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Rear Admiral William S. Sims to Secretary of the Navy Josephus Daniels

April 27th.1917.   

From: Rear-Admiral W.S.Sims,

To: Secretary of the Navy.


     1.   Owing to danger of sending confirmations of cipher dispatches during war, I am depending upon the past three years experience of the Embassy which indicates that all dispatches are understood unless inquiry to contrary is received. I have sent      dispatches to date and will hereafter number all dispatches commencing with No.

     2.   The following memoranda is herewith attached:-

(a) a list of certain anti-submarine devices which have been tried and discardedfor reasons stated – forwarded to prevent duplication of effort.

(b) Tactical use smoke-producing apparatus for merchant men

(c) Confidential instructions issued to Merchant Masters British vessels,

(d) Report of Admiralty conference with Merchant Captains.1

     3.   All essential information has been covered by cable dispatch. Up to the present my time has been too fully occupied in ascertaining and confirming information concerning the military situation to give much attention to questions of materiel.

     4.   I strongly recommend that expert representatives of the Bureau of Construction and Repair, Ordnance and Steam Engineering be sent here as early as possible, as all channels of information are now open. Such representatives should be of as high rank as practicable.

     5.   ANTI-SUBMARINE HOWITZER. The British have about one thousand bomb throwing howitzers for use on trawlers and similar vessels against submarines. Of these thirty are of three and a half inch caliber throwing 200 lb. bomb with 94 lb. bursting charge. Those recommended are as follows, all of about 350 foot seconds:-

No. on hand.

Max. Range.



Weight Bomb.

Bursting Charge.




Rifled B.L




60 ton blow.







Recoil cylinder and R.O. springs.

Also one 12.5” experimental Bomb Thrower.2


          There is attached description and instructions concerning portable smoke producing apparatus which has been issued to all ships armed, about 2000. It is to be noted that there are two types of smoke producing apparatus, one the Cowl or smoke producing plant and the other the bomb type which may be thrown overboard or triced up in the rigging.3


        About 2000 merchantmen have been armed with one gun aft. The guns have been mounted aft primarily to force the merchant ships to maneuver away from the submarine. About 5000 more guns are under contract both for ships not now armed and to increase the number of those already having one gun.


          Confirming my dispatch concerning these mines the Admiralty reports this type of mine as originally designed has not proven satisfactory and that service improvements found necessary and developed since war began are essential to its efficiency. In fact the British are now abandoning the type in favor of the German type, similar to the Carbonnit mine as covered by intelligence reports of Lieut.Babcock before the war.4

          The principal changes made in the Elia mine have been in the anchor and firing mechanism. It has been found essential to keep the anchor and mine together as a unit for some time after launching. The latest Admiralty modifications do not permit mine and anchor to separate until both have sunk about ten feet. A special pawl, developed by Admiralty, is used on mooring line reel. Shearing pins formerly used in firing mechanism have been eliminated. A new type of firing mechanism sleeve release had to be designed as it was found that after mine was laid two weeks the necessary force to move firing lever had increased from 10 to 70 pounds.5

          It is possible that Vickers representatives in United States are aware of these changes but in case they are not there are forwarded herewith drawings. In case questions of Patent rights should arise with Vickers during or after the war, I have assured the Admiralty that our Government will protect or indemnify them. Copy of assurance is attached hereto.

          By my request the Admiralty have detailed Lieut-Commander O.Mock, R.N.V.R. to proceed at once to the United States and place himself at the disposal of the Bureau of Ordnance.6 Lieut.Mock is thoroughly familiar with all developments to date by the Admiralty in connection with mines and is, in fact, responsible for a number of the most valuable improvements.

          9.   THE SITUATION.

               The military situation almost daily grows more critical as is indicated by my cable reports of merchant tonnage loss. The critical area continues to the southward and westward of Ireland.7

W. S. Sims.

Source Note: C, DNA, RG 45, Entry 517. At the top of each page is “To: The Secretary of the Navy. (continued).”

Footnote 1: None of these memoranda are attached to the document nor have they been found.

Footnote 2: For more on the 7.5" and 11" howitzers, including pictures of them, see, Friedman, Naval Weapons of WWI: 393.

Footnote 3: On these smoke producing devices, see Archibald Hurd, The Merchant Navy, 3 vols. (London: John Murray, 1929), 3: 106-34.

Footnote 4: Cmdr. John V. Babcock was Sims’ aide in England. Before the war he had served as an inspector in the Bureau of Ordnance. His report on mines has not been found.

Footnote 5: The Elia mine, manufactured by the Vickers Company, had a history of problems with its firing mechanism because as mud and sand built up on the “pistol” it lost sensitivity and might not detonate if it bumped up against a hull only once or twice; Friedman, Naval Weapons of WWI, 364-365. See also, Samuel L. Morison, International Guide to Naval Mine Warfare (Washington, DC: King Communications Group, 2000), 196.

Footnote 6: Lt. Cmdr. Herbert O. Mock, Royal Navy Volunteer Reserve.