Light Caliber
|
Caliber
|
Purpose
|
Revetment Size
|
Revetment Shape
|
Length of Gun
|
Length of Barrel
|
Number of Barrels
|
Type of Mount
|
Associated Fire Control
|
Average number of guns in batt.
|
Battery Pattern
|
Approx. Rage (max)
|
Elevation
(in degrees) |
Traverse
(in degrees) |
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
|
6.5mm |
Machine Gun
|
6-8' |
Square
Circular |
single
|
pedestal tripod
|
||||||||
|
7.7mm
1 |
Machine Gun
|
6-8'
|
Square
Circular |
single
|
pedestal
tripod |
||||||||
|
13 mm
2 |
AA and CD
|
single 8-10' |
Square
Circular Hexagonal Pearshaped irregular |
6'
|
4'
|
single twin
|
pedestal (twin and single) |
tracer
|
single 1-7
twin 2-4 |
irregular
|
v- 13,120'
h- 7085 yards |
90
|
360
|
|
25 mm
3 |
AA and CD
|
14-16'
|
Circular
"doughnut" shaped |
9'
|
4.5'
|
single
twin triple |
pedestal
shipboard mount |
tracer and 10cm Binocular
|
2-4
|
irregular capital "L"
|
v- 12,00'
h- 15,000 yards |
85
|
360
|
Heavy Caliber
|
Caliber
|
Purpose
|
Revetment Size
|
Revetment Shape
|
Length of Gun
|
Length of Barrel
|
Dimensions of shield | shape of shield |
Number of Barrels
|
Type of Mount
|
Associated Fire Control
|
Average number of guns in batt.
|
Battery Pattern
|
Approx. Rage (max)
|
Elevation (in degrees)
|
|---|
|
AA & CD
|
18-20' |
circular |
10.2'
|
10.2'
|
none
|
none
|
single
|
five spiders
|
3 meter RF
10cm binoculars computers sound locator |
4-6
|
acurate
trapezoidal capital "l" irregular |
v - 33,000'
h - 15,200 yds |
85
|
|
|
80 mm
5 |
CD
|
16 ft
|
square (covered) hexagonal (open)
|
10'
|
10'
|
none
|
none
|
single
|
pedestal
|
3 meter range finder
|
2-3
|
straight line
|
h - 9000 yds
|
30
|
|
120mm
6 |
AA & CD
|
22 ft
|
circular
|
21'-22'
|
12'
|
9'x10'
|
rectangular
|
single
|
pedestal set in soil or concrete
|
3 meter RF
10cm binoculars computers communication center |
4
|
capital "L" straight line
|
v - 25,000'
h - 21,000 yds |
85
|
|
120mm
7 |
CD
|
20'
|
half moon |
16.5'
|
16.5'
|
none
|
none
|
single
|
pedestal set in concrete
|
3 meter range finder
|
4
|
straight line arcuate
|
h - 17,500
|
30
|
|
AA & CD
|
33' - 38'
|
circular
|
18'
|
12'
|
8'x12'
|
rectangular
|
twin
|
pedestal
|
3 meter RF |
2
|
straight line
low triangle |
NA
|
85
|
|
|
140mm
9 |
CD
|
35' - 38'
|
circular
|
23'
|
14.9'
|
8'x8'
|
square with rounded front corners
|
single
|
pedestal set in concrete
|
observation tower on top of bombproof
shelter
electric distribution board control center |
2-3
|
straight line
|
NA
|
20
|
|
150mm
10 |
CD
|
26' - 30'
|
circular irregualr
|
20'
|
12'
|
8' long
4'-8' wide |
wedge shape
|
single
|
heavy steel spiders
|
3 meter range finder
|
3
|
straight line
|
h - 14,200 yds
|
20
|
|
200mm
11 |
CD
|
38' - 40'
|
circular
|
38.8'
|
19.2'
|
12'8" long |
single
|
pedestal set in concrete
|
observation tower |
2
|
straight line
|
NA
|
30
|
Remarks
1. Small splinter shields may be found on these guns when on pedestal mount. Found associated with A.A. and C.D. batteries.
2. Found in log and sand or earth emplacements. Used for beach defenses and associated with heavy A.A. and C.D. positions. No fire control position is associated with these guns.
3. The command center was located in a prefabricated hexagonal steel turret. Width of the gun mechanism in twin barrel mount is 5 to 6 feet.
4. Flanking searchlights in some cases. The five spiders when visible are distinctive. Guns may be found in 15' emplacement with spiders covered. Emplacement is usually sandbags or earth reinforced with logs and with ready magazines in walls.
5. A gabled type of palm branch camoflage was used at Tarawa placed over a hexagonally shaped open emplacement constructed of sand and logs. Positions distinguished in photos by aperature, spoil, beach trench system diverted around position and short entrance trenches at rear.
6. Distinguished by large conspicuous slotted shield. Fire control located in emplacement to rear-center of battery. Low earth and sandbag revetment.
7. Low earth and sandbag revetment. Rope net camoflage sometimes used.
8. Fire control located to rear-center of battery. Guns located in concrete emplacement banked with sand. Emplacements are about 40 yards apart. Ammunition chamber and electric drive apparatus located below gun. These guns captured on Tarawa were of British make.
9. These guns were mounted in concrete emplacements banked with sand. Emplacements were located about 60 yards apart. A narrow guage railroad laid in a trench led from ammunition shelter to gun position.
10. A larger emplacement (about 35') should be expected in most cases. Fire control center located in small buildings behind emplacements.
11. These guns were mounted in concrete emplacements, banked with sand. Davit-type ammunition hoist crane mounted on gun. 8' wide steel ammuntion trough almost completely encircles gun. Narrow guage railroad laid in trench led from ammuntion shelter to gun position. These guns captured on Tarawa were of British make.
Source - Japanese anti-Aircraft and Coastal Defense Guns, Photographic Intelligence Center Report USN, 1944.
Email - Jonathan.E.Stevens@wheaton.edu
copyright 2001 Wheaton, Illinois
Created 30 September 2001 - Updated 2 March 2003
