Using the same principle, I intended now to probe the underwater ice shelf which held up Botany Bay. The thought of it brought a knot into my stomach — what if I should fail? How extensive was it? All I had gathered from Kearnay was that the berg itself had tilted and the underwater shelf had lifted Botany Bay bodily as it did so. Loose ice afloat in the iceport had also consolidated, making the trap complete.
Would ten charges of ten kilograms each be enough?
First, before the actual freeing attempt, I intended by a crude imitation of the scientists' method to try and determine the thickness of the underwater shelf.
I stalked past Wegger in my preoccupation.
'Where are you off to, Shotton?'
'It's my show, isn't it?'
'It's her neck,' he retorted.
I found one of the augurs on the quarter-deck. Linn was standing, remote and strained, at the binnacle. The only concession Wegger had made was to remove the icy metal of the grenade from against her skin. It was now lashed to her shoulder.
'Bo'sun!' I called. 'Lend a hand here, will you?'
I explained quickly and tensely that I wanted three holes drilled in the ice with the augur. Wegger held the Luger on me when I requested small charges of explosive weighing only half a kilogram each and gave them only on the assurance I wouldn't ignite them myself.
The bo'sun and I went ashore. It didn't take very long to drill three holes each a foot deep, one at the stern, one amid-ships, and the third under the bow.
I tamped the charges home and lit a short length of fuse for each. Ullmann had joined Wegger, — two gun barrels followed every movement I made.
'I'm going below-decks,' I told the man. 'Fire these charges at three-minute intervals. Take cover behind the bulwarks when you do so. They're only small charges but they'll throw up splinters.'
I ordered the rest of the crew to stand clear, explained to Wegger what, I was about and went below. He eyed me speculatively but did not interfere.
I hurried below. The only light in the dark interior was a dim kerosene lamp which hung from a beam.
A figure behind bars reached hands at me, his face contorted.
I stopped with an oath. I had quite forgotten Botany Bay's cavalcade of horrors.
This was a tableau of the dreaded 'tiger's den' — and it looked it. Behind the bars was the waxwork figure of a man, stripped to the waist. A great weal from the cat-o'-nine-tails oozed make-believe blood. The first figure which had caught my attention supplicated through the bars like a caged wild animal.
I spared the tableau a passing glance and hurried on.
These were only waxworks. The living horrors walked the deck above.
At the ship's side I put my ear against the teak planking. The subsequent crash of the charge nearly deafened me. I had forgotten in my tense state that ice is such a good conductor of sound that you can hear a man speak through it at a distance of 100 metres.
Apart from an odd creak or two, the test told me nothing.
There was three minutes to go to the next shot.
I took the oil lamp from its gimbals and made my way down a central gangway amidships, specially built to show the displays of convict imprisonment on either hand. I began to sympathize with the Cape Town taxi driver's hysterical girl.
The second explosion followed. This time I kept my ear a short distance from the planking. Even so, there was a marked difference. The concussion reverberated, heavy and thudding, unlike the first smacking whiplash. Its message was plain — here the ice was solid.
The third shot, which I tracked in the ship's bluff bow, was the lightest of the three. What the tests had established was that the ice was thickest under Botany Bay's keel amidships, and thinnest in the bow and stern. She could well have been balanced with the underwater shelf acting as a fulcrum.
I returned to the deck past Wegger who had stood guard in the central gangway.
'Well?' he demanded when we reached the deck.
I avoided looking in Linn's direction.
'I don't rightly know,' I replied. I didn't, in point of fact.
'Get on with the job and stop fooling round,' he rapped out.
For the actual release attempt itself I took the final ten-kilogram charge and climbed overside under the gun muzzles to position it. I had laid the other charges previously while the crew took breathers at the capstan. I tamped it home with a length of spar. I measured an identical length of fuse to the other nine.
Now for the acid test.
'Hands to charges!' I called. One man per charge in order to have a simultaneous blast. The fuses were long enough to give everyone ample time to shelter below.
I raised my hand.
'Ready, men? Right! Light fuses!'
The matches went down.
'Everyone below!'
Wegger, Ullmann, Linn and I sheltered together near the chamber of horrors tableau. The crew kept to themselves.
We waited.
My watch said nearly nine o'clock. In the interval before the explosions were due I wondered about Smit and the other two weathermen. There was no way now that the launch could take place on schedule at ten o'clock 110 kilometres distant.
Then the hull kicked, kicked again. Even I wasn't expecting the size of the explosion. It was like a ragged broadside, the charges exploding irregularly within seconds. There was a heavy thump nearby as part of a waxwork display collapsed, and a rattle of ice falling on the main deck, followed by the heavier sound of a block or spar which had been dislodged from the rigging.
From under our feet came a grinding, rending, tearing sound. Botany Bay might have been dragging across a reef. It lasted only seconds.
Then everything went quiet.
The deck remained at its previous list.
Botany Bay was still fast.
I had failed.
I threw a desperate glance at Linn. The light was too dim to see what was in her eyes. Equally desperate was my rush of thought to try and jump our watch-dogs. Wegger, Ullmann — either one of them would get me even if I managed to grab the other's gun. I wouldn't stand a chance.
My voice sounded as harsh as the grinding ice.
'Let's get up on deck and see.'
Wegger fell back a pace or two and whispered something to Ullmann. The nerves at the base of my stomach were stretched to breaking-point.
We emerged on deck. The charges didn't seem to have done much beyond dig a few man-sized holes. The force of the explosions had dissipated mainly upwards and the main and topgallant yards were all askew as a result, like a slovenly crew's work.
The only thing that I registered in my numb dismay was that the wind had changed. Also, the berg had slewed further and the wind was now filtering through the entranceway and was stirring the protected water of the iceport.
I had to have time! Time to think, time to work out something else before the two started on Linn.
I said the first thing that sprang to mind. 'I'm going up aloft — I want to inspect the ice from high up…'
Before Wegger could reply I swung myself into the lower port shrouds. The ratlines to the maintop seemed to stretch upwards never-endingly. The ship in its ice cradle remained rock-steady.
I went up hand-over-hand to the maintop. Then up to the top-mast shrouds. Then on to the cross-trees. It was only when I was nearly up the topgallant shrouds that I got a grip on myself and slowed down — to think.
I felt the slender spar give a shudder. I threw one arm about the topgallant backstay to steady myself. My heart leapt. Was the hull, now looking like a toy more than 25 metres below me, starting to loosen? Or was it simply the over-strained mast starting to give at last?
Was it wind?
I climbed higher up the mast above the level of the iceberg's summit. The south-wester smacked me in the face.