MTDE Amazonia harness – safety check

We are informed that a particular batch of MTDE Amazonia harnesses has failed safety checks when tested in Croatia. The batch which is the problem is no. SA5117. We don’t think we have sold any harnesses from that batch but you might like to check your Amazonia to be on the safe side. The batch no. is at the top of the label.

New Petzl Duo S

“Candles are by common consent the most dependable illuminant, as they cast no treacherous shadows, though electric torches are a good standby”

H.E. Balch. Mendip: Its Swallet Caves and Rock Shelters.

Those cavers with middling-long careers will remember the occasionally reliable Oldham cells of the ’80s, with their array of bulbs – Krypton, Halogen –  and their fuses that could be bodged with the silver paper from Kit Kat wrappers. Coming into the UK this week is a new light by Petzl, the Duo S, which still has an array of ‘bulbs’ – well, LEDs – but can no longer be fixed by a Kit Kat wrapper…

The fuller specification is on the website, under the ‘Lights…’ section. Here it’s probably sufficient to say, it does a lot! Rather than repeat the facts (there’ll be lots of blurb online soon anyway), I’ll stick a couple of opinions on here (my own, and to be taken with the appropriate pinch of salt).

The current Petzl range of lights useful for caving seems to be:

1. Pixa 2, a light for centre use because it is bright enough (especially in smaller group-friendly caves, where clients work in groups of eight – twelve) without giving any battery-draining or instructor-blinding options. It has headtorch and helmet mounting options so it can double up for caving and night walks, and it can run off rechargeable and also prime AA cells, useful for times of power cut or charger failure.

2. Pixa 3, a light for club use because it gives 100 lumens (*how* much brighter than an FX2?), can be managed by sensible novices to balance run-time with appropriate brightness, and is relatively cheap – certainly for a reliable, cave appropriate unit. Running on AA cells, it is easier for a club equipment officer to manage than lithium-ion cells – if a charger doesn’t work then the local supermarket will see you for the weekend. The mounting options also make it a useful spare light, as it can be handed over to a lightless caver to fit to their helmet quite easily. Plus, it’s a perfectly good headtorch for walking back from the pub with. Incidentally it has a niche for taking on expeditions where your main light is run on a rechargeable lithium -ion array, but if the generator or solar panels fail, then at least you can still go caving. We’ve seen the Pixa 3 going to Meghalaya on the strength of this.

3. Duo Z2, a light that Petzl market as being for general use, as it runs on four AA batteries and comes within most non-student-cavers’ budgets. It has lots of nice features, but in my opinion its performance is entirely defined by the choice of power source. The given run times are 15 hours 30 minutes at 50 lumens (ambient);  6 hours 45 minutes at 120 lumens (proximity); and 2 hours at 220 lumens (movement). In context, that’s about an OFD 1 – Top Entrance trip without a battery change, with a bit of care; assuming that your rechargeables are giving as good performance as prime AA cells – Petzl don’t specify the batteries that give these results but let’s assume they’ve not chosen duff ones! It’s the usual story, you won’t get lithium-ion performance out of a sane number of nickel-metal-hydride cells; you’ll limit brightness or else you’ll limit duration. What you do get, is a significant up-front price saving – cells and chargers don’t come cheap, if you want ones that don’t blow up! Also, here, you get a high-end primary light that you can take anywhere that AA cells are available; this may be helpful if you are worried about flying with lithium-ion cells on an expedition. You’ll want battery sponsorship, and possible a team of porters to carry your spare cells, but at least you’ll have a bright light to cave on despite the worst efforts of customs officials or your expo nerd who has killed the solar panels… So if anything, I’d suggest that this is a specialist light primarily, for a subset of expeditioners flying outside of Europe; with maybe a place in the kit store of UK based cavers who want a nice bit of kit but don’t do very long or regular trips, where the battery duration / ongoing running costs will start to kick in.

4. Duo S, the new Petzl high-end caving torch, which effectively replaces the Rush, Vario etc. It runs off the same ACCU 2 (with options for ACCU4) rechargeable lithium-ion cells as its precursors; so if you had one of these but fancy the latest kit, you’ll have a spare battery and charger which can’t be bad. The brightness of the Duo S is impressive, the price is competitive for this level (the three year warranty on the lamp is nice), and the weight on the head is attractive for those who have reason to worry about this. Petzl have made a decision to keep with the ACCU 2 as standard and it should be fine for UK use; 700 lumens for 3 hours 30 minutes, 330 lumens for 6 hours and so on should be enough for most light junkies. For trips abroad it gets to be more of a balancing act. You’ll probably want more than one battery for a trip down the Berger, for instance – this is not a challenge! – and a prolonged underground camping trip might call for a significant investment in spare cells; or else you’ll need to be parsimonious with your light. We’ll probably do a ‘buy four batteries at a discount’ or similar at some point to help those who want to club together for an expo. I think that there’s a sliding scale between those whose summer involves caving in Matienzo, the Vercors or similar – excellent caving where few trips are longer than twenty four hours, rechargers at the gite – and those whose holiday consists of  living on top of a mountain where power supply is imperfect, and staying underground for four days or more. Very much a decision based upon one’s caving preferences and ambitions. The only other factors to bear in mind when thinking about the Duo Z2, the Duo S, or anything else, is the IPX67 (waterproofness) rating on the Duo, which is fine for most caving but really isn’t diveable; and also that the two Duos *don’t* allow changing from one battery source to another; at the moment the DuoS runs on the ACCU2 (or ACCU4) but it cannot be made to run off anything else like a AA or 9v cell.

SO! These are my current meanderings on the latest Petzl line up. I’ve not talked about the liminal models that are used down caves – sometimes quite successfully, like the various Tikkas or Myos, which would extend the discussion to even greater lengths! I’m very glad that Petzl have re-engaged with proper, designed-for-purpose-caving lights. For most of the last decade we had a mantra of asking our Petzl dealer “what is going to replace the Duo?” every spring. How people like the new ones, and how they go in real life, we’ll see; but at least they really are quite distinctly new, and I think they have a place in the considerations of new cavers, and those looking to upgrade.

World’s longest underwater system

The world’s longest underwater system has been created by the joining of Sac Actun, in the Mexican state of Quintana Roo, with Dos Ojos, by divers of the Proyecto Gran Acuifero Maya. The divers have found evidence of early human occupation dating from 10,000 – 12,000 years ago, along with the bones of elephants, giant sloths, bears, tigers and prehistoric horses. There is a brief write-up in the Guardian – see or for Spanish speakers there is better detail in El Pais:

The exploration website is at

Diving in Cwm Dwr

Over the last couple of months I’ve had an opportunity to make some potentially interesting dives in OFD. I was lucky enough to have the sumps downstream of The Confluence as having been dived only a couple of times previously back in the Noughties. The water encountered here is not, I think, the same as that which sinks in downstream OFD2; but I expect that this section of passage will be an inlet to the main flow.

The main activity has been underwater digging, but of such a shallow and benign nature (strong flow whips away silt within a matter of seconds) that it is very nearly a pleasure! In terms of kit, this is a twin cylinder site, the appropriate clothing is a wetsuit and diving vest (both Warmbac) with neoprene gloves as a little luxury. The best thing about this is that the carry in through Cwm Dwr in a wetsuit is actually quite comfortable through the crawls and boulder choke, even after a bit of rain. A bonus is that I’m learning the optimum route through this section of cave.

Thanks are due to various SWCC members for putting me on the trail, and also – and especially – to those Imperial College stalwarts who made the first carry in for me!

The Ario Dream

“The Ario Dream”, Paul Diffley’s film about exploration in the Picos, will premiere at the Kendal Film Festival on Sunday 19th November, 9.30 – 11.00 in the main theatre.

See the trailer here:

Northern Caves III – out now

The long-awaited guidebook to the Three Counties and the North-West is launched today – this is the geographical area of the old Volume 3. Congratulations to Sam, Beardy, and their army of helpers!

The Virtues of Vis-Bot

Generally speaking, cavers in the UK understand the benefits of knowing how caves respond to rainfall (unless your caving takes place solely in Goatchurch). With the advent of very accurate and up to date forecasts online, it is pretty easy to avoid the major weather events that, on their own, can spoil your day; we just need to be alert to key phrases such as ‘thunderstorms’, ‘heavy showers’ or ‘prolonged rainfall’. Not very hard to manage!

However, the other side of the equation is what the weather has already done in our chosen caving area. Saturated ground or snow cover can all make for nasty surprises if you add even a small amount of rain from a warm or occluded weather front. However, this information can be harder to get. For sure, most cavers have the use of their senses; if you sink knee-deep in bog on the way to Ireby Fell, or flounder through snow on the way to P8, you’ll be aware of the potential hazards. To get that information at the planning stage, before you pack the ropes and get an early night for the trials of the day ahead, is a bit harder.

This is where the Cave Diving Group can help. Visit the website at and follow the links to VIS-BOT. Here you will find rainfall graphs for various Dales and Peak locations, plus links to various weather stations on Mendip and other resources. Cave divers will also sometimes post general info on cave conditions where they have been active. Time spent on reconnaissance is seldom wasted, and online reconnaissance is the least amount of effort, as long as you trust the resources! In the case of Vis-Bot, if there is any information given, it is generally spot-on; and if you look up the locations of the various reports you can even get a sense of what the prevailing weather was over the last couple of days eg where the rain was coming from and how heavily it fell on different aspects of slope. All pretty good life-maintaining info.

So raise a toast to the volunteers who help provide this service!

Rearranging the Fan / Waste Interface

I’ve been listening to Iain Abernethy’s podcasts about practical Karate for a few years now. He says a lot of sensible things in his (admittedly non-speleological) field of expertise.

In a recent podcast he talked about re-inventing violence. There are  some forms of karate which describe themselves as being practical defensive disciplines; but, the scenarios in which their techniques would be wholly effective turn out to be elaborately unrealistic (attackers coming at you one at a time is a classic you may have seen in films). What has happened is that a martial art has evolved – moving away from its roots in conflict management, into the arena of a points-scoring contact sport.The point is, this is fine, as long as you don’t then take this highly refined sporting technique and say that it still works as a defensive strategy. The context is wrong. The fact that, in order for the strategy to work, violence has to be re-imagined into something other than its messy reality, suggests that while practitioners describe their karate as a valid defence technique, it is actually something entirely different. These highly-skilled sporting karateka  are so in love with their own expertise that they cannot appreciate its limitations; rather, they (possibly unconsciously) create the types of problems that best  fit their own capacity to solve them.

A few of us – back in the world of caving, now –  are beginning to experiment with the approach of swapping “here is a rope rescue technique, let us find the situation that fits it” for ” if ‘x’ happens, what is the resulting situation, and how can we solve it?”

In an advanced SRT practice last week, we had fun dealing with an array of unconscious casualties, on both Racks and Simples, who had slid into the loop of a rebelay. The rationale was, if an abseiler loses consciousness on these devices, they either hit the deck – traumatic but no longer a mid rope rescue – or their flight is interrupted by rigging, which *is* a pick-off. It was fascinating, and if you’ve never tried dealing with it before (we hadn’t) I recommend giving it a go.

But play safely, go carefully. Once you start tackling problems rather than practicing techniques, it’s all a bit more unpredictable. Much like life, in fact.