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16" Naval Gun; Two 16-Shot Groups. Accurate?

Discussion in 'General Gun Discussions' started by Bart B., Feb 3, 2017.

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  1. MachIVshooter

    MachIVshooter Member

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    Absolutely correct. The battleship was simply outdated once jets and missiles showed up.

    All 4 Iowa class ships were re-outfitted with more modern weaponry as part or Reagan's 600 ship navy, and saw very limited use in the first Iraq war, but the big guns are just plain ineffective compared to modern ordnance launched from destroyers, subs, and carriers/jets. A cruise missile has 50+ times the range with much more destructive power and far more precision than the (awesome!) 16" guns.

    Missouri did fire her big guns on coastal targets in Desert Storm. To my knowledge, that was the first time in a nearly a half century, and the last time the 16 inchers rang out.

    I have a love for the battleships of yore, but they have no place in a 21st century navy
     
    Last edited: Feb 7, 2017
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  2. Slamfire

    Slamfire Member

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    I remember the New Jersey being used in Lebanon in 1984. Here is a link to an article:

    U.S. BATTLESHIP POUNDS HILLS HELD BY SYRIANS IN LEBANON; BRITAIN; PULLING OUT TROOPS

    I totally agree. A battleship shelling from 15 miles from the coast is extremely vulnerable to modern weapons. A cheap land to ship cruise missile will take one out and a lot further than any 16" gun can fire. For example, the Chinese DF-21D anti-ship ballistic missile has a range of 900 miles. You can see a picture of the things here: What China's New Missiles Mean for the Future of the Aircraft Carrier

    These things are big, dangerous missiles :the Dongfeng-21D, has a maneuverable warhead that can seek and close in on its target at 10 times the speed of sound

    From what I remember reading the velocity of the shells out of a 16 inch gun was around 2000-2500 fps. Observers could actually see the shells in flight. Now, lets assume the speed of sound is 1000 fps, ten times that is 10,000 fps. That Chinese carrier buster is traveling four to five times faster than the shell of a 16 inch gun.
     
    Last edited: Feb 7, 2017
  3. Sergei Mosin

    Sergei Mosin Member

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    Sort of. Once you've achieved a straddle, a hit is only a matter of probability. A straddle means you're on target and as long as you stay on target the hits will start coming.
     
  4. Sergei Mosin

    Sergei Mosin Member

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    A brief summary of US battleships post-WWII: MISSOURI remained in service and saw action in Korea. IOWA, NEW JERSEY, and WISCONSIN were all recommissioned for Korea. All four were laid up 1955-58. NEW JERSEY was recommissioned for Vietnam 1968-69. All four were recommissioned for Cold War service beginning in 1982; NEW JERSEY saw action in Lebanon, while MISSOURI and WISCONSIN were involved in DESERT STORM. All were retired by 1992.

    As to why they were withdrawn, the Navy as a whole was gutted after WWII; battleships were obsolete in the face of air power and nuclear weapons were supposed to make massed fleets and amphibious assaults obsolete.

    Then there was Korea.

    After Korea the battleships were withdrawn because they were expensive to run and shore bombardment in future amphibious operations could be handled by cruisers or with nuclear weapons.

    Then there was Vietnam.

    NEW JERSEY was withdrawn for political and budgetary reasons as the US tried to get out of Vietnam.

    Then there was Reagan.

    The 600-ship Navy needed hulls, the Marines wanted fire support, and the Fleet needed Tomahawk shooters in those pre-VLS days. Then the Soviet Union went away, everything new could launch Tomahawks, amphibious assaults cost too many lives, and the battleships cost too much to run.

    And so they became museum ships.

    ***

    While several other navies continued to operate battleships postwar, by the late 1950s all had gone into reserve. There was only one combat use after WWII, when the French sent JEAN BART to Suez in 1956. She fired a grand total of four 15-inch rounds and that was it.

    ***

    The Chinese antiship ballistic missile is one of the more overhyped weapons systems of recent times. The targeting problem is near-insoluble; first you have to find the target, then you have to predict where it's going to be when the missile arrives, and being a ballistic missile, its ability to maneuver to correct for any targeting error is very limited. If it even gets close, it can be shot down by a suitably-equipped escort. About the only way one of those things could destroy a carrier is if you put a nuclear warhead on the thing and fired it at a port where the carrier is docked.
     
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  5. armoredman

    armoredman Member

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    ...
     
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  6. Elm Creek Smith

    Elm Creek Smith Member

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    Cruisers now share the same hull as destroyers and only have 5 inch/54 caliber guns. There is a limit to what a 5 inch projectile can do, especially if it's rocket-assisted which means the explosive load is even lighter. The use of nuclear weapons other than deterrents seems also to have ended in 1945. The Marines have been lobbying for bigger shipboard guns since the cruisers with 6 inch and 8 inch guns were withdrawn. There was even a test of a single lightweight 8 inch/55 caliber gun mount on a destroyer back in the '70's. http://www.navweaps.com/Weapons/WNUS_8-55_mk71.php

    As for cruise missiles taking out a BB, CIWS and escorts are designed to take them out. When people bring up the British losses in the Falklands War, I have to point out that those ships were completely unarmored. Battleships were designed to fight other battleships, and it would take more than a conventionally-armed Tomahawk to take one out in the increasingly unlikely event of a hit.

    Concur.
     
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  7. Bart B.

    Bart B. Member

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    http://navweaps.com/Weapons/WNUS_16-50_mk7.php

    Latest facts about 16" naval guns and their projectile specs.

    Note there was a short delay betweenthe three 16" guns in a turret firing so their projectiles wouldn't bump into each other. A couple hundredths second delay put all three out about 50 feet apart in the line of fire.
     
    Last edited: Feb 7, 2017
  8. Whiskey11

    Whiskey11 Member

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    Lots of fun and interesting things in here about the 16" Mark 7 guns mounted on board four of the best fighting ships the world has ever seen. Some misconceptions though too.

    -The death and demise of Battleships has nothing to do with cost and everything to do with aircraft and age. Cost during war time is nothing compared to the need to win whatever engagement it was. Unfortunately for the battleship, they ended before true anti-aircraft capabilities were realized. Keep in mind that as advanced as the Iowa's were in the 1940's and 1950's, their AA suite started with the 5"/38cal dual purpose gun mounts on the sides. They were entirely handled by radar and their 5" shells were capped with VT shells (basically a radio controlled detonator) and set to detonate at a specific distance from the target by the directors. This weapon became obsolete for AA duty between world war 2 and the Korean war when jets started taking over. The speed of the aircraft taxed the training and elevating motors to their limits and the shell flight time was simply too low to be effective. The US had realized that this would be a problem as early as 1940 when the design for the Montana Class Battleship was being drummed up. They ditched the 5"/38 for the 5"/54. The extra 16 calibers of barrel length made for a much more effective AA gun. Those barrels made for the Montana's 5"/54's were eventually put on the Midway class carriers (18 of them at the end of WWII). The mid range AA consisted of a boatload (literally) of 40mm Bofors which was again, obsolete by the end of WWII. The US had already developed the 3"/50 cal Mk33 guns that saw service on the Des Moines class cruisers which had more range, better velocity and more punch than the 40mm Bofors, which for WWII was a FANTASTIC AA gun but by the end was rapidly made obsolete. The short range AA was carried by 20mm Oerlikons. None of those 3 weapon systems were comfortable in jet engagements and by the end of Korea, the reactivated Iowa's basically ditched all but a handful of 40mm's and the 5"/38's.

    The problem with this assessment is that WWII/Korea was in an awkward time for missile development and a modern day "battleship" designed in today's terms would not suffer from this problem in the slightest. CWIS is nice but it's the LAST LINE of defense for AA duties.

    Age was probably the single biggest reason though as the Iowa's were launched in the early 1940's

    -Battleship Accuracy is absolutely fantastic given the intended targets and ranges involved. The longest ranged battleship vs battleship engagements occurred out around the 22km range. There were several times in which battleships engaged targets further out than that. Yamato firing at the USS White Planes achieved straddles and a single damaging near miss at ~32km. The Iowa and New Jersey fired upon the fleeing and maneuvering cruiser Nowalki and straddled her at 35km repeatedly until they were ordered to cease fire. In terms of "longest" achieved hits, around 22km is where they occurred. Scharnhorst and Warspite are frequently credited with those hits. Warspite was a WWI survivor pressed into service in WWII. On the USN standpoint, West Virginia achieved hits in five out of her first six salvo's at the Battle of Surigao Strait at a range of ~21km and the fire on Yamashiro was smothering enough to sink her. When you boil down the variables that effect battleship accuracy and consider that these engagements were happening either optically (Scharnhorst and Warspite) or via primitive Radar (WeeVee) and electro-mechanical fire computers it's VERY impressive. People want to cite the War Study accuracy where an Iowa could only get 3% of hits at a broadside Bismarck sized target at 35,000 yards but actual accuracy testing showed that this was on the LOW end of hits actually achieved during live fire testing.

    -Vertical stringing on battleships has more to do with velocity variation from barrel to barrel than bedding or barrel whip! :) There is a reason that significant time was invested in retrofitting the fire control with DOPPLER radar units and improving powder burn consistency.

    -Using the example of either Pearl Harbor or the Bismarck as the downfall of Battleships is a bit short sighted. Pearl Harbor was in a state of peace time readiness. It showed the worst case scenario of when you catch stationary, lightly crewed or non-prepared crews off guard and for all the hub bub about what happened there, only ONE Battleship was a complete loss (Arizona). Oklahoma was refloated and sank enroute to the states for scrapping due to storm damages and quick repairs to refloat her. Utah was not a battleship at the time of her sinking although technically she was a battleship hull, of dated design. The US Battleship fleet faired pretty well all things considered. Bismarck was by herself when she was sank. She had absolutely no assistance in handling 12 ships by herself. She was also not designed with nearly the AA compliment she should have had and Tirpitz's final form showed a more realistic expectation of the needs of AA defense onboard Bismarck class BB's. The USN took AA to the logical conclusion but it was by no means a perfect example of the death of Battleships "Because Carriers." Even Yamato and Musashi can't be effectively used. About the best examples here would be the massive carrier battles at the beginning of the Pacific campaign which showed just how strong a carrier could be against prepared and defended enemies.

    -A Mark 8 AP shell definitely needed to hit the ship to be of any real use. Splash damage from the relatively small bursting charge on the shell would be minimal but direct hits were absolutely devastating. As others have said, Jean Bart being hit by Massachusetts was a good example of the power of the Mark 8 shell. Washington & South Dakota vs Kirishima was less of an example as the older Mark 5 2250lb AP shell would have been just as devastating to Kirishima as the Mark 8 was. At 12600 yards, where the Washington opened up on Kirishima, the Mark 8 had nearly enough penetration to penetrate through the ship entirely if it were not for the fuses in the shells to detonate them! :)

    In a lot of ways the 16"/45cal Mark 6 guns were considered superior by BuOrd. The weapon system was well known, limitations well understood, but more importantly the angle of fall from the slower moving shells meant more reliable deck penetration at all ranges. The USN was obsessed with deck penetrations since the early 1900's. All of the US Standard Battleships (Nevadas, Pennsylvania's, New Mexico's, Tennessee's, and Colorados) were designed with more deck armor than their peers and the armor profile was specifically chosen to maximize protection at long ranges. Contrast this with Royal Navy battleship design or German battleship design that still focused on the close engagements of the North Atlantic. The faults of their designs were shown at Jutland in WWI and confirmed multiple times throughout WWII.

    -USN Radar in WWII was accurate enough to track the small 5" shell splashes on water and I suspect that had there been sufficient view of the horizon, could have tracked land hits as well although the primary job of the optical gun directors was to track shell splashes since their job had been made basically obsolete by the time the North Carolina Class Battleships hit service in WWII and DEFINITELY by the time the Iowa's entered service. The USN was playing with radar for fire control as early as the mid 1930's.

    -The optical horizon at which an Iowa could effectively see was comparable to it's gun range as a ship's superstructure and masts could be seen well enough to get a range. There were ways to get accurate ranges by optical methods at those ranges but Radar was far more reliable and less prone to operator fatigue. Also the US tied their radars directly into the fire control computers which was a significant advantage. Japan had, by wars end, a radar capable of accurately measuring shell splashes and range, etc but it was never tied into any fire control system.

    -Washington never got within 8400 yards of Kirishima on that night. South Dakota sailed, due to an electrical problem, within 5,000 yards of Kirishima but never returned fire. Washington began her engagement at 12800 yards and yes, hit with at least 9 confirmed hits, although 20 is more probable given the damage sustained by Kirishima and what was reported by the crew of Kirishima. NavWeaps has a fantastic article on the damage of Kirishima: http://www.navweaps.com/index_lundgren/Kirishima_Damage_Analysis.pdf

    -Early barrel life of battleship guns was quite low but by the time the Iowa's were reactivated in the 1980's the advancements in powder tech reduced barrel ware to the point where the ships would not feasibly wear out the liners in their service.

    -South Dakota and Iowa classes are frighteningly similar. The armor design of the Iowa's was nearly identical to the South Dakota in layout and thicknesses. Only a small number of changes to the armor layout were made. A thicker outer hull (1.5" STS armor plate instead of 1.25" STS armor plate on the SoDaks), slightly thicker front bulkhead on the Missouri and Wisconsin (and Kentucky and Illinois, although these two were never completed). The major design consideration for the Iowa was to achieve 33 knots at 45,000 tons of displacement with 16"/50cal rifles on board. To do this they took the SoDaks and basically lengthened them and added more power to get them moving at 33 knots. So while Iowas were newer, there was A LOT of South Dakota in Iowa.

    -Float Planes were definitely used to spot shot fall until Radar took over. Unfortunately for USN Floatplane pilots their job was made obsolete basically by the time the US entered WWII. The USN had been toying with radar since the mid 1930's for fire control and had radar accurate enough to track main battery shell splashes by Pearl Harbor and by the end of the war it was accurate enough to not only track the large caliber shell splashes but the small ones and with enough accuracy to correct each battery's fire. Many captains demanded that their floatplanes be removed as they created substantial fire risk on board and the aviation fuel storage could be used for other purposes like storage of more AA ammo! :D

    -An Iowa Class Battleship, ignoring the cost and manpower requirements to do so, would only have one real threat on the modern battlefield: Submarines. That threat has always existed but the Iowa's torpedo protection system was designed for direct impact torpedoes launched shallow enough to hit the side of the ship, not the modern torps designed to detonate under the keel. Nuclear weapons have a near zero chance of being used on a battlefield because of the high probability of world wide destruction following their use. Modern missiles are designed to punch the thin hulls of modern destroyers, cruisers, and aircraft carriers. Guided bombs from aircraft are a threat but the fall back here is that your battleship's AA also includes an extensive battery of surface to air missiles and your battlegroup consisted of plenty more ships with them too. Getting close enough to use a guided AP bomb would be difficult.

    -Sub-munitions (Sabot rounds) would extend the usable range of an Iowa Class to absolutely fantastical ranges with relatively low cost but it'd require more testing than has currently been done. The US did play with Saboted 8" rounds in the 16" guns but gave up on it rather quickly.

    -The best a modern missile could hope to achieve against an Iowa class battleship is a mission kill and not a full on sinking of the ship. Keep in mind these ships have 12.1" of belt armor backed with .65" of STS armor steel and there is an 1.5" STS armor steel outer hull over all the critical machinery spaces. The Decks are multiple layers of thick armor. 0.75" of STS weather deck with 4.75" of Class B Armor steel and 1.25" of STS a deck below that and 0.65" of STS splinter protection a deck below the main armored deck. If you think a anti-ship missile designed for modern carriers, cruisers, and destroyers is going to do anything to that much armor you are high as a kite! That's not to say you couldn't kill a lot of people or cause serious damage to the combat systems (radar, directors, etc) but you would not sink the ship. The biggest threat to an Iowa today is a submarine.

    -The delay in salvo firing of the main guns wasn't to prevent shells from impacting each other but to prevent the blast from the adjacent barrels from impacting the flight of that barrel's shell and moving it slightly. As we all know, small movements at the barrel make huge impacts on target and blast from adjacent barrels fired simultaneously made some very inaccurate shots. FWIW, this is entirely unnecessary as the North Carolinas, South Dakota's, and Iowa's were all three-gun turrets and could fire, elevate, and load independently of the other barrels. This meant your salvo could have significant delays either built in or caused by crew fatigue to minimize this effect. In fact the Mark 7's gun page on Nav Weaps talks about the 1980's dispersion testing firing single barrels only.


    As an unrelated note, does anyone have a source for the picture in the OP? I've been looking long and hard for a number of technical details, including shot cards from accuracy testing, of the Iowa's. I'm also looking for details pertaining to her handling characteristics (most notably the tactical diameter/turning radius at various speeds).
     
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  9. Bart B.

    Bart B. Member

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    Vertical stringing is a right angles to range and deflection (both horizontal) stringing that's used for naval gunfire battle damage assessment. Nobody used vertical I know of.

    From "Battle Line"

    Salvo fire was easy to make spots with and the turrets left-right-center firing order centered the three-shot "group" on the turret's gun train order in the deck plane (B'gr, the computer calculated train order "Bearing, prime, gun, relative" in the deck plane clockwise from the bow). Random firing of turret guns ain't good for accuracy and spotting fall of shot.
     
    Last edited: Feb 7, 2017
  10. Whiskey11

    Whiskey11 Member

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    I was more or less examining the reasons why it exists in contrast to whether or not it's measurement necessarily mattered. It was very difficult to control for and even in the 1980's the DOPPLER units were more for getting an accurate measurement of the velocity of the shells for ranging purposes instead of trying to get the velocity exact (since there was no way to tweak the velocity).
     
  11. lysanderxiii

    lysanderxiii Member

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    Interesting bit of trivia:

    The German 38cm /L52, SK C/34 guns used on the Bismarck and Tirpitz, had a horizontal sliding wedge breech and a brass cartridge case.

    In fact, the Germans like the idea of brass cartridge cases in the big naval guns, most all of the main guns in their battleships and battle cruisers had brass cases since WW1.

    The loading sequence was projectile, a cloth propellant bag then the brass case.

    Why they did this is a good question.

    It is often stated that these cartridge-loaded guns were faster firing that the bag-gun of the British and American, however, the ability of the ammunition hoist limited the rate of fire to that of the bag gun, to one round every 26 seconds, not a significant improvement over the 2 rounds per minute of regular bag guns. Further, in combat the maximum rate of fire was rarely used, in the engagement with the HMS Hood and HMS Prince of Wales, the Bismarck fired at a rate less than 1 round per minute.

    The second reason often cited is for safety in that the fire resistance of a few hundred pounds of propellant inside a brass case is a lot better than the same in a silk bag. The thing here is that a cloth bag charge always accompanies the cased charge, up the hoist and into the gun pit. A conflagration of about 2/3 the propelling charge from the bag only would still destroy the gun pit.

    It did simplify the manufacturing of the breech, as a sliding wedge is easier to make than an interrupted screw, but the weight and size penalty was very big:

    [​IMG]

    The dark square on the side is the breech block, it slides to the right to open. Everything aft of that square is extra compared to an interrupted screw breech gun.

    Oh, and one other thing about battleships and there demise...

    Their cost did play a factor in their demise, as it had risen to such a height and their vulnerability to each other and cheaper threats, like destroyer launched torpedoes or mines was so great, that navies were hesitant to actually use them. many argue that they had become obsolete before World War 1 due to their high cost, and long construction time.

    After the Battle of Jutland the German High seas Fleet never left port, similarly the British Grand Fleet sat in anchor for the remainder of the war. In fact, the main driving thought behind both sides thinking and tactics during the Battle of Jutland was to avoid damage to the fleet. Normally, in combat one tries to avoid losing equipment, and/or men, but some loses are deemed acceptable to assure victory, however, during the Battle of Jutland a draw (either tactical for the British, or strategic for the Germans), with minimal losses to the fleet was preferable to outright destruction of the enemy fleet with high losses.

    In a similar vein the entire Gallipoli campaign was brought about because the battleships were far to vulnerable in the restricted waters of the Dardanelles to mines and shore based artillery.

    The Germans used capital ships very sparingly against the Russian convoys, even though the threat of air attack was limited due to weather, because even the best outcome of a one-on-one battleship action would result in heavy and expensive damage.
     
  12. Hangingrock

    Hangingrock Member

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    Having been the recipient of naval gun fire support and field artillery fire support. Beggar's can't be choosers, but I'd opt for the 155mm field artillery howitzer support as opposed to 5inch naval support. Best of all in my experience was the 8-inch howitzer. The 155mm gun had range but accuracy suffered at maximum range limits. The Army 176mm had range but it was an area destruction weapon as opposed to pin point accuracy. For volume of fire within its range limits the 105mm howitzer. 3rd Bn-12th Mar fired in excess of two thousand rounds during operation Starlite August of 1965 Viet-Nam. If you want to know what close support is, its when the concussion hits your body while hugging mother earth.
     
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  13. Steel Horse Rider

    Steel Horse Rider Member

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    What I know of the Iowa and the Korean War is that an old farmer neighbor of ours was in the army in Korea and he told us once that the best sound he ever heard was the Iowa's shells flying overhead when they were being evacuated when the ChiComs were pushing them back to the sea. I am sure he was not concerned about the cost per shot or the relative lack of accuracy in MOA....
     
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  14. Bart B.

    Bart B. Member

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    Yes, there is a way to control velocity.

    New Jersey's turret 2 captain in the late 1960's was a Chief Gunners Mate who also was on the USN Rifle Team as a coach and shooter. He told Jersey's Gunnery Officer he would have his turret crew take different amounts of powder out of those 110 pound bags to find the charge weight for best accuracy; exactly like he did hand loading 30 caliber loads for 1000 yard match rifles. 16" barrels with more bore erosion would have a few more pounds/ounces of powder in bags marked for them. He had a modified USN RifleTeam logo painted on the turret's control room bulkhead labeled "US Navy Very Long Range Rifle Team."

    Probably not an official way.
     
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  15. lysanderxiii

    lysanderxiii Member

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    Two - the USS Oklahoma was deemed a total loss after a thorough survey was taken after righting her, that's why they decommissioned her and sold her to a scrapyard in 1944.

    The Bismarck, in 1940, had a better AAA compliment than any of the capital ships in Pearl Harbor, in 1941.

    The reason there were no major battleship actions in 1942 was because the US had few battleships to take into action.

    And, those same carrier duels showed how vulnerable the carrier was to other carriers. Most people don't realize just how dire things were, even in late 1942 to mid 1943, six months to a year after the Battle of Midway. From late October to December 1942 the US Navy had only one operational carrier in the Pacific, and that one still had unrepaired damage from an air attack that occurred three months ago. From January to May 1943, there were only two operational carriers.

    You are assuming the missile is going to make a side attack. Further, you are assuming that if there still were battleships in service, missile design would not be tailored to attack them, but just continue to use the methods employed against lighter destroyers and larger destroyers (current US cruisers aren't really cruisers, they are built on destroyer type hulls).

    A more likely attack for a missile against a battleship would be a pop-up, then plunging attack with a dedicated AP warhead, or a last minute sub-surface attack.
     
    Last edited: Feb 7, 2017
  16. Bart B.

    Bart B. Member

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    Read years ago that Bismark's solution time on their fire control systems were 2 to 3 times longer than British and American systems. But their end result was more precise. The article's author believed "He who shoots first shoots best."

    Accuracy for USN ship's big guns for short bombardment was improved by manual inputs to rangekeepers for target course and speed. Own ship's course and speed was set to zero then target speed was set the same as ships's speed (usually less than 5 knots." Target course was set in 180 degrees from own ships course. Target's future range and bearing was calculated by ship's navigators. They would tell the plotting room rangekeeper operators "On my mark, the target will bear 136 degrees, range 23,550 yards . . . . . . standby. . Mark!" Rangekeeper operators would note the calculated target bearing and range then make corrections to target course and speed inputs. A minute or two later this would repeat. When the rangekeeper's predictions matched actual values, "Plot set!" Was reported to battery control who then gave the load and shoot commands.

    Then the turret selected to shoot the first "spotter" would be told by the man at the firing keys: "One round, high capacity, fuse quick, full charge; load and be ready." When the turret crew did so, the turret captain told main battery plot: "Turret ready." The order "Shoot!" went to the man at those firing keys who then closed the salvo warning key twice in quick succession followed two seconds later by closing the firing key.

    Five seconds before the projectile was calculated to hit, the Shore Fire Control Party would be radioed "standby" then "splash" at impact time. Spot correction followed then the whole scenario was repeated.

    https://www.google.com/search?q=bat...8&hl=en-us&client=safari#imgrc=-lc6wtnOG14DBM:

    https://www.google.com/search?q=mk8+rangekeeper+pictures&client=safari&hl=en-us&prmd=imsvn&tbm=isch&tbo=u&source=univ&fir=an8GICJc-nO1cM%3A%2Cy-5kfPcofFIl6M%2C_%3BvGsTiJuxIxUWRM%3A%2C0OXStIDJrUIu2M%2C_%3BTB0qLwPNjIfoeM%3A%2CBpdCKOjeci3fTM%2C_%3BtvqNwFxXM4FV7M%3A%2CHjc8KnjsJ4h8eM%2C_%3BBZrExBpE0d0LxM%3A%2C0OXStIDJrUIu2M%2C_%3BT6O_GJLZjsPtoM%3A%2CU-IC1JEBl6xWmM%2C_%3ByEa_4IBBcPOGFM%3A%2CHjc8KnjsJ4h8eM%2C_%3B-lc6wtnOG14DBM%3A%2CL_Qz5YiSmnUP9M%2C_%3B05FvZ8GCJ3xbCM%3A%2CG49mhkw0HO4s0M%2C_%3BPrJiBZxL8Asx9M%3A%2CG49mhkw0HO4s0M%2C_%3BhEOQTSWiCTs5lM%3A%2CdY0md0WjY7905M%2C_%3Bih0YAmJSLvLfvM%3A%2CuzNxbE2-3Qhb6M%2C_%3BNLXAxDNQrudoxM%3A%2Cuq4eXUUjZ26HvM%2C_&usg=__wcfvBRNa4aS8s8I72NW1-Rnjojg=&sa=X&ved=0ahUKEwj_mOqJvoDSAhVW82MKHdGEDxcQ7AkIOA&biw=1024&bih=671#imgrc=vGsTiJuxIxUWRM:
     
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  17. Merle1

    Merle1 Member

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    During Viet Nam there was a minor change, at least in the destroyer world. Same procedure, but the final call was "STANDBY, OUT"
     
  18. Bart B.

    Bart B. Member

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    I was told that "standby ..... out." came about be as some ground force general asked the naval force admiral to say that because navy projectiles don't "splash" going into earth. They go "out" of sight burrowing in dirt before exploding. So the Navy complied. Agreement on inter service terminology is critical in combat.

    Now that you mention it, that may be what the two destroyers I served on did. My mind was set on surface target engagements wherein big bullets really do "splash" in the ocean. My memory's dropped to 99% since the late 1950's. ;)
     
  19. BrocLuno

    BrocLuno Member

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    I just know I do not want to be downrange within a mile of the impact zone ...
     
    Merle1 likes this.
  20. lysanderxiii

    lysanderxiii Member

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    No.

    "Standby . . . out" is broadcast by the FDC, and it means the shell is going to impact in about 5 to 10 seconds, as the time of flight was calculated. It is broadcast so the FO isn't scratching his ass or swatting a fly when the projectile impacts and he knows he'd better get his binoculars up to his eyes and watch the target. Figuring out how close an airburst is to the target for range and deflection corrections means you have to see it go off, even with fuse-quick, you need to should see the impact for accurate corrections.

    "Splash . . . out" is broadcast to the FO at the calculated end of the time of flight of the projectile so the FO can confirm that the saw the impact, and so the intended spotter round is not confused with anything else that might be exploding in the area (in combat, not uncommon). If he does not confirm the impact that means the impact was outside his field of vision and someone really screwed up the firing calculations.
     
    Last edited: Feb 8, 2017
  21. Bart B.

    Bart B. Member

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    What's "FDC" as I don't recollect that being used aboard ships?
     
  22. lysanderxiii

    lysanderxiii Member

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    The main range finder for the main battery of the Bismarck was a 10 meter base stereoscopic rangefinder with 50X magnification.

    The US main battery directors for the North Carolina, South Dakota and Iowa classes used the 26.5 foot (8.08 meter) base rangefinder, I am not sure what the magnification was in the Mark 45 rangefinder.

    They were longer but not anything like 2 to 3 times.

    The major problem with the German stereoscopic rangefinders was they require intensive training for the operators and were physically tiring to operate, due to eye-strain. The coincident rangefinders used by the British and Americans were extremely accurate at shorter ranges, and less exhausting for the operators, but had difficulty in poor lighting or smoke. Nothing is perfect.

    What this senario is actually doing is aligning a gyroscope to the target course and speed. When "mark" is announced the main director is supposed to track the target keeping the crosshairs centered, and continually dialing in the changing range, either manually from the optical rangefinder or automatically from the radar. The slew rates on the director turret feed the angular rate to the computer, and the range wheel fed the rate of range change. From these two feeds the computer would calculate the target's projected location as long as it did not change course.* Although, as long as the director tracked the target and the correct range was continually fed into the computer, it would re-compute the predicted course and speed. With the target's speed and course predicted, the firing solution was finalized with the ship's course and speed known, as well as all the other atmospheric variables. [ship-to-ship action, for shore fire, the target does move so the solution is simpler, but continued used of these protocols allows for better accuracy as it accounts for the movement of the ship due to currents and the like.]

    Amazingly, enough the same system, in much smaller scale and without range inputs, was used with the Mark 51 gun directors for the 40mm Bofors. The director operator would continually track the target, and the system would continually aim the guns for a proper lead. The Mark 51 could also direct a 5 inch battery in AAA work

    __________________________
    *One reason the the Yamashiro was hit with the first salvo from the West Virginia, the Yamashiro maintained a steady course and speed up the strait, oblivious to the fact she was being ranged by several US battleships.
     
    Last edited: Feb 8, 2017
  23. lysanderxiii

    lysanderxiii Member

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    FDC "Fire Direction Center", the field artillery term for a battleship's Gun Fire Control Center.

    Naval gunfire support uses the same radio protocols as field artillery.
     
  24. Acera

    Acera Member

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    From this site regarding the Iowas......................not the directors I know, but what was on the turrets.
    http://www.navweaps.com/Weapons/WNUS_16-50_mk7.php




    .
     
  25. Bart B.

    Bart B. Member

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    My first destroyer had two MK 63 systems using MK34 radars with antennas on quad 40mm's feeding range and range rate to the lead computing MK 29 gunsights on MK 51 directors. Radar rooms were under the quad 40's on each side.

    A twin 40 and a MK 15 gunsight was centered atop the aft upper deck between 5" mounts 53 and 54.

    I operated both for several months.
     
    Last edited: Feb 8, 2017
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