Description

A good anti-destroyer weapon, this was the secondary gun on the Littorio class battleships and the main gun on the Garibaldi class (5th "Condottieri") light cruisers. The Model 1934 was made by Ansaldo and were of monobloc construction with a loose liner and a horizontal sliding breech block. The Model 1936 was made by OTO and was constructed of two tubes, loose liner and a horizontal sliding breech block.

These guns were a significant improvement from earlier 152 mm (6") guns in that they were more widely spaced in the turrets, were separately sleeved and had a lower and more reasonable muzzle velocity from the beginning. The increase in barrel length from the previous weapons was in attempt to obtain improved thermodynamic performance. Whatever the reasons, these new guns did prove to be the most accurate of all the Italian 152 mm (6") guns in service during World War II with dispersion patterns with APC being 260 to 300 feet (80 to 90 m) at a range of 19,140 yards (17,500 m). However, dispersion with HE rounds was much larger, 525 to 656 feet (160 to 200 m) at a range of 19,140 yards (17,500 m). This larger dispersion with HE was attributed to the shape of the nose and nose fuze used on these projectiles. Studies were underway in 1941 to alter the shape of the round and their internal weight distribution but a new design did not enter service.

Historical note: These cruisers were named after Italian military leaders.

Gun Characteristics

Designation 152 mm/55 (6") Models 1934 and 1936
Ship Class Used On Littorio and Garibaldi classes
Date Of Design 1934 / 1936
Date In Service 1940
Gun Weight 8.9 tons (9,689 kg)
Gun Length oa about 348 in (8.840 m)
Bore Length 330.0 in (8.382 m)
Rifling Length 287.4 in (7.301 m)
Grooves 40
Lands N/A
Twist Uniform RH 1 in 30
Chamber Volume 1,537 in3 (25.19 dm3)
Rate Of Fire 4 - 5 rounds per minute

Ammunition

Type Separate
Projectile Types and Weights AP: 110 lbs. (50 kg)
HE: 97.9 lbs. (44.4 kg)
AA: N/A
Bursting Charge AP: 2.05 lbs. (1.0 kg)
HE: 5.18 lbs. (2.3 kg)
AA: N/A
Projectile Length AP: 24.8 in (63.0 cm)
HE: N/A
AA: N/A
Propellant Charge 36.05 lbs. (16.35 kg) NAC
Muzzle Velocity AP: 2,986 fps (910 mps)
HE: 3,100 fps (945 mps) 1
AA: N/A
Working Pressure 20.8 tons/in2 (3,270 kg/cm2)
Approximate Barrel Life N/A
Ammunition stowage per gun Littorio: 210 rounds 2
Others: N/A
  • ^New gun MV for HE was 3,133 fps (995 mps).
  • ^Outfit for Littorio class was 840 AP, 1,428 HE and 252 AA. I lack information on the AA projectile, but they probably would have been similar in size and weight the the HE projectile.

Range

Range with assorted shells
Elevation 110 lbs. (50 kg) AP 97.9 lbs. (44.4 kg) HE
45 degrees 28,150 yards (25,740 m) 27,231 yards (24,900 m)

Armor Penetration

Armor penetration with 110 lbs. (50 kg) AP
Range Side Armor Angle of Obliquity
15,300 yards (14,000 m) 3.4" (86 mm) 0
19,700 yards (18,000 m) 1.6" (40 mm) 40

The above information is from "The Littorio Class."

Mount/Turret Data

Designation 1a 2a Two-gun Turrets 3a
   Garibaldi (2): Model 1934

Three-gun Turrets 4a
   Littorio (4) and Garibaldi (2): Model 1934
   Vittorio Veneto (4) and Roma (4): Model 1936
Weight Twin: N/A
Triple: 133.3 tons (135.4 mt) [not including shield]
Elevation -5 / +45 degrees
Elevation Rate N/A
Train about +120 / -120 degrees
Train Rate N/A
Gun recoil N/A
Loading Angle -5 to +20 degrees
  • ^These mountings were electrically powered training and elevation. Rammers were pneumatically powered. Cartridge cases were ejected from tubes under the gun barrels.
  • ^The gun axes were about 50 in (127 cm) apart for both the two-gun and three-gun mountings.
  • ^In the twin mountings, each gun had separate shell and cartridge endless chain hoists. Projectiles and cartridge cases were transferred automatically to the loading trays at any elevation up to 20 degrees by swinging arms which pivoted about the trunnions. Loading was by telescoping hydraulic rammers.
  • ^In the three-gun mountings there were lower endless chain hoists for each gun which ended in a handling room located below the gunhouse. Upper endless bucket hoists for each gun ran up to the gunhouse.
  • Armor thickness for the Littorio Class
    Face 11.0 in (28.0 cm) KC
    Front Sides 5.1 in (13.0 cm) KC
    Rear Sides 3.1 in (8.0 cm)
    Rear 3.1 in (8.0 cm)
    Front Roof 5.9 in (15.0 cm)
    Rear Roof 4.1 in (10.5 cm)

    These figures are from "The Littorio Class: Italy's Last and Largest Battleships 1937 - 1948".

Additional Pictures

Sources

"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
"Anatomy of the Ship: The Cruiser Bartolomeo Colleoni" by Franco Gay and Valerio Gay
"Cruisers of World War Two" by M.J. Whitley
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Marina Militare

Page History

21 September 2008 - Benchmark
26 May 2012 - Updated to latest template
19 December 2012 - Added information on gun construction
12 January 2013 - Added ammunition information
10 January 2015 - Added armor penetration table, dispersion with HE, armor thickness, minor other additions to Ammunition and Mount / Turret sections
03 January 2022 - Converted to HTML 5 format, added loading details
12 April 2024 - Updated historical note