chapters will be largely concerned with that pint of water in the night.
The plastic sort of bag is like the western side of Scotland. It’s warmer, but also wetter.
This book is about misery that’s mixed in with pleasure, rather than taken straight: about self-indulgence rather than mere survival. However, all bivvybags do have a secondary function as survival aids, and it’s true that you can’t have much of either fun or suffering if you died the previous winter.
For pure survival, there are various items offered of lightweight plastic or so-called ‘space blanket’. These cost very little, weigh very little (about 100g/3oz) and they’re very little use.
That’s not the same as no use at all. After the London Marathon they gave us aluminised plastic wrappers with the sponsor’s logo. Thus we became, among the streaked concrete of Waterloo Embankment, a fluttering blue and silver throng as we consumed an other-worldly sports drink which itself tasted strongly aluminised. Space blanket claims to conserve 90 per cent of body heat. This is misleading. Heat is transferred by radiation, conduction and convection. When lying under a stone wall in a snowstorm, heat is lost by conduction (into the freezing ground below) and by convection (into the passing breeze above). Aluminised plastic reflects only radiant heat.
However, when strolling on the Embankment damp with sweat and wearing only your undies, the blue and silver wrapper is what you need over damp skimpy shorts and a Galloway Sheep tee-shirt.
This wrapper came free – I only had to run 26 miles to get it. And while it was of little use, it was also of little weight, which could be good value; so I took it on the Mountain Marathon. On these events a cooker is compulsory: so I also brought along some delicious savoury rice. Alas! When Glyn unwrapped the cooker it was of a purely formal sort – small paraffin blocks, a stove like a dead spider sculpted out of rust, and a foil tub for saucepan. The super-lightweight saucepan had been remarkable value: less than £2.50, with its first hot meal, plus beansprouts, included at no extra charge. However, it had been on several mountain marathons already and was no longer rice-tight.
Ideal bivvybagging in the Picos de Europa, Spain
A saucepan liner cut from the London blanket turned out to be just the thing. It shrivelled above the soup-line, but held below. The moral? Anything’s useful, so just take whatever weighs least…
However, for serious survival (which means survival of snowstorms) you need a serious survival bag and this weighs 300g/10oz. This is thick enough to hold in heat as well as air, and stiff enough that the breeze won’t mould it against your body. The books say you should bite a hole in the corner of it to breathe through and then enter it head first. This makes sense: warm air rises and stays in the bag. However, I’ve never been quite desperate enough to bite a hole in something that cost me five shillings.
Two are not twice as warm as one in a bag, unless the bag’s a very big one. If the bag gets tight it compresses your clothing and the bits of you pressing against the outside get very cold indeed. There are, however, group bags: these are specifically designed for several people to get miserable in together.
PLASTIC BAG FOR PLEASURE PURPOSES
Some of us are too mean to buy a proper bivvybag, and some of us just like to see how much we can do without. I come into both categories. So here is the technique for primitive plastic travel.
If plastic bags get wet on the inside, the way to stay dry is to stay outside the bag. A foam mat is one of the things you probably didn’t bring, and the double layer of plastic underneath is insulation of a sort as well as groundsheet.
When it starts to rain, you can postpone the damp by moving under a nearby tree. When the rain starts to drip through the leaves, it’s just possible it may already have finished raining outside.
Otherwise, it’s time to get into the bag. Position it with the feet end slightly uphill. This means that condensation in the bag has a chance to trickle out the entrance. It also means that raindrops on the outside will drip off the doorway rather than trickling back inside. If you hold the entrance well open, air can get in and evaporate some of the condensation.
You wake up moist but warm. It’s the next night, the crawling back into a bag that’s already damp, that’s going to be really horrible. So the advice is not to do that next night, but to head off the hill to civilisation with its youth hostels and shops selling proper breathable bags.
However, it may quite possibly not rain at all. In which case you simply keep going until you run out of muesli. You lie late to let the sun take the dew off the plastic, amble down to the village whose lamps had lightened your night-time, and discover that, late though you lay, it’s still two hours too early for the shops.
POLYBAG FACTS
The basic polythene survival bag should cost between £5 and nothing at all – they may be given away free with outdoor magazines. A fertiliser sack does the same job more cheaply, though the bedtime reading printed on the outside is less entertaining. (The big-bag style is a good size: it’s important to wash out all traces of the previous contents as fertiliser damages the skin.)
The more the bag weighs the more effective it is – but the more it weighs, obviously. Eight to twelve ounces is a good balance between heaviness and uselessness. It should be long enough to be able to get right inside with boots on, and fold down the end so as to let the rain drip – this means 2m/7ft. If planned for two, it should be big enough to hang loose around them rather than stretched tight about their bodies.
The multi-person shelter does offer a significant weight saving, quite apart from the conviviality. The three/four person ‘Windblokka’ weighs 600g/1lb 4oz and is made of proofed ripstop nylon. It costs about £45. It’s designed for sitting up in rather than lying down and going to sleep.
One night under the moon in a plastic bag should persuade you that you want more nights under the moon, but in something other than damp plastic. Rawhide? Potato sacks? Stout Harris tweed? In the next chapter we’ll study various historic bivvybags even less accommodating than polythene.
Chapter 2 BIVVY HISTORY
Brian an augury hath tried
Of that dread kind which must not be
Unless in dire extremity,
The Taghairm called; by which, afar,
Our sires foresaw the events of war.
That bull was slain: his reeking hide
They stretched the cataract beside.
Crouch’d on a shelf beneath the brink,
Close where the thundering torrents sink,
Midst groan of rock, and roar of stream,
The wizard waits prophetic dream…
The period from 1900 to roughly 1969 was a dark age of outdoor technique.
When the Marathon was reintroduced as an Olympic sport a hundred years ago, it was considered unnecessary and unsporting to drink water along the way. As a result, Marathon runners tended
