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16-in Guns vs Hard Targets : A Reality Check
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Originally posted by SteaminDemon View PostWell, the NRAC chart is from the rail gun folks. The 24.9 is based on the actual energy content of the explosive used for ERGM which is 92.5% HMX.
I think NOT.
Originally posted by SteaminDemon View PostDidn't know old Mickey got his degree in physics.
Originally posted by SteaminDemon View PostWell, the above numbers equate to *far greater*.
Originally posted by SteaminDemon View PostWell, you have many more google links than I.
What are your sources ?
Originally posted by SteaminDemon View PostThanks to zen again.
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Originally posted by SteaminDemon View PostI'll be back to respond another time though
Originally posted by SteaminDemon View PostI am going to go enjoy my fourth of July. Have a Happy fourth of July.
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Vietnam vs Korea : Relative Effectiveness of 16-inch vs 5-inch
Relative Effectiveness of 16-inch rounds compared to 5-inch (assuming probability of a hit is independent of range) :
Korea (average, all targets) :
* 5-inch (38-cal) : 1
* 16-inch : 1.79
Vietnam (average, all targets) :
* 5-inch (38-cal) : 1
* 16-inch : 3.60
Relative Effectiveness of 16-inch rounds compared to 5-inch (assuming probability of a hit is inversely proportional to square of range) :
Korea (average, all targets) :
* 5-inch (54-cal) : 1
* 16-inch : 9.80
Vietnam (average, targets = bunkers + area + interdiction, i.e. 73.5% of total 16" ammunition expanded) :
* 5-inch (54-cal) : 1
* 16-inch : 9.84
Sources : see post #34
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What's wrong with Mickey Mouse Law of Physics...
Originally posted by SteaminDemon View Post16" Mk-13 HC:
Available chemical energy 154.8 LB, 3,789 Joules per gram for explosive D = 264,334,584 Joules. At maximum range @ 1552 FPS it gives the projectile 96,452,984 Joules of kinetic energy. Total energy (both chemical and kinetic) at the target is about 361 MJ
1. 16" Mark-13 HC
Kinetic Energy :
Per OEG Study 506, the average range for 16" missions in Korea for the period considered was 22,700 yards.
At 22,700 yards, striking velocity for the Mark-13 HC projectile is 1,519 fps, i.e. 463 mps (with IV = 2,690 fps).
The mass of the Mark-13 HC projectile is 1,900 lbs, i.e. 862 kg.
Kinetic energy is therefore equal to : 1/2 * 862 * 463^2 = 92 MJ
Chemical Energy
Bursting charge for the Mark-13 HC is 154 lbs, explosive D.
Assuming 3,789 Joules per gram for explosive D, this yields a chemical energy of 264 MJ.
2. 5" Mark-35 AAC
Kinetic Energy :
Per OEG Study 506, the average range for 5" missions in Korea for the period considered was 9,700 yards.
At 9,700 yards, striking velocity for the Mark-35 AAC projectile is 965 fps, i.e. 294 mps (with IV = 2,500 fps).
The mass of the Mark-35 AAC projectile is 55.18 lbs, i.e. 25 kg.
Kinetic energy is therefore equal to : 1/2 * 25 * 294^2 = 1 MJ
Chemical Energy
Bursting charge for the Mark-35 AAC with PD fuze is 7.55 lbs, explosive D.
Assuming 3,789 Joules per gram for explosive D, this yields a chemical energy of 13 MJ.
3. Mickey Mouse Laws of Physics
Based on Mickey Mouse Laws of Physics, total energy (both chemical and kinetic) at the target is :
* 92 + 264 = 356 MJ for the 16" Mark-13 HC
* 1 + 13 = 14 MJ for the 5" Mark-35 AAC
Mickey Mouse is therefore tempted to conclude that relative effectiveness of 16-inch rounds compared to 5-inch is ~25:1.
4. Reality Check
Per OEG Study 506, relative effectiveness of 16-inch rounds compared to 5-inch is somewhere between ~2:1 (assuming probability of a hit is independent of range) and ~10:1 (assuming probability of a hit is inversely proportional to square of range).
IOW 2.5 to 12.5 times less than what Mickey Mouse Laws of Physics predict.
5. Conclusion
Mickey Mouse Laws of Physics...Last edited by Shipwreck; 04 Jul 08,, 23:42.
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Originally posted by Shipwreck View PostDon't feel obliged to respond (especially if you've got nothing interesting to say )...
Happy 4th to you. :)
I had more graphs, and other info but lost them between computers (virus on old comp). I am no weapons expert, someone like Mr. Okum is and would be able to explain these things way better than I. However, keep on posting, just not one sided. You have not posted one thing about the lack of effectiveness of the 5" or 8" at all, and there are reports that explain that which I am sure you have;).
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Bunkers in Vietnam : 16-inch vs 8-inch vs 5-inch
Data for Target Type = BUNKERS
Basis = Successful Missions
Relative Effectiveness of 16-inch rounds compared to 5-inch (assuming probability of a hit is independent of range) :
* 5"/54 : 1
* 8"/55 : 1.35
* 16"/50 : 2.63
Relative Effectiveness of 16-inch rounds compared to 5-inch (assuming probability of a hit is inversely proportional to square of range) :
* 5"/54 : 1
* 8"/55 : 1.61
* 16"/50 : 6.08
Source : see post #34Last edited by Shipwreck; 09 Jul 08,, 23:30.
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Erratum
Originally posted by Shipwreck View PostRelative Effectiveness of 16-inch rounds compared to 5-inch (assuming probability of a hit is independent of range) :
Korea (average, all targets) :
* 5-inch (38-cal) : 1
* 16-inch : 1.79
Vietnam (average, all targets) :
* 5-inch (38-cal) : 1
* 16-inch : 3.60
Relative Effectiveness of 16-inch rounds compared to 5-inch (assuming probability of a hit is inversely proportional to square of range) :
Korea (average, all targets) :
* 5-inch (54-cal) : 1
* 16-inch : 9.80
Vietnam (average, targets = bunkers + area + interdiction, i.e. 73.5% of total 16" ammunition expanded) :
* 5-inch (54-cal) : 1
* 16-inch : 9.84
Sources : see post #34
Data for Vietnam = 5-inch (54-cal)
Sorry for the typo in original post.
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Bombardment of Brest, 24 August 1944
Battleship Warspite by V.E. Tarrant :
During August 1944, the Americans were investing a powerful force of 40,000 German troops which wa cut off and squeezed up in the tip of the Brest peninsula.
The lynch-pin of their defenses was a girdle of old French forts dating from the time of Louis XIV (1774-93) and casemates armed with heavy guns.
In the confined space of the peninsula, the Americans could not take these fortifications, which commanded all land approaches, except at a heavy cost in casualties.
Warspite, therefore, was called upon to silence them with her 15-inch guns.Attached FilesLast edited by Shipwreck; 19 Sep 08,, 23:20.
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Bombardment of Brest, 24 August 1944 - Targets
Battleship Warspite by V.E. Tarrant :
The control station ashore gave five targets to be engaged; fifty rounds to be fired on each in thirty minutes. Firing to be completed in 2.5 hours, before the assault by the attacking troops commenced.
Target #1 : Keringar 11-inch gun battery (called Graf Spee by the Germans). Target was found with four ranging salvoes. Spotting aircraft reported near misses on all gun turrets. Fifty-seven rounds expended.
Target #2 : Les Rospects 6-inch gun battery in casemates. Range 29,000 yards. Eight salvoes were fired before firing for effect. All salvoes after the fifth were in the target area. Twenty-two salvoes were fired - 47 rounds expended.
Target #3 : Toulbroch Fort, including two batteries running 1,000 yards to the west. Range 32,000 yards. Target was found with two salvoes. Eleven salvoes were fired - 32 rounds expended.
Target #4 : Minou Fort. Range 31,000 yards. Target was found in three salvoes. Several salvoes were not seen owing to smoke and dust over target area. Eighteen salvos were fired - 51 rounds expended.
Target #5 : Montbarey Fort. Range 32,000 yards. Target was found in four salvoes - 26 rounds expended.
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Bombardment of Brest, 24 August 1944 - Keringar
Keringar Battery (aka MKB Graf Spee of 5/MAA 262) in Lochrist near Brest was armed with 11-inch SK L/40 naval guns.
Originally built for the Braunschweig and Deutschland pre-dreadnoughts, the SK L/40 used as coast defense gun fired a 626-lb projectile to a maximum range of 30,250 yards.
Three of the four guns were in open pits, and only one in a large casemate shown in the pics below :
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Bombardment of Brest, 24 August 1944 - Targets
Top to Bottom :
1. & 2. : Les Rospects
3., 4. & 5. : Toulbroch
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Bombardment of Brest, 24 August 1944 - Results
Battleship Warspite by V.E. Tarrant :
It was while Warspite was engaging Montbarey Fort, that the control station ashore made the signal at 17:45 : "Afraid your time is up, cease fire".
Simultaneously with the receipt of this signal, came the first reply by enemy. Huge fountains of sea-water rose near Warspite from 11-inch shells falling short, fired by the Keringar battery.
Ten salvoes were fired at Warspite, three of which fell so close on the starboard bow and beam, that splinters from the shells hit the funnel, motor-cutter and starboard HA director.
(...)
In total, Warspite had fired 213 high-explosive and armour-piercing shells. Results were disappointing. Although one of the forts and a few of the batteries were silenced, others survived practically intact, and were able to put up a stiff resistance to the attacking troops.
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