A Summer Storm – 27/7/13

On the 27th July 2013 a storm hit the UK, falling on dry ground and empty watercourses the rainfall soon entered the cave systems of the Peak District. My wife and I took the opportunity to visit Bagshawe Cavern in flood condition.

WARNING – Never enter a cave in flood or at risk of flood without proper experience and training, even then think twice! Both myself and Beth have visited Bagshawe dozens of times and know it intimately.

Over the previous 30 days up until the 27th July the Castleton area had only received 26mm of rainfall according to the Peak District Caving Info website.
Rivers were very low and underground, the streamways and sumps of the Peak District were in a typical very low summer state.
The ground conditions were dry, not parched as there had been 11mm of rainfall on the 23/7/13. Observations after this rain showed no change in surface or underground streamways.

At 20h00 on the 27th July 2013 a storm from the South began to pass over the Peak District. Approximately 80mm of rainfall fell in the area over the next 12 hours. This caused localised flooding, swollen rivers and streams and, as expected, flood conditions underground.

We made a visit to Bagshawe Cavern at 15h00 on the 28th July, 19 hours after first rainfall.

Normally dry Upper Passage:OLYMPUS DIGITAL CAMERA

The head of the 8m deep Dungeon Pitch: OLYMPUS DIGITAL CAMERA

The Dungeon Pitch completely submerged: OLYMPUS DIGITAL CAMERA

For more photos see here: http://www.flickr.com/photos/peakinstruction/sets/72157634832233688/

For a non-flood view of the Dungeon Pitch see here: http://www.flickr.com/photos/peakinstruction/sets/72157634832233688/

We made our way upstream to the area just before the 1st crawl up and over rocks on the left. We could have got through but it would have been a swim. The stream level varied from calves to knee deep.

You could visit the initial main sections of the system today without risk of flooding, from the entrance to the base of the steps by the Dungeon Pitch. Although more drippy than usual, the puddles in the miner’s level hadn’t filled back up to normal high levels and were surprisingly still low.

Across the hill, Peak Cavern’s resurgence had gone from the lowest level for some time to full-on flood level discharge in 12 hours. This speed and volume was interesting as the system normally shows more of a delay in response during Summer. Something to consider there for all leaders in the system.

New Bolts at Pindale Farm

Recently I have been spending a lot of time swinging about on the surface, either through testing knots or coaching SRT skills. For all of this I’ve been using the excellent tower facility up at Pindale Farm near Castleton.
The SRT platform offers scaffolding bar belays and back-ups and the surrounding walls of the old mining buildings are equipped with many 8mm anchor sleeves (Spits) and a few alloy Troll hangers. You can rig just about any permutation of SRT pitch your brain could possibly come up with.
Using the tower over the past few years I’d noticed the deterioration in some of the anchors and as I was such a frequent user I thought some of the replacement anchors should be paid for out of my pocket.

Yesterday (19th March 2013) I managed to procure both equipment and assistance.
Jez Parr CIC (contact) was kind enough to loan me his SDS drill and all the bits for the job.
Nigel Ball CIC (Website) donated half of the anchors and 90% of the expertise in the operation.

We placed 4 new Petzl P38 Longlife anchors on the main wall of the facility; a line of 3 forming a traverse and pitch head which then drops to a rebelay or deviation on the 4th anchor.
We also lubricated and cleaned out all of the 8mm sleeves with a threaded tap to give them a new lease of life.

The tower is now a mix of anchors and can be used with or without hanger plates. Please bare in mind that the tower is equipped by volunteers/individuals and is on private land so booking is essential. Users are reminded to check the anchors they use are safe before commiting their life to them as they would underground and that anchors should never be used alone but as part of a safety chain.

Pindale Farm is an excellent place to stay in the Peak for caving or any other reason. They have camping and bunkhouses on their site as well as the excellent SRT tower.
http://www.pindalefarm.co.uk/.

One of the best and most important aspects of camping is how it helps you build and strengthen relationships. When you go camping with friends or family, you get a chance to talk and visit without distraction, even late into the night. Physical fitness: Time spent camping is physical time. To better better be prepared against animals and snakes you may run in to the way, visit campingfunzone.com for their vast information about camping, insects and animals.

New bolts circled:Pindale Tower

2nd round of testing on the Bowline-on-the-Bight knot

Thinking that 2 heads were better than one I set out today with a good friend and colleague, Jez Parr. Jez in another CIC holder with many years of experience. He was also my mentor through the CIC scheme and the ideal person to bounce ideas off.

Our first stop was local gear shop and purveyor of lovely shiny things, Hitch N Hike. We purchased 5 metre lengths of all the most commonly used semi-static rope they had, in both 9 & 10mm. The test this time was set up identically to the ones done previously on the 8th Jan. We had a mock Y-hang arrangement that allowed us to position the test ropes at varying heights and angles as well as a solid bar from which to rig a secure dynamic safety back-up for ourselves.
The aim of the first testing done previously was to identify the main contributing factors that caused the failure in the Bowline-on-the-Bight, or BotB. This was achieved and we could generate failures almost 100% of the time. This test is written up in the last blog post.
Today’s testing was all about trying to get a failure in a normal use environment with normal conditions. All the tests we did were on knots that has been tied, dressed and set as we would and have done thousands of times underground. We were not wanting to tie sloppy knots, we wanted to see if it would fail when it was done well.

Results:

For every test of every rope in every combination of orientations we tried, so long as the cowstail was attached through both loops of the knot there were no failures. This was as expected and ties in with the best practice advice that has been taught for years with the use of the BotB – ALWAYS CLIP BOTH LOOPS.

For tests carried out where we dropped onto a single loop – the one formed from the traverse line or stopper knot, we could also generate no failures. However this is outside the intended use of the knot so little time was spent investigating that scenario.

When connected to the Bowline-on-the-Bight with a cowstail attached to the single loop formed by the pitch rope we were able to generate failures in knots that were tied and dressed correctly that had been hand tightened or on occasion body weight tightened.

Below are a pair of images showing slip through the knot. Note the blue mark.
BotB test 3

BotB test 4

A second set of test images:

BotB test 1OLYMPUS DIGITAL CAMERA

For the previous test film see here:

Conclusions:

The Bowline-on-the-Bight can fail when you are clipped into a single loop and the knot is dressed correctly and tightened. The failures we generated included ones where we both agreed that we had tied a perfectly acceptable BotB before testing.
Although we can identify many modes in which we could not get a failure to occur, the fact that one can occur in normal* use is very worrying.

* normal use if you only use one loop to attach your cowstails as is against the best advice – always clip through both loops!

So now what?

Cavers should draw their own conclusions from these tests or indeed conduct their own perhaps.
I believe that it is still appropriate to teach the Bowline-on-the-Bight as one of the standard knots for caving alongside the information about how to use it safely and the consequence of misuse.
I will copy this information to the British Caving Association for review. It is not my place to advise on caving policy for the UK.

I have been offered the chance to use a rope tester to look at potential replacements for the BotB. The test will give us a chance to see how a replacement compares with the existing methods in terms of strength and durability.
The French’s preferred option – the Fusion Knot, which has also been called the Karash Knot, is high on the list of contenders but I feel that a similar knot to the BotB would be more easily absorbed by the caving community. Both myself and Jez think a closer look at the Double-Bowline tied on the Bight may give a very good alternative. We’re calling it a D-BoB, or Double Bowline-on-the-Bight, until we can establish its correct name.

Testing a method of failure with a Bowline-on-the-Bight knot

A recent video clip has come to light on UKCaving Forum from the French Caving School which identifies a method of failure for the Bowline-on-the-Bight knot. The School’s film shows a failure that could lead to serious injury or even death when clipped into only one arm of the Y-hang.
I have not seen or heard of any occasions where this failure has happened in the U.K. and have certainly not seen it with my own eyes until today’s tests. It is rare for such a statement to come in regards to such a well used technique so I had to investigate.
We made use of the excellent training facility at Pindale Farm in the Peak District and the not so excellent weather.

Background:
The Bowline-on-the-Bight or ‘BotB’ knot is widely used and taught as a preferred knot for most SRT rigging applications involving Y-hangs and SRT. The knot has certain shock absorbing and self equalising properties that make it a good choice. These traits form one side of a double edged sword, the other side being the knot is easy to undo and therefore easier to loosen in use. It is this property of the Bowline knot family that can lead to slipping failures like the one we are looking into here.
For anyone who does not know the BotB knot, I will not explain it here as there is a wealth of literature and information on them online. Spend 5 mins Googling or pick up a copy of a UK caving manual.

The Failure:
The problem occurs when a caver is clipped into one arm of the Y-hang formed by a BotB. The two arms are formed from different parts of the knot, one coming from the pitch rope up into the knot, twisting round and emerging to form a loop and the other from the traverse line or on occasion a stopper knot.
Being clipped solely into the arm formed from the pitch rope can cause the rope to pull through and effectively untie the knot when loaded by the caver. If on a straight pitch with no other attachment the caver could fall to the floor. Even with a re-belay or end of rope knot present to stop the rope being pulled totally up the slip can still occur. I ruined a length of rope today, wearing through the sheath on a slip of less that 2 metres.

Observations:
We managed to work through a set of differing conditions and factors to arrive at a scenario where we could generate an almost 100% failure rate. We used the same rope throughout the tests, although the knot was tied in different sections to prevent too much damage to the same area.
The rope was a 5 year old length of 10.0mm semi-static rope widely used by cavers. We also tested a length of smaller diameter rope from another brand with similar results. The rope was stiff but could still form and hold a knot well.
We varied the knot for each test in the following ways:

  • Dressed correctly or not
  • Tightened or not
  • Evenly loaded or not
  • Clipped into left or right arm
  • Clipped into both arms
  • 10 & 9mm rope tested
  • Wet and dry

In the outdoor world we use a accident analogy called the ‘Lemons’. If you imagine a slot machine is your work and the tumblers and their ‘fruits’ are the small events that happening, the lemons are the poor practice, bad judgement or bad events.
As a lemon appears on a tumbler it is usually outweighed by a good fruit, i.e. a bad thing/poor practice is safeguarded by the other good practices along with it and the chance of an accident is low.
When all the lemons come up on a line together we have a series of poor decisions or events that collectively form a chain of events and choices which dramatically increase the chance of having an accident. Hence, it is better to follow the adage of prevention being better than cure. It is this analogy that I think fits perfectly with this method of failure in the BotB.

When the following conditions were met we experienced a near 100% failure rate.

  • Wet rope (very high rate of failure on dry too)
  • Knot not fully tightened
  • Y-hang arms not equally loaded – specifically the one formed by the pitch rope
  • Caver only being clipped to the loop formed by the pitch rope
  • A dynamic fall similar to someone slipping on the lip of a pitch
  • Knot recently tied – i.e. first person down after rigging.

It is worth noting that we did have other failures with different test conditions but on a far smaller percentage of tests. The loose arm being the common factor in all of our testing.

Best Practice:
We teach what is known as best practice. This ideal of coaching changes and we are constantly evolving our advice. This is one of the reasons I went and did these tests today, to ensure that what I did was still the best it could be.
Current best practice advice for SRT, rigging and progression where relevant to this article is as follows:

  • Rope used should be of good condition and supple enough to hold a knot well
  • The rigging should be tight and all knots dressed correctly and tightened down before use
  • Y-hangs should be loaded equally
  • The caver should always have their cowstails clipped into both arms of Y-hangs (you’ll notice we use larger krabs than most for this reason)

Conclusions:
We experienced no test where a failure occurred when all of the best practice conditions above were met.
Failures did occur in other tests, the chance was lower unless all of the ‘Lemon’ factors were involved.

Under no circumstances should you use a technique that is unfamiliar to you. Get trained, get experienced, get informed.

First Look at Gleistein GeoStatic NE 9mm semi-static rope

Here is a quick set of initial observations on Gleistein GeoStatic NE semi-static rope. A full write up will follow in the future.

So, a few weeks ago I was chatting to a caving friend of mine who has turned outdoor gear importer/supplier and was told about a new type of semi-static rope available in the U.K. The reason this particular rope caught my attention was down to it’s specs, the sheet described a 9mm rope with full Type A certification and a strength exceeding that of Beal 10mm Antipodese, I had to get some!
The rope in question has just landed at Hitch n Hike in the Peak District and I ran down there today after work to collect a length for testing. What I’ve got here is just a few initial observations for the interested caver.

Length:
I was aiming for a 30 metre length after shrinkage so was expecting to be buying around 34m today. An examination of the GeoStatic data sheet showed a shrinkage of only 0.7%, thats 70cm in 100m! The rope must be pre-shrunk before being placed on reels to get a figure that low. I opted for 32m to be on the safe side.

Edit – It’s now March 2014, a year and a half after buying. I’ve just re-measured this rope and it is just over 29m, a shrink of 3m since purchase. This is a shrink of about 9% in longer term use. For comparison I also re-measured a length of Beal Spelenium Gold which had shrunk from 32m to 27m over its 3 year life so far, 15.6% shrinkage from the cut length.

Handling & appearance:
You are in no doubt that it is a 9mm rope, a coil of 31m looks like it could fit in a handbag, a significant size reduction on the Mammut Performance semi-static I generally use. It handles like a supple dynamic half rope, bending almost flat as you make a teardrop in your hand and not feeling at all stiff as you turn it to form knots.
The rope is apparently manuractured in a number of different main colours, all with a common single white line woven spirally. The colour currently available from Hitch n Hike is orange, so would not look out of place underground alongside the current Mammut orange rope (+double black fleck). Other colours like blue may result in people asking if you are using dynamic rope!
The single white band corresponds with the generally accepted method of identifying 9mm ropes with a single line of flecks – Beal use a single line of red and black and Mammut a single black line.

Preparation for use:
As with all new ropes, the first thing I do is soak them in a bucket of water. This serves a duel purpose, allowing the rope to shrink and washing any residue of the manufacturing process off (that slippy white liquid). The shrinkage I will measure and report back on. The rope appears to have been pre washed and shrunk because after one hour there has been no discolouration to the water. The rope’s colour changes to a nice dark shade of orange once wetted, a small point but you’d easily be able to tell if it was dry.

Next step:
I will leave the rope to soak over night and hang to dry tomorrow. I will measure the length to the nearest half metre and mark it up with gear tape.
I’ll be using the rope as much as possible in the coming weeks to get a real feel for it. After a dozen or so uses I’ll remeasure it and report on any further shrinkage.

I’ll put up a more in depth reveiw of the rope after I’ve used it a bit more, but for now the manufacturer’s site is here and the Hitch n Hike site is here.

Specs:
Gleistein GeoStatic NE 9mm
4% stretch
0.7% shrinkage
39/61 sheath to core ratio
27kN breaking strength (epic)
54g per metre