Glaciers in Winter
The light powder snow which is swept from rock and ice ridges is deposited on the broad glacier snow-fields, which therefore receive more than their fair share of snow. In midwinter there are few open crevasses to be seen, save at the icefalls, and most traces of concealed crevasses disappear from the upper névés. None the less, the danger from concealed crevasses is by no means trivial. The dry powder snow forms the most brittle of snow-bridges.
In the Grenz glacier accident a snow-bridge fourteen feet thick collapsed beneath a party of ski-runners. Of course, sooner or later, most crevasses are bridged, not only by powder snow, but various forms of wind-driven snow and wind-formed crust. Such crust is, of course, less brittle than powder snow-bridges, but it is quite brittle enough. The low temperature tends to increase the brittleness of snow-bridges.
In the early hours of a summer morning a snow-bridge two or three inches thick will usually be safe enough; for such bridges are generally formed of a mixture of ice and hard snow which is due to alternate melting and freezing. Such crust is much more compact, more solid, and far less brittle than crust formed by wind.
Glaciers are, in fact, safer in summer than in winter; for though there are many more crevasses open, there are far fewer dangerous crevasses whose existence cannot easily be detected. The droop on the snow and other unmistakable signs in ordinary seasons betray most concealed crevasses to the experienced eye. In winter the winds are so powerful, and their effect is so much greater (for reasons explained on pp. [446-447]), that they obliterate all traces of underlying crevasses. The surface of the snow is apparently one uniform field of wind-driven snow, and even the most expert cannot possibly detect the presence of concealed crevasses.
This raises the very vexed question of ski-ing on a rope. It is quite easy with a little practice to ski at a reasonably high speed on a rope, and to make combined swings. Roped running is, in fact, quite enjoyable, but it is not, and never can be, as enjoyable or as easy as free ski-ing. Consequently, many ski-runners will never consent to rope on the descent, save on glaciers, which are known to be badly crevassed.
There are three methods of ski-ing on a glacier:
1. A Roped Descent.—For the technique of ski-ing on a rope, see pp. [452-456].
2. A Descent in exactly the same Tracks as were used for the Ascent.—This method is based on the presumption that a snow-bridge which held in the morning during the ascent will hold during the descent. Obviously the strain is much less during the fast descent than during the climb. Also, as the variations of temperature in winter are of no great importance, provided that the temperature remains below freezing, a snow-bridge which holds in the morning should hold in the afternoon, though the same cannot, of course, be said in summer. As the tracks of the ascent were presumably made on sealskins, the descent must also be made on sealskins if it be desired to follow with any accuracy the line of the ascent and to avoid rapid swings and turns which are liable to test severely a snow-bridge strong enough to resist the ordinary uphill track. For my part, though this method is sometimes used, I consider that the necessity to wear skins and to keep exactly along one line is just as troublesome and not nearly so safe as the rope.
What usually happens when people start a descent without skins, but with the pious intention of keeping to the uphill tracks, is that they very soon find themselves curving and swinging some considerable distance from their old tracks.
3. A Free Descent Unroped.—If you discard the rope, you should be doubly careful to reduce risk to a minimum by paying attention to the general laws of crevasse formation. The middle of a glacier is usually the safest part of the glacier in winter. Lateral crevasses, i.e. crevasses at the side of the glacier, are wider, more numerous, and more complicated than transverse crevasses. The crevasses in the middle of a glacier are usually at right angles to the line of flow, so that a ski-runner who is running straight will cross them at their narrowest breadth. Lateral crevasses usually run at an angle of 30-45 degrees to the line of flow,[23] so that they will usually be crossed by a ski-runner at a more or less wide angle, and the danger of running along the whole length instead of across a snow-bridge is therefore great.
The principal rules for glacier ski-ing in order of importance are as follows: (1) Don’t fall. (2) Don’t make sudden swings. (3) Run straight. (4) Don’t use your stick. (5) Keep to the middle of the glacier.
In other words, run as straight as you can consistent with not falling. It is better to run straight and to use your stick to reduce your speed than to check your speed by swings and turns, for a swing to a standstill above a crevasse is more likely than any other ski-ing manœuvre to break a snow-bridge.
Keep close together on the descent, but not too close. Above all things, avoid crossing the same snow-bridge while another member of the party is crossing it. In the Grenz glacier accident three members of the party fell into the same crevasse.
Avoid short sharp turns, and cultivate long gentle turns if you cannot run straight.
It is often advisable to follow the leader’s tracks, for if the leader has passed over a crevasse without falling in, the chances are that you will be equally fortunate.
There should be two ropes in the party, so that if one rope disappears with its bearer into a crevasse the second rope may be available to pull him out.
At least one rope, and, in addition, the first-aid case and mending apparatus for ski, should be in the rear of the party, as nothing is more annoying than to see the leader disappearing far below with the spare ski-tip just as your ski-point has snapped off.
“Always rope on snow-covered glaciers.” This is the law, and in theory the law admits of no exceptions. But in winter, as in summer, this law is often broken. Few climbers have a clear record on this point. The temptation to break the law is, of course, much stronger for the ski-runner than for the foot-climber. There have been comparatively few accidents in which ski-runners have fallen into crevasses. On glaciers that are known to be little, if at all, crevassed in summer, only a pedant would rope in winter. Local knowledge is therefore very useful indeed, and if a local guide can be taken, so much the better.
Such accidents as have happened have been either on the ascent, or during a more or less level traverse, or as the result of a sudden swing or stem which has disturbed the snow. I know of no case in which a ski-runner has fallen into a crevasse during a fast, free, unchecked descent. Indeed, I should doubt if it would be possible to break through a snow-bridge while moving fast and running straight. I have myself shot an open crevasse about ten feet or more in breadth while travelling at a fairly high speed.
Most ski-runners would rope in winter on a glacier that was known to be very crevassed in summer. Many ski-runners always rope in winter, but far more only rope when they know the glacier to be very crevassed.
In May or June there is no reason to rope for the descent, save under very exceptional circumstances. The risk of falling into a crevasse in May or June is so slight that the rope may usually be discarded.
Ski-ing on a Rope.
Ski-ing on a rope is not so difficult as the inexperienced might suppose. Experts who have practised together can attain high speeds, and perform all the turns while roped together. A couple of good runners with a little practice should be able to run safely at a fair speed. But practice is necessary, and an hour or two of roped running in the valley is well worth while.
Two is the most manageable number on a rope, and of course, there need never be more than three, for larger parties can divide up into two twos, a two and a three, etc.
First a word as to roping. Most guides make a loop at the very end of the rope. This is quite unsound. The loop should be made about four feet from the end of the rope, and this four feet of spare rope should again be tied round the waist. Otherwise, if you fall into a crevasse, the pressure on your waist may almost suffocate you before you are withdrawn; whereas, if you have four feet of spare rope, you can uncoil this, make a new loop into which you can place a foot, thereby at once relieving the pressure on your body. With a little effort you should be able to wriggle out of the main noose, standing in what may be called the stirrup noose. If you are not exhausted, you might then be able to swarm up the rope, which would of course be quite impossible if, as would otherwise be the case, the end of the rope was originally tied round your body. Two men on a glacier alone sometimes adopt Mummery’s plan of wearing a second rope, which, in the event of a fall into a crevasse, is untied by the man above and wound round the head of an axe driven into the snow. The man below pulls on to the rope wound round the axe. The man above pulls on to the rope round the fallen man’s body. Thus there are virtually two men pulling one.
There is another method of roping sometimes used when three ski-runners are tied to the same rope, which—though it has been employed by experienced guides—seems to me most unsound. In this method two ski-runners are tied to one rope, along which runs a small iron ring. To this ring a second rope is fastened, and to this second rope the third ski-runner attaches himself. The theory is that the third ski-runner, being attached to a rope which in turn is attached to a movable ring free to slide on the main rope, is far less constrained in his movements than if all three were on the same rope. This is true, but I should be sorry to be the third ski-runner if I was to fall into a crevasse. Suppose the other two ski-runners are on opposite sides of this crevasse. The man in the crevasse is then attached to a rope which slides helplessly with the ring along the main rope. The iron ring probably buries itself in the lower lip of the crevasse. I do not quite see how any tension is to be exerted on the secondary rope.
It is simpler to begin by considering the case of two ski-runners, A and B, running on a rope. If there is a marked difference in the ability of A and B, the poorer ski-runner should lead, for it is much easier to lead on a rope than to be the last man. The last man on the rope has to moderate his pace and his direction in accordance with the movements of the leader. If, however, A and B are equally good runners, then the leader should be the one whose ski are the faster: I do not mean the faster ski-runner, but the one whose ski are running better, either because the ski themselves are faster and more slippery, or because their owner is the heavier of the two, and therefore, other things being equal, tends to get downhill quicker. For if, on a gradual slope which is to be taken straight without braking or stemming, A (whose ski are faster) is constantly overrunning B, the rope will get mixed up with the ski, and A will have to regulate his pace by stemming or braking in order to keep the proper distance. On the other hand, if A leads, his extra speed will keep the rope taut, and the tension of the rope will enable B to keep a uniform distance.
On easy ground A and B can ski in single file. B, whose ski are slower, will be kept in line by the tension of the rope. It is not necessary nor desirable for B to follow exactly the same spoor as A: his spoor should be an inch or two to the side of, and parallel to, A’s spoor.
B must be on the look out for sudden increases in pace on the part of A: A may, for instance, come to a steeper gradient, and B, if he is not on the look out, is liable to be pulled over and pitched on to his head. Similarly B, if A runs on to a gentler gradient, will have to guard against overrunning A, and thereby rendering the rope useless; for if A and B are on the same snow-bridge they may both fall in. At least 75 feet of rope should be allowed between A and B. On easy ground this rope may be allowed to be taut; on more difficult ground B should keep a coil of rope in his hand to allow a margin in the event of A suddenly increasing his speed.
The normal position for straight running should be modified. In free running lateral strains may usually be disregarded; the main risk of a fall lies in fore and aft changes of speed. Consequently, for normal running the narrow groove and the lengthened base, as in the Telemark position, are usually preferable to a broad track. But a ski-runner on a rope is always liable to lateral strains. It is rare that one runs exactly in line; whenever one’s track is parallel rather than coincident with the track of the leader, and whenever the leader changes his direction, however slightly, the rope exercises a certain amount of sideways pull. The greater the distance between the parallel tracks, the greater the lateral tension of the rope. Consequently, the ski-runner on a rope must be prepared, not only for forward and, in the case of the leader, for backward jerks, but also for sideway strains.
The best position for roped running is to hold the ski about 8 inches apart. One ski should be a few inches ahead of the other, and the knees should be loose. The body should be slightly bent below the waist. The Telemark position is, of course, most unsound.
On average ground the ski-sticks should be held together in the left hand, leaving the right hand free to hold a spare coil of rope. If it is necessary to brake or to control your speed, you should do so by stemming and not by the stick.
On difficult ground you should use the stick to control your speed—a recourse which is seldom, if ever, justified, except when running on the rope. It is quite easy to hold both the sticks and also a spare coil of rope in your two hands; and if you intend to brake with your sticks, you must, of course, put your sticks together and get both your hands on to them. The most efficient stop turn on a rope is the Christiania helped out with the sticks. If you are unroped, a yard or two of sideslip after a sudden stop is quite a good thing, but if you are roped, you need to stop in the smallest possible compass, especially if you are leading and the man behind falls. For this purpose there is nothing to beat the stop Christiania helped out with the sticks. As a rule, however, stemming is sufficient without using the sticks. Good runners can, of course, make a series of linked turns on ski, and there are few prettier sights than a skilful party on a rope descending in a series of Stemming turns.
Whether leading or going last, always keep your partner fully informed as to your changes of speed or direction. If the back man feels that he is going to fall, he must shout out at once, so as to give the leader time to stop by a stick Christiania. Similarly the leader, if he comes to a steeper gradient, should warn his partner that the speed is likely to increase.
Be prepared to fall neatly and with the maximum of effect. Should the leader fall into a crevasse, don’t allow yourself to be dragged after him. Throw yourself on the ground, and bring your ski round, as you fall, at right angles to the track and below you. This is more difficult than might be imagined. An indifferent runner, or even a good runner who had not trained himself to expect a fall, would run a big risk of being pulled into the crevasse by the first man.
The ‘falling Christiania’ is the best method of avoiding being pulled after the leader into a crevasse.
On fairly steep slopes it is best not to run in line. A and B should run side by side. Provided the rope is long enough (and at least 75 feet should be allowed between each partner), there is no danger that A and B will fall into the same crevasse. A and B will probably not be exactly side by side. B will be just a little behind A. In other words, the line of the rope will not be exactly at right angles to the parallel lines of the two tracks cut by A and B. This side-by-side method is much easier than running in line; if A suddenly quickens in speed, the only result is that A, instead of being side by side with B, tends to run on ahead, and the two tracks tend to close up together until the speed is readjusted. So, too, if B falls suddenly, A has much more chance and more room in which to make a stop Christiania than if they were running exactly in line. Also it is not necessary for either A or B to hold a coil of rope in his hands. If the snow is smooth, the rope need not be taut between the runners if they are running side by side. It cannot be allowed to hang loose and to sweep the snow.
All that has been said above applies equally to three men on a rope: three on a rope is, however, a more difficult combination; the position of the middle man liable to both fore and aft jerks is far from enviable. The best man should be placed in the middle. It is, however, surprising how easily a party of three practised roped runners can execute straight running and even combined turns on a rope.
Ropes that are employed in winter should be new. Old summer ropes should not be used up in winter. Ropes break much more easily in winter than in summer, and the strain is much greater in the event of a fall into a crevasse owing to the greater speed on ski than on foot.