Tunnel Top entrance resin anchored

[andrewmcleod]

The entrance pitches to Tunnel Top have been resin anchored by Caving Wales. The first hang is still from the in situ scaffold bar, and one stainless through-bolt is used for a deviation; otherwise only IC anchors are used. Currently deviation cords are in situ (without carabiners) but this should not be relied on. All in situ ropes have been removed from the entrance pitches. It is no longer possible to exit via the show cave (and hasn't been for most of a decade or more I think?).

Nothing has been done further into the cave (e.g. the free-climbable 15 foot pot still has an old 9mm rope from the late 90s or early 2000s on it I believe as a handline).

If you don't know about Tunnel Cave, there is a survey on the wall in the long common room of SWCC. It's on the way to Pwll Dwfn above Dan-yr-Ogof. Personally I think the entrance pitches would make a relatively pleasant place to teach SRT or rigging (Pwll Dwfn can be a bit much). Beyond the pitches, the cave continues with a lot of traversing at different levels until you reach the concrete wall and PVC door that blocks access to 'Cathedral cave' (a part of the Dan-yr-Ogof show caves but not Dan-yr-Ogof itself). There are other routes in the cave and navigation can be a bit tricky due to the different levels. For example if you don't stay high initially, you end up at a dead end, but if you stay very high then you get turned left at a junction you don't see because the straight-on route only happens lower down (caught me out last time)...

Keys are available from SWCC in the same way as for OFD; there is currently only one guest key available and one SWCC members key. If this becomes a problem I'll try and arrange for more keys to be available.

The rigging topo will be available on the Caving Wales website but is currently available here on the SWCC web site:

Rigging Topos

swcc.org.uk

 

[andrewmcleod]

Incidentally the location of the bolts for the second pitch (i.e. the first bit with a deviation in it) was driven by the rock (or lack thereof). I was originally hoping to do a simple drop off the wall where the remaining rawl bolt is (which you can still use as a traverse anchor if you wish which is why I didn't take it out). However, further examination (and a convenient old drill hole near it) showed that it's entirely in calcite, which was far too thick to put a resin anchor in at that location. Hence putting the bolts further along in a hopefully not _too_ awkward place (the height difference isn't shown very well on the topo; it's actually more than that so you should be well-protected by the previous Y-hang while rigging).

We could have put anchors in for a straight drop without the deviation but it would probably have been more awkward. The rock quality on the left is also generally a bit suspect, consisting of a load of downwards flakes. After putting in the anchors, I nudged a bit of rock on the left wall and a few pieces fell off (which were then sent down the pitches) but this revealed a much larger dubious flake. On the return trip, a crowbar easily pulled a substantial flake off the wall (maybe 50cm by 50cm by 20cm or so?), but I think it's mostly cleaned up now.

As always, take care with loose rock! It's not too bad, but the entrance shaft has a bit of small shrapnel/gravel you can send down if people are silly enough to hang around at the bottom, and lots of fist-sized rocks collect on the first big calcite slope which could do with being gardened a bit (as they will bounce all the way to the bottom if they start rolling).

 

[liltom]

The entrance pitches to Tunnel Top have been resin anchored by Caving Wales. The first hang is still from the in situ scaffold bar, and one stainless through-bolt is used for a deviation; otherwise only IC anchors are used. Currently deviation cords are in situ (without carabiners) but this should not be relied on. All in situ ropes have been removed from the entrance pitches. It is no longer possible to exit via the show cave (and hasn't been for most of a decade or more I think?).

Nothing has been done further into the cave (e.g. the free-climbable 15 foot pot still has an old 9mm rope from the late 90s or early 2000s on it I believe as a handline).

If you don't know about Tunnel Cave, there is a survey on the wall in the long common room of SWCC. It's on the way to Pwll Dwfn above Dan-yr-Ogof. Personally I think the entrance pitches would make a relatively pleasant place to teach SRT or rigging (Pwll Dwfn can be a bit much). Beyond the pitches, the cave continues with a lot of traversing at different levels until you reach the concrete wall and PVC door that blocks access to 'Cathedral cave' (a part of the Dan-yr-Ogof show caves but not Dan-yr-Ogof itself). There are other routes in the cave and navigation can be a bit tricky due to the different levels. For example if you don't stay high initially, you end up at a dead end, but if you stay very high then you get turned left at a junction you don't see because the straight-on route only happens lower down (caught me out last time)...

Keys are available from SWCC in the same way as for OFD; there is currently only one guest key available and one SWCC members key. If this becomes a problem I'll try and arrange for more keys to be available.

The rigging topo will be available on the Caving Wales website but is currently available here on the SWCC web site:

Rigging Topos

swcc.org.uk

View attachment 21651

Thanks for doing this Andy: having done this cave recently, the bolts at the bottom of the shaft weren't in the most ideal position. Just to confirm, has the In-situ rope for the traverse line also been removed?

 

[andrewmcleod]

Yes, the in-situ rope (which was an 'SWCC Official Fixed Aid') on the traverse has also been removed; it should be fairly easy to rig with your own rope (and less scary than wandering across it hoping the anchors at the end are in good nick, and then being disappointed when you get there!).

The last Y-hang is now positioned slightly further left and higher (but still a very easy height to rig) to avoid the messy rope rub from the old anchors.

PS the very last bit at the bottom (marked as an extra 10m) is really unnecessary but it feels rude to pass the perfectly positioned calcited thread in the floor without using it, and I've always had enough rope left over, so I've normally rigged it anyway

Both calcite slopes are more of a steep walk with significant consequences than pitches, and you can (almost) do the traverse bolt-to-bolt if you have a very long extendable cowstails (I can neither confirm nor deny that I did this after I derigged the traverse and then realised I'd forgotten to photograph the anchors on the traverse to get the serial numbers).

PS as with all my topos, the exact levels of floor and ceiling are the products of my deranged rememberings and imaginations rather than taken from an elevation survey or similar. They are certainly not to any sort of scale! There are actually short passages leading off the pitches at various levels e.g. from the end of the traverse and from the bottom of the steeper part of the lower slope.