CONTENTS.
| Page. | ||
| Chapter I. | Definitions and general principles | [ 7] |
| II. | Matériel of the system | [11] |
| III. | Loading room duties | [34] |
| IV. | Locating distribution box, laying multiple cable, | |
| marking out mine field | [42] | |
| V. | Assembling and planting mines | [48] |
| VI. | Test of mines and apparatus | [56] |
| VII. | Taking up mines | [62] |
| VIII. | The mine command | [65] |
| APPENDIXES. | ||
| 1. | Explosives | [69] |
| 2. | Oil engine and generator | [77] |
| 3. | Storage battery | [84] |
| 4. | Submarine mine cable | [92] |
| 5. | Care and preservation of matériel | [107] |
| 6. | Instructions for masters of mine planters | [111] |
| 7. | Manual for small boats | [115] |
| 8. | Supply list | [121] |
CHAPTER I.
DEFINITIONS AND GENERAL PRINCIPLES.
A submarine mine consists of an explosive charge inclosed in a water-tight case, and a firing device, the whole intended to be submerged in a waterway which it is desired to close against the passage of an enemy’s vessels.
With respect to the position of the case containing the explosive, submarine mines are of two classes, buoyant and ground.
In the buoyant mine, the case contains the explosive and the firing device, and has such excess of buoyancy that it would float were it not held below the surface by a mooring rope and an anchor. The submergence is such that, while the mine would be struck by the hull of a passing vessel, it is not so near the surface as to be seen.
Buoyant mines may be planted and operated successfully in water 150 feet deep. They should not, in general, be used where the depth of water is less than 20 feet.
In the ground mine, the case contains the explosive and the firing device, and is heavier than the displaced water; it therefore rests upon the bottom and requires no anchor. Ground mines are not used where the depth of water exceeds 35 feet.
With respect to the means used to fire them, mines may be classed as mechanical and electrical.
Electrical mines are, in turn, of two general classes, controllable—in which the firing device is under control after the mine has been fixed in position; and noncontrollable—in which no such control is had.
Mechanical and noncontrollable electrical mines are intended to be fired only by the blow of a passing vessel. When once in position they are dangerous alike to friend and foe, while controllable mines may instantly be made safe for friendly vessels or as quickly made dangerous to vessels of the enemy.
Controllable electrical mines are arranged so as to give a signal to the operator when they are struck. They may be set to fire automatically when struck or tampered with, or may be fired at the will of the operator. In the latter case the firing may be delayed, in which case the operator fires the mine some short interval after the signal indicates that it has been struck; or by observation, in which case he fires it after the position-finding system shows that the vessel has come within the mine’s destructive radius.