Convoy (31 page)

The third mate was a particularly poor lookout, apart from having a panicky manner, whereas Reynolds had sharp eyesight and, it was quite clear to Yorke, very sensibly only reported things to the third mate when action was needed: reporting to him a sighting of something not connected with the
Marynal
would usually provoke a spasm of near panic, recrimination and needless shouting. The risk that Reynolds ran was that the third mate might subsequently sight something and bellow across in front of the wheelhouse (thus ensuring that the captain in his cabin on the deck below would hear), pretending not to hear Reynolds’ reply that he had already sighted the object and decided not to report it. However, Captain Hobson was not the man to be impressed by the third mate, Yorke realized, but for the sake of discipline there was nothing he could do about it.

The DEMS gunner acting as additional bridge lookout and watching the
Penta
reported nothing unusual. He was a careful man and took out a notebook and read the entries to Yorke: an officer had walked out to the port wing of the bridge and read the log, like that in the
Marynal
, which was streamed from a boom amidships with a repeater recording the distance run at the inboard end; an officer and someone with the four stripes of the captain had gone up to the monkey island and, with binoculars, had inspected the ships in the convoy. That was all.

Had they shown an interest in any particular ship, Yorke asked.

‘No, sir; looked to me as though the captain slept late, then came up to the bridge and had a look round with the officer o’ the watch to see who bought it last night.’

‘Any interest in the escorts – their positions, that sort of thing?’

‘No, sir, I was watching for that ’ticularly. Neither looked at ’em nor ignored them. Just about what one would have expected, sir.’

‘And no garbage?’

‘No, sir, I’ve been watching for that, too.’

In the course of a day a ship created a great deal of garbage: eggshells from, say, forty breakfasts, and odd scraps of bread, often a few mildewed loaves, empty jam and marmalade tins…on top of them, as the day progressed, there would be potato peelings, the outside leaves of cabbages or cauliflowers, chunks of white fat cut from pieces of meat. All had to be disposed of in the sea, the universal dustbin, but standing orders for merchant ships said it was not to be thrown over the side until nightfall. Under no circumstances was it to be thrown over in daylight. Submarine commanders, Allied and German, were skilled detectives where floating rubbish was concerned: from half a dozen bad oranges, a few leaves of cabbage or a sodden loaf, a submariner could tell how long it had been in the water. The line in which the rubbish floated on the water – usually the cook’s mate had two or three drums to empty – could show the ship’s course (or its reciprocal).

A submarine commander examining a few sodden bits of garbage could, if he recognized that it had been in the water for, say, six or seven hours, know for certain that within forty miles or so in one direction or its opposite there was a convoy. In little more than two hours on the surface at fifteen knots he should sight it… So rubbish was thrown over as night fell, things like the big tins used for jams and marmalade were supposed to have holes pierced in the bottom so that they sank, and bottles were to be broken, but cooks’ mates had little imagination, and rooting round in old oildrums – the usual dustbins – was something they would do only if the chief officer was standing over them. As it was, throwing over the rubbish at nightfall gave a short enough margin – twelve hours of darkness, and during that time a six-knot convoy would be lucky to have steamed seventy miles. A zigzag or two might throw off a pursuer, but zigzags, as Jemmy was only too keen to point out, were only zigs to one side and then zags to the other of a straight line from Point A to Point B, and because the whole book of zigzag diagrams was given to every neutral ship sailing in a British convoy, it was obvious the German U-boat commanders had copies, too, so finding point B was not too hard.

No messages from Johnny Gower, so there were no ideas from the escorts. And, he reflected bitterly, no messages from him to Johnny Gower either. Sailing in the
Marynal
was a crazy idea, and one he would never have had except that he was getting desperate. A contented mind might be a continual feast, but a desperate mind is a fertile ground for crazy ideas. Now he was stuck for weeks in this damned convoy. If only one of the frigates – better still one of the corvettes, because that would not weaken the escort too much – developed some defect that required her to go into Londonderry, or anyway return to the British Isles – then he could cadge a lift back and report to Uncle.

It was hard to guess what Uncle’s reaction would be. Perhaps patient and accepting that the only way to be sure the Swedes were not up to some nonsense was to sail in a convoy and watch them. He might be irritated, having had second thoughts himself soon after Yorke left London. He might be under great pressure from Downing Street, in which case Yorke would receive a monumental bottle, and Uncle was just the kind of man – quick tongue, fluent command of the language – to be good at handing out bottles to errant lieutenants.

Well, standing up here on the bridge looking astern, like a seagoing Wellington surveying the lie of the land at Waterloo (well, perhaps not a battle that later rated a railway station; maybe one of his defeats. Or just staring down from the heights of Torres Vedras was more like it) was achieving nothing. He had some old copies of
Horizon
to read – it was always amusing to read that bunch of Spanish War poets and writers patting each other on the back and saying how wonderful they were, even if several had fled to the safety of America, shouting across the Atlantic how freedom must be defended at any price. He went down to his cabin, knowing they would irritate him so much he would end up reading a pre-war
Blackwood’s
again – there were several left in the bookcase.

He had been reading for less than half an hour when Cadet Reynolds came down to report that the
Penta
had just received permission from the commodore to complete her repairs. Yorke put on warm clothing and went up to the bridge, where Captain Hobson was standing inside the wheelhouse, examining the Swedish ship with binoculars.

‘She’s swinging out now and reducing speed,’ he said. ‘It’s what he told the Commodore last night.’

‘Doesn’t seem to be smoking much,’ Yorke commented.

‘Aye, but I had a word with our chief engineer. He says the smoke yesterday could have been just the normal sooting up, and what the Swede actually stopped for might have been something quite different.’

Yorke went back to his cabin and tried to forget about the
Penta
until, an hour before nightfall, he watched her rejoining the convoy. There was the same high speed approach from over the horizon, the same slowing down two or three miles astern, and the same leisurely return to her position in the convoy.

He commented to Captain Hobson: ‘That’s just how we’d do it. And he hasn’t called up the commodore so I suppose all his repairs are completed.’

Wind force six to seven from the south-east, ten-tenths cloud, attack began at 1955, the first three ships in the sixth column torpedoed. The second of them had been abreast the
Penta
, the third abeam of the
Marynal
.

As an angry and baffled Yorke sat in his cabin and wrote the details of the second night’s attack in his notebook he was still looking for patterns. In the previous night’s attack when two ships had been torpedoed in column four and one in column five, the two ships had obviously been hit by the U-boat’s bow tubes and the single by the stern tube. Assuming the U-boat was firing single torpedoes, the first night’s attack had cost him three fish.

Tonight’s attack had been much simpler: the German had not used his stern tube: he had probably stayed in the same place between columns five and six and fired single torpedoes as the first, then the second and then the third ship in the column passed across his sights. Three ships were hit within a hundred yard square. The second had probably been hit before she had time to swing clear of the first; the third was hit because the U-boat turned slightly. That much was clear from the timing of the explosions and the positions – the third one had been abreast of the
Marynal
when the torpedo hit.

Three torpedoes probably used up tonight, three last night, six in all. Eight more left. Or perhaps the U-boat had missed one ship. That would make seven, but no one was likely to see a miss because the Germans were using electric torpedoes.

All of which meant that this insider still had seven or eight torpedoes. By now he was probably many miles away from the convoy, surfaced to charge batteries. He might even be sending the brief signal to Kernevel, telling Doenitz of his success.

The signal need only be brief, giving the grid square of the convoy and its course and speed, and that the U-boat had sunk six ships (and the
Oberleutnant
would probably guess at their total tonnage). Or he might wait a day or two until he could add that he was returning to base. In this weather, with a following sea, he could probably make fifteen knots on the surface – a cold, wet and wild pitch-and-roll ride but no one would mind because they were heading for home after a successful operation. They would cover a good three hundred and fifty miles a day until they came into the range of Coastal Command; then they would have to be wary, probably moving submerged in daylight. But in three days they would be in somewhere like Brest or Lorient, St Nazaire or La Pallice, perhaps Bordeaux. No action damage to be repaired and cockahoop at having sunk at least six enemy ships without having one depth charge dropped by the convoy escort…

Yorke found himself writing:

1 Has the Ted skipper eight fish left?

2 Will he attack tonight and still firing singly?

3 Why would he risk another attack, having sunk six ships? Answer. He should be confident in view of lack of opposition.

4 So it is probable that if he has fish left, he’ll attack again tonight.

5 If the
Penta
drops astern again today and there is an attack tonight will that be significant? Not really, on present evidence.

He looked again at the last few words ‘…not really, on present evidence.’ It was as simple as that: there was nothing that linked the
Penta
to the insider, and that was that.

The whole thing made as little sense out here in the North Atlantic as it did in the ASIU’s underground room at the Citadel. The question then was the same as it was now: how does the bloody insider get inside?

The escorts made the convoy into a box open at the top (but U-boats couldn’t fly) and the bottom. So the only way for a U-boat to get inside the convoy was through the bottom – by approaching submerged. That much was obvious, even to an imbecile.

How many times had he gone over all this before leaving London? The U-boat could get ahead of the convoy, dive, hide beneath a cold layer of water where the escorts’ Asdics would not pick it up, and then come up to periscope depth after the leading escorts had passed and the convoy was steaming above, like someone popping his head out of a manhole to say ‘Boo’ at the passing ladies. So far, so good, for the insider. All very practical, and nothing even an escort commander as smart as Johnny Gower could do about it, providing the Ted captain found the cold layer.

Now for the
but
. It was a large-sized ‘but’ and one on which the waiting-ahead-of-the-convoy theory sank in a flurry of foam. It was a fact of German U-boat life (and confirmed by trials made in the U-boat recently captured intact by the Royal Navy) that although it could make nineteen knots on the surface using its diesel engines, once it dived and had to use its two electric motors, its speed and range were limited by its batteries. It could make nine knots for an hour before its batteries were flattened, or it could stay under for three days (in an emergency) making one or two knots. In other words the batteries contained only so many ampere hours, and the captain could use them up at a rush by going fast for a short time, or eke them out by going slowly. Like an alcoholic with a bottle of whisky – empty it in an hour, or make it last three days.

What the U-boat could not do was make six knots submerged for days on end… Unless he was making only a knot or two, he had to surface every twenty-four hours and run his two big diesels so that the generators recharged the batteries.

How is he escaping from the convoy box after a night’s attack so that, out of sight of the escorts, he can run on the surface and charge his batteries? We have answered that – he just dives deep and lets the convoy pass over him. And he stays down until he knows he is out of sight of the convoy, then he surfaces, starts up the diesels, gives the lads a breath of fresh air, and lets in the clutches on those big generators, so that the batteries start getting a charge for the next night’s operation.

All well and good: Yorke had gone over the sequence enough times in the Citadel, with Jemmy and the Croupier joining in. There was no set time required for charging the batteries – obviously it depended how much current the electric motors had used the previous night. Perhaps five hours; maybe ten. Jemmy had been emphatic that three days submerged would leave the crew in a poor state because of lack of oxygen and humidity, and probably flatten the batteries. Such a long dive was usually the last resort, when a hunted U-boat was trying to sneak away from an attacker who had the time to stay around and pursue the search.

How did the bastard get back into the box?

That was the question that stumped them in the ASIU headquarters at the Citadel; and now he had seen a convoy attacked by an insider on successive nights, he still had no idea. Captain Hobson had decided that the U-boat simply got ahead of the convoy again during the day, submerged, and came up to periscope depth at the right moment among the columns.