Decryption and Intelligence | The Battle of Jutland - Centenary Initiative
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Decryption and Intelligence

Jellicoe’s confidence (as well as Beatty’s) was severely shaken, as he had heard from the Admiralty at 12.48 pm, just four hours before Hipper opened fire on the Lion, that the Friedrich der Große still seemed to be in the Jade Basin; he then found within the next hour that this was not the case but that she was, with her screens of cruisers and destroyers, at sea and close behind Hipper.

The quality and timeliness of battlefield intelligence for command are fundamental. Jutland revealed many instances of wretched intelligence and communications failures; there were myriad mistakes and oversights in information management between London and the fleets.

After signalling that the Germans would take the Horns Reef route, Jellicoe was not given any subsequent intelligence that would have restored his faith in the earlier blunder. He was not told that Michelsen’s destroyers were to rally there, nor that Scheer had ordered Zeppelin reconnaissance.

Between 11.30 pm and 1.48 am Room 40 intercepted various pieces of intelligence, including orders that the German torpedo flotillas had been ordered to meet at the Horns Reef at 4.00 am.

All of this vital information made it plain where Scheer was going, yet incredibly none of it was passed on to the Commander-in-Chief by the Operations Department. The tragic result of this lamentable performance – criminal neglect is not too strong a term – was that Jellicoe was left completely in the dark, when he might have turned north to intercept Scheer at daybreak and inscribed another Glorious First of June in the Annals of the Royal Navy.

His adversary, by contrast, knew that the 64 British destroyers had been placed at the Grand Fleet’s rear and running into them confirmed that he was breaking through at the right point. Jellicoe:

The lamentable part of the whole business is that had the Admiralty sent all the information which they had acquired … there would have been little or no doubt in my mind as to the route by which Scheer intended to return to base. As early as 10.10 pm, Scheer’s message to the airship detachment … was in the possession of the Admiralty. This was practically a certain indication of his route but it was not passed to me.

Jellicoe was attacked on many fronts, for all sorts of tactics that the armchair admirals would have used, in the years before his death but the fact is that it is difficult to bring to battle an enemy that is set on not being engaged. As Admiral Bacon summarised:

Such was Jutland. It proved what everyone already knew, that you cannot make an enemy fight if he does not want to fight, unless you have greater speed and sufficient daylight in which to overtake him; or you can get between him and his harbour and keep him there till he does fight.

Had Jellicoe been better served by intelligence from the Admiralty, and by effective reconnaissance and reporting, his strategy would have improved greatly.

Jellicoe was sent information implying that the destination of the High Seas Fleet was the Horns Reef (although this part of the message was left out). The problem was that, by that point, the Commander-in-Chief had lost confidence in admiralty intelligence, and preferred to rely on his own instinct and the little signals information he was receiving locally:

“German battle fleet ordered home at 10.10. Battle cruisers in rear. Course SSE ½ E. Speed16 knots.” The message was transmitted at 10.41 pm and received in the cipher room on the Iron Duke around 12.05 am. Jellicoe saw the signal between 12.15 and 12.30 am. The chart plot at 10.00 pm would have shown Horns Reef as the destination, even if it was not mentioned by name in the signal.

Jellicoe’s confidence had been shaken by two factors: being told that the High Seas Battle fleet was in harbour and being given information at midday that was clearly wrong.

Kommodore Heinrich’s 10.13 signal to the 2nd and 6th Flotillas (“Our own battle fleet is square 165 epsilon, lower part, at 10.00 pm, Course South”). The Regensburg’s DR was estimated to be about 10 miles out and it did not help that Jellicoe himself was at that exact position at the time stated. This was received by Jellicoe at 10.45 pm, giving the rear most position of the German line as 56° 33’ N, 5° 30’ E on a southern course.

Throughout the night there was a long sequence of signal and reconnaissance failures. Using a combination of Tarrant, Hines and Koever, the following sequence of signals seems to represent the critical ones that could have had a significant impact on the Battle of Jutland, and highlight failures of intelligence co-ordination, carelessness and, according to Hines, a policy of secrecy designed to protect the British access:

  • 21:06. C-in-C to airship detachment: “Early air reconnaissance at Horns Riff is urgently requested”. Decrypted at 22:10 but not passed to Oliver and not sent to the Grand Fleet. “Considered by historians to be one of the key signals of the battle since it clearly showed Scheer’s intended route”.
  • 21:14. C-in-C: “Our own main body is to proceed in, maintain course SSE ¼ E, speed 16 knots”. Decrypted / passed to Oliver / Operations at 21:55 but seen by Jellicoe after 23:30. From this point Beesly contends that “no fewer than sixteen decodes, all of which would have added in some degree to Jellicoe’s knowledge, were passed by Room 40 to Operations Division. Only three of them were sent to Jellicoe”.
  • 21:46. C-in-C to HS Fleet: “Our own main body course SSE ¾ E”. Decrypt passed to Operations at 22:10 and signal sent to Jellicoe at 22:41, a full hour later reading “German battle fleet ordered home at 9.14 p.m., cruisers in the rear, Speed 16 knots. Course SSE ¾ E”. This signal combined the information gleaned from the 21:14, 21:29 and 21:46 signals but left out the 21:06 signal (on air reconnaissance). The 22:41 transmission was received in the cipher room on the Iron Duke around 00:05. Jellicoe saw the signal between 00:15 and 00:30. Almost four hours had elapsed. A chart plot at 10.00 pm would have shown Horns Reef as the destination, even if it was not named.
  • 23:06. C-in-C to High Seas Fleet: “Our own main body at 11 p.m. 12 epsilon (56°15’ – 5°42’ E), Course S.E. ¾ E”. Deciphered at 23:50 but not passed to Jellicoe.
  • 23:14. Flag to the Nassau and the Westfalen: “Course S.E. ¾ S in the direction of Horns Reef”. Intercepted by the Fearless (see Hines) but only decrypted after the battle.
  • 22:32. OC 1st TD to all TBD flotillas: “Be assembled with our main fleet (my italics) at 4 a.m. at Horns Reef or course round Skaw”. Deciphered at 23:15 but not passed to Jellicoe and the vital phrase “with our main fleet” was even carelessly left out of the version passed to the Operations Division.
  • 00:31 (June 1st). AC 2nd SG: “Where is the head of our main fleet at 12.30 a.m? My own position is 106 alpha centre (56°3’ – 6°42’ E)”. Deciphered and passed to Ops at 01:05
  • 00:43 (June 1st). C-in-C to Lützow: “Our main body’s position at 12.30 a.m. 073 alpha”. The response was not passed to Jellicoe.
  • 01:03(June 1st). C-in-C to AC 2nd SG: “Head of our own main fleet at 1 a-m., bottom of alpha (55°50’ – 6°25’ E)”. Deciphered and passed to Ops at 01:25. Not passed to Jellicoe.
  • 02:30. C-in-C: “Main fleet in 101 alpha right middle (55°33’ – 6°50’) course SE by S. Speed 16 knots.” Deciphered and passed to Ops at 03:05. This was passed to Jellicoe at 03:29.
Tactics and Technologies

  1. Range Finding and Course Plotting
  2. The Long range Battle and Shell debate
  3. Battleship Design and Anti Flash
  4. Ordnance
  5. Signaling
  6. Gunnery Performance
  7. Torpedoes
  8. Destroyers, submarines and Torpedoes
  9. Decryption and Intelligence
  10. British Battlefield Intelligence
  11. The line of Battle, Crossing the T versus independent action
  12. The Nelson Touch – Initiative – versus the thinkers