Italy 100 mm/47 (3.9") Model 1931, 1935 and 1938 for Submarines

Italy
100 mm/47 (3.9") Model 1931, 1935 and 1938 for Submarines
Updated 23 September 2012

A slightly improved version of the 100 mm/47 Model 1928 specifically intended for submarines but also used on a few auxiliary vessels. Manufactured by OTO. Slightly shorter than the other 100 mm/47 guns.

100 mm/47 OTO 1937 guns on Argo in 1942
Photograph copyrighted by Elio Andò

100 mm/47 on Torelli at St. Nazaire in December 1941
Photograph by E.C.P. Armées

100 mm/47 on unidentified Marconi class submarine at Bordeaux circa 1941
Photograph by E.C.P. Armées

Submarine 100 mm/47 gun
Image courtesy of Museo Tecnico Navale della Spezia

Gun Characteristics .

Designation	100 mm/47 (3.9") Models 1931, 1935 and 1938 for Submarines
Ship Class Used On	Glauco, Marcello, Cappellini, Liuzzi, Marconi, Cagni, Sirena, Perla, Adua, Argo, Acciaio and Flutto classes Foca and Brin classes as rearmed
Date of Design	1931, 1935 and 1938
Date In Service	1932
Gun Weight	N/A
Gun Length oa	194.5 in (4.940 m)
Bore Length	N/A
Rifling Length	N/A
Grooves	N/A
Lands	N/A
Twist	N/A
Chamber Volume	473.5 in³ (68.79 dm³)
Rate Of Fire	8 - 10 rounds per minute

Ammunition .

Type	Fixed
Complete Round Weight	N/A
Projectile Types and Weights	HE - 30.4 lbs. (13.8 kg)
Bursting Charge	N/A
Projectile Length	N/A
Propellant Charge	N/A
Muzzle Velocity	2,756 fps (840 mps)
Working Pressure	N/A
Approximate Barrel Life	N/A
Ammunition stowage per gun	N/A

Range .

Elevation	With 30.4 lbs. (13.8 kg) HE shell
Range @ 35 degrees	13,800 yards (12,600 m)

Mount / Turret Data .

Designation	Single Mountings OTO 1932 Others?
Weight	4.6 tons (4.7 mt)
Elevation	OTO 1932: -5 / +32 degrees Others: -5 (?) / +35 degrees
Elevation Rate	Manually operated, only
Train	360 degrees
Train Rate	Manually operated, only
Gun recoil	N/A
Note: All submarines carried one of these guns.

Data from
"Naval Weapons of World War Two" by John Campbell
"Italian Warships of World War II" by Aldo Fraccaroli
"Marconi Class Submarines at War" article by Pierre Hervieux in Warships Volume VIII

Page History

07 December 2007 - Benchmark
23 September 2012 - Added picture of museum gun