Colin Ross beat Richard on the shoulder and bellowed over the deafening combination of engine, rotor, wind and water, ‘And it’ll get more complicated. As the berg melts it will rise — float higher in the water. That little beach will be a kilometre wide in a week and the reef which is two hundred metres down will be one fifty metres down. If you anchor your boats above submerged ice, they’ll end up aground.’
‘That’s another thing you’ll have to watch anyway, even with one as big as this,’ added Kate anxiously. ‘It will keep going straight up out of the water as it melts until its centre of gravity gets too low to support it. Then it will roll over. It’s difficult to predict and there’ll be no warning. It’ll roll right over on top of you.’
Richard nodded. He knew about the instability of icebergs, but they had problems which needed to be dealt with before they had to worry about the whole berg turning turtle on them.
‘What we need, then,’ yelled Tom Snell, ‘is a matching pair of steep-sided bays with no ice bottom. One on each side. They have to be big enough to berth the last two boats. The bays have to have a wide enough beach to tether a line fore and aft and maybe midships as well. The back ends of the bays really need to be open — sufficiently so, at any rate, for the ice not to interfere with the thrust of the ships’ screws. This is particularly important because the two ships are oil-powered single-screw jobs, extremely powerful but not as flexible as the other four. They will be the main motive force for your dash along the North Atlantic Drift. So their placing is of paramount importance.’
Richard nodded again. There was nothing more to say, really; Tom had summed up the situation perfectly. He roared through to Doug Buchanan, the pilot, ‘Take us down.’
The Sea King dropped over the western edge of the cliff and started working south along the fifty-kilometre flank of ice. The wall before them varied in height and sheerness — it was not all vertical by any means. Some of it reached out in dangerous overhangs, extravagantly fanged with massive icicles, the longest of which dropped off to stab the ocean as soon as the rotors disturbed the air around them. Sections of it were honeycombed with massive caves into which the waters washed, losing their dull greyness at once and taking on the hues of blue and green so spectacularly lacking in the mass of the dead-white ice. In some places the cliffs fell back into broad bays backed by gentle slopes and apparent dunes. The bays were floored by ice running like white sand beaches far, far out into the dull grey water. Only one tenth of the iceberg’s enormous volume was visible in the ice island — the dry ice, they called it — above the surface of the sea. The rest was submerged and plunged out as well as down, in those huge submarine reefs. Because of the dictates of chance, augmented by the work of the engineers and explosives experts, the submerged ice reefs which swept out like wings for two-thirds of the iceberg’s length vanished altogether for the one-third nearest to the bow section. For the thirty kilometres of the high, artificially created forecastle, the cliffs plunged vertically into the depths.
After ten kilometres flying south towards this forward section, the edge of the reefs became visible, swinging up and in to meet the side of the island, and after sixteen and a half kilometres, the reefs ended altogether — and so did the protection they afforded to the sheer sides of Manhattan’s main island.
‘Take us down closer,’ ordered Richard.
This was the area which Colin, Kate and he had discussed at such length, for which they had great hopes. Here the dry ice lost its submarine protection from the battering rams of the surf, and the effect was all but inevitable. Under the solid overhang of cliffs, a great eye socket had been carved by the action of the following waves. They had chosen to start here because this was the side which had been best protected by the hook of ice blown off by Paul Chan and his men. And there it was. The very bay they had been looking for. The perfect place to start.
‘Take us up and over,’ Richard yelled. ‘There should be a matching bay on the other side. If there is, then we can really get to work.’
There was.
The two bays were similar in structure as they had been caused by the same forces working in similar circumstances upon material in the same state. As the waves swept in over the last edge of the submerged ice reef, it thundered against vertical walls of ice. Such was the force of the collision that the cliffs inevitably yielded and so the bays were born. At first, no doubt, they had been more like caves, with beetling overhangs of ice cliff, but as time wore on and ice wore away, so the spray-weakened overhangs began to collapse and at last the caves opened out enough to be called bays. The process which Kate Ross had warned about took a slight hand here and the ice rose sufficiently to cause a relative fall in water level; the last shoulder of the reef rose up and broke the force of the waves for a while, and a beach — a simple, near level slope of ice which had been beneath the reach of the waves’ action — was revealed.
So matters stood at the moment. All Tom Snell and his men had to do was to blow the overhanging slopes down into the sea and make the upper sections of the ice safe, and the very bays they needed would be opened up. The beaches and the last dry heaves of the ice reefs would make perfect anchorage points. The bays would easily accommodate the awaited ships, and could hardly be better placed. Richard felt a huge swell of hopeful excitement as he looked onto the giant white eye socket staring blindly down towards the writhing back of the serpentine Stream which they were so soon to join. It was quite possible that the positioning of the two great ships just at the point where the greatest force of the upper sea pushed hardest against the ice would make the counter-thrust of their great engines all the more effective. It seemed logical. He would have to check it with John and Bob; if it did work like that, it would be quite a bit of good luck.
‘Back!’ he yelled. The Sea King swept out and up. Richard turned to Tom Snell and gestured at the overhangs falling away beneath them. ‘You’ve got until the day after tomorrow.’ If we get through tonight, he thought.
The soldier was no mind-reader. He grinned a tight grin and gave him a thumbs-up.
The Sea King pirouetted and dropped its nose, heading across the ice to Titan, thirty kilometres distant, invisible behind a wall of fog so solid it resembled the ice cliffs below; so huge it dwarfed them. Richard’s elation cooled further: the swirling vapour marked the first tentative meeting of the southward-flowing Labrador Current and the strongly eastward North Atlantic Drift.
Niobe hit the North Wall first, at midnight on the dot.
Richard was standing on Titan’s bridge, staring tensely out into the dark while Sally Bell and the other navigating officers tended the banks of instruments around him. There was nothing to see. The long deck before him carried running lights as required but they and it were cloaked in fog. The foghorn was hooting and out on the bridge wing it was possible to hear Niobe’s horn answering like the call of some mythical beast. He remembered reading of the fogs in these waters being ‘so thick you could cut them and spread them on your bread, like butter’. They were there because of the mixing of cold water and warm somewhere in the depths. There was no sign of the Wall yet. But soon, soon.