by Andy Selters
To minimize the seriousness of crevasse falls, the most important thing team members can do is to keep as much slack as possible out of the rope between them. Any slack in the rope is distance that a falling climber accelerates (at 32 feet per second squared!) before the adjacent partner can begin to brake the fall. With a slack-free rope, the force comes onto the adjacent partner immediately, before the falling climber gets very far into the hole and before the fall generates an impact velocity. Thus, with a slack-free rope many crevasse falls can be held simply by leaning against the pull (see fig. 2.5), without resorting to ice-ax arrest.
Slack-free does not mean taut, however. Ideally, the rope simply drapes from each climber to the next with neither slack nor tension (see fig. 2.6). A climber who constantly pulls rope tension on his partners generates emotional tension as well.
Glacier travel would be a simple matter of parading together on a snug rope if it weren't for people's different paces, and for hills and corners in the way. These factors must be coordinated. Obviously, the team can go no faster than its slowest member; faster climbers must have patience, and dawdling climbers must consider their partners! Other than this, a simple rule of thumb can greatly help rope coordination: each member tries to keep the proper amount of slack in the rope ahead.
By this rule, when one member starts up a hill and slows down, the partner behind slows down as well. When the person ahead reaches easier ground or starts downhill, the partner behind tries to speed up, although the person ahead must also take it a bit easier Experienced travelers can anticipate speeding and slowing, and at appropriate times give bursts of effort to steady the overall progress, knowing that a slowing rest will come shortly.
In addition to keeping the rope free of slack, to reduce the seriousness of crevasse falls members need to be concerned with keeping the rope perpendicular to the direction of the surrounding crevasses. When a climber falls into a crevasse and the rope is oblique to the crevasse wall, he or she will pendulum farther into it (accelerating at something less than 32 feet per second squared), coming to rest at a point directly below the adjacent partner who held the fall. With the rope nearly paralleling a crevasse there's also the danger that two or more members will end up over the same crevasse, and if one goes in the other(s) probably will too.
Figure 2.5 Holding a moderate crevasse fall
Thus, when a rope leader chooses to circumvent a crevasse, the other members heading around it should not follow the leader's tracks to the edge of the crevasse; they should start moving in the leader's direction, keeping the rope as perpendicular to the crevasse as possible. Of course, they also must be careful not to walk into another crevasse.
Turning a corner; which usually means end-running a crevasse, requires similar but more subtle coordination (see fig. 2.7). As the for ward member starts around the corner; the following member still travels somewhat toward him, and slack tends to accumulate (see figs. 2.7a and 2.7b). Thus the lead member should speed up some and the following one should slow (see fig. 2.7c). When the rope span is halfway “around” the corner they reach an inflection point, and the two travel somewhat away from each other, tending to generate tension. To compensate, the lead member slows and the following one speeds up (see fig. 2.7d).
Figure 2.6 Appropriate amount of slack rope
“Among glacier ambuscades a party that has not found unity will fall to pieces.”
—Geoffrey Winthrop Young, 1946. Mountaincraft.
Figure 2.7 Turning a corner or end-running a crevasse (top view)
When crevasses run generally perpendicular to a team's intended route, keeping the rope perpendicular to them poses little problem. But when the crevasses generally parallel a route, the only solution is to travel en echelon, where members travel not in the leader's path, but take their own parallel course off to the side (see fig. 2.8). While en echelon, team members ideally travel in the same direction, but on opposite sides of the crevasses. All members must coordinate their individual courses with their partners.
Ideal conditions for traveling en echelon don't arise often, however. Crevasse systems can lead members in different directions, making it difficult to coordinate travel or even to return together. In a heavily crevassed area one member might come to a dead end and then the whole team must retreat until that member can find a way around. Too, if there are novices in the party it might be wise to not trust their ability to avoid crevasses on their own. This means that, before deciding to fan out, a party must balance potential safety with practicality.
WHITEOUTS
Glaciers exist because they're in cloudy places that receive more snow than sunshine, and it's an unfortunate fact that light refracts through clouds about the same way it reflects off snow—;giving clouds and snow the same white color: All too often clouds envelop a glacier, making the world white, destroying any sense of depth, diffusing even the nearest bumps and dips into a seemingly infinite, omnipotent whiteness. Disorien-tation in such a featureless world can be profound even in a familiar area, and it can seep into the emotional corners of the mind. Even experienced climbers have made the most basic mistakes in whiteouts, for example mistaking east for west while looking at their compasses. So, the first rule about traveling in whiteouts is don't.
Figure 2.8 Traveling en echelon
When the first rule must be broken, the second rule is to assess the situation analytically, gathering all the information available to you. It's very helpful to have your own or someone else's tracks definitely leading where you want to go, but realize how dependent you are on those tracks. Think twice about going farther if there's a chance of snowfall or wind filling them in. When snowfall is likely to obscure crucial tracks, climbers will mark their routes with wands, as close as a rope's length apart if conditions have the potential to get really bad. A trick for introducing some contour to the ground immediately in front of you is to toss snowballs ahead; with this added texture you can at least see what angle the nearby ground runs at. If it gets to this point though, your best hope may be clever use of map and compass.
For a map to help, you need to establish where you are on the map, and plot a course on it to where you want to go. You'll need to locate yourself as precisely as possible, potentially with only one piece of information: the direction of up and down. Take a compass bearing directly down your whited-out slope, and on the topographical map find the slopes on which you could possibly be standing—;that is, slopes where the contour lines run perpendicular to your reading (see fig. 2.9). Chances are there won't be more than a couple of possible slopes. To help you find just where you are on that slope, an altimeter can be invaluable. Of the altimeters commonly available, only the expensive ones are accurate enough to be really helpful, and even these should be calibrated to a mapped elevation at least once a day. Once you've formed a hypothesis of where you are, plot a course on the map, and take careful note of the aspects of the slopes that your planned route should cross. Then set your compass to the bearing of your plotted route and start out on that bearing. As you go, frequently compare the aspects of the slopes you've traveled (by taking bearings directly downhill again) against those of your hypothesized plot. Based on this, you can reevaluate your hypothesis and, if the new information doesn't jibe, make a new hypothesis.
Figure 2.9 Compass bearing directly downslope will be perpendicular to contour lines on map
In following a compass bearing, it can help to give the compass to the person behind the lead member: This second person sights along the rope going to the leader and directs the course; the lead member has nothing to sight against, and will more easily stray from the bearing. The best attitude for successful whiteout travel is to find and trust the compass readings with mathematical fervor The one who gets lost in the fog often is the one who decides that intuition is smarter than the needle.
These procedures can work easily in an area with relatively “typical” slopes, but in gentle, featureless terrain or heavily crevassed, “densely featured�
� terrain they can present serious challenges. The record includes both successes and failures. One party traversing an icefield in the Canadian Coast Mountains followed careful compass readings through a complete whiteout for 20 miles, and found a crucial cache. On the other hand, an experienced friend of mine chose to wait out a whiteout storm on the Columbia Icefield. After two failed attempts to exit, and with no food or fuel left, he and his partner dug a cave and waited five days before visibility returned.
Those who plan trips across extensive glaciers and icefields find that Global Positioning System devices are very helpful. A GPS unit can allow you to nail your location and can point you in the right direction even better than a compass. However to use these facts effectively it is still imperative to know the fundamentals of routefinding in the mountains, and to track your progress on a map.
HOLDING FALLS: THE GLACIER TRAVELER'S BELAYS
Usually team members depend on one another's body weight, readiness, and ability to ice-ax arrest (in that order) to hold their crevasse falls. Warnings from the leader about potentially weak bridges can serve to remind team members about the importance of maintaining a slack-free rope, since the force of a crevasse fall bearing on a partner via a snug rope often won't pull the partner off balance. The partner resists as shown in figure 2.5, with the force held by the overhand grip on the rope and the leg braced in the snow. If the force does pull the partner off balance, then he or she immediately goes into ice-ax arrest. In areas that are potentially more dangerous, it's smart to carry your ax in an ice-ax arrest grip. A problem with depending on an ice-ax arrest is the inherentdroop of slack rope when members travel together—slack that allows acceleration in a fall. Therefore, hazardous crevasse crossings call for a more substantial belay, where the adjacent partner eliminates all slack and focuses on holding a potential fall. There are four general cases when a belay might be needed (see fig. 2.10):
Figure 2.10 Dangerous situations where a belay might be needed
Crossing fragile bridges over wide crevasses.
Crossing fragile bridges where for whatever reason the rope runs oblique to the crevasse.
Crevasse crossings where one must climb down the near wall and/ or climb out the opposite wall.
When the adjacent climber is on steep and/or icy ground above the crevasse.
Of course, what is “wide,” “oblique,” or “steep” is a matter of judgment. Also, in any of these situations, the severity of the force on the adjacent or belaying climber will be much greater if the crevasse lip is hard and icy.
For places where the potential fall does not justify the set-up time of a full anchored-belay, the boot-ax belay is the most common quick belay. Operated properly, a boot-ax belay should offer improved security over arrest readiness, as the belayer carefully monitors the rope to keep out all slack. Yet with practice it takes but seconds to set up. It should only be used when another ropemate is ready to back up the belayer and to come anchor the rope for rescue if necessary.
Carefully study the drawing of the boot-ax belay (see figs. 2.11a to 2.11d). This is how to set it up:
Figure 2.11a Boot-ax belay
Figure 2.11b Holding weight with a boot-ax belay
Sink your ax nearly to the head, tilting it away from the potential force about 45 degrees. You might have to stamp on it to get it into hard, late-summer snow, or in soft conditions you might have to stamp down a firmer platform.
Loop the rope around the shaft (see fig 2.11b).
Press your “uphill” boot—;the one away from the load—;against the shaft under both strands of file rope, and take the rope in your “downhill” hand (see fig. 2.11c). This is your brake hand, ready to hold a fall by wrapping the rope around your ankle, thereby bending the rope in an S curve. Take careful note of the solid stance shown, with the climber ready to lean on the bent “uphill” leg
This belay should not be counted on to hold a hard fall, and even to hold a moderate force you must be practiced and ready to make it a dynamic belay. That is, you must dissipate the force of the fall gradually, by letting rope through for a second or two, wrapping it around your ankle gradually.
A practiced belayer can set up a boot-ax belay literally in seconds, and with reasonably good snow and a solid, balanced stance it can hold a surprising force. However, as with any belay designed to hold only moderate falls, it is imperative to practice and develop judgment about when it can and cannot be trusted. Spend time with a partner on a steep slope of summer snow, taking in and paying out rope, and practicing mock falls with it.
A similar but more reliable belay that takes slightly more time to setup is the harness-ax belay. Basically, this works by running the rope through a belay device and then through a short extension on the buried ax. Stand with a similar open stance, with your “uphill” leg bearing on a short runner connected to the ax. Clip the climber's rope to a carabiner on that runner, and then run it up to your belay device. (see figure 2.12).
Figure 2.11c Paying out rope
Figure 2.lld Taking in rope
Figure 2.12 Harness-ax belay
When you're faced with the unusual case of a fairly serious crevasse crossing, you'll want to set up an anchored-sitting belay, just as in rock or ice climbing (see fig. 2.13). It will take more time to set an anchor and rig this belay, but with a well-placed anchor in reasonable snow a good belayer can hold the force of virtually any crevasse fall. Anchors are discussed in the chapter on rescues, so at this point suffice it to say that when you set an anchor, make sure you set it to hold in the direction that the potential fall will come from. Tie into the anchor with a runner or the climbing rope, sit down between the climber and the anchor with a minimum of slack in your tie-in, and rig a hip belay or belay device. Compared to a hip belay, a belay device is more foolproof, is easily rigged with a pack on, and it is essential if the belayer needs to “tie off” a fallen partner (see Chapter 4). It's a good idea to carry a belay device for use in a rescue-hauling rig anyway, as described in Chapter 3.
Figure 2.13 Anchored-sitting belay
When setting up any belay across a crevasse, it's crucial to realize that if a climber does fall very far at all, the rope will have to be anchored off. With three or more in a party this usually isn't a problem, as a free member should be able to come over to the belay and do the job. But a two-person party must take this fact more seriously, as the belayer will have to anchor the rope alone, while holding the weight of the fallen partner. (see Chapter 4).
ICE SLOPES
Many crevasse injuries and fatalities are the result of falls from icy slopes, where a waiting crevasse was a catchment. There are two primary concerns here. First, icy slopes demand critical climbing skill, with crampons absolutely secure on your boots, sure posture over your crampons, and positive use of your ice ax. The unforgiving consequences of a fall insist that relaxed concentration and accurate footwork be maintained all the time.
Second, glacier travelers on an icy slope need to recognize when they cannot depend on ice-ax arrest to stop a fall. Too often, teams roped together for crevasses progress up onto an icy slope where an unanchored rope only ensures that one falling climber will pull off ropemates. It's critical to recognize and prepare for this transition from a snowbridge hazard to a slope hazard. Ice-ax arrest can be counted on to stop falls on moderate slopes with favorable snow conditions, but few people fall on this type of ground. Steeper icier slopes where falls are more likely require additional backup.
The running belay (or simul-climb) system is a way to keep moving efficiently on moderate slopes where a backup is wanted. The leader drills in an ice screw or sets a fluke or picket, and clips the running rope to it. The team then keeps moving together with the following members adjusting their pace to keep out extra slack. If the going is easy and the anchors are solid, the leader may choose to have only one anchor along the rope's length, or if the team is challenged or the anchors are dubious, as many new anchors as deemed necessary can be set and clipped. When
rope partners reach an anchor they clip past it, and the last member to reach it notifies the leader If it hasn't been done already, the leader adds a new anchor while the last member collects the old one.
Regardless of the belay system, a team is inherently safer traveling diagonally on a slope instead of directly up or down, because any fall in that scenario will be a pendulum, bringing the force onto teammates and anchors slowly instead of at the sharp end of a plummet. If the slope is icy and/or so steep that any members in the party find their climbing abilities challenged, the team should initiate an anchored belayer-leader system.
AVALANCHES
Winter persists for a majority of the year in glacial terrain, and winter mountaineers who want to live long lives look out for avalanche conditions and avalanche-prone slopes. Avalanches occur when bonds in the snowpack fail; therefore, some of the conditions that cause weak snow-bridges can also cause avalanches. For instance, a substantial spring or summer storm followed by a warm sunny day will generate mushy bridges and probably wet snow avalanches as well.
Most avalanches on glacial terrain come during or soon after heavy storms, or when daytime melting is especially strong. Slopes of 30 to 45 degrees—;moderate steepness—;stand at a middle angle that's shallow enough to accumulate deposits, but steep enough to release an unstable slab. It's smart to stay away from these slopes following a big snowstorm. During summer climbing seasons it's melt-freeze cycles that settle the snow, and it's a game of educated guesses to decide after how many cycles and at what time of day the new snow is stabilized.
