Captain William V. Pratt, Assistant (Acting) Chief of Naval Operations, to Naval District Commandants
C O P Y
Office of Naval Operations
November 20, 1917.
From: Chief of Naval Operations.
To: Commandants, First,
Eighth Naval Districts:
SUBJECT: Preparations for Mine Planting on Atlantic Coast
1. The spheres of mining along the United States Coast may be considered under two headings: - First, mine fields under the guns of coast fortifications which, after joint consideration of the Army and Navy, is delegated to the War Department. Second, on the coast beyond the reach of fixed fortifications of the military forces. This latter is considered the province of the Naval Districts.
2. Mining in the vicinity of non-continental bases, and in coastal areas offshore, as well as offensive mining in the face of the enemy, are under the province of the Mine Force, or specially prepared vessels for that purpose.
3. At the present time there are few if any vessels in the Naval Districts which are suitable for extensive mine planting. However, it is believed that, for the purpose of mine planting in the Districts, ferry boats could be readily equipped; and, while it is not desired to withdraw such vessels from their ordinary employment, the equipment for so preparing them can be gotten ready for placing at short notice. Vessels of this class can be selected which would have sufficient maneuvering powers, light draft, carrying capacity, and clear deck space. They would be suitable for outside work in smooth water, and a breakwater could be built forward on the main deck which would probably enable them to work in a moderate breeze if with sufficient structural strength.
The weight of the mines carried is not great. Twenty-nine mines to 100-feet of track and five feet athwartships for each track is the closest spacing in practice. This would give a weight of 25 tons to 500 sq. ft. of deck area.
4. Training with mines is given at the torpedo stating and Mark IV mines are available in considerable number, both for training now and planting later if wanted. The equipment for mine planting vessels consists mainly of track to carry the mines, a curved section of track for launching, and means for embarking the mines on board from shore or other vessels. Where ferry boats are not available, or it is undesirable to withdraw them from present employment, training in planting may be had by using flat lighters, of the Navy standard coal barge type, either wooden or steel. A tug alongside can handle the mine planting barge with sufficient precision.
5. It is desired that the first eight Naval Districts be prepared to plant mines on short notice and that plans be developed and recommendations made as to vessels as suggested above that might be considered for this duty, together with alterations that might be necessary to adapt them for the service. The training may be had by the detail for a short time of petty officers to the torpedo station. The ordnances pamphlet on the two marks of Mines (III and IV) which would be suppled is so complete that there may be no necessity for some or any of the Districts to send personnel for training.
W. V. Pratt,