UKC

Here is a very short questionnaire about the sound of loose rock, I need you/as many people as possible, to give your knowledge of what loose rock sounds like. Its sonic qualities and markers. The things which make you decide not to use that section. I understand a lot of it is visual too but my investigation is concerned with sound and vibration.

I am in the final year of studying for an acoustics/audio degree. As my final dissertation topic I have married climbing and acoustics. I was wondering what the actual acoustic properties of loose (unsafe for climbing) is?   

If you are interested in the method of investigation and/or results then please comment or message me. Thanks to anyone who replied or answers the questionnaire. Equally, any advice is much appreciated...  even if you think what I am doing is asinine! Happy Climbing

10/10. A proper survey at last. For your follow up, try the sound that ice makes. Every strike always assessed for sound until a suitable tone is achieved (unless one more would remove whatever ice is left).  Then assessed for apparent physical strength

10/10. A proper survey at last. For your follow up, try the sound that ice makes. Every strike always assessed for sound until a suitable tone is achieved (unless one more would remove whatever ice is left).  Then assessed for apparent physical strength

Just completed your survey.

From many years of new routing (particularly on slate) I have developed an ear for the different sounds of both solid and loose and hollow rock. I would like to think that anyone who has ever placed a bolt on a route would also be in tune with the various sounds of both good and poor quality placements.

You need to send this survey to Gary Gibson

Seems like you are turning what should be hard science into social science.  If you do it with a survey you'll find out what people *think* bad rock sounds like. Different people will hit the rock with varying degrees of force and with different objects and describe what they hear differently, many of them may think rock is bad when it is good or vice versa.   The stimulus, the response and the good/bad criterion are all unreliable.

If you went out and bashed some 'known good' and 'known bad' rock yourself and took measurements you would have hard data on what good and bad rock sounds like that could be the starting point for recognizing it with signal processing/machine learning algorithms.

Maybe that's the point?

This. OP, it would be useful to share your methodology.

Done,

Where abouts in Spain is the photo from?

That seems a bit unfair - surely it is about investigating people's judgement and seems a reasonable avenue of curiosity/investigation. One of the pleasures of climbing is that it is subjective and creative (like we see with grade discussions). We all use our own subjective judgements, which inevitably vary in reliability and include numerous biases.

Taking readings might simply be 'measuring because something is measurable' even though it may not actually be helpful.

Even if we all used something like a Schmidt Hammer to take readings, you'd have to be able to compare with a typical range for the rock type, bearing in mind that it isn't a manufactured product within narrow tolerances of "good/bad criteria". Readings would also be localised to the test area and not necessarily representative of the surrounding mass.

I wouldn't recommend anyone going out and bashing the rock unnecessarily.

If you wanted to investigate people's judgement you'd need to be a lot more rigorous.  You'd need to go and find multiple samples of known good and known bad rock, tap them yourself with a standard weight/object and record the resulting sounds and then play the sounds to the people so that everybody was hearing the same sounds.   Then you would want to give the respondents 'benchmark' sounds and 'standard' descriptions so everyone used the same language to describe the sounds.  After that you could ask people for their opinions on whether particular sounds implied good or bad rock and check against your record of whether that sample actually corresponded to good or bad rock.

If you don't get rigorous you just collect a bunch of data which may be interesting at a superficial level but is useless from a scientific perspective.  What can you learn from 'some guy once tapped some piece of rock in an unspecified way and gave an imprecise description of what he heard.  He thought that the rock was bad (but it might actually have been good)'.

Hello! Fellow climbing acoustician here!

Where are you studying?

I'd definitely be interested in reading your findings.

What else are you including in your study? Are you taking actual noise and vibration measurements of popular methods of testing rock for safety? How are you deciding what is safe and what isn't? 

I have answered what I consider to be the sounds associated with safe / unsafe rock, however I have no way of knowing if rock that in the past I have assumed to be unsafe, has actually been unsafe, because as a result of my assessment I have not used it.

Difficult to express this in your questionnaire, so....

I've done a fair bit of new routing on Limestone in the UK, a mix of bolted and trad. Usually you can tell just by looking that the rock is OK.

However, when placing bolts I've always got a hammer, so can test the rock by tapping it. A dull "thud" noise from the hammer would indicate that the rock isn't sound that there is some form of weakness as (I assume) the rock has a significant fracture near the tapping site. As such, I'd check elsewhere for the bolt placement to go.

If there is a more high-pitched "ting" from the rock, then I've assumed that this is a much better location to place a bolt, as experience has shown me that this noise means i'm tapping something solid.

When just climbing, the whack with the fist doesn't give much audible feedback, but might dislodge something that looked solid, but moves when thumped. If it's moved, I now know to avoid it. However, I only give it a thump if it doesn't "look" 100% solid - not scientific and open to errors in judgement (evidenced by several stitches in my head).

The drawback with sound as an indicator of looseness is the larger the loose block the better the ring from a hammer blow but the more likely it is to kill you if it falls off!

Agreed Jim - that's why a visual check is always part of the process

Done, difficult to answer actually despite doing it many times. Would be good to compare views with some objective measurements and give us some feedback

This is something I've always wanted to do, but never got around to. I think it would mostly be vibration rather than airbourne acoustics, but it'd be amazing to work out the vibration of a sound (and varying degrees of unsound) pick placement (once you've worked out how to sort a standardised uniform ice reference for the placement) and then pull test every placement and see if you can get a good correlation.

Then you could go on to exciting those vibrations in an axe (preferably after being hit into a solid damping object - you'd have to deal with getting rid of the vibrations from that) and then asking people how strong they think that placement was to see if people can genuinely tell from the feel how well it has placed.

Then you could look into different ice structure to see how it varies, and then you could come up with something to attach to your axes which graded each pick placement you made!

Then it wouldn't work and someone would break their back soloing whilst stupidly relying on your device and it'd all go to shit...

Done.

All i'm hearing is an excuse to buy some gear and get into ice climbing!

I am including ice climbing striking techniques in the write-up as they are applicable to a study of the used test methods. It would probably be a lot easier to define a method in an investigation for ice climbers as everybody uses the same tool in the pretty much the same way, from my limited understanding anyway. If I get access to Ice/Gear/Funding and so on then I will definitely follow up with this!

Do you know of any good sources on ice climbing "tapping" techniques ?

Thanks,

Ed

Thanks for completing the survey. Its great to get a response from someone who has bolted routes! 

So far it seems that everyone is using the same kind of techniques and hearing the same description of sounds. which is pretty much what I thought would be the case. Now to figure out what the physics says.

A couple questions; Do new routers have any tools to test with? I read some people use hammers, do you? Also, if I were to make a gizmo that could say "this rock is probably bad" or "this rock is probably good" would you be willing to test it when new routing? not as a decision making device but as a critic of the answers the device gives (this is a long way off development, just probing the question). annnd how likely would you think other new routers would be willing to do the same thing?

Cheers, ed

That would be awesome! I have looked for a way to contact but cannot see one. Any suggestions?

Hello tom_in_edinburgh,

The survey was designed to do just that. See how similar people are in there responses, even though they will hit differently and so on. Partly why the project is hard to come up with a definable test method! This is only one side of the project, just understanding what people do/think they understand.

On the other side is exactly what you have described at the end. The hitting of the hard stuff with a defined test method. Then taking that data and try to create a spectrum of good to bad rock and have a program understand/learn this. 

So all-in-all, I completely agree with you and what you have described is pretty much my project  

Hello!

Method is the hardest part of this project. The closest semi-applicable defined methods come from standards within the worlds of material testing for construction or rock face testing for quarrying materials. In these industries they have no problem bashing at the rock or shoving some explosive in there as well. I doubt I'd be too popular if I broke bits off your projects.

 So with respect to the ethics and the standards that are out there, I've had to come up with my own test method; This boils down to understanding the acoustical parameters of solid rock. I have done this by testing significant amounts of sandstone at this point, in an anechoic chamber using as many methods of striking and mounting the rock as possible. This is to find what actually makes a difference. Apply these methods to fake/constructed loose rock in the chamber as a primer for acoustic markers of "bad rock".

Then the testing will be taken outside with climbers deciding whats good and whats bad as they test the rock using my defined method. This will be repeated. A lot. Until a picture emerges of the connection between what people understand is "bad" and what the acoustics say is "bad".

It's quite difficult to break it all down as its still taking shape as an investigation, therefore things could change.

Are there any specifics you want me to explain more? As i probably didn't do such a great job

Cheers,

ed

Cheers krikoman! Good eye...  I'm cannot remember what crag exactly but Its in Calp near Alicante definitely. Possibly Sierra de Toix or Olta maybe?

Ed

"One of the pleasures of climbing is that it is subjective and creative (like we see with grade discussions). We all use our own subjective judgements, which inevitably vary in reliability and include numerous biases."

I didn't think about this comparison, But I definitely agree! If there is information, you decide to use it or argue with it. 

Absolutely! Thats the problem with using all defined and standardised methods like Schmidt hammers and impact testing, I'd be crucified (rightly so) for damaging rock. I imagine ultrasonics would work but then it isnt really usable information for climbers. Hence why i'm trying to conclude what it is we think we are hearing and pair that with acoustic testing. Could be interesting if not, hopefully informative. 

I should have read both comments before replying. But this is essentially the discussion I have with my supervisor!  And is the next step in testing once I have that defined method, to find those benchmarks, If it is as simple as "good" benchmark/ "bad" benchmark. I suspect It'll be more like having a list of markers in the time domain and in the frequency domain that will be tells for "bad" rock. Then the varying degrees of "bad" rock will be to do with the associated amplitude of the telling frequency or length and repetitions of peaks in the time domain.

I appreciate your questioning, it helps to clarify my understanding of what I am actually doing!

This seems like a really good project.  Probably a lot of work compared with the amount of time available for a final year dissertation but it should be possible.   Maybe when you have all the data you will be able to train people to accurately determine whether rock is bad.  I've heard of devices to test for fractures in aircraft wings based on acoustics but I think they were using ultrasound rather than audible frequencies.

Hello Andy,

I'm studying in Southampton. Not purely acoustics, its an Audio Engineering BSc, but acoustics is the direction I have taken it. 

Good to hear someone with experience and a knowledge of acoustics would be interested in reading my findings. I've taken not of the forums I have posted on and will repl the discussions once I have completed the analysis.

So for the most part I will be taking noise and vib measurements to establish the connection between what people believe is unsafe rock and the acoustic emission that marks this. Once/If this is done I will explore other ways to test the rock for the indicators, using different measuring tactics.

To decide what is safe I have come up with a method;

1. Test solid rock in anechoic chamber find suitable testing method and establish solid rock.

2. Construct unsafe rock in chamber to give an idea of what's to look out for

3. take method to rocks and have as many climbers as I can make their personal judgement of multiple rocks. Good through to bad. Get recordings. Use as benhmarks. 

Its pretty hard to say whats "bad" rock, but Its much easier to say whats "good" rock, Thats why I am starting there and then anything else can be examined as possible bad rock. Good point about not knowing what is bad, Its tricky and if you have any suggestions on how I could clarify this I'd be all ears.

Thanks, ed

Thanks for your responses, good to hear from new routers and someone with lots of experience.

I definitely agree, most on the time its a visual first check and a supporting knock to add another sense in there. But I do think with the scope of this project you could take it further and maybe understand more about the rock face from sound than any visual scanning techniques. But I'm biased as someone who studies sound I know!

Ah cool, so is there a specific hammer that all new routers agree on as being good for sound? or specs which you look for? I keep seeing that you are using hammers so will definitely add this into my investigation. 

Wow stitches, sounds gnarly! Do you think this could have been avoided with a tap and listen? or nay?

Totally agree, discretion definitely advised with anything like this! This is a parameter I have taken into account, Larger/heavier rock it less likely to have any sort of response as its coupling with the rockface is far greater.

Cheers, Ed

Ill post my finding on this chat once I muddle through the analysis. Objective measurements are being done as we speak

Haha...   the brutal truth.

Thats a very enticing outline for an investigation, If you ever undertake in such a venture I would be more than happy to help! Ill learn how to ice climb as soon as I finish my dissertation!

I rarely tap with a hammer and they are all much the same anyway, you get more information from the drill in my opinion.

There´s a difference in checking holds for looseness as it´s always a suprise what actually holds and what doesn´t (and to be honest it doesn´t really bother me if a few fall off) compared with selecting a placement for a bolt where it´s important they don´t fail. There is a classic photo on the internet of a roughly 2m cubed with the belay bolts in it which fell to the ground, no hammer test would ever tell you a 25 ton block is safe or not.

The way I see it is you're not testing for good or bad, you're testing to see whether the acoustic response fits with your expectation based on experience and a visual assessment, if it does you have some reassurance you've probably understood what you're faced with, if it doesn't you have a clue that something isn't quite what it seems for better or worse. Doesn't always work, the bigger the looseness the more normal the abnormal acoustic response and the smallest holds can't be effectively tested by human hands and ears.

jk