United States of America
6"/47 (15.2 cm) Mark 16
Updated 08 February 2008
These guns were used to arm the Brooklyn and Cleveland class light cruisers, the latter being the most numerous class of cruisers ever built.  Developed from experiments with old 6"/50 (15.2 cm) Mark 8 guns with various modifications to test new ideas, this weapon was to a new design and was capable of using the "super heavy" AP projectile.  These new projectiles had almost double the penetration performance when compared against the previous 6"/53 (15.2 cm) gun used on the Omaha class (CL-4) light cruisers.

Constructed of monobloc autofretted barrel secured to the housing by a bayonet joint.  Later mods included chrome plating and a tapered liner.  All used a semi-automatic vertical sliding breech block.
WNUS_6-47_mk16_Manchester_pic.jpg

USS Manchester CL-83 during Korean War
U.S. Naval Historical Center Photograph # NH 97180
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Click here for additional pictures
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Gun Characteristics
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Designation 6"/47 (15.2 cm) Mark 16
Ship Class Used On Brooklyn (CL-40), St. Louis (CL-49), Cleveland (CL-55) and Fargo (CL-106) classes
Date Of Design 1932
Date In Service 1937
Gun Weight 6.5 tons (6.6 mt)
Gun Length oa 300 in (7.620 m)
Barrel and Bore Length 282.3 in (7.169 m)
Rifling Length 238.3 in (6.053 m)
Grooves N/A
Lands N/A
Twist Uniform RH 1 in 25
Chamber Volume 1,470 in3 (24.1 dm3)
Rate Of Fire 8 - 10 rounds per minute
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Ammunition
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Type Separate
Projectile Types and Weights
(see Note 1)		 AP Mark 35 Mods 1 to 11 (super heavy) - 130 lbs. (59 kg)
HC Mark 34 Mods 1 to 7 - 105 lbs. (47.6 kg)
Illum Mark 32 Mod 0 - 94.5 lbs. (42.9 kg)
Illum Mark 38 Mod 0 - 105 lbs. (47.6 kg)
Bursting Charge AP Mark 35 - 1.95 lbs. (0.9 kg) Explosive D
HC Mark 34 - 13.22 lbs. (6.0 kg) Explosive D
Projectile Length 27 in (68.6 cm)
Cartridge Case Type, Size and Empty Weight
(see Note 5)		 Mark 4 - Brass, 152 x 970 mm, 28.2 lbs. (12.8 kg)
Mark 4 Modified - Brass, 152 x 635 mm, N/A
Propellant Charge
(see Note 6)		 Full Charge - 33 lbs. (15.0 kg) SPD or SPDN
Full Flashless Charge - 34 lbs. (15.4 kg) SPCG

Reduced Charge - 21 lbs. (9.5 kg) SPDN
Reduced Flashless Charge - 22 lbs. (10.0 kg) SPDF
Muzzle Velocity Full Charge - New Gun
   AP Mark 35 - 2,500 fps (762 mps)
   HC Mark 39 - 2,665 fps (812 mps)

Reduced Charge - New Gun
   AP Mark 35 - 2,050 fps (625 mps)
   HC Mark 39 - 2,225 fps (678 mps)
Working Pressure 18.5 tons/in2 (2,910 kg/cm2)
Approximate Barrel Life
(see Note 2)		 750 - 1,050 rounds
Ammunition stowage per gun 200 rounds
Notes:

1) The HC Mark 34 projectile body could be used with Point Detonating (PD), Mechanical Time (MT) or with proximity (VT) nose fuzes.  When used with PD fuzes, they were considered to be HC rounds while those with MT and VT fuzes were considered as AA rounds.  All versions used a base contact fuze.  A specially cavitized HC Mark 34 projectile was produced to be used with a VT fuze.  This projectile was unique in that it was the only VT fuzed projectile of the World War II period that used a base fuze.

2) The sources listed below differ as to barrel life.  I have chosen to use the figures given in "The Naval Institute Guide to World Naval Weapon Systems 1991/92."

3) The cartridge cases were sealed with cork plugs which extended about 2.5 in (6.4 cm) past the mouth of the case.

4) Bourrelet diameter was 5.985 inches (15.2 cm).

5) Mark 4 was used for Full Charges while the Mark 4 Modified was used for Reduced Charges.

6) Some SPD cartridges had flashless pellets added which gave them a "reduced" flash.
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Range
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Elevation
With 130 lbs. (59 kg) AP
Striking Velocity
Angle of Fall
3.3 degrees
6,000 yards (5,490 m)
1,799 fps (548 mps)
4.15
6.5 degrees
10,000 yards (9,140 m)
1,428 fps (435 mps)
9.7
14.5 degrees
16,000 yards (14,630 m)
1,129 fps (344 mps)
24.3
22.3 degrees
20,000 yards (18,290 m)
1,102 fps (336 mps)
36.6
44.5 degrees
26,000 yards (23,770 m)
1,209 fps (369 mps)
58.1
47.5 degrees
26,118 yards (23,881 m)
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Elevation
With 105 lbs. (47.6 kg) HC
Striking Velocity
Angle of Fall
46.6 degrees
23,483 yards (21,473 m)
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Note:  Time of flight for AP Shell with MV = 2,500 fps (762 mps)
   10,000 yards (9,140 m): 16.2 seconds
   20,000 yards (18,290 m):  44.7 seconds
   26,000 yards (23,770 m):  77.3 seconds
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Mount / Turret Data
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Designation Triple Turrets
   Brooklyn (5), St. Louis (5), Cleveland (4) and Fargo (4)
Weight
(see Note 5)		 Brooklyn and St. Louis classes:  154 to 167 tons (156 to 170 mt)

Cleveland and Fargo classes:  165 to 173 tons (168 to 176 mt)
Elevation -5 / +40 degrees as designed, later modified to +60 degrees
Elevation Rate Brooklyn and St. Louis classes:  10 degrees per second

Cleveland and Fargo classes:  11 degrees per second
Train about +150 / -150 degrees
Train Rate All:  10 degrees per second
Gun recoil 21 in (53 cm)
Loading angle -5 to 20 degrees
Notes:

1) These mountings did not have the guns individually sleeved.

2) Each gun was supplied by its own projectile and cartridge hoists.  The cartridge hoist was an endless conveyor type with open flights rather than powder cars.

3) Each turret required a crew of 3 officers and 52 enlisted men.

4) Projectiles and cartridges were rammed together.

5) The Cleveland and Fargo classes had a slightly heavier and larger turret with more protection than the ones used for the Brooklyn and St. Louis classes.  Weight differences within a class were due mainly to the rangefinders, which were installed only on superfiring turrets.
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Data from
"Naval Weapons of World War Two" by John Campbell
"US Cruisers:  An Illustrated Design History", "US Naval Weapons" and "The Naval Institute Guide to World Naval Weapon Systems 1991/92" all by Norman Friedman
"Cruisers of World War Two" by M.J. Whitley
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"Naval Ordnance and Gunnery - 1952" Navpers 16116-B
"U.S. Explosive Ordnance:  Ordnance Pamphlet 1664 - May 1947" by Department of the Navy
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Special help from Leo Fischer