United States of America
14"/45 (35.6 cm) Marks 8, 9, 10 and 12
Updated 02 February 2014

During the modernizations of the the battleships during the 1930s, old 14"/45 (35.6 cm) guns were constructionally upgraded and their chamber volumes enlarged to allow larger charges for an increased muzzle velocity.  Marks 1, 3 and 5 became Marks 8, 9 and 10, respectively.  The Mark 12 was a further conversion which added chromium plating to increase barrel life.  Guns had either a horizontal or a down opening Welin breech block and used a Smith-Asbury mechanism.  These guns were interchangeable and most battleships had a combination of Mark numbers.

The Nevada (BB-36) and Pennsylvania (BB-38) battleship classes were further upgraded during the 1930s to increase their maximum turret elevations to 30 degrees.  These ships were also now supplied with a heavier AP projectile and by 1942 with a HC projectile.  The enlarged propellant charges allowed the heavier AP shell to be used without significant muzzle velocity losses.  USS New York (BB-34) and USS Texas (BB-35) were not modernized and their existing shell hoists could not handle the new, longer AP and HC projectiles, so modified versions with shorter windshields were produced for these ships.

It is often stated that USS Arizona (BB-39) never fired her guns in anger.  However, the 14"/45 (35.6 cm) guns removed from her Turret 2 were installed into Turret 1 on USS Nevada (BB-36) in the fall of 1944.  These guns were then used for shore bombardments during the 1945 Pacific campaigns, so it may be technically said that Arizona's guns were fired in anger after all.  USS Arizona's turrets 3 and 4 were removed intact and were then used as coastal artillery in Hawaii, but these installations were not completed until nearly the end of the war.  Arizona's Turret 1 and its guns were considered too badly damaged to salvage and so still remain on the sunken battleship.

Two 14"/45 (35.6 cm) Mark 12 guns removed from Pennsylvania during her last refit are now on display at the The Pennsylvania Military Museum.

WNUS_14-45_mk10_Pennsylvania_guns_pic.jpg

USS Pennsylvania BB-38 in 1930s
U.S. Naval Historical Center Photograph # NH 50758

.
Click here for additional pictures
.
.
Gun Characteristics
.
Designation 14"/45 (35.6 cm) Marks 8, 9, 10 and 12
Ship Class Used On New York (BB-34), Nevada (BB-36) and Pennsylvania (BB-38) classes
Date Of Design As Modernized:  1928
Date In Service As Modernized:  1933
Gun Weight 62 tons (63 mt)
Gun Length oa 642.5 in (16.318 m)
Bore Length 630 in (16.002 m)
Rifling Length 542.7 in (13.530 m)
Grooves 84
Lands N/A
Twist Uniform RH 1 in 25
Chamber Volume 17,943 in3 (294.0 dm3)
Rate Of Fire about 1.25 - 1.75 rounds per minute
.
Ammunition
.
Type Bag
Projectile Types and Weights
(see Notes 1 and 2)
AP Mark 16 Mods 1 to 11 - 1,500 lbs. (680.4 kg)
AP Mark 20 Mod 1 - 1,500 lbs. (680.4 kg)
HC Mark 19 Mods 1 to 6 - 1,275 lbs. (578 kg)
HC Mark 22 Mod 0 - 1,275 lbs. (578 kg)
Bombardment Mark 9 Mod 4 - 1,410 lbs. (639.6 kg)
Bursting Charge AP Mark 16 - 22.90 lbs. (10.4 kg) Explosive D
AP Mark 20 - 22.90 lbs. (10.4 kg) Explosive D
HC Mark 19 - 104.21 lbs. (47.3 kg) Explosive D
HC Mark 22 - 104.21 lbs. (47.3 kg) Explosive D
Bombardment Mark 9 - 105.0 lbs. (47.6 kg) Explosive D
Projectile Length New York class
   Mark 20 AP - 54.38 in (138.1 cm)
   HC Mark 19 Mod 1 - 54.38 in (138.1 cm)
   Bombardment Mark 9 - 56.00 in (142.2 cm)

Nevada and Pennsylvania classes
   Mark 16 AP - 56.00 in (142.2 cm)
   HC Mark 19 Mods 2 to 6 - 56.00 in (142.2 cm)
   HC Mark 22 Mod 0 - 56.00 in (142.2 cm)

Propellant Charge Full Charge - 425 lbs. (192.8 kg) SPD

Reduced Charge - 205 lbs. (93.0 kg) SPDN
Reduced Flashless Charge - 210 lbs. (95.3 kg) SPCG

Muzzle Velocity Full Charge - New Gun
   AP - 2,600 fps (792 mps)
   HC - 2,735 fps (834 mps)

Reduced Charge - New Gun
   AP - 1,935 fps (590 mps)
   HC - 2,065 fps (629 mps)

Working Pressure 18.0 tons/in2 (2,835 kg/cm2)
Approximate Barrel Life Marks 8, 9 and 10:  175 - 200 Rounds
Mark 12:  250 Rounds
Ammunition stowage per gun 100 rounds
Notes:

1) As noted above, the New York class (BB-34) used the shorter AP Mark 20 and HC Mark 19 Mod 1 projectiles while the newer ships used the longer-nosed AP Mark 16 and HC Mark 19 Mods 2 to 6 and HC Mark 22 Mod 2 projectiles.  Other than the length of the windshield, the AP projectiles were identical.  Some of the older AP Mark 8 projectiles were also issued during World War II, possibly only to the New York class.

2) HC Mark 22 was similar to the HC Mark 19 except that the rotating band was about 1.25 inches (3.2 cm) closer to the base.  HC projectile bodies could be used with Point Detonating (PD) or Mechanical Time (MT) fuzes.  When used with PD fuzes, they were considered to be HC rounds.  When used with MT fuzes, they were considered to be AAC rounds.  MT fuzes were probably set by hand on the loading trays.

3) After 1941 AP rounds had a nominal 1.5 lbs. (0.68 kg) dye bag, but this was allowed to be as large as 3.0 lbs. (1.36 kg) in order to bring underweight projectiles up to standard.  The following colors were assigned to these ships:

   Nevada - Orange
   Pennsylvania - Red
   New York and Texas - No dye

New York and Texas were probably not assigned dye colors because they were not upgraded to handle the newer AP projectiles.

4) Bourrelet diameter was 13.977 inches (35.5 cm).

5) Propellant was in four bags.

6) Bombardment rounds had thick walls and used only a base fuze.  At the time of Operation Torch in 1942, HC rounds were not available.  For that reason, the Commander, Battleships Atlantic Fleet ordered that USS New York (BB-34) and USS Texas (BB-35) be modified to carry these bombardment rounds.  Turrets 2 and 4 on both ships had their hoists modified before the battle in order to carry these significantly longer projectiles.

.
Range
.
Elevation
With 1,500 lbs. (680.4 kg) AP
With 1,275 lbs. (578 kg) HC
Range @ 15 degrees
(max elevation of
unmodernized turrets)
23,000 yards (21,030 m)
(probably AP Mark 20)
23,500 yards (21,490 m)
(probably HC Mark 19 Mod 1)
Range @ 30 degrees 
(max elevation of
modernized turrets)
34,300 yards (31,360 m)
(probably AP Mark 16)
34,700 yards (31,730 m)
(probably HC Mark 22)
Range @ 45 degrees
40,000 yards (39,502 m)
---
.
Armor Penetration with 1,500 lbs. (680.40 kg) AP Mark 16 Shell
.
Range
Side Armor
Deck Armor
11,500 yards (10,520 m)
18" (457 mm)
---
13,500 yards (12,350 m)
---
2" (51 mm)
14,800 yards (13,530 m)
16" (406 mm)
---
18,800 yards (17,190 m)
14" (356 mm)
---
23,400 yards (21,400 m)
12" (305 mm)
---
24,500 yards (22,400 m)
---
4" (102 mm)
28,300 yards (25,880 m)
10" (254 mm)
---
31,500 yards (28,800 m)
---
6" (152 mm)
34,300 yards (31,360 m)
8" (203 mm)
---
36,300 yards (33,190 m)
---
8" (203 mm)
Notes:

1) These figures are taken from armor penetration curves issued in 1942.

2) The AP Mark 20 probably had slightly less penetration, as its shorter, less aerodynamic ballistic cap would have resulted in somewhat lower striking velocities.

.

Mount/Turret Data
.
Designation Two-gun Turrets
   New York (5) and Nevada (2)

Triple Turrets
   Nevada (2) and Pennsylvania (4)

Weight Two-gun Turret
   New York Class:  532 tons (541 mt)
   Nevada Class:  618 tons (628 mt)

Triple Turret
   Nevada Class:  748 tons (760 mt)
   Pennsylvania Class:  714 - 724 tons (725 - 736 mt)

Elevation
(see Note 2)
New York class:  -5 / +15 degrees
Others:  -5 / +30 degrees
Rate of Elevation about 4 degrees per second
Train about -150 / +150 degrees
Rate of Train about 2 degrees per second
Gun Recoil 40 in (102 cm)
Loading Angle +1 degree
Notes:

1) Only the guns in the two-gun turrets were individually sleeved, the triple turrets had their guns in a common slide (cradle).

2) Some references erroneously claim that the New York class were reworked in November 1941 to increase their maximum elevation to +30 degrees.  However, my personal inspection in 1984 of the guns and mountings on USS Texas BB-35 quickly showed that she was not modified and that her guns cannot elevate past the original +15 degree maximum elevation.

3) Triple mountings had delay coils fitted in the early 1930s which delayed the firing of the center gun by about 0.060 seconds (60 milliseconds).  These reduced the dispersion pattern by about half.

4) See 14"/45 (35.6 cm) Mark 1 data page for other information on these mountings.

.
Data from
"Naval Weapons of World War Two" by John Campbell
"US Naval Weapons," "US Battleships:  An Illustrated Design History" and "Battleship Design and Development 1905-1945" all by Norman Friedman
"Battleships:  United States Battleships, 1935-1992" by W.H. Garzke, Jr. and R.O. Dulin, Jr.
and
Tony DiGiulian's personal data files
---
"USS Massachusetts 1945 Gunnery Doctrine" USN BuOrd Publication
"U.S. Explosive Ordnance:  Ordnance Pamphlet 1664 - May 1947" by Department of the Navy
---
Special help by Keith Allen, Ed Jackson and William Jurens
Page History

20 October 2008 - Benchmark
02 February 2014 - Added link to The Pennsylvania Military Museum