This was the standard Italian close-range AA weapon used on larger ships during World War II. The guns used in the Model 1932 twin mounting were water-cooled with a recirculating pump, all other mountings used air-cooled guns. The magazines held only six rounds, but it was possible to load them sequentially and thus maintain a high rate of fire.

Differences between models were mainly mounting related.

Gun Characteristics

Designation 37 mm/54 (1.5") Models 1932, 1938 and 1939
Ship Class Used On Battleships and Cruisers
Date of Design 1932
Date In Service 1934
Gun Weight 611 lbs. (277 kg)
Gun Length oa N/A
Bore Length 78.7 in (1.998 m)
Rifling Length N/A
Grooves N/A
Lands N/A
Twist N/A
Rate Of Fire Selectable: 60, 90 and 120 rounds per minute cyclic


Type Fixed
Weight of Complete Round 3.59 lbs. (1.63 kg)
Projectile Types and Weights HE: 1.814 lbs. (0.823 kg)
Bursting Charge 0.053 lbs. (0.024 kg) TNT
Projectile Length 6.4 in (16.25 cm)
Complete round: 15.1 in (38.4 cm)
Cartridge Brass, 37 x 251 mm
Propellant Charge 0.44 lbs. (0.2 kg)
Muzzle Velocity 2,625 fps (800 mps)
Working Pressure 17.8 tons / in2 (2,800 kg / cm2)
Approximate Barrel Life N/A
Ammunition stowage per gun about 1,500 rounds


Range with 1.83 lbs. (0.83 kg) HE
Elevation Distance
45 degrees 8,530 yards (7,800 m) max.
4,370 yards (4,000 m) effective
AA Ceiling 16,400 feet (5,000 m)

Mount/Turret Data

Designation Twin Mounts: Model 19321 and 1938 2 3
Single Mounts: Model 1939 4 and RM 1939 5
Weight Model 1932: 4.9 tons (5.0 mt)
Model 1938: 4.2 tons (4.3 mt)
Model 1939: 1.48 tons (1.5 mt)
RM 1939: 1.97 tons (2.0 mt)
Elevation Singles: -5 / +90 degrees
Twins: -10 / +80 degrees
Elevation Rate Manual operation, only
Train about +120 / -120 degrees
Train Rate Manual operation, only
Gun recoil Model 1939 and RM 1939: 3.9 in (10 cm)
Others: None (fixed barrel)
Number of barrels on all mounting types
Littorio 20
San Giorgio 6
Trento 8
Zara 8
Alberto da Barbiano 8
Raimondo Montecuccoli 8
Emanuele Filiberto Duca d'Aosta 8
Giuseppe Garibaldi 8
"Capitani Romani" 8 (these replaced the planned 65 mm guns)
  • ^Model 1932 was a circulating water-cooled twin mount with a stabilized line of sight through +/-10 degrees of roll.
  • ^Model 1938 was a simpler twin mount without water cooling. Both of these mountings had bad vibration problems as the barrels remained fixed and only the breeches recoiled and thus the mountings needed a strong supporting structure to compensate. Stabilization was via a simple but heavy device that allowed the trunnion axis to list to either side. A system of rollers was used between the platform base and the base of the mounting with a heavy weight that tried to keep the mounting stable. This system did not work well and was discontinued. Magazines fed vertically into the guns.
  • ^Gun crew for the Twin Model 38 consisted of gun captain, layer, trainer, two first loaders and two ammunition handlers. Guns were normally supplied from ready lockers located close to the guns.
  • ^Model 1939 was a single collapsible mounting used on the forecastles of the Littorio and Duilio classes.
  • ^RM 1939 was a conventional single mounting. These single mountings had less vibration than did the twin mounts as they had an equilibriator linked to the cradle which allowed the entire gun to recoil. Magazines fed horizontally into the guns. This gun was popular in the Italian Navy and proved to be an accurate weapon.

Additional Pictures


"The Italian Navigatori Class, 1926" article by Elio Andò in "Warship Special 2: Super Destroyers" edited by Antony Preston
"The Littorio Class: Italy's Last and Largest Battleships 1937 - 1948" by Erminio Bagnasco and Augusto de Toro
"Naval Weapons of World War Two" by John Campbell
"Italian Warships of World War II" by Aldo Fraccaroli
"Battleships: Axis and Neutral Battleships in World War II" by W.H. Garzke, Jr. and R.O. Dulin, Jr.
"Italian and French Explosive Ordnance: Ordnance Pamphlet No. 1668" by Department of the Navy
Special help from Larry Sawh

Page History

31 January 2008 - Benchmark
26 May 2012 - Updated to latest template
23 September 2012 - Added pictures of museum guns
11 October 2012 - Corrected projectile weights, added number of guns and added notes about vibration problems
11 January 2015 - Added additional pictures page, additional ammunition and mount / turret data
22 April 2018 - Updated to HTML 5 format, added burster weight
14 February 2021 - Added photograph by Graham Overman