The B-2 gun was a submarine wet mount modification of the 4"/60 (10.2 cm) Pattern 1911. This design was started in 1927 and accepted into service in 1930. The mounting was apparently unchanged from the older weapon, as the new gun was unbalanced, resulting in unequal forces needed to raise and lower the gun. This weapon had numerous design defects including a low rate of fire and difficult loading at angles above 45 degrees. These problems were never resolved and production stopped in 1933. Produced at the "Bolshevik" factory with a total of 24 guns being built.
The B-18 was a twin mount intended for river gunboats. Unlike the B-2 gun, the guns in this mounting were balanced. A total of 7 twin mounts were installed on river monitors.
Construction of both of these guns was very similar to the 4"/60 (10.2 cm) Project 1911. Actual bore diameter was 101.6 mm (4.0").
| Designation | 102mm/45 (4") B-2 Pattern 1930 102mm/45 (4") B-18 Pattern 1934 |
|---|---|
| Ship Class Used On |
|
| Date Of Design | B-2: 1927 B-18: 1931 |
| Date In Service | B-2: 1931 B-18: 1934 |
| Gun Weight | B-2: 2.087 tons (2.120 mt) B-18: 2.090 tons (2.123 mt) |
| Gun Length oa | B-2: 179.92 in (4.570 m) B-18: 179.69 in (4.564 m) |
| Bore Length | Both 172.21 in (4.374 m) |
| Rifling Length | B-2: 140.28 in (3.563 m) B-18: 140.24 in (3.562 m) |
| Grooves | B-2: 24 B-18: 24 |
| Lands | N/A |
| Twist | N/A |
| Chamber Volume | Both: 461.3 in3 (7560 cm3) |
| Rate Of Fire | B-2: 4 - 6 rounds per minute B-18: 6 - 12 rounds per minute |
| Type | Fixed |
|---|---|
| Weight of Complete Round | HE mod 1915: 66 lbs. (30 kg) FRAG mod 1915: 66 lbs. (30 kg) Shrapnel: 66.36 lbs. (30.1 kg) Star Shell: 54.01 lbs. (24.5 kg) |
| Projectile Types and Weights | HE mod 1915: 38.58 lbs. (17.5 kg) FRAG mod 1915: 38.58 lbs. (17.5 kg) Shrapnel: 39.02 lbs. (17.7 kg) Star Shell: 33.25 lbs. (15.08 kg) AA mod 1915: 36.27 lbs. (16.45 kg) |
| Bursting Charge | HE mod 1915: 4.63 lbs. (2.1 kg) FRAG mod 1915: 4.15 lbs. (1.88 kg) Shrapnel: 0.48 lbs. (0.218 kg) Star Shell: 0.03 lbs. (0.015 kg) AA mod 1915: 3.09 lbs. (1.4 kg) |
| Projectile Length | HE mod 1915: 5 calibers FRAG mod 1915: 5.18 calibers Shrapnel: 4.38 calibers Star Shell: 4.7 calibers AA mod 1915: 4.75 calibers |
| Propellant Container Type and Weight | Cartridge: 27 lbs. (12.3 kg) |
| Propellant Charge | HE mod 1915: 10.58 lbs. (4.8 kg) FRAG mod 1915: 10.58 lbs. (4.8 kg) Shrapnel: 10.58 lbs. (4.8 kg) Star Shell: 10.58 lbs. (4.8 kg) AA mod 1915: 10.58 lbs. (4.8 kg) |
| Muzzle Velocity | HE mod 1915: 2,477 fps (755 mps) FRAG mod 1915: 2,477 fps (755 mps) Shrapnel: 2,466 fps (751.5 mps) AA mod 1915: 2,477 lbs. (755 mps) |
| Working Pressure | 2480 kg/cm2 |
| Approximate Barrel Life | about 500 rounds |
| Ammunition stowage per gun | Dekabrist: 120 rounds Pravda: 227 total Zheleznyakov: 150 rounds normal (250 rounds max) |
| Elevation | Distance |
|---|---|
| Max Range | 18,010 yards (16,470m) |
| Designation | Open Single Mounts: B-2 Twin Turret Mount: MK-2-4 |
|---|---|
| Weight | B-2: 6.4 tons (6.5 mt) MK-2-4: 3.69 tons (37.5 mt) |
| Elevation | Both: -5 / +60 degrees |
| Elevation Rate | MK-2-4: 5 degrees per second |
| Train | 360 degrees |
| Train Rate | MK-2-4: 6 degrees per second |
| Gun recoil | Both: 27.95 in (710 mm) |
| Loading Angle | Any |
Data from:
- "Sovetskie Boevye Korabli 1941-45: IV Vooruzhnie" (Soviet Warships 1941-45: Volume IV Armament) by A.V. Platonov
- "Entsiklopedia Otechestvennoi Artillerii" (Encyclopedia of Fatherland (Russian) Artillery) by A.V. Shirokorad
Special help from Vladimir Yakubov
- 10 May 2006
- Benchmark
- 12 August 2012
- Updated to latest template