Transcriber’s Notes:
Underscores “_” before and after a word or phrase indicate _italics_
in the original text.
Equal signs “=” before and after a word or phrase indicate =bold=
in the original text.
Small capitals have been converted to SOLID capitals.
Illustrations have been moved so they do not break up paragraphs.
Old or antiquated spellings have been preserved.
Typographical and punctuation errors have been silently corrected.
The text has numerous references to “figure 18”, the schematic diagram
for the “Operating Board”, however this figure appears to be not
available.
MANUAL FOR
SUBMARINE MINING
[Illustration]
EDITION OF 1912
[Illustration]
WASHINGTON
GOVERNMENT PRINTING OFFICE
1912
WAR DEPARTMENT,
Document No. 399.
_Office of the Chief of Staff._
This Manual for Submarine Mining, revised to 1912, is
approved and published for the confidential information
and guidance of the Army of the United States. Under no
circumstances shall its contents be divulged to persons not
in the military or naval service of the United States.
By order of the Secretary of War:
WM. H. CARTER,
_Major General, Acting Chief of Staff_.
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.
LOCATION OF MINES.
The considerations involved in the location of mines are of two general
classes, tactical and local.
Tactical considerations deal with the position of mines with reference
to the other defenses. Local considerations deal with the width and
depth of the channel, the swiftness of the current, the variation of
the tide, and the relative importance of the harbor.
Where ordinary ship channels are unobstructed it is possible for modern
battleships, with their high speed and heavy armor, to run by shore
batteries, at least in the night or during a fog; hence the defense of
such channels should not be left to guns alone.
On the other hand, where mines are unprotected by the fire of shore
batteries it is possible for an enemy to remove or disable them.
Therefore guns and mines, the two elements of the fixed defenses of a
harbor, are mutually dependent, and when the location of one has been
decided upon that of the other must conform thereto.
Within the zone between 4,000 and 8,000 yards of the main defense the
fire of heavy guns is destructive for warships, yet the latter are at
such a distance that their rapid-fire guns will be of little effect
against the batteries.
Moreover, at 4,000 yards vessels are just beyond the inner limit of
mortar fire.
If possible, therefore, hostile vessels should be held in this zone by
some obstacle. Such obstacle is afforded by a mine field.
On the other hand, attacks upon a mine field are most liable to be made
by small boats at night. If the mine field be at too great a distance
from the defenses, these boats will not be revealed by the mine
searchlights. Furthermore, for protection against such attacks, the
defense relies upon rapid-fire guns of relatively limited range.
Due to the above considerations the outermost mines are usually placed
between 3,000 and 4,500 yards from the main defense.
In general, there should be in each main channel at least three lines
of mines.
ELEMENTS OF A MINE SYSTEM.
The elements of a mine system are:
1. =The mining casemate=, consisting typically of four rooms: (1) The
operating room, containing the power panel and the operating boards;
(2) the engine room, containing the engine and the generator; (3) the
battery room, containing the storage battery; and (4) the sleeping room
for the personnel.
2. =The multiple cables=, 7 and 19 conductor, leading from the casemate
out to the distribution boxes, one of which is in the center and rear
of each group of mines.
3. =The single-conductor cables=, radiating to the front from the
distribution boxes, one leading to each mine.
4. =The mines=, in groups of 19 or less, extending across the waterway
to be defended, planted approximately 100 feet apart and anchored so
as to have a submergence of about 10 feet at low water. The groups are
numbered 1, 2, 3, etc., from left to right of the observer stationed in
rear of the line, and the mines in each group are numbered similarly,
No. 1 being on the left, No. 10 in the center, and No. 19 on the right.
The groups composing a line of buoyant mines are not usually planted
in prolongation of each other, but with a space for the passage of
friendly vessels, and also for the movement of the planter when at
work upon adjacent groups. Groups of ground mines may be placed in
prolongation of each other or between the groups of buoyant mines, as
they will always be below the hulls of passing vessels.
5. =The mine planters= and other boats with the necessary equipment for
planting and maintaining the planted mines.
6. =The range-finding system=, the same as or similar to that used for
the guns, enabling accurate plotting of the positions of the individual
mines, and consequently permitting vessel tracking and observation
firing.
7. =The searchlights=, for illuminating the mine fields at night.
8. =The rapid-fire guns=, for the protection of the mine fields.