Ice Station Zebra (7 page)

      Swanson bent over to check the plot, closely watching the tiny pinpoint of light and the tracing pencil move back toward the approximate center of the elongated triangle formed by the four red crosses. "All stop," he went on. "Rudder amidships." A pause, then: "All ahead one third. No. All stop."
      "Speed zero," Raeburn said.
      "Twenty-one twenty feet," Swanson said to the diving officer. "But gently, gently."
      A strong, steady hum echoed in the control center. I asked Hansen, "Blowing ballast?"
      He shook his head. "Just pumping the stuff out. Gives a far more precise control of rising speed and makes it easier to keep the sub on an even keel. Bringing a stopped sub up on a dead even keel is no trick for beginners. Conventional subs never try this sort of thing."
      The pumps stopped. There came the sound of water flooding back into the tanks as the diving officer slowed up at the rate of ascent. The sound faded.
      "Secure flooding," the diving officer said. "Steady on one hundred feet."
      "Up periscope," Swanson said to the crewman by his side. An overhead lever was engaged, and we could hear the hiss of high-pressure oil as the hydraulic piston began to lift the starboard periscope off its seating. The gleaming cylinder rose slowly against the pressure of the water outside until finally the foot of the periscope cleared its well. Swanson opened the hinged hand grips and peered through the eye-piece.
      "What does he expect to see in the middle of the night at this depth?" I asked Hansen.
      "Never can tell. It's rarely completely dark, as you know. Maybe a moon, maybe only stars, but even starlight will show as a faint glow through the ice-if the ice is thin enough."
      "What's the thickness of the ice above, in this rectangle?"
      "The sixty-four-dollar question," Hansen admitted, "and the answer is that we don't know. To keep that ice machine to a reasonable size, the graph scale has to be very small. Anything between four and forty inches. Four inches we go through like the icing on a wedding cake: forty inches and we get a very sore head indeed." He nodded across to Swanson. "Doesn't look so good. That grip he's twisting is to tilt the periscope lens upward and that button is for focusing. Means he's having trouble in finding anything."
      Swanson straightened. "Black as the earl of hell's waistcoat," he said conversationally. "Switch on hull and sail floodlights."
      He stooped and looked again. For a few seconds only. "Pea soup. Thick and yellow and strong. Can't see a thing. Let's have the camera, shall we?"
      I looked at Hansen, who nodded to a white screen that had just been unshuttered on the opposite bulkhead. "All mod cons, Doc, Closed-circuit TV. Camera is deck mounted under toughened glass and can be remote-controlled to look up or around."
      "You could do with a new camera, couldn't you?" The TV screen was gray, fuzzy, featureless.
      "Best that money can buy," Hansen said. "It's the water. Under certain conditions of temperature and salinity, it becomes almost completely opaque when flood-lit. Like driving into a heavy fog with your headlights full on."
      "Floodlights off," Swanson said. The screen became quite blank. "Floodlights on." The same drifting, misty gray as before. Swanson sighed and turned to Hansen. "Well, John?"
      "If I were paid for imagining things," Hansen said carefully, "I could imagine I see the top of the sail in that left corner. Pretty murky out there, Captain. Blindman's buff, is that it?"
      "Russian roulette, I prefer to call it." Swanson had the clear, unworried face of a man contemplating a Sunday afternoon in a deck chair. "Are we holding position?"
      "I don't know." Raeburn looked up from the plot. "It's difficult to be sure."
      "Sanders?" This to the man at the ice machine.
      "Thin ice, sir. Still thin ice."
      "Keep calling. Down periscope." He folded the handles up and turned to the diving officer. "Take her up like we were carrying a crate of eggs atop the sail and didn't want to crack even one of them."
      The pumps started again. I looked around the control room. Swanson excepted, everyone was quiet and still and keyed-up. Raeburn's face was beaded with sweat, and Sanders' voice was too calm and impersonal by half as he kept repeating, "Thin ice, thin ice" in a low monotone. You could reach out and touch the tension in the air. I said quietly to Hansen, "Nobody seems very happy. There's still a hundred feet to go."
      "There's forty feet," Hansen said shortly. "Readings are taken from keel level, and there's sixty feet between the keel and the top of the sail. Forty feet minus the thickness of the ice-and maybe a razor-sharp or needle-pointed stalactite sticking down ready to skewer the _Dolphin_ through the middle. You know what that means?"
      "That it's time I started getting worried too?"
      Hansen smiled, but he wasn't feeling like smiling. Neither Was I, not any more.
      "Ninety feet," the diving officer said.
      "Thin ice, thin ice," Sanders intoned.
      "Switch off the deck flood, leave the sail flood on," Swanson said. "And keep that camera moving. Sonar?"
      "All clear," the sonar operator reported. "All clear all around." A pause then: "No, hold it, hold it! Contact dead astern!"
      "How close?" Swanson asked quickly.
      "Too close to say. Very close."
      "She's jumping!" the diving officer called out sharply. "Eighty, seventy-five." The _Dolphin_ had hit a layer of colder water or extra salinity.
      "Heavy ice, heavy ice!" Sanders called out urgently.
      "Flood emergency!" Swanson ordered--and this time it was an order.
      I felt the sudden build-up of air pressure as the diving officer vented the negative tank and tons of seawater poured into the emergency diving tank. But it was too late. With a shuddering, jarring smash that sent us staggenng, the _Dolphin_ crashed violently into the ice above, glass tinkled, lights went out and the submarine started falling like a stone.
      "Blow negative to the mark!" the diving officer called. High-pressure air came boiling into the negative tank; at our rate of falling, we would have been flattened by the sea pressure before the pumps could even have begun to cope with the huge extra ballast load we had taken aboard in seconds. Two hundred feet, two hundred and fifty, and we were still falling. Nobody spoke; everybody just stood or sat in a frozen position staring at the diving stand. It required no gift for telepathy to know the thought in every mind. It was obvious that the _Dolphin_ had been struck aft by some underwater pressure ridge at the same instant as the sail had hit the heavy ice above. If the _Dolphin_ had been holed aft, this descent wasn't going to stop until the pressure of a million tons of water crushed and flattened the hull and in a ificker of time snuffed out the life of every man inside it.
      "Three hundred feet," the diving officer called out. "Three fifty--and she's slowing. She's slowing."
      The _Dolphin_ was still falling, sluggishly passing the four hundred-foot mark, when Rawlings appeared in the control room, tool kit in one hand, a crate of assorted lamps in the other.
      "It's unnatural," he said. He appeared to be addressing the shattered lamp above the plot which he had immediately begun to repair. "Contrary to the laws of nature, I've always maintained. Mankind was never meant to probe beneath the depths of the ocean. Mark my words, these newfangled inventions will come to a bad end."
      "So will you if don't keep quiet," Commander Swanson said acidly. But there was no reprimand in his face; he appreciated as well as any of us the therapeutic breath of fresh air that Rawlings had brought into that tension-laden atmosphere. "Holding?" he said to the diving officer.
      The diving officer raised a finger and grinned. Swanson nodded and swung the coiled-spring microphone in front of him. "Captain speaking," he said calmly. "Sorry about that bump. Report damage at once."
      A green light flashed in the panel of a box beside him. Swanson touched a switch and a loud-speaker in the deckhead crackled.
      "Maneuvering room." The maneuvering room was in the after end of the upper-level engine room, toward the stern. "Hit was directly above us here. We could do with a box of candles, and some of the dials and gauges are out of kilter. But we still got a roof over our heads."
      "Thank you, Lieutenant. You can cope?"
      "Sure we can."
      Swanson pressed another switch. "Stern room?"
      "We still attached to the ship?" a cautious voice inquired.
      "You're still attached to the ship," Swanson assured him. "Anything to report?"
      "Only that there's going to be an awful lot of dirty laundry by the time we get back to Scotland. The washing machine's had a kind of fit."
      Swanson smiled and switched off. His face was untroubled; he must have had a special sweat-absorbing mechanism on his face. I felt I could have done- with a bath towel. He said to Hansen, "That was bad luck. A combination of a current where a current had no right to be, a temperature inversion where a temperature inversion had no right to be, and a pressure ridge where we least expected it. Not to mention the damned opacity of the water. What's required is a few circuits until we know this polynya like the backs of our hands, a small off-set to allow for drift and a little precautionary flooding as we approach the ninety-foot mark."
      "Yes, sir. That's what's required. Point is, what are we going to do?"
      "Just that. Take her up and try again."
      I had my pride so I refrained from mopping my brow. They took her up and tried again. At two hundred feet and for fifteen minutes Swanson juggled propellers and rudder  until he had the outline of the frozen polynya above as accurately limned on the plot as he could ever expect to have it. Then he positioned the _Dolphin_ just outside one of the boundary lines and gave an order for a slow ascent.
      "One hundred twenty feet," the diving officer said. "One hundred ten."
      "Heavy ice," Saunders intoned. "Still heavy ice."
      Sluggishly the _Dolphin_ continued to rise. Next time in the control room, I promised myself, I wouldn't forget that bath towel. Swanson said, "If we've overestimated the speed of the drift, there's going to be another bump, I'm afraid." He turned to Rawlings, who was still repairing lights. "If I were you, I'd suspend operations for the present. You may have to start all over again in a moment, and we don't carry all that number of spares aboard."
      "One hundred feet," the diving officer said. He didn't sound as unhappy as his face looked.
      "The water's clearing," Hansen said suddenly. "Look."
      The water had cleared, not dramatically so, but enough. We could see the top corner of the sail clearly outlined on the TV screen. And then, suddenly, we could see something else again, heavy, ugly ridged ice not a dozen feet above the sail.
      Water flooded into the tanks. The diving officer didn't have be to told what to do: we'd gone up like an express elevator the first time we'd hit a different water layer, and once like that was enough in the life of any submarine.
      "Ninety feet," he reported. "Still rising." More water flooded in, and then the sound died away. "She's holding. Just under ninety feet."
      "Keep her there." Swanson stared at the TV screen. "We're drifting clear and into the polynya--I hope."
      "Me too," Hansen said. "There can't be more than a couple of feet between the top of the sail and that damned ugly stuff."
      "There isn't much room," Swanson acknowledged. "Sanders?"
      "Just a moment, sir. The graph looks kinda funny-- No, we're clear." He couldn't keep the excitement out of his voice. "Thin ice!"
      I looked at the screen. He was right. I could see the vertical edge of a wall of ice move slowly across the screen, exposing clear water above.
      "Gently, now, gently," Swanson said. "And keep that camera on the ice wall at the side, then straight up, turn about."
      The pumps began to throb again. The ice wall, less than ten yards away, began to drift slowly down past us.
      "Eighty-five feet," the diving officer reported. "Eighty."
      "No hurry," Swanson said. "We're sheltered from that drift by now."
      "Seventy-five feet." The pumps stopped, and water began to flood into the tanks. "Seventy." The _Dolphin_ was almost stopped now, drifting upward as gently as thistledown. The camera switched upward, and we could see the top corner of the sail clearly outlined with a smooth ceiling of ice floating down to meet it. More water gurgled into the tanks, the top of the sail met the ice with a barely perceptible bump, and the _Dolphin_ came to rest.
      "Beautifully done," Swanson said warmly to the diving officer. "Let's try giving that ice a nudge. Are we slewing?"
      "Bearing constant."
      Swanson nodded. The pumps hummed, poured out water, lightening ship, steadily increasing positive buoyancy, The ice stayed where it was. More time passed, more water pumped out, and still nothing happened. I said softly to Hansen, "Why doesn't he blow the main ballast? You'd get a few hundred tons of positive buoyancy in next to no time, and even if that ice is forty inches thick, it couldn't survive all that pressure at a concentrated point." -
      "Neither could the _Dolphin_," Hansen said grimly. "With a suddenly induced big positive buoyancy like that, once she broke through, she'd go up like a cork from a champagne bottle. The pressure hull might take it, I don't know, but sure as little apples the rudder would be squashed as flat as a piece of tin. Do you want to spend what little's left of your life traveling in steadily decreasing circles under the polar ice cap?"
      I didn't want to spend what little was left of my life in traveling in steadily decreasing circles under the ice cap, so I kept quiet. I watched Swanson as he walked across to the diving stand and studied the banked dials in silence for some seconds. I was beginning to become a little apprehensive about what Swanson would do next. I was beginning to realize, and not slowly, either, that he was a man who didn't give up very easily.
      "That's enough of that," he said to the diving officer. "If we go through now with all this pressure behind us, we'll be airborne. This ice is even thicker than we thought. We've tried the long, steady shove and it hasn't worked. A sharp tap is obviously what is needed. Flood her down, but gently, to eighty feet or so. A good sharp whiff of air into the ballast tanks, and we'll give our well-known imitation of a bull at a gate."