Jump to content


Photo
- - - - -

Scylla or Charybdis?


  • Please log in to reply
12 replies to this topic

#1 Carronade

Carronade

    Ace

  • Members
  • PipPipPipPipPipPipPip
  • 1,485 posts

Posted 05 August 2011 - 02:50 PM

These were the two Dido class light cruisers armed with eight 4.5" guns rather than the designed ten 5.25s, due to slow delivery of the latter. The smaller guns caused them to be nicknamed "toothless terrors", but the 4.5 actually proved a better antiaircraft weapon than the 5.25 - which brings me to my question:

I've read that the sixteen Didos were collectively credited with shooting down fifteen enemy planes during the war, with one ship getting credit for seven, unfortunately no name given. I wonder if this might have been Scylla or Charybdis. They were the best AA ships of the class. Scylla - my first guess - served on Arctic convoy PQ-18 which involved intense air attacks and heavy German losses. Charybdis took part in several Malta convoy operations, so both of them had ample opportunity to engage aircraft. Anyone know for sure?

If one of them was the seven-shooter, that would mean the fourteen 5.25" gunned ships share credit for at most eight aircraft between them. The 5.25 seemed like a great idea, but was disappointing in practice.

#2 TiredOldSoldier

TiredOldSoldier

    Ace

  • Members
  • PipPipPipPipPipPipPip
  • 2,836 posts

Posted 05 August 2011 - 04:39 PM

Who is your source? IMO any author that obviously had the full info but only put down half of it deserves to be shot.
Are you sure we are talking about 14 ships? the total figure of 15 planes looks pretty low, sometimmes the Dido and Royalist were considered distinct classes .
Neither Charybdys nor Scylla surived the war Charybdys was lost in a surface action in 1943 something her 4.5 armament made her very unsuited to, Scylla was declared a constructive total loss after the 1944 mine damage. My guess goes to Scylla, if it was one of 5.25 ships then the whole "conventional wisdom" about the 4.5 being a better AA gun than 5.25 goes down the drain.
Most reports I have on the 5.25 do not make it unqualified success, still it was retained for HMS Vanguard so the RN still believed in it.

EDIT: can't find my reference for artic convoys but Roskill credits most German losses agaist PQ18 to HMS Avenger's hurricanes and the "anti aircraft cruiser" HMS Ulster Queen (a converted merc with 3 twin 4" gun mounts).

Edited by TiredOldSoldier, 05 August 2011 - 05:03 PM.

Truth is the first victim of conflict

#3 Carronade

Carronade

    Ace

  • Members
  • PipPipPipPipPipPipPip
  • 1,485 posts

Posted 05 August 2011 - 05:40 PM

15 for 16 is in both Fleets of World War II by Richard Worth (who sometimes posts here as Tiornu) and Cruisers in Action by Peter Padfield (correction, Peter Smith). (Smith) gives the seven by one ship but annoyingly omits the name, a bit odd since he did name the top scorers among C class AA conversions (Carlisle, the longest lasting of the prewar six, 11) and conventional cruisers (Penelope, 7).

The 5.25 mountings in Vanguard and the Royalist class/subclass were improved, including Remote Power Control, and their rate of train increased from 10 to 20 degrees per second. Vanguard also featured American Mark 37 directors, probably the best dual-purpose gunnery control system of the time.

Edited by Carronade, 06 August 2011 - 12:07 PM.


#4 Carronade

Carronade

    Ace

  • Members
  • PipPipPipPipPipPipPip
  • 1,485 posts

Posted 05 August 2011 - 06:06 PM

Might as well finish this off. Worth and Padfield (correction, Smith) both credit British cruisers with shooting down 97 planes during the war. Padfield breaks this down as 31 by the eight C class AA conversions (my guess, mostly by the six that were in service from the beginning of the war), 15 by Didos, leaving 51 for the rest.

The RN, RAN, RNZN, and RCN operated a total of 92 cruisers during the war:

27 WWI-era ships:
HMAS Adelaide, actually a pre-WWI Town class
13 C including eight AA
8 D including Delhi, AA conversion with US 5"/38 guns
2 E
3 Hawkins

15 8", County classes

34 modern 6", Leander class through Swiftsure

16 Dido/Royalist

The WWI era ships, other than AA cruisers, tended not to be exposed to air attack, and the 8" ships spent much of their time in distant waters. The modern 6" ships were extensively used in theaters like Norway and the Mediterranean. So probably around forty 6"/8" cruisers came under heavy air attack at some point in their careers, and they shot down 51 aircraft, while six of them were lost (Cornwall Dorsetshire, Southampton, Gloucester, Fiji, Trinidad).

Edited by Carronade, 06 August 2011 - 12:06 PM.


#5 Duns Scotus

Duns Scotus

    Member

  • Members
  • PipPipPipPip
  • 84 posts

Posted 26 October 2011 - 02:32 AM

Carronade-former ''Toomtabard'' here. Charybidis is featured in a virtual reality presentation on the Channel Island of Jersey which is situated inside one of the German gun bunkers who engaged HMS. Charbydis when the latter bombarded German occupid Jersey.
I visted Jersey in 1993 and the soundtrack of the virtual reality presentation said that the ship was damaged during German fire during this action.
But Royal Navy A-A guns proved futile on sevral occasions.I've read crew members of the sunk battleships ''Prince of Wales ' and ''Repulse'' saying that prior to being sunk by Japanese aircraft off the coast of Malaya in December 1941 they had great faith in their ''Chicago pianos'' as the called the rapid fire Pom Pom AA guns on both ships.
Brian Donald

#6 Poppy

Poppy

    grasshopper

  • Members
  • PipPipPipPipPipPipPip
  • 3,646 posts
  • LocationShambhala http://www.youtube.com/watch?v=hv9DwzU3KP0

Posted 26 October 2011 - 03:09 AM

Why were the 4.5's better than the 5.25's ?

#7 Carronade

Carronade

    Ace

  • Members
  • PipPipPipPipPipPipPip
  • 1,485 posts

Posted 26 October 2011 - 01:26 PM

The 5.25" was a great idea but disappointing in practice. It never achieved its designed rate of fire, firing 7-8 rounds per minute instead of the hoped-for 12. The mounting was cramped and the 80lb shell was pushing the limits for manual loading. The rate of train of the mount and rate of elevation of the guns were 10 degrees per second, which proved inadequate against fast-moving aircraft. Maximum elevation was 70 degrees, which limited their effectiveness against dive bombers.

As noted, later versions of the mounting in Vanguard and the Bellona class cruisers (modified Didos) were better, rate of train and elevation were doubled, and they had Remote Power Control, that is, the guns moved automatically in response to the control system instead of the manual follow-the-pointer system used earlier. Some references also say the rate of fire was improved, but I have not seen detail on how that might have been accomplished.

The 4.5" with shells around 55lb was able to maintain a higher rate of fire. It came in a variety of mountings; S & C had the Mark III Upper Deck twin mount, a shielded, open-backed type with IIRC 80 degree elevation. This also appeared in Ark Royal and several depot ships (submarine/destroyer tenders).

Although the Didos were generally not effective as anti-aircraft ships, it's also true that none of them were sunk by air attack, although they saw extensive service in the Mediterranean.

#8 Carronade

Carronade

    Ace

  • Members
  • PipPipPipPipPipPipPip
  • 1,485 posts

Posted 26 October 2011 - 01:56 PM

Hi Duns, thought I recognized you! The multiple pom-pom massing four or eight barrels was an excellent concept, AFAIK the first such weapon, but it was getting a little long in the tooth by WWII. The actual 2pdr gun was of WWI vintage, and although it and its ammunition had been somewhat improved, its muzzle velocity and therefore effective range were often inadequate to engage WWII-era aircraft before they released their bombs or torpedos.

The 2pdr was supplanted by the 40mm Bofors; for example in destroyers the quad pom-pom gave way to a Hazemeyer twin 40mm; this incorporated advances like a computer and radar on the mount, but it's still notable that two Bofors were considered an improvement on four 2pdrs.

The RN also developed a six-barreled 40mm for larger ships, first appearing on Vanguard just after the war. Again the timing was unfortunate as 40mm-class weapons were soon phased out in favor of 3".

#9 TiredOldSoldier

TiredOldSoldier

    Ace

  • Members
  • PipPipPipPipPipPipPip
  • 2,836 posts

Posted 27 October 2011 - 06:51 PM

...
Although the Didos were generally not effective as anti-aircraft ships, it's also true that none of them were sunk by air attack, although they saw extensive service in the Mediterranean.

AFAIK HMS Spartan was lost to air attack off Anzio (though it required a glider bomb).
Truth is the first victim of conflict

#10 Carronade

Carronade

    Ace

  • Members
  • PipPipPipPipPipPipPip
  • 1,485 posts

Posted 27 October 2011 - 07:32 PM

True, I should have said something like conventional air attack. Thanks for the correction.

Funny thing, a mistake often opens an opportunity for further discussion. The 5.25" was big for a DP gun when it and the ships that carried it were being designed, and may have pushed the envelope a bit too far, but within a few years the advent of guided missiles had navies trying to develop DP automatic 6" guns.

Also just noticed I used the same phrase in two different posts above.

#11 Marmat

Marmat

    Member

  • Members
  • PipPipPipPipPip
  • 292 posts
  • LocationHuronia, Upper Canada

Posted 29 October 2011 - 09:58 PM


I don't normally quibble about technical details or relative numbers, I believe that no naval service greater exemplified the old adage of doing the best with what you have to achieve a purpose than the Royal Navy did in WWII. That said, some of your numbers need to be qualified, you may be right, but for the wrong reasons.


When referring to the 5.25in QF Mk I you state “The mounting was cramped and the 80lb shell was pushing the limits for manual loading”, loading is debatable as we shall see, but the 80 lbs. is more accurately described as “Weight Projectile”. The 5.25in fired a separate projectile and brass cartridge cased propellant charge, weighing some 40 lbs., which were rammed together.


Similarly,“4.5" with shells around 55lb” represents “Weight Projectile”, but the 4.5in fired a fixed complete round containing both the projectile and the brass cased propellant charge, which was manually handled as one and weighed in at up to 91.75 lbs. If a 80lb shell was pushing the limits for manual loading, 91.75 lbs. and 49” long certainly exceeded it. What's more, the projectile and cartridge often separated when handled, in any extended engagement the 4.5in's rate of fire plummeted drastically. This was recognized at the time, when the 4.5in. was later adopted as the standard RN post-war deck gun, the projectile and cartridge were separated for ease of handling and rate of fire.


The 4.5in QF Mks I & III as employed in the pair of Didos may have been superior AA weapons to the 5.25in QF Mk I in WWII, but it had more to do with thesuperior Mk III mounting than it did with ammunition handling or even rate of fire.

For sustained AA fire, the 4in. QF Mk XVI was arguably the best gun the RN had for the first half of the war at least, especially when limited fire control required barrage firing for protection to be effective, it was the most numerous in any case. Ships were often hit after they had "fired out" all of their AA ammo.


Going back to your cruiser numbers, this RCN vessel, armed with 10X4in. QF Mk XVI* in twin turrets (2 forward, 3 aft) in a superfiring arrangement, 8X2-pounder pompoms (later updated to 8-12X40 mm Bofors) and 12-15X20mm Oerlikons, with top notch director and radar, for aircraft warning, surface detection and fire control, one of the best single ship AA kits in the British Commonwealth, but with Asdic and 4 depth charge throwers thrown in. She would end the war in Subic Bay, newly assigned AA escort duties for British Pacific Fleet carriers. From 1940 until that time, she had served in the Atlantic, the Pacific (in Hawaiian waters daysbefore the Japanese attacked), the Aleutians, AA escort for troop liners, the Med. & Gibraltar, protecting convoys and Support Groups in the Bay of Biscay from Luftwaffe guided weapons (reputably detonating one with 20 mm fire before she herself was struck), refitting & missed Normandy (although her 2 near sisters were there) and was arguably the most powerful for much of the war, and the most travelled ship in the RCN. Why do I mention all this? You won't find her named anywhere in Richard's “Fleets” (but there's even a photo in Lenton & Colledge), that's the fly.


While she could be easily mistaken as warship built, she was in fact HMCS Prince Robert, like HMS Ulster Queen mentioned above, one man's Armed Merchant Cruiser, is another's “auxiliary” AA vessel, is another's AA Cruiser ... I point this out merely to illustrate what I mean about technical details, relative numbers, stats. etc. - certainly useful, but take them with a grain of salt.

It appears that I can't, otherwise I'd post a photo!

Moderator edit. We have limits on new members, but I can fix that for you.

Edited by Slipdigit, 30 October 2011 - 01:04 AM.
photos!

  • Gromit801 likes this

#12 Carronade

Carronade

    Ace

  • Members
  • PipPipPipPipPipPipPip
  • 1,485 posts

Posted 31 October 2011 - 05:57 PM

I managed to find this link for Prince Robert which includes some nice pictures; she certainly was more warship-looking than some of the other AA ships. Still had an F pennant number though, F56, vice I or D which the RN used for cruisers.

HMCS Prince Robert Tribute: Hillman WWII Scrapbook

#13 Carronade

Carronade

    Ace

  • Members
  • PipPipPipPipPipPipPip
  • 1,485 posts

Posted 02 November 2011 - 01:15 PM

In their initial wartime incarnation as armed merchant cruisers, Prince Robert and her sisters Prince David and Prince Henry looked more military than most of their ilk. They mounted four 6" guns in superfiring pairs fore and aft, like modern destroyers or WWI-era light cruisers. Most of the British AMCs carried their guns - commonly eight - in a broadside arrangement. The Canadians did extensive alterations to the superstructure, including trunking the first two (of three) funnels into one, presumably so the bridge could be a bit further aft and free up space for the two gun positions forward, whereas most AMCs retained their liner configuration.

As noted Prince Robert was converted to an A/A ship, twin 4" replacing the 6" and a third mount added aft, an unusual but effective arrangement.

<Some of the other A/A ships like Tynwald or Palomares were remarkably homely IMO though they seem to have been effective>

David and Henry became Landing Ships Infantry (Medium), the British equivalent of attack transports. This role also called for reasonable AA armament, so they received twin 4" in A and Y positions; of course most of their deck space and topweight capacity went into landing craft.

Edited by Carronade, 02 November 2011 - 08:12 PM.
missing word





0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users