspections for 2016 (important update)

Inspections for 2016 (important update)

nwmines

This years round of inspections is nearing its end, having had some very long days out!! Thanks to all who’ve come out to help out and share your thoughts, and particularly Les for managing such a busy schedule!

There has been some changes which anyone visiting either Rhiwbach or Cwmorthin must ensure they are familiar with, more details have been forwarded to the registered email addresses of those who’ve bought into last years reports. 

The full inspection reports will be made available to those buying into the scheme as soon as they’re ready.

Gethin

Morris
Damp pitch
New venue…
Formations in ByP
Tell tale
Corris
Wrysgan floor 1 (no go)
New venue…
Tell tail
Damp pitch in ByP

Wrysgan bolting/cable

nwmines

Information for users of Wrysgan mine.

On Monday the 1st Feb myself Jim and Andy paid a visit to do some stabilisation work on the alternative route between floor 1 and 2. There was a rough route up almost immediately inside the first chamber on floor 1. Half way up this rubble slope there was a large step with a very dodgy pack wall. We reduced this to a slope and spent some time stabilising the path and moving it closer to the chamber wall. Being close to the wall, the slope should hold up to downhill traffic better than the original route. It will require some traffic to bed it down so take a little care for the time being.

On Monday the 8th Feb a visit was made by me to the mine to place some new anchors and remove the old cable on floor 3.
2 new Collinox resin anchors were placed on the rising traverse from floor 1 to 2, one near the floor and one near the top. These 2 Collinox bolts split 2 of the longer sections of the traverse and make it slightly less exposed rigging uphill and reduce potential slide distances for clients. To make use of these, pack an extra couple of karabiners or maillons and allow a metre or so of extra rope. All the Goujons in the area were checked and tightened where required.
Up on floor 3, near the dressing sheds entrance, a new Collinox anchor was placed close to an existing one to create a compact and high anchor pair for rigging abseils and lowers. It should also be possible to use the 2 bolts as pull through anchors.

Some of the older, more corroded anchors were cut out in these areas to try to de-clutter the mine. There remains a number of Petzl stainless steel plate hangers attached to regular steel spit sleeves with very corroded bolt heads. These anchors should probably not be trusted and there are nearby resin anchors to use in preference in most cases anyway. It is always best to keep steel or alloy types consistent in sleeve, bolt and hanger anchors in fixed rigging to prevent accelerated corrosion.

The cable on floor 3 was also removed during this piece of work, it now being redundant as the traverse can be rigged bolt to bolt at a higher level.

Any feedback is welcome on the new rigging or guides.

Pete

New anchors in Rhiwbach

nwmines

 

Following the discussions on Friday, I placed 2 new anchors in Rhiwbach today. One midway along the traverse on floor 1 around the deep pool, so if you feel the fixed traverse rope is too slack for your group you could clip a krab to the anchor and raise it.
Another anchor has been placed on the left (as you’re looking up) of the waterfall climb not far above the initial steep section, so you can create a belay (using one of the anchors midway up the manway as well) in the middle (or wherever you choose) of the climb, if you choose to belay groups up the short steep section.
Gethin

North Wales Mines Users meeting summary

nwmines

Thank you to everyone who came along to the meeting on Friday, it was really valuable to get such a broad range of opinions chatting about the use of the mines in such a positive way.

I’ve sent out a summary of the action points to the mine reports group. If you want a copy get in touch and I’ll send a copy out (I don’t want to publish it online as it lists all attending and has a few email addresses in it)

Gethin