Anchor testing completed

Anchor testing in Rhiwbach, Bwlch y Plwm, Wrysgan and Fish Caves has now been completed (to be fair Pete finished off Rhiwbach and Bwlch y Plwm over the Summer!)

Anchors within the blue routes were visually inspected, and where appropriate pull tested with a Hydrawjaw test rig up to 6kN for 15sec. To pass the test the anchor needs to hold the load for that period without fluctuating.

All anchors that passed both the visual (i.e. recognisable, no signs of corruption, not deformed, no movement) and pull test will have a green cable tie fixed to them, any that failed (but we’ve not been able to extract) will have a red cable tie. Anchors with no cable ties may not have been tested as it wasn’t possible to fit the test rig over the anchor.

Rigging plans with all the tested anchors are available here, with the exception of Wrysgan which just needs double checking, all will be added to the Mine Inspection Reports folders available through Google Docs.

Several anchors failed during the tests (see video).

In several cases old 12mm SPIT type anchors (found in Wrysgan) pulled at relatively low loads. These all showed signs of corrosion. There are several Petzl long-life (see photo) anchors in Bwlch y Plwm that were not tested, if using these you do so at your own risk. Any expansion anchor to be tested really needs to have the anchor plate removed and the pull device attached directly to the anchoring component. This isn’t possible with the Petzl long-lifes. Petzl Longlife

Notably several anchors in Fish Caves failed, and frustratingly it was not possible to remove them. The failure mechanism looks to have been a resin/rock bond failure which suggests the holes were more cleaned throughly before placing the resin. The failed anchors are all on the second pitch in Fish Caves and so requires a slightly different approach to rigging (see rigging diagram). I’m afraid this is going to persecute the short!

Fish Caves is rigged predominantly with DMM anchors. These flex when the tested so it’s not unusual to see the resin around the head of the anchor crack (see the image of a passed anchor below). Do not be alarmed by this if using these anchors. However as will all anchors ultimately the user must make a decision if they feel it’s safe to use. Before each use check;

  • Do you recognise the anchor (i.e. is it PPE, manufactured by a reputable company)
  • Check for signs of corrosion
  • Is the anchor set properly (i.e. nor proud of the rock)
  • Check the anchor isn’t deformed or have any sharp edges (especially if tying in direct)
  • Does the rock around the anchor look sound?
  • Does the anchor move if twisted by hand

Please report any defective anchors through the mines inspections email account, through facebook or direct here:

Users meeting & Wrysgan

Thank you to all who’ve contributed to the poll looking at peoples availability for a users meeting. If you’ve not done so feel free to let us know: CLICK HERE TO FILL OUT THE POLL

We’ll look to fix a date this Monday.

Anyone looking to use floor 6 of Wrysgan should have a discussion with whoever you’re working for as there has been some changes noted within the mine.

Gethin

Inspection (Wrysgan and Geironydd) update, March 2017

Inspections are going well. Today we looked at Wrysgan and the Geironydd trials.
There was very little of concern in both, however our mine engineer has suggested we monitor the brow of the adit that leads outside on floor 5 of the mine (the wet way out) as there looked to be some blocks that look like they may fall at some point, although there’s no evidence of a fall on the floor. This is the exit directly next to the eased block that fell several years ago (photo attached) directly above the solid ladder, and potentially somewhere groups may gather having scrambled up the ladder.
Also within Geironydd the frequently used trial (opposite the waterfall that drops into a short adit) had several bats in the back of the stope. There is a circular route that follows the back of the stope around several timbers and drops down via a short slide/slab. It may be prudent to avoid that section of mine in the Winter as the bats are hibernating.

Floor 5, wet exit

Wrysgan Rock fall

Sounds like there’s been a small (but worth taking note of!) rock-fall above the traverse on floor 3 of the mine:

Hi Gethin,

Picture attached of a recent rock fall in Wrysgan. Abseil stance at the end of the L3 traverse, after the island!

Obvious missing bits from the roof but I couldn’t see anything hanging….waiting to drop!!

Couple of pieces managed to make it down to L2 at the bottom of the pitch!!

Regards

Jim.image002.jpg

Wrysgan bolting/cable

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

Wrysgan & Rhiwbach update

Quick heads up that there’s been some reports of further (small) rock fall on floor 2 of Wrysgan. This is the same area we’ve been monitoring. If anyone has more info could you let us know?

Also the raft in Rhiwbach has been damaged, as has the traverse rope around the flooded pool on floor 1. The fray in the ropes been isolated and raft possibly fixed. Again if you’ve more info please let us know.

Cheers

Gethin