We have been producing a regular quarterly journal for over six years now, it is nine years since Phil Ingham chaired the first BCRA discussion group from which the Cave Radio & Electronics Group - the first of a growing number of BCRA Special Interest Groups - was to emerge. To stretch a point, it is the tenth anniversary of the first suggestion of a Group. The Cave Radio Group has given rise to two spin-offs; the Cave Surveying Group and Underground Photographer (which isn't a BCRA SIG, but an independent society). These are all (so people tell us!) highly successful and world-leading publications; but this is only because so many people are willing to contribute. Here, in CREG, we are especially pleased that so many European cavers are starting to get involved in the Group. The most important advice I could offer to other similar groups is that you must publish regularly, even if it is only a single sheet of paper with some brief news items on it. People will not waste their time writing letters/articles if they do not think you are taking the job seriously. I attribute CREG's success, ultimately, to the fact that we have all been determined to produce a regular publication.
I have been fond of saying that the Group doesn't really exist at all. This is true - it does not exist; it is only the people in the group who exist. This means that statements like "why doesn't the Group do such-and-such" really have no meaning. I mention this now because we are getting an increasing number of enquiries from people wanting communications equipment for expedition use; from rescue groups (both in the UK and abroad) who want to improve on their existing equipment; and from commercial organisations. It is not the job of "the Group" to provide this equipment - we do not have the resources. Instead, it is the Group's purpose to pass on these enquiries as best we can. If people do want "the Group" to provide comms equipment then it is really a question of encouraging someone to issue their own equipment - perhaps channelling it through the Group (and that probably means channelling some money the other way because production quality equipment does not come for free).
If "the Group" does not exist then it certainly cannot exist as a pressure group. This question has arisen recently in the context of the 73kHz amateur allocation (see Nick Negus's letter in issue 25, p33) and also in the context of a possible safety-critical frequency allocation in the induction radio band (see my article in issue 25, p31). We (the CREG committee) do not feel that we have a mandate from our members, or from the BCRA, or from the BCRC (the British Cave Rescue Council) to act as a pressure group for the representation of cavers' radio interests to the RA. We have specifically left this up to individuals. If the caving community thinks "the Group" should be doing this then this is something we should discuss. We would be interested in your views.
David Gibson.
(First published in CREG Journal 25,
September 1996, as
"Twenty Five Issues and Eight Years")
The concept of a "caver pager" was outlined in a couple of articles in CREG Journal 23, (March 1996). A small radio receiver would be carried by a caver and could be activated by a surface party to warn the underground team of impeding danger, such as imminent flooding. The warning could be by means of a number of pre-agreed codes, or by transmitting short text messages, in much the same way as a conventional pager.
A "paging system" was suggested in 1979 by the coroner in Powys, South Wales, after two cavers were drowned in Ogof Ffynon Ddu. (After an appalling weather forecast, the cavers had proceeded up the main streamway, and were duly washed away). The Coroner may have had in mind a klaxon rather than a radio; and the idea was, as I understand, dismissed in court as impractical and unworkable. Instead, the local rescue team settled for the simple, but effective, idea of fixing reflective markers in the streamway to indicate places where it was possible to climb away from rising water and, in some cases, to reach alternative dry routes out of the cave.
So why was a pager scheme deemed unworkable? In 1979 the radio equipment would have been fairly bulky, and it is difficult to see cavers willing to carry a pager unless it could be shrunk to the size of, say, an avalanche beacon. With today's technology and expertise this is feasible, and the antenna does not have to be a large loop, slung around the body - a miniature ferrite rod antenna would be adequate. But the size of the equipment is not the main obstacle to overcome - there are other reasons why pagers may not be practicable. Carrying a pager requires a surface team to be constantly on standby to send messages, and it requires the cavers to make a difficult decision in the presence of what could be a rather vague warning (that being the characteristic of a pager). Suppose there is a possibility of a thunderstorm? You know that there is a significant danger of flooding, or you would not have arranged to take a pager. You know that if you need the pager you should not really be there, but you go anyway. So what real use is the pager! A brief "flood" warning arrives. What do you do? Which bit of the cave is flooding? How fast? When? Do you sit tight or do you try to make your way out before the flood pulse arrives? A simple pager, as envisaged, cannot tell you that. Two cavers were trapped in Marble Steps Pot a few years ago - they did not have a pager, of course, but they knew the water was rising. One decided to make a rush for the surface and got through - just. The other stayed put, and drowned. Marble Steps is a simple cave - how would a flood warning help you in a cave where the catchment area was large and the water flow unpredictable?
Much UK caving consists of "sporting" trips and does not have, nor need, the surface planning and underground camping which is a feature of "expedition" caving, and of an assault on some of the deeper continental caves. This might be why the UK rescue organisation has dismissed pagers as "not a practical proposition". The French team which dealt with the flooding in the Gouffre Berger in '96 has expressed surprise at this attitude, but CREG has never managed to drum up much enthusiasm for radio within the UK teams.
Although I am sceptical of the worth of pagers in UK caves, the pager has several advantages for expedition usage, especially since it has a large range and can store messages. An underground camp could be supplied with up-to-date weather forecasts. A flood warning could be of use to rescue teams; and if there were several teams searching an extensive system they could easily be recalled when the incident was over.
A pager can be defined as a small, portable unit by which a caver on the move can receive text or message codes from a fixed surface station. The opposite of this is a "rescue beacon" which transmits from a caver, or a fixed underground camp, to a mobile surface station. An underground food/first-aid dump could contain a powerful beacon transmitter - a mobile underground unit would have to be much smaller (but this only limits the data rate). If a party ran into trouble (trapped by floods, accident, overdue etc.) they could set off the beacon, and send a typed message. The narrowband signal would be picked up by a specialised surface receiver. The rescue team would then radio-locate the beacon so that the surface unit was in a better position to receive a speech signal.
There could be problems implementing a permanently installed rescue beacon. A permanent surface station would be needed to pick up the distress signal, and that means permission from landowners, planning permission, licensing from the Radiocommunications Agency (in the UK), vandal-proof and weather-proof enclosures etc. - problems which could, of course, be overcome (for example, the surface station does not have to be directly above - or anywhere near - the underground station).
Pagers and beacons are characterised by being miniature, portable, capable of operation in "permanent standby" and in any orientation. Are they, as one body of opinion has it, merely an interesting academic exercise and of no practical use to cavers? Or are they destined to be an important part of cave rescue communications, as envisaged by a French rescue team? Would cavers actually use pagers and beacons, if they were available?
David Gibson
(CREG Journal 28, June
1997)
Radio amateurs do some pretty strange things, and slow-scan television must be one of them. The recent experiment, reported by John & Rosy Rabson in Journal 28 (Cave Television, pp27-28) was an interesting milestone, but it used a fairly old and non-standard technique (even amongst amateur radio enthusiasts!). How much more satisfying it would now be to do it properly - transmitting digital images, JPEG-encoded, or using Internet video systems such as CU-SeeMe, or RealVideo. But, fun though cave video might be, does it have a serious use? John & Rosy Rabson suggested that a video image of a medical injury could be transmitted to the surface to obtain medical advice. They also commented on the possibility of using patient monitoring equipment to transmit medical telemetry from underground to a doctor on the surface. Does this suggestion meet the needs of cavers, or are we in danger of inventing specious uses for cave radio? Would a digital telemetry link be any more use than a voice radio?
In 1970 Dr John Frankland of the UK Cave Rescue Organisation (CRO) wrote a paper on "cave hospitalisation". The thought was that a badly shocked patient would be stabilised for some hours before being moved. The techniques that Dr Frankland described have never, in 27 years, had to be used in the UK. Current practice is to "load and go" rather than "stay and play". In an attempt to find out the merits of the techniques, I asked people on the Speleonics e-mailing list to comment.
Graham Naylor reported that, during the Gouffre Berger rescue last year in France, one of the Hungarians was found in a very critical situation and was revived in a sleeping bag before being brought out several days later. Frank Reid reminded me of the report in Speleonics 7, which described how a doctor attending a caver with spinal fracture consulted a neurosurgeon in a distant city. The patient is now paraplegic but the doctor's underground action was credited with preserving his urinary function. Jeff Disler described an incident during a cave dive, where the surface support team were called using a single-wire telephone and asked to rig an alternative exit route to rescue a stranded diver. In the absence of this support, the rescue, through several sumps would have been much more protracted.
So cave hospitalisation, and general rescue can benefit from radio - but what of other techniques? Dr Keith Conover though that video and telemetry sounded like "a technology looking for a use". Conover is a long-time medic and now a medical command doctor for wilderness and cave rescues. "Voice is all you need for medical direction", he says. "Video is generally useless, provided you have a paramedic who can use standard medical language". Conover pointed out that "video or even digital smell-o-rama misses lots of information that is available at the scene - for example, the diagnosis of a shoulder dislocation requires palpation and kinesthetic information and I doubt that we'll be able to develop cost-effective robotic waldoes to provide this for cave rescue". [Its good to see that the sci-fi term "waldo" has made it into the general language!].
Michael Hale (a.k.a. "slug") of the CRO was also sceptical of the need for medical instruments underground. He pointed out that some instruments are almost too delicate for hospital use, let alone underground. In addition, ECGs, pulse oximeters and other monitoring equipment do not work well when the patient is cold, is shivering, in motion or suffering from shock. Advisory defibrillators containing complex software and DSP are standard-issue to ambulance crews; and the Langdale/Ambleside mountain rescue team has use of a Propak instrument, which monitors the patient and faxes the data to a cardiologist at the hospital. But how much of this equipment would be useful underground? How much would cavers bother to take with them? The design of the instruments is far beyond amateur "spare time" enthusiasts, with much of the difficulty being in the extensive software "template-forming" algorithms that are used.
Instead of putting money and effort into trying to develop high-tech high-bandwidth communications, the effort might be much better put into better medical training for cave rescuers!
David Gibson
(CREG Journal 29, September
1997)
John & Rosy Rabson's description of what may be the world's first cave TV broadcast (Journal 28, pp27-28) captured the mood very well, but I think it over-sold the relevance to cavers of the 73kHz amateur band.
It is not true to say that "the licensing regime for induction radio has made it difficult to develop new cave radio designs". Licensing is the least of the problems - what are in short supply are skills, time and money. It is, in fact, rather easy to obtain a DTI test and development licence - I had no problems at all in obtaining mine! (I probably had fewer obstacles in my way than someone applying for a notice to operate on 73kHz). The cost of my T&D licence was minimal compared with other development costs, and it allows me to have a much freer use of the band than do radio amateurs.
Using a T&D licence to operate cave radios on a day-to-day basis is admittedly less convenient - licensing and type-approval are not intended for "amateur" home-built rigs, but for commercial manufacture. But it would be wrong to suggest that the amateur band solves this problem - it does not! The band is of little direct use to cavers and cave rescue groups because of the restrictions that limit operation to qualified radio amateurs.
I recognise, of course, that 73kHz has encouraged radio amateurs to get involved, and that John Hey G3TDZ in particular has made a welcome and significant contribution. But the 73kHz amateur band does little to further the operational use of cave radios. By suggesting that it does we could end up discouraging cavers - who can be rather reactionary - from providing the participation and feedback we are hoping for. I not denying that using the band is "fun" but the future of cave radio is, in my opinion, not on 73kHz and not on an amateur band.
David Gibson
(Letter in Journal 29, September
97)
Some 20 years ago Bob Mackin's Molefone revolutionised cave communications. Since then many people have built induction radios. One particularly good design, in its time, was Ian Drummond's CB transverter, many of which are now used in the USA and Canada. In Europe, too, several radio projects have achieved good results. The Cave Radio Group has published several designs for home-made radios. The most popular of these is John Hey's radio. This is a conventional 87kHz SSB radio operating into a tuned loop. John's radio is easy to tune, unlike some designs, and is suitable as a home construction project. Quite a few of these radios have now been built, both in the UK and on the continent. (note: you need to be aware of the UK licensing requirements).
John Hey's is a conventional Molefone. Several people are now thinking along the lines of a "second generation" cave radio (2GCR) with added features. Such a radio could easily adjust itself to the operating conditions and link automatically to a VHF network to the public telephone system. It could also utilise much smaller antennas than existing designs, and could transmit data as well as voice (e.g. .the patient monitoring system used in ambulances). David Gibson is studying some aspects of 2GCRs in PhD research at Leeds University.
On the practical side John Hey is now re-designing his radio into a belt-mounted version. In fact, a number of people throughout the world are now undertaking innovative design and experimentation and, slowly but surely, a "next-generation" radio system is emerging. However, the designers (many of whom are not active cavers) must be careful not to invent specious uses for cave radio. Is cave radio really that much use anyway? Although a common theme of the rescue groups seems to be "our radio equipment is falling to pieces and unserviceable", when pressed the opinion is "we don't really use it that much anyway".
In fact, we have not had a great deal of success in inviting comments and suggestions from cave rescue groups. We have asked several times, both formally and informally, if they would like to get involved in a discussion with us on thefuture of radio comms, but we have met with a deafening silence. However, I was talking to a CRO member recently and he broached the subject of replacement radio gear. It seems that the "grass roots" members are happy to get involved, and we suspect that our initiatives are being blocked at a higher level by the secretaries and comms officers for various odd personal and "political" reasons. That may be being a bit paranoid - what is more likely is that there is a "catch-22" situation: we are viewed as "out of touch with the sharp end of things", so the rescue groups dont want to start a dialogue.But if we dont have a dialogue then we dont know what is needed, so we remain out of touch.
Whatever the source of the problem is, it seems likely that the major practical innovations in cave radio will come from cavers in France and Switzerland, with UK members of the Cave Radio Group providing a theoretical backing for new work. If the UK rescue groups will not tell us what they require then they might find themselves being overtaken by events - all of Europe will have powerful, versatile radios except the UK which will still have equipment that is "falling to pieces and unserviceable".
David Gibson
It seems that Long Churn Cave, in the Yorkshire Dales, is a popular place for resistivity tomography tests. In Cave & Karst Science, Dawn Walker reports the results of tests there, which she undertook as part of her MSc studies (Walker, 1997). A few years ago, Mark Noel & Biwen Xu (1992) performed tomography tests at the same location. However, I question whether resistivity tomography is as good at detecting cavities as is sometimes suggested. Experimental results over known shallow caves are certain to give a positive result, but this fact, on its own, does not verify the technique; and I question Dawn Walker's statement that Long Churn Cave was an adequate control.
Nobody doubts that resistivity tomography, microgravity, and so on, are powerful tools and that they can detect sub-surface features. But then, nobody doubts that Long Churn Cave exists either! I suggest that a better control for a cave detection experiment would be to run the test over an area of rock where there were no cavities, and to verify that none were detected there. Clearly, this is somewhat difficult to do, but Walker has gone some way to demonstrating this with her statement that the technique "also identified a previously unmapped feature that was interpreted as an air-filled cave or fissure 40m to the south of the main passage". Now, if this cavity does not exist the experiment has refuted the technique; but if the cavity does exist then, instead of concluding that the technique works, we must find a new area where there are no known cavities and repeat the test.
I understand that, in fact, a surface feature suggests that this "previously unmapped feature" may well exist, but whether it is a fissure or a navigable chamber remains to be seen. A chamber - perhaps the entrance to a new system - would be good news for cave explorers, and the common-sense conclusion would be that tomography works, but I remain sceptical as to whether this conclusion is valid. The data inversion process caused some features to be smeared and, as Walker says, "in some cases anomalies from separate features were combined". I might be being overly pessimistic but, without a proper control, could this be interpreted as saying that the technique did not actually identify anything? (Hamlet: "Do you see yonder cloud that's almost in shape of a camel?").
Long Churn is clearly a tempting target for people to test tomographic equipment but experimenters should also be reporting the results they obtained over areas of limestone where there were no known caves. It would be embarrassing if every reading showed the presence of a cavity, which we then proceeded to explain away, where necessary, as being some small sediment-filled fissures "smeared together".
My thoughts about an adequate control were echoed by Peter Styles, who gave a talk on microgravity techniques at the recent BCRA regional meeting in North Wales. He pointed out the difficulty of proving that there was no anomaly where none was detected. In commercial applications of microgravity tomography, positive results are confirmed by drilling boreholes, and thus arises a sufficient confidence in the technique for statements to be made about negative results. Peter Styles demonstrated the extensive data processing that can be applied to a large and dense grid of readings in order to filter the effects due to anomalies at different depths. The amount of data is crucial - the chances of hitting a 1m diameter cavity by drilling boreholes on a 2m grid is under 20%. With tomography, this fact manifests itself as a small signal/noise ratio when a high resolution is required.
Perhaps the problem is not with tomographic techniques in general, but with a lack of adequate data processing?
David Gibson
(CREG journal 32, June 1998)
Professional designers have to work to very tight budgets because the mark-up on consumer electronics is so high. For example, the cost of manufacturing a £15 flashgun is probably under £1. Amateur designers do not have this restraint - they can spend more on components and often still build for less than the purchase price of a consumer product. But they can have trouble copying professional/commercial designs because these often use obscure or custom-designed parts. Far from this being a restriction, I suggest that this gives the competent amateur an 'edge' because he can afford to explore other design avenues that would not be cost-effective in a consumer product.
You may be surprised at the extent to which custom parts are used in industry. As a design engineer in what was quite a small manufacturing company, I used to specify custom components frequently. High-wattage resistors, transformers, heat-sinks, special assembly tools and fasteners were some of the custom parts we habitually used. But we also had power transistors specially selected for us by a major manufacturer, and my job was the design of large custom logic gate arrays - something that puts a design out of the reach of amateurs altogether. Custom electrolytic capacitors were normal, and were actually cheaper than 'catalogue' parts because a capacitor production line is easy to 'tweak'; and parameters like power dissipation, surge capability, ripple current and even lifetime are easy to trade against each other, for what are significant commercial savings.
A photographic flashgun is a good example of how an amateur builder may have difficulties in copying a consumer-orientated design. Application notes for strobes and beacons are commonplace and, almost without exception, they use a transistor oscillator driving a multi-winding high-frequency transformer. The transformer is very cheap to make by the million, and the transistors are only a few cents - and far cheaper than, say, a switching-regulator IC. But winding a complicated inductor, and getting the material and core spacing correct, can be tedious for the amateur. A flashgun uses a special customised 'flash' capacitor, which is optimised for small size and low power dissipation. This is possible because it operates on a very low duty cycle in a flashgun; and the customisation saves money. They are also spiral-wound to give a higher-than-usual inductance. However, a heavy-duty power supply capacitor works nearly as well (though you may then benefit from an external air-cored inductor, as Chris Vernon uses in one of his designs). Flashtubes themselves are devices that are usually customised in batches, as I found out when I tried to order an 80J tube a few years ago. What I actually received was the end of a batch from a customer-alteration, making it a 140J tube; but I could not re-order it as that energy rating.
So, the amateur approach to a flashgun design can be completely different - you want a unit that can be made for perhaps £10, which still saves you £5; and you want additional features that are not commercially viable. Faced with this, you may decide to adopt a different approach, perhaps using an SMPS (switch-mode power supply) chip, for example. However, there is a thin line to be drawn between 'exploring other design avenues' and just producing a 'clumsy' design, characteristic of the 'hobbyist' magazines. The salient point about using an SMPS chip here is that you are not building a power supply. Considerations such as line and load regulation, ripple, stability etc., are not relevant. This frees the amateur designer to consider other fascinating options - how about a direct PWM output from a RISC microcontroller? The end result could be a superior product, tailored to your requirements, even though it may not be commercially viable. Although, who knows, in the caving world, perhaps people would pay for special features that were not commercially available.
Taking the example of a flashgun to its conclusion - you may decide that a better option is to buy a cheap flashgun and spend some time cave-proofing it. It is not always worth designing your own consumer product. I found this out when, a few years ago, some colleagues and I spent a long time laying out PCBs to build our own personal computers. We later discovered that we could obtain fully-populated boards, shipped direct from Taiwan, for a lower cost than getting our bare boards manufactured in the UK.
I have used the example of a flashgun, because it is relevant to CREG designers, but the same principles apply to other projects. Do not be mislead into thinking that published application notes are the only way to do your design - but neither should you adopt a crude 'sledgehammer' approach to your design. Use the opportunity to be inventive!
David Gibson
(CREG journal 36, June 1999)
This is the fortieth edition of the Cave Radio Group's Journal. We have already had 25th issue and tenth anniversary 'specials' (see 29, Sept. 97) so we thought we would play it down this time. However, it is worth reflecting that, since the Group's creation we have published over 700 articles, and that over 100 authors have contributed to the journal. There are other 'specialist' caving groups in the UK, but what is it about CREG that makes us successful? You can probably suggest several possibilities but, ultimately, the reason that we manage to produce a quarterly journal is that new authors continually come forward with contributions. And the reason that they do this is probably only because they know that their article will be published, and that the journal will appear on time. It's a self-reinforcing circle, and the single most-important thing for any small, voluntary group like ours is to publish on time! We have managed it so far, but I wonder how long we can continue? It is very easy to delay an issue, or miss one out, and that is the start of a rapid decline, as the members/subscribers lose interest and move on. It's a 'catastrophe curve', and we operate on the cusp of it. I can think of several other specialist caving groups that have befallen this fate, or seem to be about to do so; including the BCRA's official mouthpiece Caves & Caving which looks likely to lose two issues this year.
But in these days of electronic publishing, you may ask why we go to the trouble of assembling a printed journal at all. Our USA-based 'sister' group, Speleonics seems to have abandoned paper publication, but thrives in the form of an Internet mailing list 'chat room'. There are similar subscriber-lists for cave surveying and other specialist topics; and these are generally more useful than Usenet (the Internet newsgroups) which mostly seem to contain little of value. Mailing-list forums are worthwhile, but I do not believe that they are a substitute for a collection of properly researched and written articles - whether these are published on paper, on CD-ROM or on a web site.
With 40 issues of the CREG journal to search through, finding information on, say, battery chargers is no longer an easy task. Hopefully, the various indexes we have produced (including Chris Trayner's InDepth Bibliography, and my on-line Digest at www.caves.org.uk/radio/) will simplify the task; but it may now be time for us to start re-appraising early CREG articles, bringing them up to date, collating the information and republishing them. Perhaps we should produce some 'fact files' or 'information sheets'?
But let's not 're-invent the wheel'. CREG journals are not the only place you should be searching for cave-electronic projects. There are several 'hobbyist' electronics magazines in the UK, and designs for 'smart' battery chargers, VHF transceivers and PIC micro-controller projects feature regularly. One of my local bookshops stocks USA hobby magazines, so I was able to compare them. With one or two exceptions I found them to be rather dull and lifeless compared with the UK offerings; but even the UK magazines seem to have lost some vitality - or perhaps Im just getting older? The best magazine - and one that has had its share of 'smart' battery chargers and the like, is Elektor, www.elektor-electronics.co.uk. This is actually Dutch-owned and versions of it are published in several European countries. It is possible to buy sets of back issues of Elektor on CD-ROM; shareware and datasheets are also on CD-ROM, all at very reasonable prices.
Elektor is generally very good but, like all the magazines, it still drops a clanger from time to time - there was a project for a solar-powered battery charger, recently, which was based on a complete misunderstanding of how solar-panels work. In fact, you must treat most of what you read with some scepticism - mistakes frequently slip through.
Electronics World (formerly Wireless World) has a searchable index on disc, which I find useful for searching my 20-year collection; but mention "searching" to most people and they probably think of the Internet. Web-searching is good for lazy people, but is the best medium to search? Each year, I set a couple of projects for final-year students at Leeds University. Invariably they complain that "I couldn't find anything on the Web"! And recently, there was a letter in the IEE Review from a university lecturer who had "searched the Internet" but couldn't find information on what was a simple 'textbook' topic. Universities have libraries full of books - does no one use them any more?
David Gibson
(CREG journal 40, June 2000)
A friend of mine - an experienced hill walker - nowadays always slips a mobile phone and a GPS navigator into his rucksac before he goes out. As he says - he might not need to use either; but it is handy to know they are there; just like his mini-stove, spare food and survival blanket. Probably many of you have heard examples of how a mobile phone has helped to save a life - a victim of a bad climbing accident on a distant crag; a lone walker who slips and falls, and so on. I am equally sure that you have heard horror stories of mobile phones - children being sent up a mountain whilst the parents stay in the pub, and told to dial 999 if they get lost. The inevitable question arises: do mobile phones and GPS navigators simply encourage inexperienced people to get into difficult situations? Some of the tales are almost unbelievable. The following news report (by Angelique Chrisafis) appeared in The Guardian newspaper (p13) on Oct 20th this year.
Children rescued on moor
Police have criticised two youth workers for taking 17children onto desolate moorland without a map and with no idea how to use a compass. The 11 and 12-year-olds, from schools in Salford, were found on Bleaklow Moor, Derbyshire, early yesterday morning, 12 hours after setting off for a walk. After seven hours, one supervisor had called police on his mobile, saying he had no idea where he was.
Last night Derbyshire police said it had faced having to search 12 square miles of bogs and gritstone landscape without landmarks at night
The children, in trainers and anoraks, were too cold to show up on heat-seeking equipment carried by a police rescue helicopter. "We sent out police cars with lights flashing and sirens going, hoping the party would see them and lead us to them. They saw nothing" said a police spokeswoman. Eventually, the party spotted the helicopter at 12.30am and guided it to them by mobile phone. Mountain rescue then took more than three hours to rescue the group.
The spokeswoman concluded: "The Peak District is highly dangerous. Anyone should be properly equipped, with the right clothing, a compass, map and provisions. It is very easy to get lost, as there are no landmarks."
It is, perhaps, futile to attempt to debate the question I raised above; certainly in this short article, anyway. But it is interesting to look for parallels in our own activity of caving. Since I started caving 20 years ago advances in clothing, lamps and SRT (rope) equipment have meant that a solo caver, or a team of two can now tackle caves that would, previously have required far larger parties and much longer trip times. What, I wonder, will be the impact of electronic equipment on sport caving trips?
No one would deny that the presence of food and first-aid dumps in the further reaches of distant caves is anything but a good idea. At one time, I proposed that such dumps could also contain an emergency cave radio beacon. Similarly, no one would suggest that it was wrong to lay a telephone line in large cave system during a protracted trip. But suppose cave radios become like mobile phones - what then?
I do not suppose that such a device would ever be sold 'off-the-shelf, but the time is not too distant when an enthusiast could buy the components to build a hand-held cave radio for, say, £100, and have the surface station relay automatically to his mobile phone. This puts the inexperienced solo caver only a few key presses away from the rescue services. Is that likely to happen in the near future? Will it be a problem? Is the problem really any different to the ones we have at the moment - after all, novices and non-cavers getting into mortal trouble in caves is not a new phenomenon.
It is not just radios we need to watch out for. We are not long from the time when electronic sensors in a cave could report on whether a flood-prone passage is open, or whether a sump will need bailing. Neural networks could be used to process hydrological data to give an indication of the likely flood risk. (With the current work being done on flood pulse logging this is not as far off as you might think,). What happens if cavers start to rely on this data?
Having said that - and perhaps it was all nonsense after all - I am not about to abandon cave radio development. Graham Naylor points out, in this journal, the advantages to using digital signal processing in cave radios. This, and other developments mean that yet another "new generation" of smaller, cheaper, more versatile and digital cave radios (with speech processing, noise reduction, miniature wideband antennas) may not be far away!
David Gibson
(CREG journal 42, December
2000)
Copyright Notice: The author asserts his Moral Rights under the Design, Copyright and Patents Act 1988. Reproduction of part or all of the contents of any of these Web pages is prohibited except to the extent permitted in the notice which follows, unless prior agreement has been obtained from the author. These Web pages may be downloaded onto a hard disk or printed for your personal use provided that you include this copyright notice on each copy and that you make no alterations to any of the pages and do not use any of the pages in any other work or publication in whatever medium stored. No part of these pages may be distributed or copied for any commercial purpose.