Authors: Dudley Pope
Tags: #code, #convoy, #ned yorke, #german, #hydra, #cipher, #enigma, #dudley pope, #u-boat, #bletchley park
‘Without breaking a leg,’ Yon added.
‘Yes, I shall regard that as par for the course.’
He found the Croupier and Hazell radiating excitement. Hazell, earphones clamped over his head, was writing rapidly on a signal form, a number of which the Croupier was already holding and inspecting like a bridge player who had just been dealt a perfect no-trump hand.
The Croupier turned to Ned and explained above the dull roar of the diesels: ‘Old Doughnuts is just sending off his night orders and questions. We’ve copied signals to five U-boats, and one for us is just coming over now. I thought you’d like to be here when I put it through the cash register.’
Ned shook his head with sheer frustration. BP, the Admiralty and ASIU now had no idea where the U-boats were, thanks to the switch from Hydra to Triton and the Mark III Enigma, but here on board the prize U-boat an ASIU group had an actual machine, the key to the cipher, a pile of signals…and a pair of burnt-out valves.
Hazell’s right hand kept jotting as his ear heard the Morse dots and dashes and his brain translated them into letters. From time to time his left hand moved up to the front panel of the receiver to make a slight adjustment to the tuning.
He tore a page from the pad, handed it to the Croupier and continued writing on the new sheet.
‘That’s all for us,’ the Croupier said. ‘Let’s get the book and put it through the cash register. You have the keys…’
Ned went through to the Captain’s cabin opposite, pulled out the padded panel, unlocked the safe and took out the manual. As he relocked the door and pocketed the keys, he found he was holding the Triton manual as though it was an early Shakespeare, and was startled to find when he returned to the wireless cabin that the Croupier was cocking his Walther automatic.
‘Just in case the prisoners have worked out why we’re here and try to rush us since we’re surfaced,’ he explained, reaching for the manual. ‘Just think, Ned: this flatulent typewriter –’ he tapped the Enigma machine which was, indeed, like a plump portable – ‘and this manual are the key to the Battle of the Atlantic, and the Battle of the Atlantic is the key to the war, and freedom for millions.’
Ned smiled patiently and said: ‘Yes, quite. Hurrah and whizzo. I’ve been wearing my Freedom braces and working on that basis ever since Watts and I went to see the PM.’
‘Oh, you’re a miserable sod,’ the Croupier grumbled. ‘Get excited just for once! This is Robin Hood and Christmas and V for Victory and Cowboys and Indians and bugger Cromwell all rolled into one!’
‘Yes – but just bear in mind, Red Riding Hood, that you have to keep an eye open for the Big Bad Wolf!’
The Croupier opened the manual. ‘Right, I’ll translate and read it out, and you juggle with the rotors. Now, let’s find the right day.’ He flipped through the pages. ‘Here we are. Now, these settings for today would have been put on the Enigma at just past midnight.’
Ned opened the lid of the machine, revealing the typewriter keyboard in front, then the three rows of glass-topped letters duplicating the keyboard, and then four rotors already fitted, with four spare rotors in a rack to the right.
‘The four-rotor Mark III isn’t any bulkier than the models the Wehrmacht and Luftwaffe use,’ he commented. ‘Perhaps an inch or so wider.’
The Croupier nodded, and with his right index finger marking a place in the manual said: ‘Right, from those eight rotors – no, wait a second; take out the four they were using the last time and the four spares. Now, here’s the first one we need.’ He pointed to the Roman numeral VI. ‘Find that.’
Ned sorted through the rotors until he found one with the number engraved on it. ‘So I put that one in position, out of the way.’ He glanced curiously at the rotor, with its twenty-six letters of the alphabet neatly engraved round it, so that it looked like a huge coin with letters replacing the milled edge.
‘Right,’ the Croupier said briskly, ‘now II…then VII…and finally I.’ He had been reading them out so that seven was ‘vee one one’.
Ned clicked the rotors in position, put the remaining four spare rotors in the rack to the right, and waited for the next instruction.
‘Right, now we have to fix each rotor in relation to its disc, or wheel.’ He glanced up at Ned, noted his look of impatience and said: ‘Yes. I know, but let’s work slowly and avoid mistakes. So here we go. The first disc number is twelve.’
Ned counted on his fingers the letters of the alphabet until he reached twelve. ‘L.’ The Croupier nodded in agreement and Ned turned the notched disc of the first rotor until a mark on it was against the letter L on the rim.
‘Three,’ the Croupier said. ‘This is like housey-housey. Letter C!’ Ned took out the second rotor, rotated the notched wheel, and replaced it.
‘Twenty-two…’ The Croupier started counting but Ned quickly went back four from Z. ‘V – for victory, by jingo!’ He adjusted the third disc.
‘Now fifteen.’
Ned turned the fourth disc until the mark was against O on the rotor, and after replacing it read out the sequence: ‘L,C,V,O.’
‘Right,’ said the Croupier, ‘now we’ve set each rotor in relation to its own disc. Now we have to set the four rotors in relation to each other.’
As Ned shut the lid of the machine he was conscious that Hazell was still writing on the signal pad, and that he had four or five pages held down under his left elbow.
‘Here we go,’ the Croupier said. ‘Four figures representing letters of the alphabet.’
Ned looked down at the machine. The four small slots in the lid, side by side, revealed a single letter of the alphabet on each of the four rotors, and alongside each window a section of a notched wheel also protruded.
‘Ten,’ said the Croupier, adding: ‘That’s the letter J.’
Ned pressed down on the first notched wheel and rotated it until he could read the letter on the rotor in the window.
‘Second is nineteen.’
‘S!’ said Ned, rotating the second wheel.
The third letter proved to be P and the fourth was R.
Ned dropped the hinged front of the box ready for the next and last settings – fitting a series of small plugs into sockets, the whole thing looking like a miniature telephone switchboard.
‘The
Stecker
, as the Teds call ’em,’ said the Croupier. ‘Only four for today – connect the F plug to the S socket, T to M, that’s it; then P to K, and S to B. Now we’re ready to see what old Doughnuts has for us.’
Ned swung round the back of the chair, sat down in front of the machine and flipped up the on-off switch.
The Croupier put the sheet from the signal pad in front of him and Ned slid a blank pad and pencil close by.
‘Right – the preamble, which isn’t in cipher,’ the Croupier said. ‘We might as well write it all down. Ready? “
B der U
to ULJ, time of origin 18.22, 44 letters in text, first part of one part then…”’ The Croupier’s brow wrinkled. ‘Oh yes, that three-letter bit means it’s in the Triton cipher. All the preamble setting is BJEK.’
Ned leaned forward and turned each of the four discs until they showed, from left to right, the four letters BJEK in the windows.
The Croupier picked up the pencil and pad. ‘Ready,’ he said, ‘the magic word is ZCAL.’
Then, with the rotors set at BJEK, Ned slowly typed ZCAL, with the Croupier noting down the corresponding letters as they lit up on the lamp board.
‘There we are, WLDP. We’re nearly there, Ned!’
Ned turned the discs until the engraved letters on the edges of the four discs showing in the windows were WLDP.
‘Let’s check,’ said Ned. ‘First we had the machine on the correct setting for the day.’
‘Correct.’
‘Then we set the discs to BJEK, which are the random letters chosen at Kernével.’
‘Correct.’
‘Then we typed the first four letters of the signal, ZCAL, which with the BJEK setting gives us WLDP on the lamps.’
‘Correct. Now you set the discs to WLDP…’
‘And then we’ll get the hot words from Doughnuts,’ Ned said cheerfully. ‘Right, you read out the letters from the signal, and then as I type you write down whatever letters these lamps show.’
The Croupier read letter by letter and as Ned tapped the corresponding key the Croupier wrote down the letter lit up by the lamp.
Finally, with the last letter typed and its encoded equivalent lighting up, the Croupier groaned.
‘Brief and not very exciting. Doughnuts is telling us: “Report position and fuel and torpedo expenditure.”’
‘Sounds as though we should have made a routine signal last night: and this is the routine reminder.’ Ned commented. He swung round on the seat and saw that Hazell was still busy taking down more signals.
‘Let’s knock out some more of those and see what he’s telling other boats.’
The Croupier took the pile of signals forms from under Hazell’s elbow and the two went back to work with the Enigma machine. As the Croupier copied down the last letter coming up on the lampboard, he grunted.
‘That’s more like it. Doughnuts to UL. “Proceed full speed grid square QA 94 convoy reported course 095 speed six knots.”’
Ned pictured the gridded chart. ‘That’s several hundred miles east of us.’
‘Right, so let’s do the next.’
As the Croupier glanced at it, he commented: ‘Ah, this is a boat report to Doughnuts.’
The signal was brief but explicit as the Croupier translated and read it out, explaining that he was inserting punctuation: ‘“Sunk two ships ten thousand tons, depth-charged fifteen hours, after hydroplanes damaged. Contact with convoy lost. Returning to base.” That’s UBT.’
He took another signal ‘Another to Doughnuts.’
They began to work at the Enigma again as Hazell pulled up one earphone with a sigh. ‘Phew, must have been children’s hour for the U-boats! They can keep quiet for ten minutes now, so I can give my hand a rest!’
Again the Croupier grinned. ‘Another U-boat reporting to Doughnuts from grid square LA 19 –’
‘That’s near us,’ Ned said.
‘…Well, he’s damaged. He says: “Attacked convoy grid square LA 19 zigzagging seven knots through mean course 085 heavily depth-charged and lost contact.”’
They put five more signals through the machine and found them to be either routine sighting reports, or Kernével requesting meteorological reports and ordering several U-boats to report their positions.
Finally the Croupier looked at his watch. ‘Time to give Jemmy a spell.’
‘Very well. He’d better have a quick course on this machine before he turns in. We’re going to have to put every signal Hazell picks up through the cash register. A week’s U-boat signals will be welcome at ASIU and Operations Room.’
‘Sobering thought, isn’t it?’ muttered the Croupier as he switched off the Enigma and gave Ned the manual to return to the safe, ‘that these signals –’ he waved the pages ‘– are being read by Doughnuts and his U-boats, and by us: the cuckoo in the nest.’
Screaming alarm bells, as though they were trapped inside a bell with madmen hammering the outside, froze all three men for a moment. Hazell automatically shut off the receiver without realizing he did it, and threw open a row of knife switches. Ned grabbed the Triton manual and the Croupier shut down the Enigma lid.
‘Alarm,’ Hazell said. ‘Diving alarm.’
By then Ned was already taking the half a dozen paces into the control room, arriving as the first of the oilskin-clad lookouts landed with a heavy crash at the foot of the ladder, his cork-soled boots acting like mallets on the steel plating, and cursing the second man who landed on top of him before he had time to roll clear. The two men, clumsy as bears in oilskins, looked as though they were wrestling as they tried to get out of the way, knowing two more lookouts and a lieutenant were due any moment. They were too slow to avoid the last two lookouts, although the four writhing and angry men managed to get clear while Jemmy stopped in the conning tower to secure the hatch.
Ned, for once utterly out of his element, realized that he had in a few moments heard a complete sequence of orders, from the bridge and from Yon, who was now standing beside the two men operating the hydroplanes.
First had been the alarm bells clattering through the ship, followed by Jemmy’s bellow of ‘Clear the bridge for diving!’ Then Yon had given orders, repeated on the telegraphs, to stop the diesels and disengage the drives. Then more telegraphs as Yon ordered the electric motors to be engaged with the propeller shafts, at the same time telling other men to close the diesel air intakes and exhaust ports.
Then the engine room had signalled to the control room. ‘Ready to dive’, the other compartments in the boat had reported they were prepared for diving, and then the four lookouts had done their Marx Brothers act. And, as the hatch closed in the conning tower, Jemmy shouted as he spun the wheel to clamp it down hard on its rubber seal: ‘Flood! Take her down fast, Yon!’
Ned stood fascinated but helpless, still holding the Triton manual, as Yon gave a string of orders, his voice loud now the fierce thunder of the diesels had stopped.
Everything seemed to happen at once: there was a great roaring as air was thrust out of the ballast tanks by the sea rushing in; from aft came the ever-increasing whine of the electric motors and the vibration of the propellers turning, and the boat began diving, her bow dipping sharply.
Above and outside the hull there were a couple of crashes as waves hit the conning tower, then the sea was silent as the boat slid downwards below the surface.
That seaman, Ned worked out, is operating the forward hydroplanes and his dials show he has them hard down, forcing the bow to dive. Next to him was Ordinary Seaman Keene, responsible for the after hydroplanes, but a dial seemed to show he had them adjusted for ten degrees, which should mean the stern was lifting slightly and thus helping to force the bow down in a steep dive.
Jemmy, obviously standing at the top of the conning tower hatch, shouted down: ‘How’s she going, Yon?’
Yon glanced up at the moving needle on a dial.
‘Nicely, sir: sixty-five feet and descending.’
‘Take her down to a hundred and fifty and put Hazell on the hydrophones. Is the Commander there?’