TABLE OF CONTENTS









SECTION X - WWII JAPANESE MILITARY EQUIPMENT

SECTION I - WWII JAPANESE MILITARY EQUIPMENT INTRODUCTION.

1. GENERAL.

a. General. Most Japanese equipment shows evidence of careful thought to adapt it to the needs of the soldier. The Japanese army expects to fight, mostly on foot, in all the varied climates and terrains of Asia, where roads often are lacking. The equipment therefre is made as light in weight as is practicable, and when possible, is arranged to pack on horses or to be carried by men.

The Japanese have have given much attention to animal pack, and there are a great variety of pack saddles for specialized purposes. All of the organic heavy infantry weapons are designed for animal pack and can be manhandled when necessary.

b. The two wheeled military cart is the most common vehicle. This art, of which four types are known, is built almost entirely of wood. The smallest has a capacity of about 400 pounds. It is strong and light and is pulled by one horse which the driver leads. A larger type, of greater capacity, is pulled by two horses. A heavier miltary vehicle also has been developed which often is designed to carry artillery spare parts or other heavy equipment. This vehicle is pulled by either 2 or 4 horses.

c. Most of the Japanese Army's automotive equipment is of foreign design and construction. However, Japanese models have been designed and constructed. These are two general types: a 4 wheeled commercial design of about 2 tons capacity, and a 6-wheeled military vehicle of larger size, made in several capacities but according to the same general design. Originally, these heavier vehicles were equipped with 6 cyulinder, heavy duty, gasoline engines, but later types have Diesel engines. This trend toward Diesel power no doubt will be intensified.

d. Japanese engineering equipment is fairly complete, and includes a wide variety of amphibious, construction, maintenance, and demolition equipment. Heavier equipment, however, does not appear to have been developed on a scale comparable with the American standard. The following types of Japanese equipment are described in the chapters indicated below:

TYPE OF EQUIPMENT CHAPTER
Air corps equipment --------- 4
Chemical equipment --------- 9
Armored unit equipment --------- 9
Personal equipment --------- 11


Definite information concerning ordnance and other mobile maintenance equipment has been omitted because of lack of available data (1944). There is sufficient evidence, however, to conclude that such equipment exists in the Japanese Army.

SECTION II - WWII JAPANESE INFANTRY EQUIPMENT.

1. GENERAL.
Details of infantry equipment have not been shown in this section when it has been possible to place them under specific heading. For example, personal items issued to the individual soldier have been described, where possible, under Chapter 11, while weapons are treated in Chapter 9.

2. WWII JAPANESE OBSERVATION EQUIPMENT.
All reported specimens of Japanese optical instruments have been of good quality and have been found to resemble German designs. A particularly wide range of patterns has been developed, and specimens examined have been characterized by sturdy construction. In all cases definitions in the central part of the field of view wa good. There are no indications taht the Japanese have attempted to tropic-proof these instruments.

a. Binoculars. Details of binoculars, having a magnification in excess of 8 X, are shown in the Artillery Equipment section of this chapter. Tabulated below are the characteristics of some Japanese binoculars, of 8 X magnification or less.

MAGNIFICATION FIELD OF VIEW SIZE OF OBJECTIVE LENS
8 X 6.25 degrees 56-mm
7 X 7.1 degrees 50-mm
6 X 9.3 degrees 24-mm



Figure 283.
Japanese binoculars, filters, and carrying case.

Figure 283-a. Japanese 10 x 70 binoculars, filters, and wooden carrying case.





Figure 283-b. WWII Japanese 7 x 50 binoculars, Suzuko, Tokyo.

Figure 283-c. WWII Japanese army issue binoculars.





Figure 283-d. WWII Japanese High ranking officer 7 x 50 binoculars.

Figure 283-e. WWII Japanese army issue binoculars.




b. WWII Japanese Periscopes.

Characteristics;
1. Weight --------- 1.9 pounds.
2. Magnification --------- 10 X .
3. Field of view --------- 3 degrees.

Figure 284. WWII Japanese army periscope binoculars.


Hand held periscope Characteristics;
Figure 285.
1. Weight --------- 2.3 pounds.
2. Magnification --------- 5 X .
3. Field of view --------- 10 degrees.


Complete with the carrying case.







Figure 285-a

This another example of a WWII Japanese hand held periscope. Of metal construction. Black color. High quality optics. A side handle comes as part of the kit. It screwa to the side of the bottom section.

The carrying case is of metal construction. It opens at the top. A hinged flap is secured with a single lever. Olive drab color. A cloth shoulder strap is provided.

Figure 285.
The hand held periscope has a 5 X magnification and 10 degrees field of view.


Figure 285-a. Hand held periscope with carrying case.





3. WWII JAPANESE INFANTRY FIRE CONTROL EQUIPMENT.

a. WWII Japanese Range finders.

Figure 286.
Model 92 (1932) 40-cm range finder is calibrated for measuring ranges up to 1,500 meters (1,640 yards). It is a coincidence type of range finder with a 4 X magnfication.


b. WWII Japanese Aiming and laying devices.


Figure 287. Collimator sight for Model 97 (1937) infantry mortar. Of high quality construction.

Figure 288. Panoramic sight for Model 94 (1934) mortar. It has a 3 X magnification and a 13 degree field of view. Micrometer drums enable readings to be made to the nearest mil. Very clear, high quality optics.



Figure 289. Telescopic sight for Model 96 (1936) 6.5-mm light machine gun. The magnification is 2.5 X, the field of view is 13 degrees, and the weight is 20 ounces. The reticle (graticule) pattern provides for drift and windage, and is calibrated for a maximum range of 1,500 meters (1,640 yards).

Figure 290. Telescopic sight for Model 92 (1932) 7.7-mm machine gun has a 4 X magnification, a 10 degree field of view, and a weight of 3 pounds, 6 ounces.



Figure 291. Telescopic sight for the Model 94 (1934) 37-mm gun.




4. WWII JAPANESE PERSONAL ARMOR.

a. WWII Japanese Model 99 (1939) armor shields, portable.


Figure 292.
Model 99 (1939) armor shield with the Model 96 (1936) 6.5-mm light machine gun.


(1) General. While shields are suitable for use in the open, specimens, constructed from what appears to be face-hardened plate, have been found built into the weapon ports of pillboxes. Two sizes have been recovered, the larger measuring 14 x 20 x 1/4 inches (figure 293) and the smaller 12 x 16 x 1/4 inches.

(2) Penetration. Tests have shown that these shields will resist penetration by a .30 caliber ball ammunition at 100 feet. However, some damage may be caused by flaking (chipping). These shields have been penetrated rapidly by .30 caliber AP ammunition as indicated below:

NUM RANGE (Yards) Angle of Impact from Normal RESULTS
1. 33 10 to 15 degrees
2. 100 30 degrees
3. 200 Normal
4. 500 Normal


b. WWII Japanese Army Body armor.

(1) WWII Japanese Bullet proof vest.
The vest (Figure 294) is made from Olive Green drill cloth, with 3 pockets on each side to accomodate armor plates arranged in fish-scale fashion. Characteristics are as follows:

1. Weight complete --------- 9 pounds.
2. Thickness of plates --------- 0.08 inch.
3. Place overlap --------- 0.05 inch.


It is believed that the weight of this vest would preclude its general use by infantry and probably would tend to confine its use to special troops. Tests have shown that the plates are penetrated easily by .303 ball ammunition at 100 yards range, with a 30 degree angle of impact from normal.

(2) WWII Japanese Body protector.
No details are available concerning this body protector (Figure 295), but it is reasonable to assume that it is made from an armor plate of thickness approximating that of the bullet-proof vest. It is possible that the armor plate is in 3 sections for purposes of flexibility.

c. WWII Japanese military Steel helmets.
See Chapter 11.




SECTION III - WWII JAPANESE ARTILLERY EQUIPMENT.

1. GENERAL.

a. Optical instruments.
Optical instruments are cut standing among specimens of Japanese artillery equipment. Examination of them shows good, versatile design, sturdy construction, and satisfactory definition. Knowledge of antiaircraft fire-control equipment is limited; specimens examined to date are obsolescent, although it is entirely possible that much improved designs exist, but have not yet been encountered.

b. Artillery communication equipment.
Artillery communication equipment is described in the signal equipment section of this web chapter. Trucks and other automotive equipment are described in the Automotive and Land Transport section.

c. Although the Japanese army is provided with a variety of prime movers, few types of these have been encountered in forward areas. these have been older models; mode modern types, with improved specifications, well may exist.

2. WWII JAPANESE ARTILLERY FIRE CONTROL INSTRUMENTS.

a. General
Illustrated and described on teh following pages are various examples of artillery fire control equipment used by the Japanese. Their optical equipment is well made, sturdy, and versatile, but none examined differs from standard optical design. Panoramic sights for artillery weapons have not been recovered, but sights for infantry guns and mortars (described in section II) suggest that the Japanese have suitable sights for use on artillery pieces.

b. Off-carriage fire control instruments.

The 75-cm base range finder is an inverted coincidence-type range finder with the following Characteristics;

1. Magnification --------- 12 X
2. Vertical field of view --------- 2 degrees.
3. Horizontal fiedl of view --------- 3 degrees.
4. Maximum range --------- 10,000 meters.


Figure 297.
One meter base stereoscopic range finder. The reticle of this instrument is graduated from 250 to 6,000 (presumed to be meters). markings inidcate an 8 degree X magnification, a 45 degree vertical and a 5 degree horizontal field of view.



Figure 298.
The Model 93 battery commander's telescope permits measurement of angle of site from -300 to +300 mils, as well as measurement of azimuth. An unusual feature is that the telescopes cannot be placed in a horizontal plane for betetr stereoscopic vision. It has an 8 X magnification and a 6 degree field of view.

Figure 299.
this batery commander's telescope has an 8 X magnification and a 6 degree field of view. It is constructed so that the telescopic arms may be placed in a horizontal position for better stereoscopic vision.



Figure 299-a. WWII Japanese artillery periscope.


Figure 300.
Battery commander's telescope. Although giving a high magnification and wide field of view, the individual telescopes cannot be placed in a horizontal position to improve stereoscopic vision.

Figure 301.
This artillery spotting telescope may be used with three different eyepieces, each of which gives a different magnification, the maximum being 33 power. Provisin is made to measure azimuth, and elevation (from -30 degrees to +30 degrees).


c. WWII Japanese Aiming and laying devices.


Figure 302.
This panoramic sight appears to have been designed for use on more than one artillery piece. It is shown above mounted on the Model 41 (1908) infantry gun. The sight has a 3 X magnification and a 13 degree field of view.

Figure 303.
This aiming circle has a 4 X magnification and a 10 degree field of view. Similar to the American aiming circle, it is used by artillery units for measuring angles in azimuth and site, and for general topographical work.



Figure 304.
This gunner's quadrant is calibrated from 0 to 90 degrees, with a vernier reading to 1/16 of a degree.

Figure 305.
This gunner's quadrant is calibrated in units of 10 mils, extending from 0 to 1,410 mils (79 degrees). A vernier scale enables adjustments to the nearest mil. It is considered possible that this quadrant has been designed primarily for use with the Model 41 (1908) 75-mm infantry gun.



Figure 304-a. WWII Japanese artillery quadrant with carrying case.


3. WWII JAPANESE ANTIAIRCRAFT FIRE CONTROL EQUIPMENT.

a. Automatic weapons. The Model 92 (1932) 7.7-mm and the single mounted Model 93 (1933) 13-mm machine guns, described in Chapter 9, are provided with antiaircraft ring sights. The latest type ring sight recovered, illustrated in Figure 306, is rotated automatically around its horizontal axis as the gun is elevated. It is believed that the purpose of this design is to correct automatically for the angle of approach.

The following automatic weapons are provided with more complex sights than the ring sights.

(1) Dual mounted Model 93 (1933) 13-mm machine gun. To date (1944) only incomplete sights (Figure 307) have been examined on dual mounts. They are constructed in such a manner that estimates of target course and speed are fed into the instrument, which then applies the appropriate deflection to the sighting telescope. The sight would appear to require 3 men for its operation.

(2) Japanese Model 98 (1938) 20-mm automatic cannon.
Complete antiaircraft sights for this weapon have not yet been recovered. It is known that some form of computing sight is used.

(3) Japanese Model 96 (1936) 25-mm automatic cannon.
A computing sight, similar to the one described in a (2) for the 13-mm machine gun, is provided for this weapon (Figure 308).

(4) Japanese Vickers Tpe 40-mm automatic cannon.
This weapom also has a computing sight for use in antiaircraft fire. In addition, an automatic fuze setting mechanism is provided. The time setting given to each fuze is adjujted, thru a complex series of gears and linckages by the manipulation of the gun in elevation and depression.

b. Heavy antiaircraft weapons.
According to modern standards the Japanese heavy antiaircraft fire control equipment seen to date has been outmoded and designed for use with the Model 88 (1928) 75-mm antiaircraft gun. Off-carriage fire control instruments and computing mechanisms used with these guns are as follows:

(1) 2-meter base height and range finder. This instrument (Figure 309) is of good optical construction and standard, but most specimens recovered had no provision for electrical data transmission. It supplies the "present attitude" to the guns.

(2) Target speed and course angle calculator. This instrument (Figure 310) is mounted on a tripod for use. The illustration in Figure 310 does not include an elbow telescope, which must be mounted on its top in order to operate the instrument. The calculator supplies the angle of approach (course angle) of the target at the present position and ground speed of the target.

(3) Corrector scale. This is a metal board (Figure 311)on which may be read mechanically the correction angles required for wind direction and powder temperature.

(4) Spotting binoculars. These are used to obtain spot corrections, and have 15 X magnification and 4 degrees field of view (Figure 312).

Data from each of the instruments shown in figures 309, 310, 311, and 312, are shouted to the gun crew, certain individuals of which operate the "on carriage" components. This procedure theoretically results in the gun being correctly aimed and the time fuzes being so adjusted that the projectiles burst on the target. The "on carriage" components are:

(a) Elevation computing apparatus.
(b) Azimuth computing apparatus.
(c) Auxiliary elevation and lead correction disc.
(d) Fuze setter.

Figure 306.
Front and rear antiaircraft sights mounted on the Model 92 (1932) 7.7-mm machine gun.





c. WWII Japanese artillery Computing director.
A few data computing directors have been captured, and provision for electrical data transmission has been seen on height finders. Mounting surfaces for data receivers have been found on some Model 88 (1928) 75-mm antiaircraft guns. There is evidence of more general use of electrical data transmission and computing directors than would be indicated by the equipment captured to date (1944).


Figure 307. -- Computing head for antiaircraft sight used on dual mounted Model 93 (1933) 13-mm machine gun.


Figure 308.
Computing sight for Japanese Model 96 (1936) 25-mm automatic cannon.


Figure 309. -- 2 meter base height and range finder.

Figure 310.
Target speed and course angle calculator with carrying box.



Figure 311.
Powder charge temperature and wind correction scale. Circular shape with Japanese writing on the face.

Figure 312.
Model 89 (1929) 10-cm antiaircraft (AA) spotting binoculars. Very nice quality. Clear optics.


d. WWII Japanese Searchlights.
Japanese searchlights include the following sizes:

60-cm (23.6 inches).
90-cm (35.4 inches).
98-cm (38.6 inches).
100-cm (39.4 inches).
110-cm (43.3 inches).
150-=cm (59.1 inches). (Figure 313)


The following equipment is used by Japanese searchlight units:


Figure 313.
150-cm searchlight.

Figure 314.
Searchlight comparator.




(1) Generator truck (standard 2-ton truck chassis).

(2) Searchlight comparator. The searchlight comparator illustrated in Figure 314 is an instrument with which an observer, by keeping a plane in the crosslines of the telescope, automatically directs the searchlight on the plane. It was found satisfactory for operation of U.S. searchlights.

(3) Sound locator. Several varieties of Japanese sound locators are known to exist. One of teh small models is illustrated in Figure 315.




Figure 315.
Small sound locator.

4. WWII JAPANESE PRIME MOVERS AND TRACTORS.

a. Japanese WWII Komatsu tractor.
This small, full-tracked vehicle (Figure 316) is designed solely for towing purposes. Steering is of the clutch-brake type, with hand levers opertating the clutches. Two foot brakes are located on the right side, and are so placed that either or both brakes may be operated by the right foot.

The gear box allows 3 forward and 2 reverse speeds. The vehicle is supported by 4 small bogie wheels on each side. Examination of a specimen revealed that a number of bearings were of swedish manufacture. Characteristics are as follows:

1. Weight --------- Estimated 3 tons.
2. Length --------- 8 feet. 2 inches.
3. Width --------- 4 feet. 4 inches.
4. Engine --------- 4 cylinder. gasoline.
5. Cooling --------- Water.
6. Ignition --------- Bosch magneto.
7. Length of track in contact with ground --------- 5 feet 7 inches.
8. Width of track --------- 10 inches.

Figure 316.
Komatsu tractor.



b. WWII Japanese Light prime mover.
The model number and date of manufacture of this vehicle (Figure 317) are not known. In the case of a specimen examined, the word "seventy" was found marked in English on the side of the radiator, probably indicating the engine horsepower. A name plate on the power unit shows it to be a "Kato engine model K 3". Suspension consists of 2 bogies mounted on each side of the vehicle.

Each bogie has 3 small wheels, and the sprocket is at the rear. Details are reported to be as follows:

Approximate characteristics:
1. Weight --------- Estimated 4 tons.
2. Length, width, height --------- No details.
3. Engine --------- 4 cylinder, gasolinge.
4. Cooling --------- Water.
5. Length of track in contact with ground --------- 7 feet 5 inches.
6. Diameter of sprocket --------- 2 feet 2 inches.

Figure 317.
Light prime mover.


c. WWII Japanese Model 92 (1932) 5-ton prime mover.
It is reported that there are 2 variations of this vehicle. Model A is powered by a 6-cylinder in-line "L" head "Sumida" gasoline engine, and model B by a 6-cylinder in-line, air cooled "Isuzu" Diesel. As far as may be ascertained, with exception of a modification in radiator design, the general appearance and suspension of these 2 models are similar. Both vehicles are reported to be identical in the following respects:

Common characteristics:
1. length --------- 11 feet 8 inches.
2. Width --------- 5 feet 11 inches.
3. Height --------- 7 feet 8 inches.
4. Ground clearance --------- 11 3/4 inches.
5. Fording depth --------- 1 foot 7 1/2 inches
6. Grade --------- 30 degrees.
7. Turning radius --------- Can pivot.
8. Winch capacity --------- 2 3/4 tons.


(1) 5- ton prime mover (Model A) (Figure 318)

Characteristics;
1. Weight --------- 5 1/3 tons.
2. Engine --------- 6 cylinder, "Sumida".
3. Cooling --------- Water.
4. Cylinder bore --------- 110-mm (4,3 inch)
5. Piston stroke --------- 135-mm (5.3 inch).
6. Horsepower --------- 64 to 98 (160 theoretically indicated hp at 2,800 RPN - based on reported engine specifications).
7. Ignition --------- Bosch magneto.
8. Generator --------- Bosch, 12 volts
9. Storage batteries --------- 2 - 12 volts, 60 amperes.
10. Fuel tank capacity --------- Main 27.5 gallons, auxiliary 12.1 gallons.

Figure 318. 5 Ton prime mover (Model A)


Note: The Model A is believed to be similar to, if not identical with, a recently examined prime mover. This vehicle was found to be well constructed and capable of operating over most types of terrain. The present gasoline engine is estimated to be of approximately 140 horsepower, considerably more powerful that the standard unit. It is believed that this particular engine is a replacement of the unit originally installed.

(2) 5-ton primer mover (Model B) (Figure 319).

Characteristics:
1. Weight --------- 5.5 tons.
2. Engine --------- 6 cylinder, Diesel.
3. Cooling --------- Air.
4. Cylinder bore --------- 110-mm (4.3 inch).
5. Piston stroke --------- 140-mm (5.3 inch).
6. Horsepower --------- 65 to 90 (135 theoretically indicated hp at 2,000 RPM - based on reported engine specifications).
7. Ignition --------- Compression.
8. Generator --------- 12 volts, 300 watts.
9. Storage batteries --------- 2 - 12 volts, 120 amperes.
10. Fuel tank capacity --------- Main 22 gallons, auxiliary 13.2 gallons.

Figure 319. 5 - Ton prime mover (Model B).


d. WWII Japanese Model 92 (1932) 8-ton prime mover.
It is reported that 2 versions exist of this vehicle; the Model A is powered by a 6-cylinder in-line water cooled gasoline engine, and the Model B by a 6-cylinder in-line water-cooled Diesel. The following data are believed to be common to both models A and B:

Common characteristics:
1. Length --------- 14 feet 1 inch.
2. Width --------- 6 feet 6 inches.
3. Height --------- 8 feet 6 inches.
4. Grade --------- 15 degrees.
5. Winch capacity --------- 5 tons.
6. Cylinder bore --------- 130-mm (5.1 inches).


Characteristics of Model A :
1. Weight --------- 8.45 tons.
2. Ground clearance --------- 11 1/2 inches.
3. Engine --------- 6 cylinder, gasoline.
4. Cooling --------- Water
5. Piston stroke --------- 5.6 inches.
6. Horsepower --------- 80 to 130 (230 theoretically indicated horsepower at 2,800 RPM - based on reported engine specifications).
7. Ignition --------- Bosch magneto.
8. Generator --------- 2 - 12 volts, 100 watts.
9. Storage batteries --------- 12 volts, 100 watts.
10. Fuel tank capacity --------- Main 39 1/2 gallons, auxiliary 9 gallons.
Characteristics of Model B :
1. Weight --------- 9.3 tons.
2. Ground clearance --------- 12 inches.
3. Engine --------- 6 cylinder, Diesel.
4. Cooling --------- Water.
5. Piston stroke --------- 6.4 inches.
6. Horsepower --------- 105 to 120 (215 theoretically indicated hp at 2,000 RPM - Based on reported engine specification).
7. Generator --------- 12 volts, 500 watts.
8. Storage batteries --------- 4 - 12 volts, 140 amperes.
9. Fuel tank capacity --------- Main 39 1/2 gallons, auxiliary 9 gallons.


e. WWII Japanese Model 98 (1938) 4-ton prime mover.
It is believed that this prime mover, powered by an 8-cylinder V type air cooled gasoline engine, is capable of hauling a load at 25 miles per hour, and that it can travel a distance of 125 miles in a period of 10 hours. Steering is of the clutch brake type, with foot and hand operated brakes. A central selector type gear box allows 4 forward speeds and 1 reverse.

Although no 4 - ton model has been encountered as yet (1944), it is believed that the following data apply:

1. Weight --------- 4 tons.
2. Length --------- 12 feet 5 inches.
3. Width --------- 6 feet 1 inch.
4. Height --------- 7 feet 3 inches.
5. Ground clearance --------- 11 1/2 inches.
6. Tread --------- No details.
7. Fording depth --------- 20 inches.
8. Grade --------- 30 degrees.
9. Turning radius --------- Can pivot
10. Winch capacity --------- Over 2 tons.
11. Engine --------- 8 cylinder V-type, gasoline.
12. Cooling --------- Sirocco type fan.
13. Cylinder bore. --------- 90-mm (3.5 inch).
14. Piston stroke --------- 125-mm (4.9 inch).
15. Horsepower --------- 73 to 88 (130 theoretically indicated hp at 2,800 RPM - based on reported engine specifications).
16. Ignition --------- Bosch magneto.
17. Generator --------- Bosch, 75 watts.
18. Storage batteries --------- 12 volts, 80 amperes.
19. Fuel tank capacity --------- Main 22 gallons, auxiliary 13 gallons.


f. WWII Japanese Model 98 (1938) 6-ton prime mover.
Examination of this prime mover (Figure 320) indicates that it is an unarmed artillery tractor, suitable for the additional roles of reconnaissence vehicle and ammunition carrier. Suspension follows the pattern of the Model 2597 medium tank. Since steering is of teh clutch-brake type, the vehicle is capable of turning within its own length. It is reported that this vehicle is used as a prime mover for the 105-mm and 150-mm howitzers and the 105-mm gun.

Details are believed to be as follows:

1. Weight --------- 7.75 tons.
2. Length --------- 14 feet 1 inch.
3. Width --------- 6 feet 9 inches.
4. Height --------- 6 feet 3 inches.
5. Ground clearances --------- 13 1/2 inches.
6. Grade --------- 15 degrees pulling field gun.
7. Turning radius --------- 19 feet.
8. Winch capacity --------- 5.5 tons.
9. Engine --------- 6 cylinder, Diesel.
10. Cooling --------- Water.
11. Cylinder bore --------- 120-mm (4,7 inch).
12. Piston stroke --------- 155-mm (6.1 inch).
13. Horsepower --------- 88 to 110 (175 theoretically indicated hp at 2,000 RPM - based on reported engine specification).
14. Generator --------- 24 volts, 110 watts.
15. Storage batteries --------- 2 - 12 volts, 180 amperes.
16. Fuel tank capacity --------- Main 17.6 gallons, 1st auxiliary 18.7 gallons 2nd auxiliary 6.6 gallons.

Figure 320. Model 98 (1938) 6 Ton prime mover.


g. Japanese Model 95 (1935) 13-ton prime mover.
This heavy prime mover is reported to be produced in two models: the Model A is powered with a 6 cylinder in-line, water-cooled, gasoline engine; the Model B with a 6-cylinder, water cooled Diesel. Both models are believed to be equipped with multiple disc, clutch type steering, with hand and foot operated brakes.

The follwing data is reported to be common to both types:

1. Length --------- 16 feet.
2. Width --------- 7 feet 6 inches.
3. Height --------- 9 feet 3 inches.
4. Ground clearance --------- 12 inches.
5. Grade --------- 13 tons, 15 degrees - 29 tons, 7 1/2 degrees.
6. Turning radius --------- 65 feet.
7. Winch capacity --------- 11 3/4 tons.


Characteristics of Model A
1. Weight --------- 14.3 tons.
2. Engine --------- 6 cylinder, gasoline.
3. Cooling --------- Water.
4. Cylinder bore --------- 5.4 inches.
5. Piston stroke --------- 6 inches.
6. Horsepower --------- 130 to 160 (265 theoretically indicated hp at 2,800 RPM -- based on reported engine specifications).
7. Ignition --------- Magneto
8. Storage batteries --------- 2 - 120 volts, 80 amperes.
9. Piston stroke --------- Main 61.6 gallons, auxiliary 9 1/2 gallons.
Characteristics of Model B
1. Weight --------- 15 tons.
2. Engine --------- 6-cylinder, Diesel.
3. Cooling --------- Water
4. Cyliner bore --------- 5.6 inches.
5. Piston stroke --------- 7.6 inches.
6. Horsepower --------- 145 to 165 (295 theoretically indicated hp at 2,000 RPM -- based on reprted engine specification.
7. Generator --------- 300 watts.
8. Storage batteries --------- 2 - 12 volts, 80 amperes.
9. Fuel tank capacity --------- 60 gallons.



5. WWII JAPANESE CAISSONS, LIMBERS, AND OTHER ARTILLERY VEHICLES.

a. WWII Japanese Caissons and limbers.
(1) Horse-drawn caisson and limber. Figure 321 depicts a typical Japanese horse-drawn caisson and limber, for use with the 75-mm field gun. Mounted on standard artillery, iron shod, wooden wheels, the two units are drawn by six horses.

Characteristics are reported as follows:

1. Total weight (empty) --------- Approximately 2,130 pounds.
2. Weight loaded
Limber only: 1,750 rounds.
Caisson only: 2,080 rounds.
3. Capacity
Limber: 40 rounds.
Caisson: 60 rounds.
. Diameter of wheels --------- 55 inches.

Figure 321. Typical horse drawn caisson and limber.


Caissons and limbers of design similar to Figure 321, but carrying fewer rounds, are provided for field guns of heavier caliber.

(2) Japanese Alternative type caisson and limber. The caisson and limber illustrated in Figure 322 is an alternative type for use with the 105-mm field gun. Primarily designed to be towed by a tractor, it also may be drawn by six horses. The heavy artillery type wheels have solid rubber tires. Characteristics are reported as follows:

1. Total weight (empty) --------- 2,530 pounds.
2. Total weight (loaded) --------- 5,040 pounds.
3. Total capacity --------- 48 rounds.
4. Diameter of wheels --------- 55 inches.

Figure 322. Alternative type caisson and limber for 105-mm field gun


(3) WWII Japanese High speed caisson. The photographs illustrated in Figure 323 show the most modern type of Japanese caisson seen to date. Constructed of metal, it is mounted on steel disc wheels, of comparatively small diameter, fitted with solid rubber tires. The probable capacity of the caisson is 48 complete rounds of 75-mm ammunition. Units of similar appearance carry a smaller quantity of 105-mm ammunition.


Figure 323. High speed caisson for 75-mm ammunition.

b. WWII Japanese Horse Drawn Battery wagons.
(1) Battery wagon for antiaircraft gun. The trailer (Figure 324) apparently is constructed for high speed transportation of communication equipment, miscellaneous spare parts, and bulk ammunition. The body is made from lightweight metal plate, which is not considered to be proof against small arms fire. compartments are provided for the stowage of the various items of equipment carried. This vehicle is mounted on metal disc wheels fitted with pneumatic tires. For antiaircraft defense, a tripod, apparently designed for the Model 92 (1932) 7.7-mm heavy machine gun, is mounted on the roof. Characteristics of the vehicle are as follows:

1. Overall length of frame --------- 11 feet 10 inches.
2. Width --------- 6 feet 3 inches.
3. Wheel base --------- 7 feet 7 inches.
4. Ground clearance --------- 12 inches.

Figure 324. Horse drawn Battery wagon for Model 88 (1928) 75-mm antiaircraft gun.


(2) WWII Japanese Battery wagons for field artillery. These units are similar to the horse-drawn limber and caisson in construction (Figure 325). They are used for the transportation of general artillery equipment, such as range finder, binoculars, battery commander's telescopes, communication materials, tools, etc.

Characteristics are reported to be as follows:

1. Total weight loaded (limber and caisson) --------- 4,318 pounds.
2. Diameter of wheels --------- 55 inches.


c. WWII Japanese Horse Drawn Spare parts wagons.
These are used for the transportation of spare parts, tools, and maintenance and repair materials (Figure 326).

Characteristics are believed to be as follows:

1. Total weight loaded (limber and wagon). --------- 3,770 pounds.
2. Diameter of wheels --------- 55 inches.

Figure 326. Spare parts wagon for 150-mm howitzer.


The two units are normally drawn by 6 horses.


6. WWII JAPANESE HORSE PACK EQUIPMENT.

a. General.
Great attention has been paid to the development of pack transportation of infantry support guns, namely, Models 41 (1908) and Model 94 (1934) 75-mm mountain pack guns (Section II, Chapter 9), as well as of machine guns, ammunition, supplies, etc. Illustrations on the following pages show in detail pack saddles, draught harness, and an infantry support gun, broken down into loads averaging 200 pounds per load and packed for horse transportation.

b. WWII Japanese Horse Pack saddles.
Two standard pack saddles are illustrated in Figure 327. The saddle is adjustable so that it comfortably fits the back and girth of the horse. Saddle A carries the weapon (such as a heavy machine gun); Saddle B is fitted to hold ammunition or spare parts chests (See also figures 328 - 334).

c. WWII Japanese Draught horses.
Extensive use of draught horses is made by the Japanese. Figure 336 shows a typical 4-horse harness hookup, with the type of saddle (which differs from the cavalry saddle) used by artillery and infantry gun crews.


Figure 327. WWII Japanese Standard pack saddles.



Figure 328. Tube of Model 41 (1908) 75-mm infantry (mountain) gun fastened to horse with a pack saddle.

Figure 329. Trail of 75-mm infantry (mountain) gun dissassembled and fastened to horse with a pack saddle.



Figure 330. 75-mm infantry (mountain) gun cradle on pack saddle.

Figure 331. Shield for 75-mm infantry (mountain) gun folded and fastened to pack saddle (with total chest attached to side).



Figure 332. Breech mechanism and tray for WWII Japanese 75-mm infantry (mountain) gun mounted on horse.

Figure 333. Wheels and axle attached to a pack saddle on a horse.






SECTION IV - WWII JAPANESE SIGNAL EQUIPMENT.

1. GENERAL.
The following data have been derived from the examination of Japanese signal equipment.

2. WWII JAPANESE RADIO EQUIPMENT.
a. WWII Japanese Ground radio.

(1) The Japanese place most emphasis on wire communication. However, radio is used initially where communications must be established rapidly or wher other means are not practicable. After wire communications have been established, radio assumes a secondary role as a stand-by communication link except where other means cannot be employed.

(2) Apparatus, to date, is of obsolescent design. Circuits and components are comparable with those used by the Allied Nations between 1935 and 1937. Transmitters and receivers almost invariably have wide frequency ranges and use plug in coils to cover the various bands. In regiments or smaller units, transmitters generally vary from approximately 1 to 50 watts. High powered sets (500 watts and above) are used primarily for Army administration traffic and air/ground liaison. Simple Hartley oscillator circuits, connected directly to the antenna, are used. The smaller receivers employ regenerative directors without radio frequency amplification. While such arrangements are simple to service and maintain, the frequency stability suffers greatly. It therefore would be difficult to "net" these ardio sets and keep them on frequency.

(3) A great variety of small transceivers and transmitter-receiver combinations of 1 to 2 watts power are in operation. Such sets are usually manpack. The transceivers are contained in one case which is carried on the chest; the batteries are carried in anoher case on the back. In the small transmitter-receiver models, the transmitter, receiver, batteries, and the hand generator for transmitter power, are all carried om separate cases, making it necessary for two to three men to pack and operate a set.

Sets of from 10 to 50 watts power are usually of the portable type, and are carried in 4 or 5 separate cases. Power connections are made by means of plugs and cables. The sets, in general, have a complexity of control which does not permit ease of operation. The many controls of the Direction Finder and Intercept Receiver, Model 94 (1934), Type 1, indicate that a comparatively long time is necessary to obtain an accurate "fix" on a transmitter. It must be borne in mind, however, that Japanese operators are well trained and capable of making good use of their equipment.

(4) Most of the transmitters have provision for crystal operation, and although few crystals have been found, it is reasonable to assume that crystal operation is used extensively. All crystal operated Army ground sets also can be employed as master oscillators.

(5) Since many ammeters, both for antenna and power, are supplied with separate shunts, the same meter movement can be used for many different sets.

(6) Examination of equipment shows that there is little indication of moisture or fungus proofing.

(7) All phone transmitters are amplitude modulated, and there is no evidence of frequency modulation.

(8) Technical characteristics and photographs of sets used by Japanese ground forces are illustrated in figures 337 to 354.


Figure 337.
Model TE-MU Type 2. Transmitter. Front view.

Figure 338.
Model TE-MU Type 2. Transmitter. Rear view. Tube shown is Japanese Type UV812. Manufactured by Tokyo electric company.







Figure 344.
Model 94 Type 5. Transmitter-receiver Model 32. Receiver.

Figure 345.
Model 94 3A No 36. Transmitter-receiver. Transmitter, 400-5700 KC. 15 watts. CW only. Power supply - hand generator. Receiver 350-600 KC. Power supply - batteries.



Figure 346.
Model 94 Type 6. Transceiver. No 23 Model H. Date: April 1940.

Figure 347.
"Walkie Talkie" Type 66. Transceiver. Model A. 2500-4500 KC. Power supply - batteries.



Figure 348.
Model 97 Type 3. Transceiver with hand generator. Pack type. Dipole elements of antenna fasten to wing nuts at ends of case.

Figure 349.
Model TM Type 2. Transceiver 4000-12000 KC. CW only. Power output about 1 watt. (also reported as 2.5 watts).



Figure 350.
Model 92 Revision 3. Tube combination TRF and superheterodyne, all-wave receiver. 200-2000 KC.
Shown with AC power supply. Delivers 75 and 200 volts DC.



Figure 351.
Model 94 Type 1. Direction finding and intercept receiver. 100-2000 KC, Loop shown dismounted from frame.

Figure 352.
Model 94 Type 3-A. Receiver only. Pack type.


b. WWII Japanese Airborne radio.
(1) Japanese airborne transmitters and receivers, sturdily and compactly constructed, are of excellent workmanship and material. More attention appears to have been given to compactness of design than to ease of maintenance. In many instances, the equipment is so constructed that it is difficult, or even impossible, to service. To some extent, sets are designed to fit a particular type of aircraft, rather than standardized for general use. It has been noted that some tubes (valves) are equipped with leather handles to facilitate removal.

Japanese equipment uses a large amount of aluminum, so that even bulky pieces are unusually light in weight. Although no precautions have been taken gainst corrosion and fungus control, reports indicate that equipment later than 1940 is far superior to that of earlier design. Electrically and mechanically, new radio equipment appears to approach Allied standards.

(2) It has been noted that not all Japanese planes have radio equipment. While radio direction finders are standard equipment on medium and heavy bombers, here have been no reports indicating that they are normally fitted to fighters.

(3) Radio equipment that was made in America, either in whole or in part, has been found on several Japanese (0) Zero fighters (Zekes). Most parts are of Japanese manufacture, but components of German and English manufacture have been noted. Exact imitations of American and German design also have been reported. there si no evidence of quantity production; indeed, all equipment noted is hand-made and of good construction. Good quality crystals are used in he majority of radios to control the frequencies of transmitters and receivers.

(4) Technical characteristics and photographs of airborne equipment are shown in Figures 355 to 363.


Figure 355.
Model 96 (1936) Type 3. Transmiter - receiver. From Tyoe 1 medium bomber (Betty).
Top of unit: receiver.
Bottom of unit: transmitter.

Figure 356.
Radio homing and D/F loop antenna used with some types of Japanese airborne equipment.



Figure 357.
Dynamotor power supply for transmitter of Model 96 Type 3 airborne radio set. Used in Type 1 medium bomber (Betty).

Figure 358.
Vibrator power supply for receiver of Model 96 Type 3 airborne radio set. Used in Type 1 medium bomber (Betty).



Figure 359.
Model 99 (1939) Type 3. Transmitter-receiver. used in single seater fighter (Oscar).
Transmitter: 2,500 - 5,000 KC.
Receiver: 1,500 - 6,700 KC.
Transmitter and receiver crytal controlled. Photo shows complete complements of equipment.

Figure 360.
Model 99 (1939) Type 3. Transmitter - receiver. Close up pictures of transmitter(right) and receiver (left).



Figure 361.
Model 96 (1936) Type 1.
Trnasmitter/receiver Model 13, from Mitsubishi bomber.
Transmitter; 7,600 - 10,600 KC
Receiver: 7,500 - 10,800 KC

Figure 361. WWII Japanese frequency meter.




3. WWII JAPANESE TELEPHONES
a. WWII Japanse Model 92 (1932) telephone.
This telephone (Figure 364) is of conventional design and normally is used on a ground return circuit, although it may be used also on a metallic circuit. It is equipped with a buzzer and key arrangement for sending code. The complete unit is encased in a metal-reinforced, wooden box, approximately 12 inches long, 5 inches wide, and 7 inches high.

Directly beneath the aluminum cover is a transmitter, handset receiver, extra single ear phone, and the buzzer key. Permanent lead-in wires are fitted to the telephone to which the field wire is attached. Current is supplied by a hand-cranked generator which generates ringing current rated at 55 volts A.C. It is not advisable, therefore, to use this set with U.S. Army generators which deliver up to 90 volts A.C. It will, however, receive and transmit clearly over U.S. Army circuits, being equipped with two 1 1/2 volt dry cell batteries which furnish 3 volts when connected in series.

These batteries normally are connected in parallel and are stored on a metal rack inside the cabinet. Compared with Allied standards, the gemeral mechanical construction of teh set is inferior. It has been found that the hand switch on the handset receiver causes frequent cut outs as well as noise during operation.

The set is contained in a heavy leather carrying case and may be carried easily by one man. A new carrying case, composed of layers of rubberized canvas, also has been observed. This material will withstand tropical climate much better than leather. The complete set weighd approximately 12 pounds.


Figure 364. WWII Japanese Model 92 field phone.

Figure 364-a. WWII Japanese Model 92 field phones.



b. WWII Japanese Model 2 (1942) trench telephone.
This telephone (Figure 365) normally is used with a ground return circuit, although it may be employed with a metallic circuit. The unit ios contained in a wooden cabinet, with metal-reinforced corners. The handset; batteries; and generator, belt, condenser, and induction coil are housed in three compartments.

The set may be operated on local or common battery circuits, while magneto signaling facilities also are included. The generator hand crank folds up and fits within the generator armature shaft. A fiber driving gear on the generator eliminates noise to some extent during cranking.


Figure 365. WWII Japanese Model 2 trench telephone.

c. WWII Japanese Sound-powered telephone.
The microphone (Figure 366) of the sound powered telephone, deriving its energy directly from the sound waves, is a reversion to the original principle of the telephone in that the receiver unit is used also as a microphone. The instrument consists of a handset, with a single dual purpose operating unit and an additional unit as an extra receiver.


Figure 366. WWII Japanese complete assembly of sound powered telephone.

It is used to provide intercommunication within vehicles, or even short lines when circumstances require rapid and simple setting up and disconnection.

d. WWII Japanese Lip microphone.
This carbon type microphone is attached to a leather and elastic strap. Total weight is approximately 3 1/2 ounces. Other than the fact that it is used with head receivers, there is nothing to indicate for what purpose it was intended. However, since the output of this microphone is low, it is possible that it may be used in connection with radio equipment in armored vehicles.

4. WWII JAPANESE SWITCHBOARDS
The Japanese have field switchboards, but in place of these they frequently connect field telephones together to form a party line system. At higher headquarters and large air fields commercial switchboards and pole lines of open wire construction have been used.

5. WWII JAPANESE MILITARY TELEGRAPH SETS.
Figure 367 illustrates the Model 95 set which can be used in conjunction with Model 92 telephone. The set has built in key arrangement. It probably is used by lower units for administrative traffic.



6. WWII JAPANESE MILITARY SIGNAL LAMPS.

a. WWII Japanese Portable signal lamp. This lamp, provided with universal adjustment, is mounted on a tripod and powered by a hand generator. At the front, a hinged cover, equipped with a shutter adjustable to 6 degrees, controls the intensity of light. A reflector and 6-volt lamp, rated approximately 32 candlepower, are contained inside the housing. Usually 3 different colored filters - are provided with each lamp. A metal reinforced wooden cainet, 10 3/4 inches long, 5 3/8 inches high, and 8 3/8 nches wide, is provided for the equipment with the exception of the generator.


Figure 368.
A - Signal lamp
B - Key with lock device
C - Carrying case with spare lamp, eyepieces, filters, etc.
D - Filters; red, amber, green
R - Hand Generator


b. WWII Japanese military Hand signal lamp. This small pocket lamp measures 3 1/2 inches long. While resembling a cylindrical flashlight, it contains no batteries; instead, a cord, connected to an external battery, passes through the hollow wooden handle. The 3.5 volt bulb and reflector are of conventional design. Installed in front of the bulb is a glass filter, divided into red, blue, amber, and clear sectors. A cover, in front of the filter, can be revolved so that its opening will disclose a lighted segment of the desired color.

Signaling is accomplished by a combination push button and slide switch on the side of the case. This lamp should be useful at short range, but the drgree of security would be limited by the fact that its beam is not highly directional.


Figure 368-a. WWII Japanese Signal lamp with battery.

Figure 368-b. WWII Japanese Signal lamp.



Figure 368-c. WWII Japanese Signal lamp with carrying box and battery.

Figure 368-d. WWII Japanese early Signal lamp with carrying box and contents.



7. WWII JAPANESE FIELD WIRE.
The three principal types of field wire in general use are as follows:

a. WWII Japanese Military Assault wire.
Assault wire is very small in diameter. It consists of a single conductor and is composed of 8 strands (1 copper and 7 steel) with an outer covering of yellow colored braid. This wire is for ground return circuits and is used between regiments and forward units.

b. WWII Japanese Military Seven-strand wire.
This single conductor, 7 strand wire (3 copper and 4 steel) is larger in diameter than assault wire. The wire is rubber insulated, and tests have shown that the insulation resistance can remain high throughout a 14-day immersion period. It has an outer covering of Yellow colored braid. Tensile strength of the wire is high, but its abresion resistance is low, and its electrical characteristics are not as good as indicated by its construction. This wire is for ground return circuits and is used between regimantal and battalion headquarters.

c. WWII Japanese Military Heavy wire.
Heavy wire, consisting of two ruber-insulated, solid conductors (one black, the oher red), is used for metallic circuits, probably between division and higher headquarters as well as at the larger airfields. It has an outer covering of green colored braid.

8. WWII JAPANESE MILITARY CABLE.
Different types of cables are used by the Japanese for various purposes. Figure 369 and Figure 370 show types used and their characteristics.


Outside diameter (inch) Cross section of cable 1 2 3 4 5 6 7 8 9 Remarks
7/16 Rubber insulation Rubber insulation Cotton string wrapping No. 14 stranded wire ----- ----- ----- ----- ----- This was taken from the power cord of a test lamp. It corresponds to ordinary rubber covered lamp cord.


7/16 Wooven steel wire sheath (lead) Impregnated cloth Impregnated paper Lead sheath Cotton cloth wrapping Rubber insulation Copper wire core ----- ----- The conductor of this cable consists of 19 strands of No. 20 copper wire. Probably used as buried underground cable.


7/16 Lead sheath Cotton cloth Jute of hemp cord filler Silk cloth Rubber insulation Solid copper wire ----- ----- ----- Each of the three conductors is composed of 17 solid copper wire.


7/16 Lead sheath Cotton cloth Rubber insulation Stranded copper wire ----- ----- ----- ----- ----- This was taken from a Japanese radar transmitter and was used to carry power to the tube filaments. The single conductor core consists of 30 strands of No. 20 copper wire.


3/8 Lead sheath Cotton cloth Rubber insulation Solid copper conductor ----- ----- ----- ----- ----- This was used to carry 600 volts to a radar transmitter. The solid copper conductor is size No. 14. The estimated impedance of the line is 100 OHMS. The capacitance of the cable has been decreased by extruding three holes in the otherwise solid rubber dielectric. These holes are in a symmetrical position around the center conductor.


9/32 Black cotton cloth Woven steel wire sheath Rubber insulation Air holes in rubber Solid copper conductor, size No. 23 ----- ----- ----- ----- The cloth covered coaxial line is used to carry video and pulse signals between the various units of a radar.


Figure 369. Anatomy of Various types of WWII Japanese cables (Radio communications, radar, etc).


Outside diameter (inch) Cross section of cable 1 2 3 4 5 6 7 8 9 Remarks
1 1/4 Tar coated hemp Spiral steel sheath.
Wound hand.
Impregnated fiber Lead sheath Impregnated paper Impregnated paper No. 10 solid copper wire 15 conductors of No. 17 solid copper wire ----- This cable is probably used as underground power cable.


1 1/16 White rubber insulation Cotton string filler 4/16" diamter stranded from No. 31 tinned copper wire Rubber insulation Rubber insulation for H.V. No. 9 stranded wire from No. 30 tinned copper wire ----- ----- ----- This cable is probably used to carry power from a power supply unit to a communications transmitter. The large wires are the filament power and the small are for B plus and bias voltages.


2 9/32 Lead sheath Brown paper Copper sheath Brown paper Polystyrene spacers every inch Copper No. 9 wire (solid) ----- ----- ----- The shielded balanced wire line is used to carry power to the antenna of a Japanese radio. Navigation aid. The characteristic impedance of the line is approximately 115 OHMS.


1 1/16 Woven wire (white)
Steel sheath
Impregnated cloth Impregnated paper Lead sheath Cotton cloth Jute or hemp cord filler Silk cloth winding Rubber insulation Solid copper conductor This is a nine conductor cable. Probably multi-conductor remote control cable. All the conductors are size No. 17.


1/2 Lead sheath Cotton cloth Black rubber insulation White rubber insulation Stranded copper ----- ----- ----- ----- This high voltage cable was used on a radar transmitter to carry plate voltage at a potential of 6 KV. The stranded core, which is size No. 11 is made up of seven strands of No. 20 copper wire.


7/16 Rubber insulation Cotton string filler Rubber insulation No. 16 stranded copper wire ----- ----- ----- ----- ----- This is probably ordinary power cable.


Figure 370. Anatomy of Various types of WWII Japanese cables (Radio communications, radar, etc).


9. WWII JAPANESE MILITARY WIRE REEL UNITS.
The Japanese use various types of hand wire reel units, most of which appear to be designed primarily for handling single conductor wire.

a. Hand wire reel unit.
The reel is carried on the shoulders, or to one side of the body, by means of a broomstick handle and it will hold approximately 1,600 feet of the larger diameter, yellow braided, field wire. No crank is provided for convinient recovery of the wire. Perforations on the head and splines of the drum tend to damage the insulation if the wire is stored on the reel for any length of time. This unit, which is light in weight and not very rugged, can readily be dismantled without the use of tools. (See Figure 371).


Figure 371.
WWII Japanese Hand wire reel unit with broomstick handle.

b. Head wire reel.
The unit (See Figure 372) is solidly made of pressed metal, with leather straps for carrying on the chest or back, This reel evidently is designed for use by troops in forward areas and normally is carried on the back to allow free use of the hands. (See Figure 372). When revovering wire for which purpose a handle is provided, the reel normally is carried on the chest. The reel may be folded up when not in use.


Figure 372. Head wire reel - Used by field artillery. At left: recovering wire. At right: reeling out wire.


10. WWII JAPANESE AIRPLANE PANELS.
clopth air-ground panels are usually 1 1/2 to 3 feet wide and 6 1/2 to 13 feet long. Some shorter panels, and some triangular panels 3 to 6 1/2 feet on each side, have been used. In most cases panels are white, but other colors, comtrasting to the terrain, also may be used.

When regular panels are not available, rags, maps, or pieces of paper may ve substituted. On occasion, Japanese soldiers have been observed to lie on the ground to form panelsignals.

11. WWII JAPANESE MILITARY SIGNAL FLAGS.
Two small hand flags, one red and the other white, are used for semaphore. For signaling Morse Code a large red and white flag, on a bamboo shaft about 5 feet long, is utilized.

12. WWII JAPANESE MILITARY DOGS.
Trained dogs, used to some extent for carrying messages, are cared for and trained by the division signal unit.

13. WWII JAPANESE PIGEONS.
Pigeons, also, are used for carrying messages.

14. WWII JAPANESE MILITARY HAND GENERATORS.

a. WWII japanese Model "F" generator.
This simple and compact hand driven generator, which weighs only 16 pounds, delivers 24 watts. It serves as a source of filament voltage (3 volts) and of plate voltage (125 volts). The mechanical transmission between driving handle and armature consists of 4 geared wheels, 2 of which are fiber, the other steel.

According to the name plate, the normal rate of turning is 70 revolutions per minute, giving an armature speed of 5,200 revolutions per minute.Harness is provided for carrying the generator and for fastening it to a support. It is possible for a man to work the generator when the straps are slipped over his shoulders, with the base resting against his chest.




Figure 373. Moel "F" hand generator right side view -- showing crank handle in place.


15. WWII JAPANESE MILITARY BATTERY CHARGER.

Two charging circuits are provided. One uses a Tungar, half-wave rectifier, delivering 14 volts at 6 amperes. The other circuit uses a Type 83, mercury vapor, full wave rectifier, delivering 150 to 160 volts at 0.1 ampere. Component parts are mounted on an angle iron framework which fits into a metal carrying case. The case is provided with ventilatingapertures, 3 weatherproof receptacles, a door at the rear, and a leather carrying handle.

The charger is capable of charging one 12 volt storage battery and one storage "B" battery at an average efficiency of 30 percent. This efficiency compares favorably with that of half-wave Tungar chargers of American manufacture. The switching arrangement controlling the active turns in the transformerprimaries allows operationof the charge from three different line voltages.





Figure 374. Battery charger, front view, showing controls.


16. WWII JAPANESE POWER UNITS - DUAL VOLTAGE DC (1300 V / 12 V).

This is a completely self contained, rope starting, power unit, consisting of a single cylinder of 1.977 inch bore x 2.0 inch stroke. The air cooled gasoline engine is coupled directly to a straight shunt, 2 pole field, dual voltage 1300 V/12V generator, inclosed in an aluminum housing. Engine and generator are ruggedly constructed and supported, indicating long-life operation. This unit can be used to furnish plate voltage to U.S. Army SCR 177.


17. WWII JAPANESE MILITARY PYROTECHNIC SIGNALS.

The Japanese make much use of pyrotechnic signals. Projection is achieved by means of Models 10 and 89 Grenade Dischargers, both of which are common infantry weapons.

Listed below ar some of the pyrotechnic signals which can be used in grenade dischargers. They frequently have been referred to by the Japanese as dragons. The nature of he signal may be ascertained by two methods:

(a) by color bands painted on the body
(b) by designs embossed on teh cover (for use in dark).


NUM SIGNAL COLOR BANDS ON BODY
1. Black smoke, parachute --------- One wide black band.
2. White star, parachute --------- One wide white band.
3. White star --------- One narrow white band.
4. White star, double --------- Two narrow white bands.
5. White star, tripe --------- Three narrow white bands.
6. Orange smoke, parachute --------- One wide yellow band.
7. Green star, parachute --------- One wide green band.
8. Green star, single --------- One narrow green band.
9. Green star, double --------- Two narrow green bands.
10. Red star, parachute --------- One wide red band.
11. Red star, triple --------- Three narrow red bands.


Signal pistol, 35-mm (1.38 inch) parachute and cluster "stars" in red, white or green colors, with a burning time of from 4 to 15 seconds, are reported to exist. The cartridge closely resembles a shotgun shell. Model 97 (1937) signal pistol; one and three barrel models of this newer type signal pistol have been reported.

The pistol is well made of a good grade of steel with an excellent finish; its overall length is 9 8/16 inches, and its weight is 1 pound 13 ounces.