Page 327 - Le Operazioni Interforze e Multinazionali nella Storia Militare - ACTA Tomo I

327
ActA
Parallel to Wemyss efforts, Fuller’s Plans Division had developed an analysis that the
captain presented in a 20 April memorandum named: “The Naval Situation Relatively
to the Offensive on the Western Front”. It outlined and discussed the implications for
the navy of three possible situations. Common to all was that Dunkerque was assumed
lost. In the first the BEF maintained a bridgehead around Calais and Boulogne. In the
second part of the army covered these two ports and the rest withdrew west with the
French. The third assumed the loss of Calais and Boulogne as the entire BEF moved
west. The second and third situations were subdivided in one situation where the front
was stabilised at the Somme and another where an Allied withdrawal to the Seine be-
came necessary. In all situations it was essential that all lost ports were destroyed and
blocked with block ships. If Germany gained control of one or more Channel ports, a
large dedicated air force should be deployed to monitor its mine clearing operations and
hamper heavy battery construction by bombardment. The navy should do its maximum
to maintain the Dover barrier. In the two first situations the Dover barrier could be main-
tained. However, in order to make its defence more robust, Fuller suggested that no mat-
ter what happened; Keyes’ Dover Patrol should be joined with Rear-Admiral Reginald
Tyrwhitt’s Harwich Force of destroyers and light cruisers. This would produce a more
unified and better use of resources. Even if Calais and Boulogne were lost, the mine-
fields off the French coast could be supplemented and supported if the front only moved
back to the Somme. However, if that effort failed, the new Royal Sovereign-Treport line
barrier should be established and the naval force in the Channel significantly increased.
Finally Fuller’s and Gibb’s plans were considered together, and the Plans Division rec-
ommended that an experienced naval officer, Captain William Munro, was attached to
the F. P. Force headquarters to make certain that the destruction and blocking efforts
were actually co-ordinated.
Fremantle noted 30 April on Fuller’s memorandum that Gibb’s preparations had been
completed as had the blocking preparations in Calais and Boulogne. Those in Dunker-
que would need four additional days. Keyes had been instructed to be ready to evacuate
movable equipment such as floating cranes and dredgers. The Naval Staff prepared min-
ing of the coastal route off Dunkerque, and in mid-May it asked the Royal Air Force to
prepare the evacuation of the naval support air squadrons from their bases in France. 17
When the BEF headquarters had been told about Gibb’s Dunkerque demolition plans
by the visiting General Maurice on 15 April, Haig decided to inform the Allied Supreme
Commander, Marshal Ferdinand Foch. This happened by letter the next day. Foch re-
acted on 18 April by asking the British to contact his naval commander in the Channel,
Vice-Admiral Pierre-Alexis Ronarc’h in his Dunkerque headquarters. Nobody seemed
to have informed Foch that the British preparations covered more than Dunkerque. On
23 April Colonel Walter Kirke, the General Staff Deputy Director of Operations, asked
Hope to ensure that Gibb contacted Ronarc’h. Gibb’s deputy, James, reacted the same
day by informing Kirke that the commander of the Dunkerque demolition unit, Lieu-
tenant-Colonel Ker, would cross the Channel for a meeting on 25 April. Five days after

17 ADM 137/710: P.D. ob5, Secret, “The Naval Situation Relatively to the Offensive on the Western Front” of
20-4-1918 with annex from 22-4-1918; Director, Air Division, 15-5-1918.