A controlled ground mine designated by the Japanese as "Type 94, Model 2". It is u-sed defensively and laid from surface craft in harbors or harbor entraces and controlled from observation posts on the shore. It was used, however, on Adak, Alaska, as a con-trolled land mine. It may also be used as a controlled mine planted in shallow water ap-proaches to beaches.

General characteristics of the mine are as follows:

Case

Shape – Hemispherical, 28".4 in diameter, 25".6 high, with a steel skirt 9" high and 24" in diameter, welded around the top. The mine is bolted to a four-wheeled cast-iron an-chor truck.

Color – Black.

Mateial - Steel.

Charge – 190 lbs. (approximately) granular Type 88 explosive.

Total Weight – 580-lbs. (approximately).

External Fittings

Booster Cover Plate – 4" in diameter, on side of case, 3".5 below edge of skirt, se-cured by six bolts. The firing cable enters through a stuffing box in the center of this plate.

Lifting Holes – Four, 1".2 in diameter, on the skirt, 90° apart and 1" below the top.

Cover Plate – 5".2 in diameter in the top center of the case.

Pad Eye – One, on the case, 13" below the upper edge of the skirt.

Cable Clamp – Shackled to the pad eye. This prevents strain on the cable from being transmitted to the detonator.

Mine Anchor Truck – Rectangular, cast iron, fitted with four wheels.

Operation

The detonator is housed in the booster during assembly, and, when laid, a rubber-co-vered firing cable connects the mine with an observation post on the shore. The mine is fired electrically by an observer.

Safety Precautions

The mine contains no self-disarming features. When used as a land mine, it is likely to be buried with other explosives.

Figure 15 – Mine Type JF.

Figure 16 – Cross section of mine Type JF.