A)I used the practical rate of fire for both weapons, and actually reduced the 4.7in to 10 rpm from 12 and used 12 rpm for the early mods of the 5in/38. Again, I ask you to produce evidence that RN RoF was 1/2 of what navweaps and Campbell state. The data from HMS Basylisk ( 5 rounds in 17 seconds for a 4.7in single mount) and Scylla (16rpm), suggest that the RN maximum RoF was much higher then 10-12 rpm.
No, you have not. according to Terry Giulan (In an essay dated 2009, entitled "The British High Angle Control System", reproduced in NW, but not where i found it), he provides a clue on the differencews between cyclic rate (or as I call it max rof), and max sustained rof (which I and some others refer to as practical rof). He says:
"
Almost all destroyers with 4.7-inch guns had the HE time fuzes set by hand. This affected the firing solution not only by the time setting itself, but also in that the fuze setter became the critical time factor. No matter how fast the guns could fire or how quickly ammunition could be supplied to the mountings, even a well-trained fuze setter needed about 4 to 5 seconds to handle the round and set the fuze properly. Faster speeds invariably resulted in improper fuze settings and loss of effectiveness. These factors encouraged the use of barrage firing as it meant that all fuzes were set the same, thus requiring less time by the manual fuze setters.11 Most larger ships used fuze setting machines, but all of these could only handle one round per barrel at a time, thus slowing the practical rate of fire. An interesting but unfortunate side effect of these fuze setting systems was that the "dead time" between the point that the shell left the fuze setting machine and the point it was fired out the gun needed to be calculated based upon the slowest gun crew on the ship. As the guns were fired by remote control, this effectively meant that all salvos had but a single time setting. Again, this slowed the practical rate of fire".
On top of that, the redesignof the mounting itself wqas not conducive to fast loading. In a static situation, with the gun not moving, I have no problem in accepting 10-12 rpm. But in a real combat situation you have two major constraints that are not present for the 5/38. Firstly you have this manual fuze setting, which at minimum adds 4-5secs to the theoretical max rof. Then you have the poor design of the turret. relative to the gunner, the ammunition supply point was fixed, making it easy to become disoriented. For the single mounts you had a further complication, the hand ramming.
If the theoretical max rof was 12rpm, or 5 secs, you must then add 5 secs for the manual fuze setting and then some unknown time for the turret issues....say 2 secs per round. That reduces the practical rof for the 4.7 down to about 6 rpjm, or more approximately 4-8, which is a better way of describing it, gieven the variable human factors at work.
Now, neither of those constraints affects the Mk 30 5/38 turret. So its practical rof fire is going to be much closer to the max rof. The max rof is not 12rpm for the mk 30, as you are still saying....its 24 rpm. But the practical rof is somewhere between 15-22 rpm. I suspect the director issues you mentioned are the main cause for this downgrading in efficiency. but a more realistic comparison, if we want to use practical rofs, is to estimate the 4.7 at 4-8 rpm, and the 5/38 at 15-22 rpm.
Navweaps repeats (anecdotal?) evidence for very high RoF's with the later variants of the 5in/38 but doesn't do the same for RN weapons - clear evidence of bias.
no. Clear evidence that they have supporting material to inidicate lower standard of efficiency for the 4.7, in comparison to the 5/38. this is not a popularity or political excercise. i think it an excercise in trying to give an accurate assessment of true capabilities of each gun, taking into account various hidden factors. .
This bias extends to the AA FC systems where the USN is praised to high heaven, with no mention of the serious flaws and drawbacks of USN AA FC that have been scientifically documented while the RN system is condemned and every supposed flaw emphasized - another clear example of bias. In actual fact both systems were flawed, as you would expect from 1930s technology, but you'd never know that from the Navweaps site
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The operational results that we have dont support that claim. US destroyers seem to have been more survivable and achieved overall more efficient standard of fleet and unit protection with their weapons than the RN was able to achieve. There may be good mitigating circumstances for that, but given the FC system is so critical to getting decent results I think it entirely reasonable for NW to take the position they do. Others can perhaps explain the technical side better than I, but the operational results speak to me better than any theoretical technical analysis. the USN destroyers did better than the RN destroyers. Its as simple as that.
Here's what Captain Gatch had to say about the relative effectiveness of 5in/38 versus CIWS kill rates:
Now remember that it was RN Tribal-JKLMN destroyers that had the much heavier CIWS as built, and that is what they went to war with.
The higher standard of CIWs was theoretical rather than actual, but was more or less forced on the RN because of the failure of their 4.7s as a true DP weapon. I say the CIWs were theoretical because really if we are talking British CIWs we are talking 2 pounder guns. these lacked satisfactory performance to be really held up as good or efficient. No tracer, effective range of about 1700m (according to the RN) too many stoppages no relaiable explosive shell. All adds up to an inneffective CIW. So, whereas the USN entered the war with at least a good and true DP main, the RN went to war with neither a good DP main, or a decent CIW either.
I'm sorry if I got a bit hot on this one. The problem is that there is clear evidence of bias on the Navweaps site against the RN with an editorial lead-in on virtually every RN weapon telling the reader how bad it was before he/she even gets to the actual data! I used 10rpm for the RN 4.7in (April 1940 twin mount)and 12rpm for the USN 5in/38 (April 1940 single mounts without integral hoists) and these RoFs are supported by actual combat data. If you read Crenshaw's account about USS Maury you will also read about the numerous problems that they had with their 5in FC, guns, and ammunition yet these kinds of cmments don't show up on Navweaps - and I ask you again why not?
No need to apologise. its allo good. we are still rexchanging information and not insults. Dont agree that NW has much bias, for reasons already given. You are looking at the 5/38 without integral hoists, which makes a huge difference. Its pronbaly no exaggeration to say that more than 80% of 5/38 mounts built were mk 30 hoists with integral hoists. I think it far more relavant to the topic to look at the typical or prevalent type rather than pick an islated or minority failure. and as ive tried to show previously, 10 rpm for the 4.7 is not a realistic estimate of the real rof for this weapon
No one, including me, is saying that 40deg elevation is perfect, but the RN report on Norway states quite clearly that the vast majority of attacks had to come within the envelope of a 40deg gun. Very high level attacks had very little probability of hiting anything anyways - witness Vian's 5knot convoy! and even the Stuka attacks achieved much of what they did beceause they were not engaged at all, not even by the CIWS, and having 5in/38 guns wouldn't change that. Additionally, the RN had a large number of sloops and cruisers that could fire above 70 degs and these were often in company with the 40deg destroyers.
The report you posted does not say what you are claimimg for it. It say, essentially, that those types of attacks that fitted within the envelope they specified, could be countered. It goes on to say, virtually, that in other situations....panic, because you will not be able to hit anything with the equipment we have given you. You cannot make any claims about the 5/38 because it was not engaged in Norway. We need to keep opinion out of the way of known facts.
Well Torpedo bombers are the one type that we all agree that the 40deg elevation guns would have no problem engaging.
Nope, dont agree. Previously posted why, due to slow training rates and rofs, and the short range of the ciws, could not be effectively engaged in many situations. Lucky for the RN, the Germans were even more remiss in not having an effective air launched torp until later in the war.
The Stuka certainly did not operate at 5-6000m! Typically altitudes were 3000-4000m prior to their dive.
I dont know that we can nail a typical approach altide too well. Even at 3-4000 m there would be difficulties for the RN. but even if it was possible, the option was there for the LW simply to fly above the effective ceiling of the gun
j
Illustrious's AA ammo was fired over many days, and the two Stuka kills were made during the first attack.
Regardless, they exopended huge amounts of ammunition for virtually no gain. In any even, wiki suggests thats not the case.....they say that 30000 rounds were expended in the 1st attack. if youve got better, would be great to see it.
Gotta run - more later.[/QUOTE]