(M.T.F.) 12 May 2017 - Added information about propellants for Target rounds of these were test-fired from USS Iowa and at Dahlgren, achieving ranges of over With reduced charges, the AP Mark 8 there were the following 16"/50 (40.6 cm) munitions in stock: During the 1980s deployments, several new projectile assemblies Sides: 10.0 in The grenades
A persistent anecdote is that the Iowa War, an HC projectile cost $1,352.
11" TM 43-0001-28, Department of the Army (1994)
The recoil distance given above is the Testing was also performed with The time of flight in the range tables in OP 1091 go to the surface impact ICM Mark 146 - 666 M42, M46 and M77 grenades (82.1 kg) Composition A-3 These AA shells do not appear to have HC Mark 13 was originally designed for the Colorado (BB-45) class battleships, Other than these two items on USS Iowa, it The 1981 inventory search (see below) The absolute, metal-to-metal recoil distance was 0.43 ESR and at 1,900 fps (579 mps) were 0.03 ESR. suspect that under actual battle conditions that these values would Videos at USS Missouri BB-63 Website may have been installed inside of an otherwise unaltered HC Mark 13 shell body, This jacket was simply a
(147 kg) Atomic Museum in Albuquerque, New Mexico, as can be seen in the photograph, In the spring or summer of The other end had a handling strap.
I
16" Naval Gunpowder Bags, as made at INAAP, Charlestown, Indiana at Eerie Indiana Blogspot projectile rings and powder handling room to bring variation back within the +/- 10 fps requirement. whose shell handling system limited the maximum projectile length to about 4 0.53 lbs. For the same reasons, the performances of the Mark 19, Mark Added during 1950s Deployments A
The Target Mark 10 was identical to the were laid down. 24 degrees each. Iowa class were found to be in excellent shape thanks to the care taken At the time of the Korean 51,000 yards (46,600 m) with a new gun muzzle velocity of 2,825 fps (861 mps). was found that the only other gunnery-related items requiring replacement Besides the normal forward bourrelet, these projectiles have two rear bourrelets, one on either side of For a memorial to the men killed in Turret II, see USS Iowa Virtual Memorial (121,519 kg) (including breech), 816 in (20.726 m) (breech face to muzzle), AP Mark 8 - 40.9 lbs. 79.2R (SRG-P No. were both redesignated as Mark 140 Mod 0. The HE Mark 19 apparently did not go into service, as USS New Jersey was suddenly decommissioned sheet of foam with a fabric border around the ends that was tied to the powder bag. Iowa (BB-61) museum. Range Table for 16-inch 50-caliber Gun" The magazines for Turret I had four sets of scuttles for feeding the --- 08 July 2015 - Clarified note regarding rear bourrelets ICM Mark 144 - 63.6 in (161.5 cm) Reinforced concrete is specified as able to withstand a pressure of 5,000 psi (352 kg/cm2). although they now exist mainly as memorials.
equipment involved. Time of flight for AP Mark 8 Shell with MV = 2,500 fps (762 mps), Time of flight for HC Mark 13 Shell with MV = 2,615 fps (797 mps). by these guns is capable of penetrating nearly 30 feet (9 m) of concrete, The HE Mark 19 used the Army M565 Mechanical Time fuze to detonate an expelling World War II. Turret I were then armor-plated over, as can be seen in the photographs, OP 769 says that the minimum crew for each turret was 1 officer sophistication of fire control radar made its special capability redundant. successful that liner life could no longer be rated in terms of ESR, as it was no was removed from all four Iowa class battleships as weight compensation During - Red - 2,240 lbs. notes for the powder room sketch. Small irk: "W.N.Y."
and 76 men, not including those in the powder magazines.
USS Missouri was not so altered as she Information on USS Iowa (BB-61) Turret II Incident at the U.S. varied about +/- 14 fps (4.3 mps) and during Vietnam about +/- 23 fps As noted above, some of these
15 May 2015 - Replaced photograph of USS Montana model with artist's conception drawing 13.65 in (34.7 cm) diameter, extended-range (ER), sub-caliber cargo "Accuracy of Gunfire of the Main Batteries of United States Battleships" AMP Report No. USS Iowa, USS New Jersey and USS Wisconsin
Here are two sources
20 July 2009 - Added Ordata as a source, added sketches of Mark 144, Mark 146 and comparison of AP Mark 8 and HC Mark 13 was about +/- 32 fps (9.8 mps). In movies or pictures, this purging can be seen as a small puff of white smoke that is emitted a few seconds
type with a special astigmatic lens which allowed it to range in on a single Target Mark 15 same 2,690 fps (820 mps) muzzle velocity. (23.2 cm) Class A armor over 0.75 in (1.9 cm) STS, "Naval Weapons of World War Two" by John Campbell practice shells during a test in 1957. freshly made during World War II, MV varied no more than +/- 10 fps (3 mps) USNFSA Concept (Proposed) See photograph and sketches below. "U.S. Navy Bureau of Ordnance in World War II" by Lt. Cmdr. These mountings used delay coils, which 14 out of the 15 landed within 250 yards (230 m)
Improved HC Mark 147(?) The primer cartridge can be fired either electrically or by percussion. By the time of the 1980s deployments, shot to shot variation
was apparently developed when USS New Jersey (BB-62) was activated for the Vietnam War. 30 May 2015 - Redid photograph of USS Iowa and added additional information on projectile stowage fired with the additive caused even less wear (0.11 ESR). USS Iowa (BB-61) did some testing in the late 1980s with 5 bag loads of D846. when the breech opens after firing. second. Burster would have been about 181 lbs. "Performance of Bombs and Projectiles against Shore Installations: OP 1172 - 9 May 1944" by Bureau of Ordnance (BuOrd), Department of the Navy
was issued in a packet that was inserted between two of the propellant bags. As a Primer patch was at one end, quilted to ensure even HE-ER Mark 148 w/o Sabot - about 1,000 lbs. contributor to USS New Jersey's poor shooting off Lebanon in 1984. distribution, and usually colored red. (290 kg) SPD. could be changed out for a nose fuze on-board ship. In the 1980s, Mark 13 and Mark 14 projectiles wear of a single AP shell fired without the additive (0.26 ESR) and that HC rounds (45.7 cm) Class B armor over 4.5 in (11.4 cm) STS As modernized in the 1980s, each turret 1980s, but development was cancelled in FY91 when the battleships were decommissioned.
The "Mark 147" designation (259 kg) for a MV of 2,690 fps (820 mps). - N/A, possibly about 181 lbs. Full and AP Target charges were stacked while Reduced charges were - 5 bags: 35,000 psi (2,413 bars). light 2,240 pound (1,016.0 kg) AP Mark 5 projectile, the shell handling says 117 in (297 cm), the same as this reference lists for the. Turret armor thickness for the Iowa Class Training arcs were restricted during the 1980s activations in order to avoid end of calendar year 1991. fluid. "Battleships" by Paul Stillwell
and added link to "Turret Crawl" and listed other data sources HC Mark 147(?) rebagged 8" (20.3 cm) propellant for HC reduced charges. problem had existed at the time of her deactivation and that major repair to simplify renovation. the newer battleships, even though their shell handling systems could accommodate There were originally a total of twenty powder magazines: Six for Turret I; eight for part of or in conjunction with the "Gunfighter" program for developing. inner wall. of the official records for detailed data on this specific problem, but More powerful than the 16"/45 (40.6 cm) Mark 6 guns exceptionally effective against personnel, aircraft and other "soft" targets. --- numbers are taken from notes and sketches made by a chief gunner's mate HC Mark 13 - 2,615 fps (797 mps) (average gun) It had somewhat (852.8 kg) 8a, Added during 1980s - 1990s Deployments found that none of existing rounds were serviceable and the projectile bodies were then used to
The fuze timing movement HE-ER Mark 148 - 3,600 fps (1,097 mps), USS Iowa Turret III: -128 / +128 degrees. perforations, each 0.060 inches (0.152 cm) in diameter with a web thickness The above table is taken from page 98 (Table 21) of "Accuracy data for the Concept is courtesy of USNFSA: Range: 100 nm the Naval Gun Factory was located. Jersey - Blue Effectively, the powder This count agrees with the description in the post-war NavPers 16116-B. (HC) shell can create a crater 50 feet wide and 20 feet deep (15 x 6 m).
issued for the AP rounds.
As part of this evaluation, USS Iowa (BB-61) successfully fired some of these 200 seconds in increments of a tenth of a second. are segmented with stepped screw threads arranged in fifteen sectors of
the mountings were not in use, thus ensuring cleanliness of the hydraulic Launch Length: 69 in (175 cm) contained a total of 666 M42, M46 and M77 sub-munitions which are Dual Purpose lbs. Like the AP Mark 8, the HC Mark 13 projectile
replacement for the original one. USS Missouri HC rounds at 2,690 fps (820 mps) were
ICM Mark 146 Mod 2 was similar to the Mod 1 but had a threaded base plug details for projectiles, comment about aging of D846 propellant, added 1989 proof pressures, added sketch of container and powder "A.A. The mountings for the Iowa class were The big-gun battleship era ended on 16 May 1991, when USS Wisconsin (BB-64) longer the limiting factor. This projectile was to be ET-fuzed with a payload of about 300 The M46 HC Mark 13 projectile with Mark 423 Point-Detonating (PD) nose fuze and Mark 48
Turret armor thickness for the Montana Class (BB-67) as This concept was developed by the United States Naval Fire Support complexities of the equipment. "16-Inch Range Table, 2,500 Initial Velocity to 42,345 Yards: OP 770 - October 1941" by Bureau of Ordnance (BuOrd), Department of the Navy the breech. and the grain diameter. black powder bag igniter (primer patch). At the time of the 1981 estimate, a plan was in place to the powder bags, which reduced the wear still further. Together such as these would have to be related to the precise conditions and the 1980s reactivations, some experiments were performed using five bag Experiments with this projectile were conducted during the For these reasons, I would assume that See powder handling room sketch.
the number of rounds that could be carried by the Iowa class. In 1989, barrel pressure was specified as follows: When first introduced into service during World War II, (1,224.7 kg) AP Mark 8 before any of the USS Iowa class (BB-61) battleships
emptied her barrels for the last time.
may have been intended more for shore bombardment purposes rather than for AA defense. angle, the precise figures (using BB-61 as a target) would suggest valves were added to the Naval supply system to ensure logistical support. The 16"/50 (40.6 cm) Mark 7 was ultimately Shell-to-shell dispersion was 123 yards (112 m), 0.36% of total range. This necessarily meant that a long
was 40,185 yards (36,745 m). The Mark 23 Nuclear shell had about then all six bags were rammed into the breech with a single stroke. This much-needed projectile was introduced in BuOrd developed AA shells for these guns which were standard HC rounds When inspected during the initial reactivation
stacked. The above information is from "Battleships: United States Battleships 1935-1992" for a (269.0 kg) D846 charge for the Each shell ring was powered by a 40 hp electric motor. projectile does not appear to have entered general service use before all of the Face: 18.0 in improve MV consistency and all of the rebagged reduced charges were then are equipped with a ribbon stabilizer which also arms the fuze in flight. - Green.
Part Target - Department of Defense Ammunition NSN Parts: 1320-DA49 - 1320-D591
full and reduced charges. shells were fired from 34,000 yards (31,900 m), five from the right gun Each gun had
2,240 lbs.
rated at having a liner life of 1,500 FER. Turret Crawl on USS Iowa - Great tour of the inside of a turret from bottom to top. The High Capacity These are all cylindrical projectile stowage compared to the other two mountings. projectile with sabot. with Iowa crewmembers and the staff at NSWC Dahlgren, performed a search Improved HC Mark 147(?) Turret II: -126 / +126 degrees system for these guns was redesigned to use the "super-heavy" 2,700 pound ships, improved the dispersion patterns. made these weapons into the most accurate battleship-caliber guns ever
Some of these were fired by USS Iowa (BB-61) and Mark 16 used blind loaded and plugged (BL&P) HC Mark 13 projectile bodies.
during tests in 1989. terms of the number of mechanical cycles. It is not clear whether or "Department of Defense Appropriations for 1982: Tactical aircraft and missile programs" United States Congress, House Committee on Appropriations, Subcommittee on Department of Defense - Jan 1981 magazines. - Orange Other Mark 13 projectiles were given "Sympathetic Detonation of 16"/50 HC Projectiles" by Michael M. Swisdak, Jr. and Francis B. Porzel, Naval Surface Weapons Center from age and use, all of the original valves were not able to hold pressure process in the 1980s, all twelve turrets on the four battleships of the the total range. (238 kg) 03 August 2020 - Added note regarding gun replacement N/A for M77 grenade, but probably around 30 grams of Composition A-5, HE-CVT Mark 143 - 64.0 in (162.6 cm) calibers. These values are in substantial agreement with armor penetration curves issued 26 April 2019 - Added projectile storage information, sectional view and overhead views of turret, electric deck, ICM Mark 144 - 1,880 lbs. The Naval Surface 22 November 2009 - Corrected typographical error Launch Weight: 650 lbs. degrade over time, a few years later during the Korean deployments MV
compartment outside of it forms a double-wall isolation between the hoists and the propellant Reduced One of the dummy prototypes is currently on display at the USS nuclear projectiles were all withdrawn from service by October 1962 with
"Swedish Additive" (titanium dioxide and wax) greatly reduced barrel wear. charge of 400 grams of M9 mortar propellant to push out the grenades. have an ASW function - details unknown.
These turrets cost about $1,400,000 US each, not including Fly Away Weight: 525 lbs. "Iowa Class Battleships" by Robert F. Sumrall ICM Mark 146 - 64.0 in (162.6 cm) be expected to achieve the above hit percentages. ring, yoke ring and screw box liner. The screw box liner and breech plug given in "Battleships: United States Battleships, 1935 - 1992": (1,225 kg) projectiles, but 100 rounds per ship per year, but that target projectiles would be exhausted by the October 1956.
according to BuOrd OP 769.
See photograph below. The bore was chromium plated for a distance of 690 inches (17.526 m) from the muzzle. During the 1980s deployments, many reduced charges were rebagged to (30.5 cm) Class A armor over 0.75 in (1.9 cm) STS a cargo of 400 sub-munition M43A1 "Bouncing Betty" grenades arranged in 20 rows of 20 Volume 4, 11 December 2008 - Benchmark Sketches of various projectiles from Ordata
for shore bombardment purposes. M46 grenade sub-munitions. Improved Conventional Munitions (DPICM) bomblets. This was apparently a - 6 bags of D846 / 2,700 lbs. The data used to calculate these probabilities came from target made. This projectile did not become an official development program, but the Navy did develop developments during the 1980s deployment led to putting a polyurethane jacket over was rebagged and issued for use with the 1,900 lbs. was installed on each train and elevation unit during reactivation. HC rounds with VT fuzes were issued late in the war, but these The Target rounds at 1,800 fps Report No. Originally intended to fire the relatively (0.68 kg) dye bag but this was allowed to be as large as 3.0 lbs. Gulf. A time scale graduated from 0 to 100 seconds was inscribed on the rotatable depending upon the range and obliquity of impact. For a webpage devoted to a gun from USS New Jersey (BB-62), see Alan Zirkle Website See sketch below. - 6 bags of D846 / 2,700 lbs. bombardments. Propellant bags were made from raw silk.
The HE Mark 19 projectile This was corrected by increasing the delay in the right gun to 1 ), Mark 42 or Mark 62 01 June 2022 - Added sketches of M43A1 and M46 Grenade sub-munitions, note about Target Mark 18 has a radius of ogive of 144 inches (366 cm) or 9crh. Range Table for 16-inch 50-caliber Gun: OP 1091 - 11 March 1944" by Bureau of Ordnance (BuOrd), Department of the Navy (861.8 kg) As typical of USN weapons built in the 1940s, the bore was chromium plated Each M46 grenade contains 30 grams of Composition A-5 Fatigue Equivalent Rounds (FER), which is the mechanical fatigue life expressed in
range of 0.193 to 0.197 inches (0.490 to 0.500 cm) between the perforations HE-ER Mark 148 - about 72.0 in (182.9 cm), HC Mark 13 - 2,690 fps (820 mps) (new gun) In addition to the charges listed above, Reduced Charges (ETF) instead of the M565 nose fuze. after her first deployment and did not return to Vietnam. unaltered Mark 13 shell body.
The normal crew size was "Naval Ordnance and Gunnery - 1952" Navpers 16116-B to the loading position, thus speeding up the firing cycle time. USS Wisconsin
centrifugal detents. stamping on the breech face actually stands for "Washington Navy Yard" in Washington, D.C. where Some powder magazines were converted to other purposes during the 1980s-1990s 06 May 2020 - Updated image from RIMPAC '90 indicate manufacturers other than the Naval Gun Factory. in 1942. During the 1980s activations, agastats (time delay relays) Mark 16 was identical to the Mark 15 but made by a different manufacturer. (69.67 kg) Explosive D lower cap, and a vernier scale to permit setting accuracy to 0.1 seconds appeared on the base. of its requirements the ability to penetrate light armor and heavy concrete of Gunfire of the Main Batteries of United States Battleships" AMP 48), produced in July 1944. spot against a target the size of an Iowa-class battleship would
of the Mark 13. The above information is from OP 1172 using a muzzle velocity of 2,690 fps (820 mps) (new gun). by simply replacing the nose fuze.
(862 kg) made it easier to predict the velocity of succeeding shots. of these were actually made useful again is unknown at this time.
"Big Guns get Better" by Scot MacDonald in "Surface Warfare" Volume 10, Issue 2 - March/April 1985 estimates raised life to as much as 350 ESR. sketches for the HE Mark 19 and the ICM Mark 144 below. Each M42 grenade contains 30.5 grams of Composition A-5 "16-Inch Three Gun Turrets BB-61 Class: OP 769 - 30 April 1968" by Bureau of Ordnance (BuOrd), Department of the Navy lasts 0.90 seconds. A 1981 inventory of naval ammunition storage facilities found that Some of these were in service during the Gulf War (1990).
The Mark 13 uses both a base delay 17 July 2022 - Added note about the number of powder magazines, minor additions to Ammunition section, Naval Weapons, Naval Technology and Naval Reunions. The explosive cavity in Anti-Personnel Improved Conventional Munition (ICM) Mark 144 none ever having been fired from a gun. Old D839 and D846 propellant lots were remixed and proved be on the optimistic side. D. Used one of the following Nose Fuzes - Mark 29 (P.D.F. fifty Mark 23 "Katie" nuclear projectiles were produced during the 1950s with HC Mark 13 projectile with the Army M732 Controlled Variable (861.8 kg) HC projectiles.
fired a single HC round into the jungle and so created a helicopter landing (22.7 kg) of propellant to extend HE-ET/PT Mark 145 - 64.0 in (162.6 cm) Warfare Center - Crane Division located at Crane, Indiana, manufactured nominal figure. Nuclear Mark 23 - 1,900 lbs. the Mark 13 has a relatively thick-wall with a fairly constant sidewall As such, I would D839 propellant grain used for full charges originally issued for this gun 08 November 2019 - Added comments regarding turret crew size and powder crewmen This rangefinder was selected as the increasing
a 60 hp motor for elevation, a 60 hp electric motor for ramming, a 75 hp be removed and replaced without dismantling the gunhouse.
Mr. Jurens' suspicion is that there
reactivation were hampered by the thirty-year hiatus since she was placed 21 May 2021 - Added blueprint of 16" (40.6 cm) AP Mark 8 Mod 1 projectile 25.4% for 'Radar Spot' regimes. had an alteration made to Turret II magazine to incorporate a secure storage Investigation of the historical records showed that the The lower height of Turret I above the water also meant that this mounting 769 "16-Inch Three Gun Turrets BB-61 Class" and OP "Artillery Ammunition - Change No. Special help by Richard Landgraff, Nathan Okun, Leo Fischer, Matthew Rodchenko and William Jurens, For further information on these weapons, see USS Iowa Website
guns were unable to hold elevation and would oscillate around at the desired 1091 "A.A. (852.8 kg) weapons. details about this projectile. Guns were individually sleeved. "Review of the Department of the Navy's Investigation Into the Gun Turret Explosion Aboard the U.S.S. Copyright 2022 by Tony DiGiulian unless otherwise indicated. efforts had been underway at that time.
obturator so that they could be used in 16" (40.6 cm) guns. smaller than the Mark 13. although one of the sources listed below says that the projectile was slightly grenade differs from the M42 and M77 in having a heavier, thicker body with a smooth Naval History and Command Website
have been implemented. One projectile was expended The ICM Mark 144 was considered "Powder and Propellants: Energetic Materials at Indian Head, Maryland, 1890-2001" by Rodney Carlisle In addition to complete projectiles and charges on hand, there were sufficient The Mark 52 weighs 10,500 lbs. thickness, getting slightly thicker at the nose. - 2,825 fps (861 mps) In the case of a misfire, the cartridge can be manually removed and replaced without opening (0.24 kg) pressed TNT block was used under the Auxiliary Fuze. the driving bands, to improve shot centering as the projectile exits the muzzle. HE-ET/PT Mark 145 - 1,900 lbs. driving hydraulic gear. 16 December 2018 - Added turret sketch, added to note regarding turret design problem, minor formatting changes 21 February 2020 - Minor changes 52 used in Turrets II and III and Coincidence Mark 53 in Turret I. Time (CVT) nose fuze. (1,015 kg). Buford Rowland, USNR, and Lt. William B. Boyd, USNR the same weight and ballistic shape as did the HC Mark 13 projectile and,
(1.36 The cartridge is automatically ejected
"Reactivation of 16-inch Three Gun Turrets in the Battleships" by Art Romano, Naval Sea Systems Command has been estimated that four AP shells fired using this additive approximated the Anti-Personnel ICM Mark 146 Mark 53 was a coincidence (18.55 kg) Explosive D, Full Charge for AP or HC - 660.0 lbs. (7 mps). their own sub-caliber cargo round, the HE-ER Mark 148 described above. Approved in June 1939, the AP Mark 8 muzzle velocity of 2,500 fps (762 mps) and is based upon the USN Empirical Formula for Armor Mark 9 but used a dye spotting load.
planned 2,240 lbs. result, the NSWC Dahlgren facility and USS Iowa were tasked with improving 02 January 2021 - Added photographs of gun pit and liner insertion the elevation/range performance of the Mark 23 would be similar to that
03 October 2019 - Added link to U.S. To ensure detonation, either the Booster Mark 5 or a special
Bags were transferred from hoist to loading tray three bags at a time and proj: 49,400 psi (3,406 bars) In the 1967 and 1980s deployments, the use of In 1986 there was a project authorized to convert some of these to The M725 could be set for times between 0.2 to
--- deployments, D846, originally manufactured for the 16"/45 (40.6 cm) Mark 6 guns, as the US Navy routinely refuses to confirm or deny which ships carry nuclear Because of deterioration 22 September 2014 - Minor additions to captions and the rest were deactivated. All full-caliber projectiles have a bourrelet diameter of 15.977 inches (40.058 cm). "The Iowa Class Battleships" by Malcolm Muir as noted above, the nuclear warhead may have been installed in an otherwise This may have been the result of the age Each Full Charge D846 powder bag had a 0.77 lbs. The AP Mark 8 had a nominal 1.5 lbs. may have been an oblique reference to an alignment problem in some document
(862 kg) Range Table for 16-inch 50-caliber Gun", Penetration of Reinforced Concrete with AP Mark 8, Penetration of Reinforced Concrete with HC Mark 13, 267,904 lbs. the best battleship gun ever put into service. This (590 kg) less explosive weight in terms of percent than most foreign projectiles area for these projectiles. (0.35 kg) black The above information is from OP 1172 using a muzzle velocity of 2,500 fps (762 mps) (new gun). some HC projectiles in 1969 and these were designated as Mark 14, but they and nose contact fuzes for greater reliability under differing conditions, Wisconsin differed from her sisters in having a 1 second delay for (79.5 kg) 20 January 2022 - Corrected typographical error, minor navigational improvements m) beyond that. Later Base HE-ET/PT Mark 145 or a Nose Plug - projectile was usually issued with a nose plug which See Armor note below. was a spring-driven clockwork mechanism secured in the unarmed position by setback pins and
A persistent anecdote is that the Iowa War, an HC projectile cost $1,352.
11" TM 43-0001-28, Department of the Army (1994)
The recoil distance given above is the Testing was also performed with The time of flight in the range tables in OP 1091 go to the surface impact ICM Mark 146 - 666 M42, M46 and M77 grenades (82.1 kg) Composition A-3 These AA shells do not appear to have HC Mark 13 was originally designed for the Colorado (BB-45) class battleships, Other than these two items on USS Iowa, it The 1981 inventory search (see below) The absolute, metal-to-metal recoil distance was 0.43 ESR and at 1,900 fps (579 mps) were 0.03 ESR. suspect that under actual battle conditions that these values would Videos at USS Missouri BB-63 Website may have been installed inside of an otherwise unaltered HC Mark 13 shell body, This jacket was simply a (147 kg) Atomic Museum in Albuquerque, New Mexico, as can be seen in the photograph, In the spring or summer of The other end had a handling strap.
I
16" Naval Gunpowder Bags, as made at INAAP, Charlestown, Indiana at Eerie Indiana Blogspot projectile rings and powder handling room to bring variation back within the +/- 10 fps requirement. whose shell handling system limited the maximum projectile length to about 4 0.53 lbs. For the same reasons, the performances of the Mark 19, Mark Added during 1950s Deployments A
The Target Mark 10 was identical to the were laid down. 24 degrees each. Iowa class were found to be in excellent shape thanks to the care taken At the time of the Korean 51,000 yards (46,600 m) with a new gun muzzle velocity of 2,825 fps (861 mps). was found that the only other gunnery-related items requiring replacement Besides the normal forward bourrelet, these projectiles have two rear bourrelets, one on either side of For a memorial to the men killed in Turret II, see USS Iowa Virtual Memorial (121,519 kg) (including breech), 816 in (20.726 m) (breech face to muzzle), AP Mark 8 - 40.9 lbs. 79.2R (SRG-P No. were both redesignated as Mark 140 Mod 0. The HE Mark 19 apparently did not go into service, as USS New Jersey was suddenly decommissioned sheet of foam with a fabric border around the ends that was tied to the powder bag. Iowa (BB-61) museum. Range Table for 16-inch 50-caliber Gun" The magazines for Turret I had four sets of scuttles for feeding the --- 08 July 2015 - Clarified note regarding rear bourrelets ICM Mark 144 - 63.6 in (161.5 cm) Reinforced concrete is specified as able to withstand a pressure of 5,000 psi (352 kg/cm2). although they now exist mainly as memorials.
equipment involved. Time of flight for AP Mark 8 Shell with MV = 2,500 fps (762 mps), Time of flight for HC Mark 13 Shell with MV = 2,615 fps (797 mps). by these guns is capable of penetrating nearly 30 feet (9 m) of concrete, The HE Mark 19 used the Army M565 Mechanical Time fuze to detonate an expelling World War II. Turret I were then armor-plated over, as can be seen in the photographs, OP 769 says that the minimum crew for each turret was 1 officer sophistication of fire control radar made its special capability redundant. successful that liner life could no longer be rated in terms of ESR, as it was no was removed from all four Iowa class battleships as weight compensation During - Red - 2,240 lbs. notes for the powder room sketch. Small irk: "W.N.Y."
and 76 men, not including those in the powder magazines.
USS Missouri was not so altered as she Information on USS Iowa (BB-61) Turret II Incident at the U.S. varied about +/- 14 fps (4.3 mps) and during Vietnam about +/- 23 fps As noted above, some of these
15 May 2015 - Replaced photograph of USS Montana model with artist's conception drawing 13.65 in (34.7 cm) diameter, extended-range (ER), sub-caliber cargo "Accuracy of Gunfire of the Main Batteries of United States Battleships" AMP Report No. USS Iowa, USS New Jersey and USS Wisconsin
Here are two sources
20 July 2009 - Added Ordata as a source, added sketches of Mark 144, Mark 146 and comparison of AP Mark 8 and HC Mark 13 was about +/- 32 fps (9.8 mps). In movies or pictures, this purging can be seen as a small puff of white smoke that is emitted a few seconds
type with a special astigmatic lens which allowed it to range in on a single Target Mark 15 same 2,690 fps (820 mps) muzzle velocity. (23.2 cm) Class A armor over 0.75 in (1.9 cm) STS, "Naval Weapons of World War Two" by John Campbell practice shells during a test in 1957. freshly made during World War II, MV varied no more than +/- 10 fps (3 mps) USNFSA Concept (Proposed) See photograph and sketches below. "U.S. Navy Bureau of Ordnance in World War II" by Lt. Cmdr. These mountings used delay coils, which 14 out of the 15 landed within 250 yards (230 m)
Improved HC Mark 147(?) The primer cartridge can be fired either electrically or by percussion. By the time of the 1980s deployments, shot to shot variation
was apparently developed when USS New Jersey (BB-62) was activated for the Vietnam War. 30 May 2015 - Redid photograph of USS Iowa and added additional information on projectile stowage fired with the additive caused even less wear (0.11 ESR). USS Iowa (BB-61) did some testing in the late 1980s with 5 bag loads of D846. when the breech opens after firing. second. Burster would have been about 181 lbs. "Performance of Bombs and Projectiles against Shore Installations: OP 1172 - 9 May 1944" by Bureau of Ordnance (BuOrd), Department of the Navy
was issued in a packet that was inserted between two of the propellant bags. As a Primer patch was at one end, quilted to ensure even HE-ER Mark 148 w/o Sabot - about 1,000 lbs. contributor to USS New Jersey's poor shooting off Lebanon in 1984. distribution, and usually colored red. (290 kg) SPD. could be changed out for a nose fuze on-board ship. In the 1980s, Mark 13 and Mark 14 projectiles wear of a single AP shell fired without the additive (0.26 ESR) and that HC rounds (45.7 cm) Class B armor over 4.5 in (11.4 cm) STS As modernized in the 1980s, each turret 1980s, but development was cancelled in FY91 when the battleships were decommissioned.
The "Mark 147" designation (259 kg) for a MV of 2,690 fps (820 mps). - N/A, possibly about 181 lbs. Full and AP Target charges were stacked while Reduced charges were - 5 bags: 35,000 psi (2,413 bars). light 2,240 pound (1,016.0 kg) AP Mark 5 projectile, the shell handling says 117 in (297 cm), the same as this reference lists for the. Turret armor thickness for the Iowa Class Training arcs were restricted during the 1980s activations in order to avoid end of calendar year 1991. fluid. "Battleships" by Paul Stillwell
and added link to "Turret Crawl" and listed other data sources HC Mark 147(?) rebagged 8" (20.3 cm) propellant for HC reduced charges. problem had existed at the time of her deactivation and that major repair to simplify renovation. the newer battleships, even though their shell handling systems could accommodate There were originally a total of twenty powder magazines: Six for Turret I; eight for part of or in conjunction with the "Gunfighter" program for developing. inner wall. of the official records for detailed data on this specific problem, but More powerful than the 16"/45 (40.6 cm) Mark 6 guns exceptionally effective against personnel, aircraft and other "soft" targets. --- numbers are taken from notes and sketches made by a chief gunner's mate HC Mark 13 - 2,615 fps (797 mps) (average gun) It had somewhat (852.8 kg) 8a, Added during 1980s - 1990s Deployments found that none of existing rounds were serviceable and the projectile bodies were then used to
The fuze timing movement HE-ER Mark 148 - 3,600 fps (1,097 mps), USS Iowa Turret III: -128 / +128 degrees. perforations, each 0.060 inches (0.152 cm) in diameter with a web thickness The above table is taken from page 98 (Table 21) of "Accuracy data for the Concept is courtesy of USNFSA: Range: 100 nm the Naval Gun Factory was located. Jersey - Blue Effectively, the powder This count agrees with the description in the post-war NavPers 16116-B. (HC) shell can create a crater 50 feet wide and 20 feet deep (15 x 6 m).
issued for the AP rounds.
As part of this evaluation, USS Iowa (BB-61) successfully fired some of these 200 seconds in increments of a tenth of a second. are segmented with stepped screw threads arranged in fifteen sectors of
the mountings were not in use, thus ensuring cleanliness of the hydraulic Launch Length: 69 in (175 cm) contained a total of 666 M42, M46 and M77 sub-munitions which are Dual Purpose lbs. Like the AP Mark 8, the HC Mark 13 projectile
replacement for the original one. USS Missouri HC rounds at 2,690 fps (820 mps) were
ICM Mark 146 Mod 2 was similar to the Mod 1 but had a threaded base plug details for projectiles, comment about aging of D846 propellant, added 1989 proof pressures, added sketch of container and powder "A.A. The mountings for the Iowa class were The big-gun battleship era ended on 16 May 1991, when USS Wisconsin (BB-64) longer the limiting factor. This projectile was to be ET-fuzed with a payload of about 300 The M46 HC Mark 13 projectile with Mark 423 Point-Detonating (PD) nose fuze and Mark 48
Turret armor thickness for the Montana Class (BB-67) as This concept was developed by the United States Naval Fire Support complexities of the equipment. "16-Inch Range Table, 2,500 Initial Velocity to 42,345 Yards: OP 770 - October 1941" by Bureau of Ordnance (BuOrd), Department of the Navy the breech. and the grain diameter. black powder bag igniter (primer patch). At the time of the 1981 estimate, a plan was in place to the powder bags, which reduced the wear still further. Together such as these would have to be related to the precise conditions and the 1980s reactivations, some experiments were performed using five bag Experiments with this projectile were conducted during the For these reasons, I would assume that See powder handling room sketch.
the number of rounds that could be carried by the Iowa class. In 1989, barrel pressure was specified as follows: When first introduced into service during World War II, (1,224.7 kg) AP Mark 8 before any of the USS Iowa class (BB-61) battleships
emptied her barrels for the last time.
may have been intended more for shore bombardment purposes rather than for AA defense. angle, the precise figures (using BB-61 as a target) would suggest valves were added to the Naval supply system to ensure logistical support. The 16"/50 (40.6 cm) Mark 7 was ultimately Shell-to-shell dispersion was 123 yards (112 m), 0.36% of total range. This necessarily meant that a long
was 40,185 yards (36,745 m). The Mark 23 Nuclear shell had about then all six bags were rammed into the breech with a single stroke. This much-needed projectile was introduced in BuOrd developed AA shells for these guns which were standard HC rounds When inspected during the initial reactivation
stacked. The above information is from "Battleships: United States Battleships 1935-1992" for a (269.0 kg) D846 charge for the Each shell ring was powered by a 40 hp electric motor. projectile does not appear to have entered general service use before all of the Face: 18.0 in improve MV consistency and all of the rebagged reduced charges were then are equipped with a ribbon stabilizer which also arms the fuze in flight. - Green.
Part Target - Department of Defense Ammunition NSN Parts: 1320-DA49 - 1320-D591
full and reduced charges. shells were fired from 34,000 yards (31,900 m), five from the right gun Each gun had
2,240 lbs.
rated at having a liner life of 1,500 FER. Turret Crawl on USS Iowa - Great tour of the inside of a turret from bottom to top. The High Capacity These are all cylindrical projectile stowage compared to the other two mountings. projectile with sabot. with Iowa crewmembers and the staff at NSWC Dahlgren, performed a search Improved HC Mark 147(?) Turret II: -126 / +126 degrees system for these guns was redesigned to use the "super-heavy" 2,700 pound ships, improved the dispersion patterns. made these weapons into the most accurate battleship-caliber guns ever
Some of these were fired by USS Iowa (BB-61) and Mark 16 used blind loaded and plugged (BL&P) HC Mark 13 projectile bodies.
during tests in 1989. terms of the number of mechanical cycles. It is not clear whether or "Department of Defense Appropriations for 1982: Tactical aircraft and missile programs" United States Congress, House Committee on Appropriations, Subcommittee on Department of Defense - Jan 1981 magazines. - Orange Other Mark 13 projectiles were given "Sympathetic Detonation of 16"/50 HC Projectiles" by Michael M. Swisdak, Jr. and Francis B. Porzel, Naval Surface Weapons Center from age and use, all of the original valves were not able to hold pressure process in the 1980s, all twelve turrets on the four battleships of the the total range. (238 kg) 03 August 2020 - Added note regarding gun replacement N/A for M77 grenade, but probably around 30 grams of Composition A-5, HE-CVT Mark 143 - 64.0 in (162.6 cm) calibers. These values are in substantial agreement with armor penetration curves issued 26 April 2019 - Added projectile storage information, sectional view and overhead views of turret, electric deck, ICM Mark 144 - 1,880 lbs. The Naval Surface 22 November 2009 - Corrected typographical error Launch Weight: 650 lbs. degrade over time, a few years later during the Korean deployments MV
compartment outside of it forms a double-wall isolation between the hoists and the propellant Reduced One of the dummy prototypes is currently on display at the USS nuclear projectiles were all withdrawn from service by October 1962 with
"Swedish Additive" (titanium dioxide and wax) greatly reduced barrel wear. charge of 400 grams of M9 mortar propellant to push out the grenades. have an ASW function - details unknown.
These turrets cost about $1,400,000 US each, not including Fly Away Weight: 525 lbs. "Iowa Class Battleships" by Robert F. Sumrall ICM Mark 146 - 64.0 in (162.6 cm) be expected to achieve the above hit percentages. ring, yoke ring and screw box liner. The screw box liner and breech plug given in "Battleships: United States Battleships, 1935 - 1992": (1,225 kg) projectiles, but 100 rounds per ship per year, but that target projectiles would be exhausted by the October 1956.
according to BuOrd OP 769.
See photograph below. The bore was chromium plated for a distance of 690 inches (17.526 m) from the muzzle. During the 1980s deployments, many reduced charges were rebagged to (30.5 cm) Class A armor over 0.75 in (1.9 cm) STS a cargo of 400 sub-munition M43A1 "Bouncing Betty" grenades arranged in 20 rows of 20 Volume 4, 11 December 2008 - Benchmark Sketches of various projectiles from Ordata
for shore bombardment purposes. M46 grenade sub-munitions. Improved Conventional Munitions (DPICM) bomblets. This was apparently a - 6 bags of D846 / 2,700 lbs. The data used to calculate these probabilities came from target made. This projectile did not become an official development program, but the Navy did develop developments during the 1980s deployment led to putting a polyurethane jacket over was rebagged and issued for use with the 1,900 lbs. was installed on each train and elevation unit during reactivation. HC rounds with VT fuzes were issued late in the war, but these The Target rounds at 1,800 fps Report No. Originally intended to fire the relatively (0.68 kg) dye bag but this was allowed to be as large as 3.0 lbs. Gulf. A time scale graduated from 0 to 100 seconds was inscribed on the rotatable depending upon the range and obliquity of impact. For a webpage devoted to a gun from USS New Jersey (BB-62), see Alan Zirkle Website See sketch below. - 6 bags of D846 / 2,700 lbs. bombardments. Propellant bags were made from raw silk.
The HE Mark 19 projectile This was corrected by increasing the delay in the right gun to 1 ), Mark 42 or Mark 62 01 June 2022 - Added sketches of M43A1 and M46 Grenade sub-munitions, note about Target Mark 18 has a radius of ogive of 144 inches (366 cm) or 9crh. Range Table for 16-inch 50-caliber Gun: OP 1091 - 11 March 1944" by Bureau of Ordnance (BuOrd), Department of the Navy (861.8 kg) As typical of USN weapons built in the 1940s, the bore was chromium plated Each M46 grenade contains 30 grams of Composition A-5 Fatigue Equivalent Rounds (FER), which is the mechanical fatigue life expressed in
range of 0.193 to 0.197 inches (0.490 to 0.500 cm) between the perforations HE-ER Mark 148 - about 72.0 in (182.9 cm), HC Mark 13 - 2,690 fps (820 mps) (new gun) In addition to the charges listed above, Reduced Charges (ETF) instead of the M565 nose fuze. after her first deployment and did not return to Vietnam. unaltered Mark 13 shell body.
The normal crew size was "Naval Ordnance and Gunnery - 1952" Navpers 16116-B to the loading position, thus speeding up the firing cycle time. USS Wisconsin
centrifugal detents. stamping on the breech face actually stands for "Washington Navy Yard" in Washington, D.C. where Some powder magazines were converted to other purposes during the 1980s-1990s 06 May 2020 - Updated image from RIMPAC '90 indicate manufacturers other than the Naval Gun Factory. in 1942. During the 1980s activations, agastats (time delay relays) Mark 16 was identical to the Mark 15 but made by a different manufacturer. (69.67 kg) Explosive D lower cap, and a vernier scale to permit setting accuracy to 0.1 seconds appeared on the base. of its requirements the ability to penetrate light armor and heavy concrete of Gunfire of the Main Batteries of United States Battleships" AMP 48), produced in July 1944. spot against a target the size of an Iowa-class battleship would
of the Mark 13. The above information is from OP 1172 using a muzzle velocity of 2,690 fps (820 mps) (new gun). by simply replacing the nose fuze.
(862 kg) made it easier to predict the velocity of succeeding shots. of these were actually made useful again is unknown at this time.
"Big Guns get Better" by Scot MacDonald in "Surface Warfare" Volume 10, Issue 2 - March/April 1985 estimates raised life to as much as 350 ESR. sketches for the HE Mark 19 and the ICM Mark 144 below. Each M42 grenade contains 30.5 grams of Composition A-5 "16-Inch Three Gun Turrets BB-61 Class: OP 769 - 30 April 1968" by Bureau of Ordnance (BuOrd), Department of the Navy lasts 0.90 seconds. A 1981 inventory of naval ammunition storage facilities found that Some of these were in service during the Gulf War (1990).
The Mark 13 uses both a base delay 17 July 2022 - Added note about the number of powder magazines, minor additions to Ammunition section, Naval Weapons, Naval Technology and Naval Reunions. The explosive cavity in Anti-Personnel Improved Conventional Munition (ICM) Mark 144 none ever having been fired from a gun. Old D839 and D846 propellant lots were remixed and proved be on the optimistic side. D. Used one of the following Nose Fuzes - Mark 29 (P.D.F. fifty Mark 23 "Katie" nuclear projectiles were produced during the 1950s with HC Mark 13 projectile with the Army M732 Controlled Variable (861.8 kg) HC projectiles.
fired a single HC round into the jungle and so created a helicopter landing (22.7 kg) of propellant to extend HE-ET/PT Mark 145 - 64.0 in (162.6 cm) Warfare Center - Crane Division located at Crane, Indiana, manufactured nominal figure. Nuclear Mark 23 - 1,900 lbs. the Mark 13 has a relatively thick-wall with a fairly constant sidewall As such, I would D839 propellant grain used for full charges originally issued for this gun 08 November 2019 - Added comments regarding turret crew size and powder crewmen This rangefinder was selected as the increasing
a 60 hp motor for elevation, a 60 hp electric motor for ramming, a 75 hp be removed and replaced without dismantling the gunhouse.
Mr. Jurens' suspicion is that there
reactivation were hampered by the thirty-year hiatus since she was placed 21 May 2021 - Added blueprint of 16" (40.6 cm) AP Mark 8 Mod 1 projectile 25.4% for 'Radar Spot' regimes. had an alteration made to Turret II magazine to incorporate a secure storage Investigation of the historical records showed that the The lower height of Turret I above the water also meant that this mounting 769 "16-Inch Three Gun Turrets BB-61 Class" and OP "Artillery Ammunition - Change No. Special help by Richard Landgraff, Nathan Okun, Leo Fischer, Matthew Rodchenko and William Jurens, For further information on these weapons, see USS Iowa Website
guns were unable to hold elevation and would oscillate around at the desired 1091 "A.A. (852.8 kg) weapons. details about this projectile. Guns were individually sleeved. "Review of the Department of the Navy's Investigation Into the Gun Turret Explosion Aboard the U.S.S. Copyright 2022 by Tony DiGiulian unless otherwise indicated. efforts had been underway at that time.
obturator so that they could be used in 16" (40.6 cm) guns. smaller than the Mark 13. although one of the sources listed below says that the projectile was slightly grenade differs from the M42 and M77 in having a heavier, thicker body with a smooth Naval History and Command Website
have been implemented. One projectile was expended The ICM Mark 144 was considered "Powder and Propellants: Energetic Materials at Indian Head, Maryland, 1890-2001" by Rodney Carlisle In addition to complete projectiles and charges on hand, there were sufficient The Mark 52 weighs 10,500 lbs. thickness, getting slightly thicker at the nose. - 2,825 fps (861 mps) In the case of a misfire, the cartridge can be manually removed and replaced without opening (0.24 kg) pressed TNT block was used under the Auxiliary Fuze. the driving bands, to improve shot centering as the projectile exits the muzzle. HE-ET/PT Mark 145 - 1,900 lbs. driving hydraulic gear. 16 December 2018 - Added turret sketch, added to note regarding turret design problem, minor formatting changes 21 February 2020 - Minor changes 52 used in Turrets II and III and Coincidence Mark 53 in Turret I. Time (CVT) nose fuze. (1,015 kg). Buford Rowland, USNR, and Lt. William B. Boyd, USNR the same weight and ballistic shape as did the HC Mark 13 projectile and,
(1.36 The cartridge is automatically ejected
"Reactivation of 16-inch Three Gun Turrets in the Battleships" by Art Romano, Naval Sea Systems Command has been estimated that four AP shells fired using this additive approximated the Anti-Personnel ICM Mark 146 Mark 53 was a coincidence (18.55 kg) Explosive D, Full Charge for AP or HC - 660.0 lbs. (7 mps). their own sub-caliber cargo round, the HE-ER Mark 148 described above. Approved in June 1939, the AP Mark 8 muzzle velocity of 2,500 fps (762 mps) and is based upon the USN Empirical Formula for Armor Mark 9 but used a dye spotting load.
planned 2,240 lbs. result, the NSWC Dahlgren facility and USS Iowa were tasked with improving 02 January 2021 - Added photographs of gun pit and liner insertion the elevation/range performance of the Mark 23 would be similar to that
03 October 2019 - Added link to U.S. To ensure detonation, either the Booster Mark 5 or a special
Bags were transferred from hoist to loading tray three bags at a time and proj: 49,400 psi (3,406 bars) In the 1967 and 1980s deployments, the use of In 1986 there was a project authorized to convert some of these to The M725 could be set for times between 0.2 to
--- deployments, D846, originally manufactured for the 16"/45 (40.6 cm) Mark 6 guns, as the US Navy routinely refuses to confirm or deny which ships carry nuclear Because of deterioration 22 September 2014 - Minor additions to captions and the rest were deactivated. All full-caliber projectiles have a bourrelet diameter of 15.977 inches (40.058 cm). "The Iowa Class Battleships" by Malcolm Muir as noted above, the nuclear warhead may have been installed in an otherwise This may have been the result of the age Each Full Charge D846 powder bag had a 0.77 lbs. The AP Mark 8 had a nominal 1.5 lbs. may have been an oblique reference to an alignment problem in some document
(862 kg) Range Table for 16-inch 50-caliber Gun", Penetration of Reinforced Concrete with AP Mark 8, Penetration of Reinforced Concrete with HC Mark 13, 267,904 lbs. the best battleship gun ever put into service. This (590 kg) less explosive weight in terms of percent than most foreign projectiles area for these projectiles. (0.35 kg) black The above information is from OP 1172 using a muzzle velocity of 2,500 fps (762 mps) (new gun). some HC projectiles in 1969 and these were designated as Mark 14, but they and nose contact fuzes for greater reliability under differing conditions, Wisconsin differed from her sisters in having a 1 second delay for (79.5 kg) 20 January 2022 - Corrected typographical error, minor navigational improvements m) beyond that. Later Base HE-ET/PT Mark 145 or a Nose Plug - projectile was usually issued with a nose plug which See Armor note below. was a spring-driven clockwork mechanism secured in the unarmed position by setback pins and