Mine Identification Manual, OP 898, 1943, shows silhouettes of WW II naval mines.

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Richard Pekelney


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Deptartment of the Navy
Bureau of Ordnance






Department of the Navy - Bureau of Ordnance


This publication is RESTRICTED and will be handled in accordance with Article 76, United States Naval Regulations, 1920








1. Ordnance Pamphlet Number 898, First Revision, contains outline drawings of all types of mines in general use.

2. It is intended that this publication be given wide distribution to forces ashore and afloat for the purpose of identifying mines which may be encountered and to facilitate reports thereon.

3. This publication supersedes such parts of Ordnance Pamphlet 814 (Mine Watch Manual) as pertain to identification of mines. Ordnance Pamphlet No. 898 dated October 1942 is hereby superseded and should be destroyed upon receipt of Ordnance Pamphlet No. 898, First Revision.

4. This publication is restricted and should be handled in accordance with the provisions of Article 76, U. S. Navy Regulations, 1920.

W.H.P. Blandy,
Rear Admiral, U.S. Navy,
Chief of the Bureau of Ordnance



General Information and Instructions

This pamphlet is intended as an aid in the identification of mines. It is not intended for use as a text book, but sim-ply as an aid to mine watchers, beach patrols, and all ships at sea.

Floating spherical mines are usually found with approximately one third of the mine showing. However, this may vary if the case has been dented or punctured. In these instances the case will usually exhibit less buoyancy, and will, therefore, ride with more of its upper hemisphere awash. Mines of different nations also exhibit varying floating characteristics.

If the mine is sighted at sea, an attempt should be made to identify it by comparing it as nearly as possible to a mine in this pamphlet. The "Type Number" and position of the mine should be determined, and the time of sighting should be noted. The Chief of Naval Operations (Hydrographic Office) should be notified by dispatch or, if it is necessary to maintain radio silence by letter at the end of the voyage. Information copies of the dispatch or letter should be sent to the nearest Naval activity, which in turn will notify the Mine Disposal Unit under its command for necessary action. If circumstances permit, it is recommended that drifting mines be destroyed by gun-fire, using .50 cal. or 20 mm AP ammunition. It is possible that gunfire may explode drifting mines. Therefore, they should not be approached closer than 300 yards, and due precautions taken to protect personnel from flying fragments. No attempt should be made to take aboard or tamper with a beached mine unless designated Mine Disposal personnel are present. The fact that these mines are dangerous to personnel and hazardous to ships cannot be overemphasized.


OP 898


The following information will be of importance to interrogators when questioning survivors of ships sunk or damaged as a result of enemy action.

NOISE Dull and prolonged (rather like a depth charge). Double explosion often reported due to the time lag between pressure wave and kinetic wave. Short sharp loud (like a gun). As for contact mines, but sometimes, slightly muffled by torpedo tending to enter hull.
FLAME As a rule, no flame or smell of fumes and little smoke below 50'. Less than 50' possibility of flame, fumes, and smoke. Flame generally seen and smell of fumes often reported. Much smoke. As for contact mines.
SPLASH Height of splash depends on depth of mine. A 1500 lb. mine in 10 fathoms gives splash about 50' - 100 ft. high and approximately 100 ft. across. Splash follows pressure wave at interval of seconds, depending on depth of mine. (2 seconds interval to 100 ft.) 550 lb. mine at 6 to 10 ft. below surface will give large splash about 200 ft. high but not so wide as ground mine. Splash and explosion are coincident. As for contact mines, but splash may be spread less owing to penetrating hull.
Splash generally on both sides. Splash on one side of ship only. Splash generally on one side but occasionally on both sides if torpedo is running deep.
EFFECT Lifts ship. Ship whips and vibrates. Crew thrown up into the air. Ship lurches. Crew thrown to one side. Blast effect immediately noticeable. As for contact mines, but torpedoes tend to penetrate hull and explode inside; hence explosion appears less violent to those on deck.
DAMAGE Engines almost always stopped. Damage to bearings, beds, and castings. Ship often breaks back due to hogging and whipping. Damage general throughout ship. Ship rarely holed. Damage extensive, although not always immediately apparent. Ship generally sinks even keel. Damage localized. Ship holed. Engines often continue to function. Damage immediately apparent. Blast and splinter damage. Ship generally lists. As for contact mines.



1. Present-day mines may be divided into two general classifications-"controlled" and "independent." Controlled mines are mines which are controlled (fired) by an observer from a, safe observation point. Independent mines are mines with self-contained firing mechanisms which function automatically. Independent mines may be subdivided as "contact" and "noncontact" or "influence" mines. In the former, the firing mechanism requires that an extending "horn" be moved or bent or that a wire "antenna" or some part of the mine be touched for the mine to fire. In the latter, the mere existence of metal, sound, or other disturbing influence in the vicinity of the mine may be all that is necessary to cause it to fire. The external appearance of a mine will not, in many cases, indicate the type firing mechanism used.

2. Independent mines may be divided into three types, depending on their final position in the water. These are :

(a) Drifting Mines.-Mines which float on or just under the surface of the water.

(b) Moored Mines.-Mines which are held under the surface of the water by a chain or wire attached to a heavy weight or "anchor" which rests on the bottom.

(c) Ground Mines.-Mines which are heavier than water and rest on the bottom.


3. All types of independent mines can be laid by aircraft, surface craft, and submarines. Controlled mines are laid by special surface layers.


4. The following points may be considered in identifying mines:

(a) Color.-Mines are normally painted black but may be other colors and are occasionally

  camouflaged. This paint frequently wears off, exposing red paint underneath. Where mines have been in the water for a long time, heavy marine growth may completely cover the case and external fittings.

(b) Size and Shape.-Mines are usually spherical, spherical with a cylindrical section between the two halves, or cylindrical in shape, and vary in diameter from about 16 inches to 46 inches, and in length up to about 125 inches. There are, however, a number of mines of irregular shape which do not fall into any of the above classes.

(c) External Fittings.-Numerous fittings which are located in or extend from mine cases may be used for purposes of identification. These include:

(1) Cover Plates.-Either one or both ends of mine cases are usually covered by cover plates bolted to the mine case. These plates normally vary from one to two feet in diameter.

(2) Horns.-Approximately two-thirds of all mines have horns extending from the mine case. These horns vary in length from 1/2 inch to over 1 foot, but are normally about 5 inches in length. The three most common types are a short cop-per spike, a long steel spike, and a thick lead horn. Where used, they vary in number from 3 to 11. Horns of mines which have broken adrift are frequently bent or entirely broken off.

(3) Hydrostats.-Many mines contain one or more devices located in holes in the mine case for operating mechanisms within the mine. These devices usually do not extend beyond the mine case.

(4) Mooring Wires and Antennae.-Most types of mines are connected to steel mooring wires or chains at one end. Several types have copper antenna wires (not over 100 feet in length) connected to the other end. These antennae are usually attached to steel floats (in most cases about 1 foot in diameter and 1 1/2 to 2 feet in length), painted black and occasionally


containing horns. Mine sweeping cables or normal wear may cause the float and any part or all of either mooring cable or antenna to be missing. Floats are frequently found by them-selves, and as such are harmless.

5. In order to facilitate identification, the mines in this publication are arranged in the following order:

(a) Spherical mines.-

(1) Without horns.-Arranged in order of diameter with small mines first.

(2) With horns.-Arranged as above. Where two or more mines of same diameter are shown, the one with the fewest horns is shown first.

  (b) Spherical with center section.-

(1) Without horns.-Arranged in order of diameter. Mines of same diameter are arranged in order of length.

(2) With horns.-Same as without horns.

(c) Mines with antennae and floats.-

(1) Spherical mines.-Arranged in order of diameter.

(2) Spherical mines with center section.- Same as (b) (1).

(d) Cylindrical and odd-shaped mines.- Same as (b) (1). Where a mine of a given type may be of more than one size, it is located by the smallest size.


Table of Contents

Type-121, No Horns 3
Type-125, No Horns 4
Type-31, No Horns 5
Type-140, 4-Lead Horns 6
Type-190, 5-Lead Horns 7
Type-45, 4-Horns 8
Type-34, 6-Spike Horns 9
Type-21, 7-Spike Horns 10
Type-15, 8-Spike Horns 11
Type-87, 5-Lead Horns, 3-Spike Horns 12
Type-89, 5-Lead Horns, 3-Spikes 13
Type-83, 5-Lead Horns 14
Type-32, 7-Lead Horns 15
Type-13, 7-Lead Horns 16
Type-41, 7-Lead Horns 17
Type-84, 5-Lead Horns 18
Type-85, 5-Lead Horns 19
Type-35, 4-Lead Horns 20
Type-43, 9-Lead Horns 21
Type-124, No Horns 22
Type-123, No Horns 23
Type-122, No Horns 24
Type-71, No Horns 25
Type-11, No Horns 26
Type-12, No Horns 27
Type-19, No Horns 28
Type-41, 6-Lead Horns 29
Type-106, No Horns 30
Type-137, 4-Lead Horns 31
Type-82, 5-Lead Horns 32
Type-61, 4-Lead Horns 33
Type-16, 6-Lead Horns 34
Type-44, 7-Lead Horns 35
Type-33, 6-Lead Horns 36
Type-14, 9 or 11 Brass or Spike Horns 37
Type-86, 7-Lead Horns 38
Type-62, 4-Copper Horns 39
Type-64, 4-Copper Horns 40
Type-63, 4-Copper Horns 41
Type-65, 3-Copper Horns 42
Type-88, 4 or 6 Lead Horns, 9-Spikes on small float 43
Type-18, 6-Lead Horns 44
Type-67, 4-Copper Horns 45
Type-72, 3-Copper Horns 46
Type-20, 4-Spike Horns 47
Type-17, 4 or 8 Spike Horns 48
Type-46, 6-Horns Dimensions Not Known 49
Type-76, No Horns 50
Type-81, No Horns 51
Type-24, No Horns 52
Type-23, No Horns 53
Type-68, No Horns 54
Type-70, No Horns 55
Type-22, No Horns 56
Type-101, No Horns 57
Type-66, 3-Lead Horns 58
Type-73, No Horns 59
Type-107, No Horns 60
Type-105, No Horns 61
Type-69, No Horns 62
Type-77, No Horns 63
Type-103, No Horns 64
Type-104, No Horns 65
Type-78, No Horns 66
Type-102, No Horns 67
Type-25, No Horns 68
Type-75, No Horns 69

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