Just a small consideration of undersuits and general insulation, in the wake of my recent trip to Snezhnaja Cave in Abkhazia, and thinking about the differences between my trips of winter 2016 and 2017.
The cave itself is a steady 6C, so not too cold. However the trip itself lasted eight days, with some of the individual working days in excess of sixteen hours. Also the surface was significantly colder, with lots of snow. All these factors played a part in the selection of kit for this year’s trip.
Last year I used an MTDE Butron, and was miserably cold for days on end. Normally I find this thin, very flexible and wicking garment fine for British and most European trips, including ones lasting several days and involving underground camps. Trying to work out why it had been such a problem in 2016, I came to the conclusion that it was a combination of two factors: caving style and physical attrition.
In the first case, Russian caving is sometimes a communal affair. Especially in this cave, where each person had at least a couple of heavy tackle bags, and some parts of the cave are a little awkward or tortuous, there is a tendency to cave as a group and move kit through obstacles using a human chain. This has some benefits but it does mean that there may be periods of five to ten minutes where there is little movement, and some of these locations may be damp or very, very draughty. Also both these trips used “pod” camps, where all stoves, food, tents and sleeping bags moved with the team, so the beginning and end of each caving day involved being pretty static while bags were unpacked, tents strung up and so on. If you rely on steady movement and burning calories to keep comfortable when caving, then you’re going to have a hard time on a trip like this.
Secondly – related but not identical – it is not easy to maintain full health on a multi-day caving trip, especially in a cold cave. Nutrition is hard to manage, even with vitamin tablets, and as a veggie getting enough protein can be especially difficult. The overall effect of hard work on a stressed body seems to be to make it more prone to cold, and the effect is increased the longer the stress goes on. In the case of these particular trips, the stress begins before the cave is ever reached; as time is short, moderately strenuous kit-carries bringing equipment up to the entrance – in conditions comfortably below freezing – are taxing, and there is not time for proper recovery before the caving starts.
So this year I opted for the significantly heavier and warmer AV Illamina, which is made of full-weight Powerstretch. This proved ideal for this trip. Slightly too warm at the start of the day, but nothing too bad; as the days progressed, the body deteriorated and the fabric became more vile and unwashed, even this problem disappeared. And at the end of the day, the cold was noticeable but perfectly bearable.
The other key elements were threefold: a Powerstretch balaclava, a thin basic waterproof and a mid-weight thermal top. None of these was required while actually moving in the cave (even the balaclava – a Buff was worn at all times to maintain head warmth), but the first two fitted into a drybag and could easily be stowed into the top of a tackle bag. Thus, at the taking down and putting up of the camp, extra warmth could be added with no appreciable delay; also at the base of a large pitch on the way out. The waterproof (Decathlon’s cheapest) was sized to fit over all kit, including oversuit and SRT kit, for mid-trip pauses.
For sleeping, adding the fleece to the Illamina gave sufficiently warm nights that the balaclava could generally be used as a pillow, rather than worn. The fleece was kept with the sleeping bag, as the other two items covered all the requirements of the working day.
This system worked well, and I’d use it again in similar circumstances; all I’d add would be a dedicated set of thick warm socks for tent life – drying your caving socks over the stove is effective but not perfectly so, and in trying circumstances a little luxury is welcome.
The only caveat. This minimum amount of clothing for effective warmth will leave you smelling like a dead badger after the first week, as there’s no allowance for changing kit, but that’s the price of efficiency!