Page 326 - Le Operazioni Interforze e Multinazionali nella Storia Militare - ACTA Tomo I

326 XXXIX Congresso della CommIssIone InternazIonale dI storIa mIlItare • CIHm

wanted analyses that identified the full, negative effects of such a withdrawal. Firstly,
it had to be investigated if would it be possible at all to support the British Army on the
continent without the control of the Dover Strait ports. Secondly, the effects of moving
the Dover Patrol westward to a line such as Newhaven-Dieppe had to be worked out.
Thirdly, the influence on the merchant traffic through the Channel and to London had to
be clarified. Wemyss sought the opinions of some of his closest assistants.
His Deputy Chief of Naval Staff, Fremantle, responded the same day that he consid-
ered it essential to hold the northern ports, especially because a loss would undermine
the effectiveness of the Dover barrier. Even if the smaller tidal differences in the line
Beachy Head to Dieppe would make anchored mines more effective than those of the ex-
isting fields, the increased threat from U-boats and mines after the move far outweighed
this small advantage. The U-boats would become far more effective in all waters around
and between the British Isles, and the planned massive effort to block the northern ac-
cess to the North Sea would lose its value. Keeping control of the Flanders ports should
be rated as a decisive strategic allied interest. Fremantle was thus fully in line with
Studd’s December memorandum. On 19 April the Forth Sea Lord, Rear-Admiral Hugh
Tothill, who was responsible for supply, added that the transit time between England and
France would increase, the risks would increase, and many of the vessels now used for
cross-Channel transports were unsuitable for use further west. Another negative effect
would be on the already insufficient French railway capacity. It would be further pressed
if the troop and goods transports had to go through a smaller number of terminal ports.
The Government Transport Department observed that the negative effects would only be
fully felt when the Germans could use Calais and Boulogne as bases for U-boats and sur-
face vessels beyond the Dover barrier. This increased threat was likely to be especially
serious for the French coal import.
On 20 April Wemyss combined these arguments in a comprehensive memorandum
meant to influence the War Cabinet. He concluded that the support of the army in France
would be seriously hampered, but still possible. The losses to U-boats would increase,
especially in the Channel where they hitherto had been insignificant. Traffic to London
would be influenced, but not as severely as the coal transports to France. Seen together
the effects of the loss of the Flanders ports would be catastrophic for a naval point of
view. Keyes in Dover had also been mobilised to give support to navy’s position. In a
21 April memorandum he underlined both the seriousness of losing Dunkerque and that
the loss of Calais as well would be a disaster. Before withdrawing west Britain had to
be certain that it was possible to maintain an army in France without the control of the
Flanders ports. 16

16 CAB 1/26, Winston S. Churchill “A Note on Certain Hypothetical Contingencies” of 18-4-1918 sent to the
War Cabinet on 19-4-1918; ADM 137/710: Wemyss (initial.) Most Secret, No. 436/18 to A.C.N.S. of 18-4-
1918; Fremantle (initial.) to C.N.S. of 18-4-1918; Tothill (initial.) memo of 19-4-1918.; Fourth Sea Lord to
First Sea Lord, “Channel Ports” “The Probable Effect of Mercantile Shipping of the Evacuation of Calais &
Boulogne” from 19-4-1918; First Sea Lord and Chief of the Naval Staff, Most Secret, of 20-4-1918; Copy of
Minute of D.M.S.T. from Ministry of Shipping Paper No. 01211/18 “Effect on Communications for Army in
France in Dunkirk, Calais and Boulogne are not available for use” of 19-4-1918; Roger Keyes (sign.), Vice
Admiral, Commanding Dover Patrol, 21-4-1918.