Convoy (32 page)

Hobson had been quite sure of that until Yorke scribbled a few figures on a pad. The convoy attack had stopped by 2100 on both nights, so they could assume the U-boat dived deep at that time and an hour later was somewhere astern running on the surface, already charging batteries. By daylight next day, about 0700, he had nine hours’ charge in his batteries.

At daylight he could – if he wanted to take the risk – still see the convoy, but if he was running on the surface and able to see the convoy, then one of the escorts was just as likely to spot him, or pick him up on radar, even though the sets the frigates had at the moment were crude.

The important thing was that from 0700 until the German attacked that night was at least twelve hours. During that time the convoy had made about seventy miles, and zigzagged at least once, probably twice, and perhaps thrice. It was quite impossible (even if he had the zigzag diagrams in front of him) for the U-boat to race ahead of the convoy and submerge at a point up to fifty miles away where he knew the convoy would not just pass, but pass immediately overhead. From one side of the convoy to the other was only 1200 yards. The first two attacks had been made on the fourth and fifth columns. That meant not only was the U-boat picking a spot across which a convoy 1200 yards wide would pass, but two columns only 200 yards apart.

The Ted could tear around for half an hour at nine knots submerged so he could change his position by, say, five miles (leaving himself some juice in the batteries to manoeuvre for the various attacks), but if he moved on the surface or submerged then Johnny’s escorts would find him: the two frigates were crisscrossing ahead of the convoy all the time, night and day. Yesterday Johnny had put his third corvette right in front, only a few hundred yards ahead of the commodore, and no Asdic had produced an echo, that much was obvious. The U-boat, Yorke had demonstrated to Hobson, was not entering the convoy box that way.

Finally, almost cross-eyed with fatigue, Yorke shut his notebook. It must be black magic, an old recipe kept in an ancient sock by a charcoal burner’s great-grandmother in the depths of the Hartz mountains, levitation, knowing which form to fill in or which bureaucrat to bribe…what other explanations were there? He undressed and slid into his bed. If the weather worsened he would envy those with bunks – the only way he could stop himself sliding out of this well-sprung bed as the ship rolled would be by lying spread-eagled on his back.

Years of watchkeeping meant Yorke could waken within a few minutes of the time he set himself, and he woke just before a cadet knocked on his door, telling him it was nearly noon. After a brisk shower and a shave – during which time he could see through the porthole that the weather had improved slightly – he dressed and went up to the bridge. The
Penta
was missing.

Captain Hobson said he had called the commodore about eleven o’clock, and from the commodore’s reply it seemed the Swede was claiming engine trouble again. He had, just like the previous two days, pulled out of the column, slowed down and let the convoy draw ahead. Yorke could see for himself that the
Penta
was now out of sight astern, and the convoy had altered course at eleven thirty according to the zigzag diagram.

Grey ships steaming along on a grey sea under a grey sky; a long grey swell rolling in from the west. There had been no hint of the sun at noon, so there had been no sights; the barometer was staying the same. Yorke walked into the chartroom to look at the chart. Hobson had put a pencilled cross, with the time and date, showing the noon position by dead reckoning, and the convoy’s zigzag progress across the chart was so slight he had to use a sharp pencil. Six knots – Columbus’ little ships must have crossed to the New World at about that speed when running before the Trade winds. Six knots. A man walking briskly made five. The convoy from Liverpool to Freetown was going the whole way at slightly more than the speed of a man walking to church on a Sunday morning with a nip in the air. That was the speed at which most convoys crossed the Atlantic, simply because six knots was the speed that most small merchant ships could guarantee to maintain…

Suddenly in his imagination he saw astern, out of sight just below the curvature of the earth, the
Penta
and the U-boat. He saw them stopped close to each other, the U-boat rolling and pitching uneasily in the swell, a grey cylinder, tiger-striped with rust, the waves slopping and squirting through the gratings of the deck plating. Did the Swede lower a boat and take across fresh bread and other comforts? Pass across special hose and pump over diesel fuel?

He found himself sketching the two vessels lying close together, using the pad left for the navigator’s rough calculations. Neither merchant ship nor submarine would dare get too close to each other because even a slight collision could sink the U-boat. But if the Swede passed a cable and took the U-boat in tow at slow speed, a hose could be passed without any trouble and without any risk of collision.

In fact the
Penta
could tow the U-boat back to within sight of the convoy.

Or, more likely, the Swede could chase the convoy at full speed, say fifteen knots, with the U-boat on the surface astern of her, charging batteries at the same time… From the high vantage point of the
Penta
’s monkey island they could keep a sharp lookout for the British escorts, knowing the
Penta
’s bulk would hide the U-boat from radar, and once they were close, within three or four miles, they could slow down – as they had done before – and the U-boat could dive at the last moment.

The U-boat would still be outside the convoy, outside the box with three corvettes and two frigates circling round it, Asdics pinging, the sound waves radiating out with sensitive receivers waiting to catch even the hint of an echo from something solid. And the hydrophones, like old men’s ear- trumpets, listening for unusual noises, the sound of a U-boat’s electric motors and the swish of the propellers. But the hydrophones were useless when very close to a convoy, deafened by the pounding of the pistons of the merchant ships, whether they were steam or diesel… The effect would be the same as a quavery old lady trying to make herself heard to someone using an eartrumpet as a brass band marched by thumping out a lively ‘Colonel Bogey’.

Captain Hobson was leaning over the chart table beside him and Yorke suddenly realized the Yorkshireman was staring at him open-mouthed. ‘No one would expect what old lady to compete in what?’ a startled Hobson asked, and Yorke realized he had spoken his thoughts aloud.

‘Hydrophones,’ he said lamely. ‘They’re like an old man’s eartrumpet. Sound carries fantastically under water. Very effective, a hydrophone, providing the operator is well trained. Some chaps get a sort of sixth sense. Of course, you can’t chase something at high speed, or your own noise deafens the hydrophone operator.’

‘What about the old lady?’ Hobson asked.

Yorke was embarrassed at trying to explain his thoughts to this down-to-earth man.

‘I was thinking that an old lady wouldn’t try and compete with a brass band by shouting into an eartrumpet…’

‘I should hope not,’ Hobson said. ‘Mind you, eartrumpets have gone out of fashion now, you know. Haven’t seen one for a long time. Nor a brass band, come to think of it. Still plenty of old ladies around –
competing
old ladies, too.’

‘That bloody Swede,’ Yorke said. ‘I was thinking of her meeting the U-boat back there, over the horizon…’

‘Aye, I’m glad you’ve got round to thinking about that,’ Hobson said with an about-time-too note in his voice. ‘I’ve been thinking of them passing over bottles of schnapps and tins of Stockholm tar. And saucy postcards – you’d be surprised what those Scandinavians get up to. I see you’ve been sketching it,’ he said, pointing at the pad.

‘And fuel, too,’ Yorke said, tapping the chart table with his pencil.

‘Aye, that’d be a help; but I still don’t follow what you meant about the old lady and the eartrumpet.’

‘I’m not too sure myself,’ Yorke admitted.

‘I don’t know about competitions, but an old lady would have to be very stupid to try and shout into someone’s eartrumpet if a brass band was going by,’ Hobson said doggedly.

‘You’d think so, wouldn’t you,’ Yorke said, smiling sheepishly. ‘In fact if it was your eartrumpet you wouldn’t even
expect
the old lady to say anything until the band has gone by. Or if you were the old lady you’d keep your mouth shut until the band passed, then you’d say your piece.’

‘Aye, that makes sense,’ Hobson agreed. ‘Doesn’t seem to have much to do with wars and Swedes and U-boats and things, but it makes sense. Are you worrying about some old relative who uses an eartrumpet?’

‘No, nor anyone who plays in a brass band, but for an eartrumpet, substitute the hydrophone in an escort, and an Asdic, too. The brass band is a merchant ship. The old lady – well, she’s quiet, so let her be a U-boat. Where does that get you?’

Hobson thought for a minute or two. ‘Absolutely nowhere. A picture of an old lady playing a hydrophone in a brass band, maybe. Where does it get
you
?’

‘A Swedish ship rejoining the convoy slowly, twin screws and two engines thumping away merrily, almost deafening the hydrophone operator in an escort, and a U-boat running almost silently on electric motors just underneath her. All the hydrophone operator hears is the thudding of the merchant ship’s pistons; the Asdic appears to ping off the merchant ship’s hull – no one thinks there could be a U-boat under there. Like a double-decker bus, or a hen with a chick under her wing. Or an old lady singing
Deutschland
Uber
Alles
as she trots along in the middle of a brass band which is playing “Land of Hope and Glory”.’

‘Well, I’m buggered,’ Hobson said, his eyes wide. ‘You’ve got something there, lad. It explains the Swede slowing up for the last few miles. And the ships torpedoed are always round the
Penta
– in this convoy, anyway. The murderous bastards. What do you do now?’

The first thing was to have a word with Johnny Gower. And it had to be a word, a hail, not a flag signal or a radio conversation. The
Penta
was by far the best candidate for the crown of villainy, but it might still be someone else; someone steaming along in one of the columns and guessing that the Swede was the prime suspect. Therefore Johnny Gower had to have a good reason for coming close alongside the
Marynal
with the
Echo
, close enough for them to be able to talk with loudhailers – luckily the
Marynal
’s gunnery control Tannoy was loud enough, if the loudspeaker on the monkey island was turned round to point over the starboard side.

Getting Johnny close alongside was, fortunately, one of the situations they had visualized in Liverpool: in the list of signals was one where, when the
Marynal
hoisted the ‘W’ flag or flashed it in Morse to the commodore (it meant in the International Code ‘I am in need of medical assistance’), he immediately passed the signal by Aldis to the senior officer of the escort because the
Echo
carried a doctor, and she would immediately close the
Marynal
– a perfectly normal manoeuvre. All ships would have read the signals; all seamen could hazard a guess at what might have happened – someone in the
Marynal
had a suspected appendicitis, a seaman had broken a limb, or was running a high fever… Something beyond the capacity of the ship’s chief steward who traditionally acted as a merchant ship’s district nurse, finding the symptoms in a medical handbook and opening up the medicine chest for medicaments. His usual job in the
Marynal
, from the teasing that Yorke had heard, was painting on gentian violet in the usual fight against what the French called
papillons
d’amour
or butterflies of love, but the more prosaic British called crabs.

A few words of explanation to Hobson, and a moment later the cadet had dragged the ‘W’ flag with its pattern of blue, white and red inset squares from the pigeonhole flag lockers, clipped it to the flag halyard, and hoisted away. With the flag streaming in the wind and the halyard made up on the cleat the boy picked up the Aldis lamp, aimed at the commodore, and started calling up, flashing the dot dash of the letter A, repeated until the commodore answered with the dash standing for T, and then for good measure flashed ‘W’.

Watkins reported to the bridge with a set of spanners and was sent up to the monkey island to adjust the gunnery loudspeaker. The one and only microphone, Yorke discovered, was also on the monkey island, so he would have to stand up there for his conversation with Johnny. Muffled up in a duffel coat he would pass for one of the ship’s officers.

Yorke then went into the chartroom. With the wind on the port bow and Johnny coming up to starboard, on the lee side, it was going to be easier for Johnny to hear him than for him to hear Johnny. Still, he was forgetting the power of a frigate’s loudhailer, and the main thing was to get his ideas across in as few words as possible.

The cadet put his head round the door. ‘Commodore’s calling up the
Echo
, sir.’

‘Very well; tell me when the frigate gets within two columns of us.’

Johnny had imagination and, knowing him, he would by now be furious at losing six ships with not one depth charge dropped on a U-boat: this was his first experience of an insider attack, although in Liverpool Yorke had spent a couple of hours discussing with him all that was known about them. It had taken only fifteen minutes to give him the whole background, but Johnny was fascinated and let his imagination run. In the end he had come back to Yorke’s original idea, which he dubbed Yorke’s Law of the Recurrent Turnip, out of deference, he explained, to the neutral Swedes, who had given their name to a similar vegetable.

Swedes, turnips, insiders, torpedoes… Eleven dockets representing eleven previous attacks…and now they were watching the Swede, to be honest, because Clare had phoned him one morning.