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16-in Guns vs Hard Targets : A Reality Check

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  • #31
    Originally posted by Albany Rifles View Post
    All of which proves you have to get Infantrymen in there to finally take them out.
    Back then you did.

    Nowadays you need sufficiently accurate targeting (and IADS reduction) to put an LGB through the gun opening - which may still require Infantrymen on the ground to find it and lase it.

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    • #32
      Originally posted by Albany Rifles View Post
      All of which proves you have to get Infantrymen in there to finally take them out.
      Infantry Occupies.

      Artillery Conquers

      Comment


      • #33
        Originally posted by Shipwreck View Post
        Korea : (March 1951 - March 1952)

        * Average range : 22,700 yards
        * Number of missions / rounds : 391 / 4,411
        * Spotted / Unspotted (% of missions) : 75% / 25%

        Success Rates (basis = spotted missions) :
        * No success / unknown results : 6%
        * Limited results : 24%
        * Successful : 70%
        I want to point out that these numbers are not for hard targets. What the thread is about. This is rather, all 16in missions.

        And according to OEG Study 506, Characteristics of NGF Support in Korea
        60% of 16in missions were against Personnel and transportation assets.

        And Per the reference, your spotted/unspotted numbers are a percentage of rounds not missions.

        My reference has 54% of 16in missions spotted and 46% unspotted. My rounds spotted are the same as your numbers above.

        Also noted is that only 14% of observed 16in missions were spotted by a ground observer. The most accurate type of spotting. Air and ship radar comprised the rest of the "Spotted" missions. With fixed air comprising 29%
        and ship spotting being 5%.

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        • #34
          Clarifications

          Originally posted by Gun Grape View Post
          I want to point out that these numbers are not for hard targets. What the thread is about. This is rather, all 16in missions.

          And according to OEG Study 506, Characteristics of NGF Support in Korea
          60% of 16in missions were against Personnel and transportation assets.

          And Per the reference, your spotted/unspotted numbers are a percentage of rounds not missions.

          My reference has 54% of 16in missions spotted and 46% unspotted. My rounds spotted are the same as your numbers above.
          1. Mission Success Rates were posted in reply to post #27 regarding the performance of USS Missouri and USS Wisconsin during ODS and as such pertain to all 16" missions (except Vietnam).

          2. Data for Vietnam is for destruction missions only and doesn't include harassment missions. For the period considered (September 1968 - January 1969) destruction missions acounted for 73% of the total number of 16" missions and 90% of the 16" rounds fired by USS New Jersey.

          3. Main sources for the data are :

          Korea : OEG Study 506
          Vietnam : CINCPACFLT Analysis Staff Study 3-69
          ODS : Conduct of the Persian Gulf War, Final Report to Congress

          4. For the period covered in OEG Study 506, 54% of the 16" missions were spotted and 46% unspotted (rather than 75% / 25% as indicated earlier). Distribution of 16" rounds was 80% spotted, 20% unspotted (appendix E, fig. E-2).
          Last edited by Shipwreck; 24 May 08,, 23:36.

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          • #35
            Spotting

            Originally posted by Gun Grape View Post
            Also noted is that only 14% of observed 16in missions were spotted by a ground observer. The most accurate type of spotting.
            For the 16" missions in Korea and Vietnam, ground spotting didn't produce systematically higher success rates than air spotting :

            1. For Korea : OEG Study 506, Appendix E, Fig. E-7

            a) ground spotting and helicopter spotting produced the same percentage of missions assessed as satisfactory.

            b) in terms of missions assessed as satisfactory, ground and helicopter spotting produced slightly better results than other air spotting.

            2. For Vietnam : Staff Study 3-69, Paragraphs 73-79

            a) During USS New Jersey's first line period (28 Sep. 1968 - 7 Nov. 1968), 39% of the 16" missions were assessed as successful for air spotting versus 67% for ground spotting.

            b) During USS New Jersey's second (24 Nov. 1968 - 8 Dec. 1968) and third (23 Dec. 1968 - 11 Jan. 1969) line periods, 54% of the 16" missions were assessed as successful for air spotting versus 14% for ground spotting.

            c) The increased success rate for air spotting in the last two line periods probably has to do with variations in spotter aircraft used. As noted in Staff Study 3-69 (paragraph 77) :

            During the first line period, most of the air spotting missions were flown by relatively high performance jets in areas ranging from light to extremely heavy AAA coverage, whereas during the succeeding line periods, almost all air spotting air missions were flown by light aircrafts (OV-01 or OV-10) in areas relatively free from enemy AAA.
            d) The degraded success rate for ground spotting in the last two line periods probably results from changes in the spotters. As noted in Staff Study 3-69 (paragraph 79), during USS New Jersey's first line period :

            Spotting was provided by the personnel of First Anglico who were highly trained and who had given consideration prior to NEW JERSEY's first line period to selection of useful targets for this ship's main batteries.
            e) Overall, for the entire period considered (September 1968 - January 1969), it is noted in Staff Study 3-69 (paragraph 75) that :

            In the case of heavy gun missions [8"/55 and 16"/50], ground spotting was about as good as airborne spotting.
            Last edited by Shipwreck; 24 May 08,, 22:54.

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            • #36
              Originally posted by Shipwreck View Post
              For the 16" missions in Korea and Vietnam, ground spotting didn't produce systematically higher success rates than air spotting :

              I'll agree with that.

              But I will say that the reason was a more accurate assessment of damage that comes from the ground vice from a plane.

              BTDT. Aerial BDA is much harder than Eyes on the ground assessments.

              Just look at that great aerial BDA that we got in Allied Force.;)

              Comment


              • #37
                Originally posted by Gun Grape View Post
                Infantry Occupies.

                Artillery Conquers


                RIIIIGHT!
                “Loyalty to country ALWAYS. Loyalty to government, when it deserves it.”
                Mark Twain

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                • #38
                  Tarawa, November 1943

                  Originally posted by vannor View Post
                  Is, your hypothosis that Heavy gun bombbardment without H.E. is ineffective?
                  From The US Marines and Amphibious Warfare : its Theory and its Practice in the Pacific by Jeter Isely and Philip Crowl :

                  Page 233 : "Our high capacity projectiles, with super quick fuses, made a grand display but accomplished little if any real destruction of installations or personnel." (Rear Admiral Howard F. Kingman, Support Group Commander at Tarawa)

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                  • #39
                    Tarawa, November 1943

                    From The Battle for Tarawa by Capt. James Stockman, USMC, page 67 :

                    Tarawa served to reduce to proportion the exaggerated concept of what surface and air bombardment could do to a heavily fortified, concentrated target. The results came as no surprise to the landing force.

                    One of the great lessons learned about naval gunfire, as used against a target such as Betio, was the need for destruction rather than neutralization. There had not been enough preliminary preparation by naval gunfire and air bombardment.

                    Those who believed, before Tarawa, that planes and ships could destroy completely the enemy fortifications and personnel on a small coral island were quick to perceive their error.

                    Comment


                    • #40
                      Tarawa, November 1943

                      From The Battle of Tarawa : A Validation of the U.S. Marines by Professor Dirk Ballendorf, University of Guam :

                      Naval gunfire support is supposed to be a crucial element to enable the landing force to reach the shore and sustain the assault inland.

                      The Navy committed three battleships, five cruisers, and nine destroyers [see details here] to hurl 3,000 tons of shells at Betio, or about 10 tons of high explosives per acre. (Steinberg, p.108)

                      According to Morison however, "The navy badly miscalculated the amount of softening-up that could be done in a two and half hour bombardment." (Morison, pp.302-303)

                      Nimitz's limitation affected it. Joseph Alexander wrote, "Inadequate preliminary bombardment did little to destroy Japanese gun positions, leading to the preponderance of American casualties ashore, inland, well past the reef." ('Utmost Savagery', p.84)

                      It may not have mattered with the amount of additional time or more tonnage. Eric Hammel and Ronald Spector point out other mistakes which reduced the shore bombardment effectiveness.

                      Marines noticed that the shells fired by the battleships were skipping across Betio and exploding harmlessly over water on the far side. (Hammel, p.30)

                      What this meant was the ships were too close and had an incorrect angle of fire. The guns were aimed to low and flat. "Had the battleships and cruisers stood further out and lofted their shells at higher angles, there would have been ample destruction." (Hammel, p.30)

                      This may not have occurred either. "The high-explosive shells employed by the bombardment ships usually went off before penetrating the Japanese defense works, making for an impressive explosion but doing little real damage," reported Ronald Spector in 'Eagle Against the Sun'. (Spector, p.262)

                      Alexander cites critical errors in "range, deflection, trajectory, ammunition selection, and fuse settings." ('Utmost Savagery', p.114)

                      To compound the mistakes in execution there was "fateful lapse" of 25 minutes of near -total curtailment of naval gunfire during the final run in by the assault craft which permitted the enemy to shift and man the landing beaches. ('Across The Reef', p.11)

                      Joseph Alexander summed up the shore bombardment part of the amphibious doctrine employed at Tarawa, "the failure of the preliminary bombardment on D -Day to reduce substantially the Japanese strong points along the northern beaches became the most critical shortcoming of the battle." ('Utmost Savagery', p.113).
                      Last edited by Shipwreck; 27 May 08,, 20:34.

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                      • #41
                        Tarawa, November 1943

                        Japanese Defense Positions on Betio Island (Tarawa) :

                        (from a March 1944 Intelligence Bulletin available here)



                        Rear Admiral Shibasaki's Command Bunker, 1988 :



                        One of four 8" guns on Betio, 1988 :



                        Another 8" gun on Betio :

                        Last edited by Shipwreck; 27 May 08,, 21:35.

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                        • #42
                          British Monitors vs Bruges Canal, 11 May 1917

                          From Big Gun Monitors by Ian Buxton, page 86 :

                          From early February 1917, he [Rear Admiral Reginald Bacon] had been making plans to bombard the lock gates of the Bruges canal, which if damaged would seriously restrict the use of the important naval base at Bruges. (...)

                          To put the lock out of action both gates needed to be hit, as otherwise passage could be made using only one gate, which could be opened for about two hours around high water.

                          Each gate was only about 90ft x 30ft in size and invisible from the sea. Bacon calculated the chances of hitting such a target from 13 miles as one in sixty-three, but he halved the chances to allow for the difficulty of accurately laying a gun subject to all the motions of a ship.

                          About 250 rounds would thus be required to hit both main lock gates, even before any consideration could be given to the spare gate kept nearby. (...)

                          Fire was opened at 04:45 from about 26,000 yards, Soult and Terror taking the south gate as their target while Erebus took the north.

                          The first ranging shots fell short but were soon corrected, and shooting settled down to a steady 20-second rythm. Not all of the rounds could be spotted after their 54-second flight, as several did not burst, but the spotter reported hits with Soult's 12th round and Erebus' 26th. (...)

                          The flotilla then retired to Dover, feeling that a good morning's work had been done : 175 rounds fired of which Soult had contributed 51. [Erebus = 63 x 15" rounds; Terror = 61 x 15" rounds] (...)

                          Subsequent reports and aerial photographs were disappointing as they showed that, although several shells had fallen very close, 21 of them within 50 yards, no damage had been inflicted on the actual gates or pumphouses.
                          Last edited by Shipwreck; 28 May 08,, 20:36.

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                          • #43
                            British Monitors vs Bruges Canal, 11 May 1917

                            HMS Marshal Soult, HMS Erebus and HMS Terror were British monitors specifically designed during World War 1 to conduct shore bombardment missions. Each monitor had 2 x 15"/42 Mark-1 guns in a two-gun turret.

                            The HE 4crh shell fired by the 15"/42 Mark-1 guns for shore bombardment missions during World War 1 had a weight of 1,920 lbs and a bursting charge of 216.5 lbs (Lyddite).

                            For comparison purposes, the HC Mark-13 shell fired by the US 16" guns during World War 2 had a weight of 1,900 lbs and a bursting charge of 153.6 lbs (Explosive D).

                            Marshal Soult (source My Hobby Store) :
                            Attached Files
                            Last edited by Shipwreck; 27 May 08,, 23:18.

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                            • #44
                              Cratering Effectiveness (San Clemente)

                              Originally posted by Shipwreck View Post
                              2. Cratering Effectiveness

                              During the week of 27 July 1968, USS New Jersey also fired four rounds (either quick or base detonating fuzing) to obtain the dimensions of the craters produced by 16" HC projectiles.

                              The observed craters were shallow (max. depth at the center of 3 feet) and small (max. 27 x 7 feet), contrasting with the larger craters later observed in Vietnam.

                              This was probably due to the difference in soil consistency between the hard desert soil of San Clemente and the wet soil of Vietnam.
                              Source : Staff Study 3-69, Appendix D, paragraphs 4-6
                              Last edited by Shipwreck; 30 May 08,, 15:24.

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                              • #45
                                Cratering Effectiveness (Vietnam)

                                68. Spotters, during discussions of the craters produced by the 16"/50 burst [HC projectiles with PD fuse] have indicated that (...) the 16"/50 crater is comparable with the hole made by a 750-lb [GP] bomb.
                                Source : Staff Study 3-69, Appendix D, paragraph 68, page 25

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