dunmunro wrote:dunmunro wrote:
How did the system you mention above couple the range as found by the Radar to the FCS?
Type 280 and type 279 both had a precision ranging panel which transmitted the radar range AND range rate directly to the HACS table (computer) via magslips (syncro motors) with power follow-up for the range rate (radar operator would match the range rate to the target and that rate would continue to be transmitted to the table as long as the target maintained a steady course.
I guess we have different ideas about what the word precision means? Also, how timely was the transmission of the Plotting Table info, originally intended to control surface fire against ships, sent to the AA guns? When compared to late war USN equipment in wide spread use, just how effective were these two types?
Did they save PoW and Repulse? Not actually a fair question. How many planes did those two ships down before they were sunk? A better question would be how many planes did the Royal Navy shoot down in the entire war using either of those systems?
My point is that conversion of a surface FCS into a AA-FCS is very much harder than it looks from the internet of hind sight. See Frieden's tome "Principles of Naval Weapons Systems" from the Naval Institute Press, 1985.
http://en.wikipedia.org/wiki/HMS_Prince_of_Wales_(1939)
Sensors and processing systems:
Type 279 radar added
Type 284 radar added.
Radars added in May 1941.
4 x Type 282 and Type 285 radars added.
Radar added between June–July 1941.
Type 271 radar added.[/quote]
Type 279 and type 280 were accurate to about 25 yds (essentially the limit for any WW2 radar)
25 yards? acording to Wiki, the pulse width was 2-3 US indicating a maximum un ambiguos range error possible of 1.2 Kilometers? = 2 US= 600 M short or long of indicated Poss.and both were designed primarily for AA search and FC, with a secondary surface FC capability - transmission to the HACS table was instantaneous. HACS was a dedicated AA FC system. PoW and Repulse shot down more planes than the entire USN carrier task force AA at Coral Sea (according to Lundstrum), despite the fact that PoW's radars were largely U/S.
USN AA didn't save Lexington, Yorktown or Hornet...despite the large number of USN ships in the accompanying task forces. True! The USN did loose all of those ships and many more too!
Up to March 28 1941, the RN had made the following AA kill claims:
Certain kills: 234
Probable kills: 116
Damage claims: 134
Up to Dec 31 1942, the RN had made the following AA kill claims:
Total kill claims: 740.
Total probable claims: 266.
Total damage claims: 448
So in the year and 3/4 from March 1941, the RN claimed 504 AA kills. The USN initially claimed 447 AA kills up to Dec 31 1942, but in 1944 they revised these claims downward by 55% to a total of 228. Actual USN AA kills for 1942 probably amount to about 100, based post upon post war analysis.
Would you please post a link to this source datat? The initial USN claims probably even swayed many RN officers that USN FC was superior, but we now know that this wasn't the case, based upon the two navies actual AA kills, based upon post war analysis.
This is news to me. Can you provide a link to this "Post War" data source? Just where were all of these RN claims made and when?
I don't have the figures for the rest of the war, but RN AA almost certainly shot down more aircraft than the USN during 1942, using post war data to verify the kills.
Seems reasonable, but I am curious as to how and by which ships. Also, the USN was barely engaged in 1942. The USN was prone to wild overclaiming,
Absolutely true! and BuOrd made no attempt to accurately access the kill claims made by USN ships, and made AA weapon efficiency claims based upon these wildly inflated claims - for example at Santa Cruz the USN claimed 127 kills (including 26 by South Dakota) but Lundstrum's
Who is Lundstrum? assessment indicates only about 25 AA kills total for all USN ships involved. USN kill claims against Kamikazes have never been accurately tabulated against IJ records,
That is also true, but we do know the approximate numbers and a certain order of magnatude figure.and as such are almost certainly inflated, probably by a factor of 2 or more. In any event most Kamikazes were shot down by close range weapons (~70% according to the USN),
The book I mentioned before states just the oposite! Smaller AA Machine guns, IE 20-40 MM were much less effective at downing Kamikazi planes because of the limited damage and close range, which let the heavily damaged, or even destroyed plane still damage it's target. and made for relatively easy kills during their final approach to the the target ship, while most 5in AA kamikaze kills were made at close range using VT ammo, typically with close range directors, or over open sights using local control.
Again this is in direct contradiction of other sources. Would you please post a link to this data?
The Royal Navy's late war AA FC systems were quite impressive, and included technologies such as GRU/GRUB, ABU, and CPU that were still not present in the USN, however the RN never encountered large numbers of kamikazes, and had nowhere near as many ships in the Pacific as the USN.[/quote]
This site lists three destroyed and many damaged, but I wonder what the IJN records have to show?
http://en.wikipedia.org/wiki/Sinking_of ... nd_Repulse