For background, the British Antarctic Survey base at Halley Bay was set up in 1956 (by the Royal Society, who later passed it on to BAS) at one of the few feasible sites in that area. Much of the coastline of Antarctica is fringed by ice shelves, typically several hundred feet thick and floating with seawater beneath them, in contrast to the Inland Ice which is grounded. These ice shelves form sheer cliffs along the ice front and when the explorers of the Heroic Age encountered the Ross Ice Shelf and sailed along it without finding any landing spots, the name they coined for it was The Barrier.
In our case it was the Brunt Ice Shelf, and the Advance Party of the Royal Society found it just as much of a barrier for most of its length. Near the southern end of this ice shelf they found several fractures causing wide embayments in the sheer cliffs, which were nearly a hundred feet high. One of these clefts – which they named Halley Bay – had a gentle ramp of wind-blown snow that offered an easy route up to the flat, level surface of the ice shelf. They established their base about a mile inland from this.
Later, in the mid-sixties, summer fieldwork for surveyors and geologists based at Halley Bay took place in the mountains several hundred miles to the east, and so preparations began as soon as the lighter skies returned after the dark of winter. The mechanics overhauled the Muskeg tractors (or kegs, for short) for the heavy loads that would be hauled there for the depots, and the field party prepared equipment and resumed dog training.
On 24th August 1964 Jock Thomson finished some work on his keg and wanted to take a short test run. With a companion he drove down to the Halley Bay ramp where they found two others out for a walk. They picked these up, drove back up the ramp, and headed north towards a small cabin once used by a biologist. Apparently they were unaware that it was only fifty yards from the edge of the ice cliff. Onward they thundered, until Jock suddenly saw the edge close ahead and pulled up sharply. Gingerly they reversed clear of the drop only five yards away, and noticed as they drew back that they had already crossed a crack a foot wide. Normally no one would go that near to the edge without very careful checks, as cornices can form along the top of an ice cliff so that what seems to be the edge is really some distance out on a flimsy overhang.
This brings to mind a frighteningly similar episode from a few years earlier, but in that case with a disastrous outcome. The Norwegian-British-Swedish Antarctic Expedition had set up a base called Maudheim, also on an ice shelf and less than five hundred miles to the north-east of Halley Bay.
In February 1951 four men set off from their base on a late-night test run with a Weasel (an ex-military tracked vehicle, a type used by several post-war expeditions). Several hundred yards of the low shelf ice had broken back so that they reached the ice front sooner than they expected, with fog also confusing their navigation. The Weasel went over the edge, into the sea, and sank. The four men jumped out but all landed in the water and found that it was impossible to climb up the sheer ice front that was over ten feet high. A current was dragging them under the ice, and within minutes three of them had drowned.
The fourth managed to climb out on to an ice floe and began marching around to keep warm. At last their absence was noticed by those back at the base and the accident was discovered. The rescuers took five hours to dig a boat out of a deeply buried dump, and the lone survivor spent twelve hours marching about on his floe before they could reach him. It was fortunate that the floe had drifted no more than a mile during that time.
It was not only tractor drivers who could do silly things. My dog team in the mountains would be the Hairybreeks and I still had a lot to learn about them, their leader Bodach (we pronounced it BOE-dack), and dog-driving in general. On the same day as Jock’s adventure, several of us took the Hairybreeks out for a run despite semi-whiteout, a temperature of −30° C and a stiff breeze.
“The Gin Bottle” was our unofficial name for a feature visible some miles north-east of the Base, a low angular rise which, with a lot of imagination, could be compared to a gin bottle lying on its side. This ridge was surrounded by a crevassed zone with the official name of the McDonald Ice Rumples, and the explanation was that the seafloor here was shallow enough for the ice shelf, normally floating free, to run aground and become distorted. (Writing in 2020, the latest of the Halley Bases (VI) has again been evacuated for the winter because of major fissures extending across the ice shelf and concerns that a large section might break loose. This grounded area of the Ice Rumples is of major importance as it may be what holds much or all of the Brunt Ice Shelf in place.)
Dave Hollas had been to the Gin Bottle in the past, making glaciological measurements, so with him as a guide Mike Turner and I decided to take the opportunity to see the place from close up. With three, one had to ride on the sledge; this was always colder and often uncomfortably so. As we got moving we realised that the breeze, about 10 knots, was straight into our faces.
Bearing in mind the crevasses around the prominent ridge, we decided to keep about a mile inland of the Gin Bottle itself in order to stay clear of them. As we drew close, though, we saw a crevasse some distance ahead that was large enough to warrant avoidance. I was driving, and turned the dogs to the right until it was no longer visible ahead. It seemed likely that it would continue across our path but just as a narrow crack and I guessed that it was between twenty and fifty yards ahead. Thus I continued to ski alongside and give the command for Bodach to keep turning to the right. The safe move would have been to stop, walk to the front of the team, and lead them around, but recently Bodach had been responding to my commands of “Owk” with startlingly sharp right turns. I assumed that he would now do the same.
This time he only turned in small stages and the crevasse came into sight ahead of us, about three feet wide and directly on our course. Now a Nansen sledge will cross a three-foot crevasse with ease if it meets it squarely but on this occasion we were approaching at a shallow angle. A dog can vanish down a crevasse of that size from any angle. With more experience I would have kicked off a ski and stamped on the brake, bringing the sledge to an immediate halt. Instead, I concentrated on trying to steer away. My yells of “Owk, owk!” became more frantic as Bodach and the lead pair reached the crevasse, hopped on to the bridge, and began to run along it as if it were a track marked out for them.
Crevasse bridges range from rock-solid to eggshell-flimsy, and the best way to tell the difference is to probe them while standing on the solid surface beside them. Straying on to them will also show how sound they are but is definitely not a good way. For the moment this bridge was firm enough to take the dogs but Mike and Dave, both riding on the sledge at that point, wisely leapt off and ran alongside with one on either side of the crevasse. By now the whole team had followed the front three and were all trotting along the crevasse bridge. The sledge joined them, with the slightly sunken bridge just wide enough to take both runners and guide them neatly along. I heaved on the handlebars and with the sledge now empty I managed to swing it so that the runners led it off the bridge, at the same time as Bodach veered right again and the other dogs followed. A moment later we were back on good, safe, solid snow, and the whole incident had lasted less than half a minute.
Well clear of the crevasse, I halted the dogs and the other two rejoined us. We had had enough of both cold and excitement for one day and so we set off straight back to Base. With the wind now on our backs the return run of about seven miles seemed wonderfully warm compared to the outward leg, and we had plenty to chatter about. I for one only slowly began to realise just how close we had been to losing some of the dogs and possibly a sledge too. (As we were close to Base we could probably have returned for a salvage operation if the bridge had collapsed, but neither dogs nor sledges come well out of a crevasse fall.) We did have spare sledges but definitely no spare dogs. It was certainly a lesson for my coming field season. Back on the Base, with people chuckling about Jock and his close shave, I was relieved that the other two joined me in keeping relatively quiet about our own narrow escape.