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Vice Admiral William S. Sims, Commander, United States Naval Forces Operating in European Waters, to the Office of the Chief of Naval Operations


Date      September 16 1918

To        OPNAV

Prepared by C.S. & M.4.                      No. 4845


Your 9041 Allied Naval Council held 5th meeting Paris September 13th & 14th. Council approved practically all recommendations Malta Conference.2 Council considered Military situation would not justify revival of consideration Mid-Adriatic Mine Barrier at this time, and did not consider expedient refer question to supreme War Council.

     Completion Dardanelles Mine Fields in accordance with existing plans decided on. Completion Franco-Italian mine net barrage from Otranto to Fano Island agreed. This barrage to be reinforced by United States by mines from surface to 45 fathoms depth wherever depth of water permits use of present type American Mines and moorings. France and Italy will reinforce by laying deep nets if possible, where our mines cannot be used.

     Great Britain agreed to undertake immediately development of mine suitable for deep water, and Council agreed that whichever of United States or Great Britain should first have ready a mine capable of use in 500 to 600 fathoms of water should furnish such mine to supplement in deep water the mine net barrage from Otranto to Fano Island.

     Principle of Mine Barrage across lower Adriatic was accepted exact location to be determined at next meeting of Council in October.

     I favour barrage from Brindisi to Sasseno Island since it passes through shallower water and has strategical advantage for Italy over a barrage placed further South, since it will interpose a strong protective line between the enemy submarine bases and Italian line of communication to Valona. Italian representative strongly favoured this line, but French representative was opposed to it on account of its greater length. He will probably agree to it at next meeting. It is understood that this barrage will not be taken by United States until suitability of our Mines is demonstrated, and ample supply of wire rope assured. This barrage when laid will extend from surface to 45 fathoms, and will have a gate at western end not exceeding 5 miles, wide, in which no mines will be nearer than six fathoms to the surface.  Mines for this barrage will be provided and laid by United States who will control mining operations and maintenance of barrage. Italy will undertake at once collection of necessary hydrographic data.

     Council also approved Aegean Barrage on line recommended by United States. All mines to be provided and laid by United States except in Turkish Territorial Waters. Great Britain will furnish and lay mines in Turkish Waters. Greek Government will be requested to strengthen defences and garrison of Island of Samos as necessary. Great Britain will undertake at once collection of necessary hydrographic data.

     Several minor barrages decided on, of which details do not concern United States and will be reported by letter. Selection of mining of base left to discretion of United States, each Nation agreeing to co-operate fully to facilitate establishment of base in any selected locality.

     Although Council agreed that Adriatic Barrage was of primary importance, it was agreed that Aegean Barrage might be laid first if suitable material for deep water barrage had not been developed by the time we were ready to begin operations. Additional reason for laying Aegean Barrage without more delay than is necessary to establish base is the protection it will give against threat of strong enemy force emerging from Black Sea.3

     Council decided to continue the mobile patrol of Adriatic Barrage for the present, concentrating as far as possible on the section where re-inforcing mines could not be laid, and contemplates a possible reduction in the number of craft assigned to this barrage as soon as net and mine reinforcements are completed.

     I request Department will indicate its approval or otherwise as soon as practicable,4 so that projects decided on may be initiated at once. <112116>


Source Note: Cy, DNA, RG 45, Entry 517B.

Footnote 1: See: Daniels to Sims, 4 September 1918.

Footnote 2: See: Allied Minelaying Conference, 15 August 1918.

Footnote 3: With the Armistice in November, none of the mine barrages envisioned here were ever laid. Halpern, A Naval History of World War I: 399.

Footnote 4: The Department approved everything outlined in this cable. See: Benson to Sims, 18 September 1918.

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