The Battle of Jutland: the use and mis-use of SIGINT

   By mid-1916 the Royal Navy had a well-established Signals Intelligence (SIGINT in modern parlance) department in “Room 40” of the old Admiralty building (although it spread to other offices).  This was under the Director of Naval Intelligence, Captain (soon to be Rear Admiral) Reginald Hall (see Fig. 1 RHS en.wikipedia).

   Wireless stations of the “Y” service along the East coast of Great Britain picked up German naval radio transmissions and sent the intercepts to Room 40 (R40).  There they could usually be deciphered, largely by use of captured enemy code books.  There were also “B” stations equipped with Marconi sets for wireless direction finding on the East coast at Flamborough Head  (54.1⁰ N), near Alnwick (55.4⁰ N) and near Peterhead (57.5⁰ N).  These were spaced at 150 miles and 350 miles to provide triangulation of signal origin (Ref. 1).

   On 30^th May 1916 around 5 pm a German signal to the Hochseeflotte (HSF) “31GG2490” was picked up (Ref. 2).  While its meaning was unknown it indicated an operation deduced as to commence on the following day.  At the same time the DF stations reported a change of 1.5⁰ in the signals originating from the ships at Wilhelmshaven (the harbour specially enlarged for the HSF).  A Marconi engineer seconded to Naval Intelligence (H.G.Round) interpreted this as ships assembling in the River Jade preparatory to a sortie (Ref.3). 

   Acting on this SIGINT, the Admiralty ordered the C-in-C of the Grand Fleet (GF), Admiral John Jellicoe (Je) with battleships anchored at Scapa Flow (510 n. miles from Wilhelmshaven) and Invergordon and with battle cruisers under Vice Admiral David Beatty (By) in the Firth of Forth, to put to sea and sweep the North Sea.  He left Scapa Flow at10.30 pm on the 30^th May 1916.

   Use of SIGINT had therefore enabled the RN to be ahead of the enemy.  Unfortunately, a mis-use of SIGINT then occurred.  Ref.4, quoting the testimony of an R40 member, William Clarke, reports that Captain Thomas Jackson (see Fig. 2 at LHS, as Rear Admiral dreadnought project), the Admiralty Director of Operations (DOps), visited R40 at about 11am (Ref.5) on 31^st May and asked “Where does direction finding place call sign DK?”.  This was the personal call sign of Admiral Reinhard Scheer (Sr) the C-in-C of the HSF.  This specific question was given a specific answer:- “In the Jade”.  DOps did not make any further enquiry of R40 but signalled to Je and By that information, received at 12.35.pm (Ref. 5).  The inference was that the German sortie had been cancelled.  The British ships carried on with, what now looked like, yet another fruitless patrol of the North Sea.

   The question by DOps was inadequate.  R40 staff knew that when Scheer went to sea his personal call sign was transferred elsewhere and at sea he used the sign of his fleet flagship (Ref.4).  Why no-one in R40 corrected Jackson is an example of how people behave in an organisation as hierarchical as the early-20^th Century Royal Navy.  Nelson in 1805 at Trafalgar had accepted a sensible suggestion from his signal lieutenant about his famous message, but Tryon in 1893 had sunk his flagship, 357 men and himself when no-one had queried to his face a dangerous order!

   Had DOps asked the correct question, R40 would have had to reply that they did not know where the HSF was because Sr had maintained radio silence:  he could be anywhere half-a-days steaming at 16 knots from base.

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   By with the Battle Cruiser Fleet (a mistaken nomenclature which reinforced By’s inclination to fight his own battle, where Vice Admiral Franz Hipper (Hr) who led the German battle cruisers knew that he was Befelshaber der Aufklärung Gruppe – Commander of the Reconnaissance Group), having steamed as far East as his orders specified and with the mistaken information that he would not find the Germans, turned North at 2.15.pm to rendezvous with Je’s battleships.  Then, at 2.20.pm a scouting cruiser to his South reported “Enemy in sight!”.

   It is not proposed to re-iterate here the many accounts of the battle which followed in the just-short-of-7-hours until darkness came at 9.pm.  Neither British senior commander was a man of balanced judgement.  Beatty was a great optimist, whose major pre-battle mistake had been to insist on rapid fire from his guns regardless of laying an unbroken train of cordite from the turrets to the magazines.  Jellicoe was a profound pessimist who refused to use his scores of Destroyers, for the purpose for which they had been specifically designed, to break up a German Torpedo Boat attack while he turned in pursuit of a retreating enemy – to say nothing of using the mass of quick- firing battleship batteries also mounted for the same purpose.  He turned away passively instead.  Neither made good use of the vast superiority which a pre-war Liberal government had built or laid down for them.

   It is fair to note that pre-war Naval Intelligence had not detected the well-rehearsed Gefectswendung (simultaneous ship “battle turn-away”) manoeuvre which the Germans had perfected to counter the “crossing of the Tee” which the navies of the world had noted was used victoriously by Togo at Tsushima in 1906 in the Russo-Japanese war.  This had saved the HSF twice on the 31^st May when Sr made his mistakes.

  Nevertheless, at 9.pm on the 31^st May the HSF was trapped on the wrong side of the GF.  If when dawn broke at 2.30.am on the 1^st June it was still in that relative position, its effective annihilation by a 2 : 1 advantage in broadside weight was certain.  Je’s job overnight was to keep it there.  He had to decide which path to the mine-swept channels off the German coast, known to the British, Sr would take to home and safety.  He decided to assume the Southernmost, which was about 170 n. miles from the last known position of the HSF.  The nearest channel to the HSF was about 100 n. miles.  Je’s choice was really wishful thinking – it would give him the ideal start point for a second phase of the battle.  He did not put himself in Sr’s place and understand the German’s desperate intention to get most of his fleet home by the shortest route by a night action, for which his ships were trained (Je’s were not, even after 22 months in which they could have been). 

See Fig. 3, which shows the fleet movements between darkness at 9.pm 31^st May and dawn on 1^st  June 1916.   German SIGINT helped here.  Je had signalled his destroyers to take station 5 n. miles behind the battleships, so that these could be “Free-to-fire” on any ship seen close aboard during the night.  A German station picked this up, deciphered it and signalled it to Sr, so that he knew where to aim his fleet for minimum resistance.  He did not have the paralysing fear of torpedoes which gripped Je.

   R40 picked up and deciphered Sr’s orders to the HSF, summarised them to avoid giving clues to their origin and signalled Je as follows (he had the decoded message at 11.30.am.  (Ref. 5):-

“German Battle Fleet ordered home at 9.14pm.  Battlecruisers in rear.  Course SSE1/4 east.  Speed 16 knots.”

The speed was the maximum of the 6 pre-Dreadnought ships which Sr had un-wisely permitted to accompany him – although Je had failed to punish him for that mistake. Ref. 5 states that the course given was mis-plotted in Je’s flagship so that it appeared co-incident with the ship’s own position.  Taken in conjunction with the error in the Admiralty message of 12.35.pm Je did not accept its validity. 

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He continued to steam towards the Southernmost swept channel.  As the HSF crashed through the destroyers 5 miles behind, using searchlights and with the sound of gunnery but receiving no reports of the confused actions, Je still continued on his chosen course.  Several other messages deciphered by R40, which would have confirmed the 12.35 signal, were passed to Operations but were not signalled to Je.  He said afterwards he would have turned back if he had seen them, but this cannot be known.

(see Fig.4 RHS Warship Profile 14)

   The general in-effectiveness of the British light forces at night (they did manage to sink one pre-Dreadnought) was shown when even two badly-damaged German battlecruisers managed to run the gauntlet at very low speed, although one (Lützow) had to be abandoned later and sunk by own forces.

The failure to have trained his people to report promptly and accurately, from By down to the most junior destroyer captain, was a grave indictment of Je’s 22 months in command.  The scouting light cruisers can be praised for their reports.

   At 2.30.am on the 1^st of June 1916 at dawn the two fleets were 30 miles apart.  The battle of Jutland was over.

The controversy

   Since 1916 the battle has been analysed ad nauseam.  People have tended to take the side of either Beatty or Jellicoe.  The latter was ostensibly promoted to 1^st Sea Lord on 30^th November 1916 and Beatty took his place.  At the Admiralty, in face of the 1917 un-restricted U-boat campaign which the Germans launched in despair of their surface ships, Jellicoe gave further examples of his pessimism, opposing convoy.  He was effectively sacked at the end of 1917.

  Regarding the battle, consolation was found in a situation which The New York Times expressed  neatly: “The German Navy has assaulted its jailer but is still in jail”.

   Nevertheless, the result was a very poor return on all the effort spent by the nation to provide a vast fleet, to say nothing of the loss of life..

The last words on the battle

   In this author’s opinion, the last words on the outcome of the battle of Jutland were spoken in 1940.  While still 1^st Sea Lord in 1937 Admiral Chatfield (a gallant sailor who had stood alongside Beatty as his Flag Captain) secured for the last two new battleships of the KGV class as laid down the names Jellicoe and Beatty (Ref.6).  When they were launched in early 1940 they were named Anson and Howe.

   Mature reflection 24 years after the unsatisfactory outcome of Jutland had concluded that the performance of the two admirals did not merit their names being given to new capital ships.

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“What if” the Hochseeflotte had been effectively annihilated in 1^st June 1916?

   Two things could have happened:-

• It would have been possible for British battleships to enter the Baltic to secure passages for ships to supply Russia with the desperately-needed arms and ammunition to produce an effective “Second Front”.  With its success the Russian Revolution would not have occurred;
• With a patrol of battleships to back them, British minelayers, destroyers and light cruisers could have made a close blockade of German ports to prevent the U-boat campaign of 1917.

The biggest mistake at Jutland

   The biggest mistake was that Jutland was ever fought!  Kaiser Wilhelm II made that mistake when he listened to von Tirpitz in 1900 and chose to build a Hochseeflotte.  As an obviously direct challenge to Great Britain this turned a potential neutral in a European war to a definite opponent.  Ultimately this led to Prussian-dominated Germany losing that war.  The Hochseeflotte played a part by mutinying through loss of morale on 3 November 1918.    The 850 M gold marks spent on construction of the HSF ended up on the bottom of Scapa Flow.

Captain Jackson  

Captain Jackson, promoted to Rear Admiral just after Jutland – a step which would have been in process before it – was clearly forgiven for his errors as DOps.  He remained in that post for a year, half of which was under Jellicoe as !st Sea Lord.

The protagonists

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References

1.  www.britishbattles.com/first-world-war/the-battle-of-jutland.

Part II has a map which shows:-

• The British Direction-Finding stations;
• The positions of the 13 U-boats deployed before 30^th May 1916 to try to ambush the GF;
• The tracks of the fleets up to contact.

2. Fighting Ships of WW1 and 2  Phoebus  1976.
3. www.researchgate.net/publication/224223493.
4. www.gchq.gov.uk/home/ then select “History” for “Signals Intelligence and the Battle of Jutland”.
5. The World Crisis 1911-1918.  W.S. Churchill  Odhams Press ed.  (Vol. III, with the account and analysis of the battle of Jutland, 1^st published 1927).

The best short version of the battle but, as a friend (as he thought then) of Beatty it excuses him of mistakes.  Had he known the spiteful remark written by that officer, whose career he had saved in 1912, on WSC being forced out of 1st Lord of the Admiralty in 1915, he might have been less tender.

6. Jane’s Fighting Ships, December 1937  ed F. McMurtrie  Sampson Low, Marston.

Derek S. Taulbut.   6 October 2021.

P.S.   In Ref. 5 Winston Churchill, although later listing all the great material advantages of the GF over the HSF and analysing how its battleships (scarcely engaged) would have resisted everything that the HSF could fire at them, had indulged himself in his introduction with a catchy “soundbite”:-

“Jellicoe was the only man on either side who could lose the war in an afternoon”.

With all due respect to a great Englishman, this was nonsense!

   Jellicoe could have exchanged ship-for-ship with Scheer and emerged the victor.  The large gains to the Anglo-French-Russian alliance have been shown above.