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About Murotsu

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  1. This covers the most common Blakely in CSA use: http://www.civilwarwiki.net/wiki/12_pdr._Blakely_Rifle http://www.robinsonsbattery.org/79215.html http://vcwsg.com/PDF Files/Artillery Civil War.pdf http://www.thomaslegion.net/americancivilwar/civilwarartillerycannonweapons.html
  2. The Blakely guns are more problematic. There are several different sizes from 12 pdr up that the Confederates used in very small numbers. The ammunition was either imported, and of several different designs, or made locally by Southern manufacturers. This results in a very wide variety of shot (bolts) and shell being used with these guns. The Blakely's themselves also vary considerably in design. The most famous Confederate Blakely is probably the "Widow Blakely" a 7.5" heavy artillery piece who's barrel was cut down in length after the muzzle split during firing. What Blakely's did make it to the Confederacy were almost all field pieces or used in fortifications, not on ships.
  3. Exactly. The report shows contradictions between observed and actual weapon performance and what those interviewed were claiming. 800 meters is a very short range for AA fire. An ground attack aircraft using rockets or cannon is likely already opening fire on its target at that range. A dive bomber would have already released their ordinance. So, that means the AA gun at best is getting revenge not effectively stopping the attack. Even a torpedo plane would release beyond 800 meters from a ship target. There is sufficient dubiousness in those claims that they should likely be disregarded.
  4. That's what I meant by Japanese claims seem like puffing. When everybody else's heavy AA guns were taking 300 to 600 + rounds to bring a plane down the Japanese were claiming 125. That's nonsense. It's likely the gun crew / officer in charge wanted to look good and made a ridiculously low number up. AA gun fire effectiveness is combination of accuracy of the weapon combined with the number of rounds fired on a target. The better the accuracy and the larger the number of rounds fired, the higher the probability you will shoot down the target. Holding your fire as suggested in the report only means when you do finally open fire you shoot fewer rounds against a target before it completes its attack. The fire controls don't get more accurate because you hold fire. If anything, they are less accurate because you start later with the same initial accuracy and as you fire your predictions can improve based on observed results and tracking data you aren't getting just keeping the plane in the gun sight.
  5. So claimed the Japanese. I doubt that worked out anywhere near as effectively as they claimed. One need only look at the US data to see that there is no way that a triple 25mm could be as effective as the Japanese claimed it was. I'd put that as mere puffing and take it with a mountain of salt.
  6. That report really doesn't tell us much. But aside from that, it isn't the gun alone here that matters, it's the overall system. That is, the gun, the loading and ammunition arrangements, the fire controls (or lack thereof), type of ammunition used, etc. If any part of that is mediocre, the system will suffer as a result. That's why I will stick to a rough assertion that Japanese AA systems were far less effective than their USN counterparts. It isn't that the Japanese were stupid or didn't recognize their issues, they did. They simply didn't have the engineering, industrial, and distribution capacity to turn out better equipment in anything approaching sufficient quantity to compete. On a ship for ship basis, I'd still say that the Japanese were somewhere between 25 and 50% as effective as similar USN ships when it comes to antiaircraft firepower.
  7. But, in comparison to their closest US equivalents, they were really pretty poor weapons, particularly the 4.7" and 5" guns. These had a sustained ROF of about 8 rounds a minute. That's about half of what the US 5"/25 or 5"/38 could achieve. Their maximum theoretical rate was about two thirds of what the US guns could achieve. This is particularly true of the IJN destroyer 12.7 cm 50 cal that was theoretically dual purpose but as an AA gun really was little more than better than nothing. All of the above Japanese weapons used a manual loading tray with spring rammer or manual ramming. They all had separate fuze setting gear. This makes the loading cycle slower and the fuze settings less accurate than the US power ramming system where the fuze setter is integrated into the ramming gear and sets the fuze just before loading. So, while the Japanese might consider their 10cm "superb," it's no better than the British 4"/45 HA gun, inferior to the 4.5"/ 45, and definitely inferior to the US 5"/25 the nearest equivalent. A spring loaded rammer is not a power rammer. It uses the recoil of the gun generally to [edited] the spring and ram the next round. The British used a similar system on many of their 4.7" DD mounts. Yes, most of the Japanese mounts had electric-hydraulic power but that was solely for train and elevation, not to operate the loading cycle.
  8. You can extrapolate some idea of how effective (or ineffective) Japanese AA was by rough comparison to similar US weapons. The 25mm triple is about the same hitting power as the US 1.1". But, the Japanese gun has one less barrel, simple ring sights, and uses 15 round box magazines that seriously reduce the rate of fire. So, a rough starting point would be this mount is about one-third to half as effective as a US 1.1" mount would be. That's not so great. The 13mm machinegun would be about as effective as the US .50 M2 Browning. They're roughly analog to one and other. Again, not so useful on the whole for warships. The larger weapons are a bit more variable. Japanese gun directors are generally less sophisticated than US ones meaning these guns are less effective in that sense. All of the Japanese 4", 4.7" and 5" weapons use separate ammunition and the destroyer 5" uses bagged charges. These guns are manually rammed, rather than power rammed with a power loading tray like US ones are. They all have rates of fire of about one-half to two-thirds the US 5"/25 or 5"/38. They also have poorer fuze setting systems and use inferior shells, particularly the 3 Sanshiki shell that works like a shrapnel round using burning rubber incendiary "bullets". So, again, a rough starting point would put them at about 50% the effectiveness of their US equivalents. So, a starting point would be a Japanese destroyer would have roughly a third of the AA firepower of a similar US destroyer. Cruisers would have somewhere between a quarter and half of what a US cruiser could produce.
  9. It looks more like Leonardo Di Vinci and Galileo got to paint it while dropping acid...
  10. On South Dakota's little electrical problem... I've actually experienced that sort of thing on ships more than once, and the cause is always the same thing. On South Dakota, one of the secondary directors developed a ground fault (#3 IIRC) and the ship's electrician's went to secure power to it to eliminate the fault, which they did. The director crew, being clueless as topsiders are about things engineering, only knew they no longer had power so they switched to the alternate / emergency source and reinserted the fault. This caused a cascade failure of additional circuits. The bridge was, no doubt yelling at engineering about wth?, while the electricians tried to move through dogged watertight doors and hatches to get to the problem and reset breakers on the distribution centers that were affected, as these are not remotely operated. That took time, and while they were doing it, most of the superstructure had no electrical power... So confusion reigned.
  11. A bit late, but Theodor Krancke (Admiral), The Battleship Sheer. A good first hand account of life aboard the panzerschiffe during her "glory years." Gets a bit sketchy as the war goes on... As do many German accounts. https://www.amazon.com/Pocket-battleship-story-Admiral-Scheer/dp/B0007DV7IY I have the first edition from 1956...
  12. Hmm, whoopsie.

    Only German engineers would think it's a good idea to put the battery of a car in the trunk in a place where you have to disassemble most of that trunk to get at it and then after replacing it have to enter a security code via the car's factory stereo / radio to get it work again... (BMW).
  13. Hmm, whoopsie.

    My guess is it's the same engineers that design Mercedes and BMW's... Impossibly complex for what they do, unreliable, and too expensive to repair when they break...
  14. Like I stated, the fastest I ever saw the "prise go was just over 39 knots. That was 4 shaft torque limited, no flight ops, and the engine rooms were doing stuff like shutting down steam driven auxiliaries like fire pumps to get a little bit more steam. That was during a search for a downed pilot off San Diego on a clear day with almost no wave action. That was sitting in DC Central as Load Dispatcher for the electric plant and where you can monitor the plants and stuff like ship's speed I know in a "drag race" the battle group did the Spruance's started off in the lead but then the 'prise and the nuke cruiser dusted them after a few miles, and the cruiser left everybody else behind. That was about 38 knots for the carrier. Anything over about 25 made berthing aft uncomfortable to sleep in due to vibration and noise from the shafts and screws.
  15. The 'Pirze (aka "Mobile Chernobyl") will go quite a bit faster than the "book" value. The fastest US nuke ships were the cruisers like the Virginia class. They'd walk away from everything else. The fastest I ever saw the Enterprise do was just over 39 knots. That was torque limited on #4 shaft and steam limited on the other 3. The gas turbine ships like the Spruances could get up to speed quicker and in a "drag race" would win for the first few miles. Then the nukes all came chugging by them with the nuke cruisers leading the pack. I'd bet they could do about 42 or so knots.