Italy 37 mm/54 (1.5") Models 1932, 1938 and 1939

Italy
37 mm/54 (1.5") Models 1932, 1938 and 1939
Updated 11 October 2012

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.

37 mm/54 in Model 1932 twin mounting on a Zara Class cruiser
Photograph copyrighted by Elio Andò

37 mm/54 in Model 1932 twin mounting
Photograph courtesy of Museo Nazionale della Scienza e della Tecnica

37 mm/54 in RM 1939 mounting
Photograph by Aldo Fraccaroli and courtesy of Museo Nazionale della Scienza e della Tecnica

Single 37 mm/54 RM 1939 formerly on a Capitani Romani light cruiser
Image courtesy of Museo Tecnico Navale della Spezia

Twin 37 mm/54 formerly on the battleship Vittorio Veneto
Image courtesy of Museo Tecnico Navale della Spezia

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

Ammunition .

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	N/A
Projectile Length	6.4 in (16.3 cm)
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 .

Elevation	With 1.83 lbs. (0.83 kg) HE shell
Range @ 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 1932 and 1938 Single Mounts: Model 1939 and RM 1939
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	N/A
Notes: 1) 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 stabilization or water cooling. These mountings had bad vibration problems and needed a strong supporting structure to compensate. Magazines fed vertically into the guns. 2) 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. Magazines fed horizontally into the guns. 3) 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)

Data from
"The Italian Navigatori Class, 1926" article by Elio Andò in "Warship Special 2: Super Destroyers" edited by Antony Preston
"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.

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