United States of America
16"/45 (40.6 cm) Mark 1
Updated 15 August 2014

The final installment of "Standard Battleships" was the Colorado (BB-45) class which were armed with the new 16"/45 (40.6 cm) Mark 1.  This weapon promised twice the muzzle energy of the 12"/50 (30.5 cm) and a 50% improvement over the 14"/45 (35.6 cm).  This larger gun was designed in August 1913 and the prototype was proof fired less than a year later in July 1914.  Some minor changes were found to be necessary, and the gun was re-proved in May 1916.  The results of these tests were considered to be quite successful and production was approved in January 1917.

Consisted of A tube, jacket, liner, seven hoops, four locking rings and a screw-box liner.  A total of about 40 guns were manufactured.

In the 1930s, these guns were rebuilt and then redesignated as 16"/45 (40.6 cm) Mark 5 and Mark 8.

Nomenclature note:  The 16" (40.6 cm) Mark A was the ballistic prototype of all 16" (40.6 cm) guns.  This prototype was developed from a 13" (33 cm) Mark 2 bored out and relined for the larger projectiles.  Some data and a photograph of this gun may be found on the 13"/35 (33 cm) pictures page.

WNUS_16-45_mk1_Colorado_trials_pic.jpg

USS Colorado BB-45 running trials in 1923
This last class of "Standards" and the previous Tennessee (BB-43) class finally did away with secondaries in hull casemates and had all their 5"/51 (12.7 cm) guns on or above the weather deck
U.S. Naval Historical Center Photograph # NH 55274

WNUS_16-45_mk1_Maryland_pic.jpg

USS Maryland BB-46 approaching the New York Navy Yard in the 1920s
Note the rangefinder atop Turret II

WNUS_16-45_mk1_Colorado_pic.jpg

USS Colorado BB-45 in the 1920s
Note the hexagonal shaped turrets and the small periscope on Turret I
U.S. Naval Historical Center Photograph # NH 64514

WNUS_16-45_mk1_Transport_pic.jpg

16"/45 (40.6 cm) Mark 1 gun on transport crane at Dahlgren Proving Grounds during World War I

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Gun Characteristics
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Designation 16"/45 (40.6 cm) Mark 1
Ship Class Used On Colorado (BB-45) Class
Date Of Design 1913
Date In Service 1921
Gun Weight 235,796 lbs. (106,959 kg) (including breech) 
230,948 lbs. (104,757 kg) (without breech)
Gun Length oa 736.0 in (18.694 m)
Bore Length 720.0 in (18.288 m)
Rifling Length 616.9 in (15.668 m)
Grooves (96) 0.150 in deep x 0.2735 in (3.81 mm x 6.95 mm)
Lands 0.25 in (6.35 mm)
Twist Most mods:  Increasing RH 1 in 50 to 1 in 32 at the muzzle
Mod 1 and Mod 3:  Uniform RH 1 in 32
Chamber Volume 23,506 in3 (385.3 dm3)
Rate Of Fire about 1.5 rounds per minute
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Ammunition
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Type Bag
Projectile Types and Weights AP Mark 3 Mods 2 to 5 - 2,110 lbs. (957.1 kg)
Bursting Charge AP Mark 3 - 57.5 lbs. (26.1 kg) Explosive D
Projectile Length 56.5 in (143.5 cm)
Propellant Charge 590 lbs. (267.6 kg) SPD
Muzzle Velocity AP Mark 3 - 2,600 fps (792 mps)
Working Pressure 18.0 tons/in2 (2,835 kg/cm2)
Approximate Barrel Life 350 rounds
Ammunition stowage per gun 100 rounds
Notes:

1) The AP Mark 3 had a fairly short windshield.

2) Bourrelet diameter was 15.977 inches (40.6 cm).

3) Propellant was in four bags.

4) The AP Mark 3 had a Explosive "D" (ammonium picrate) filler.  In the late-1920s or early-1930s, a new delay-action, tetryl-boosted base fuze was used to replace the original non-delay, TNT-boosted design.

5) For data on projectiles used in the late 1930s - 1940s, see the 16"/45 (40.6 cm) Mark 5 data page.

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Range
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Elevation
With 2,110 lbs. (957 kg) AP Mark 3
MV = 2,600 fps (792 mps)
Striking Velocity
Angle of Fall
0.4 degrees
1,000 yards (910 m)
2,532 fps (772 mps)
0.4
5 degrees
10,100 yards (9,240 m)
1,981 fps (604 mps)
6.0
10 degrees
17,300 yards (15,820 m)
1,656 fps (505 mps)
13.3
15 degrees
22,900 yards (20,940 m)
1,488 fps (454 mps)
21.4
20 degrees
27,400 yards (25,055 m)
1,416 fps (432 mps)
29.3
25 degrees
31,300 yards (28,620 m)
1,402 fps (427 mps)
36.3
30 degrees
34,300 yards (31,360 m)
1,422 fps (433 mps)
42.3
45.25 degrees
(see Note 1)
39,600 yards (36,210 m)
1,559 fps (475 mps)
55.9
Notes:

1) The maximum turret elevation was 30 degrees.

2) Time of flight for MV = 2,600 fps (792 mps)
   1,000 yards (910 m):  1.2 seconds
   10,100 yards (9,240 m): 13.4 seconds
   17,300 yards (15,820 m):  25.7 seconds
   22,900 yards (20,940 m):  37.1 seconds
   27,400 yards (25,055 m):  47.7 seconds
   31,300 yards (28,620 m):  58.1 seconds
   34,300 yards (31,360 m):  67.8 seconds
   39,600 yards (36,210 m):  94.6 seconds

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Armor Penetration with 2,110 lbs. (957.1 kg) AP Mark 3 Shell
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Range
Side Armor
Deck Armor
6,000 yards (5,490 m)
25.8" (655 mm)
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9,000 yards (8,230 m)
22.2" (564 mm)
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12,000 yards (10,920 m)
18.9" (480 mm)
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16,000 yards (14,630 m)
14.8" (376 mm)
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20,000 yards (18,290 m)
11.5" (292 mm)
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Note:  This data is from "Elements of US Naval Guns" of 1918 and General Board file 430 (1916).  It is corrected for angle of fall.
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Mount / Turret Data
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Designation Two-gun Turrets
   Colorado (4)
Weight 880 - 920 tons (894.08 - 934.72 mt)
Elevation -4 / +30 degrees
Rate of Elevation about 8 degrees per second
Train 300 max 280 min degrees
Rate of Train about 2 degrees per second
Gun Recoil 44 in (1.117 m)
Loading Angle +1 degree
Notes:

1) These mountings were electrically powered through hydraulic drive gear.  The training motor was 50 hp.  Each gun had a 50 hp motor for elevation, a 90 hp motor for ramming and to drive the upper charge hoist, a 35 hp motor for the shell hoist and a 7.5 hp motor to drive the lower charge hoist.

2) Flame proof bulkheads separated the guns in each turret.

3) The distance between gun axes was about 104 in (264 cm).

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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
"A Treatise on Rifling of Guns" by Carl F. Jeansén
"Round Shot to Rockets:  A History of the Washington Navy Yard and the United States Naval Gun Factory" by Taylor Peck
"Battleships" by Paul Stillwell
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"Range and Ballistic Tables 1935" by U.S. Department of Ordnance and Gunnery
"U.S. Explosive Ordnance:  Ordnance Pamphlet 1664 - May 1947" by Department of the Navy
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Special help from Leo Fischer and Nathan Okun
Page History

31 May 2008 - Benchmark
15 August 2015 - Minor changes