Who is "we"? And what evidence do you have that anything besides the Neptune/Minotaur and stolen Tzoli pictures you posted are real vessels?
Is this the 5.25" cruiser Cunningham killed off in favour of 6" studies?
Ok so this is an earlier 5.25' concept, I was not aware of it, thank you.Is this the 5.25" cruiser Cunningham killed off in favour of 6" studies?
Sorta, they became the Crown Colony class
I think topweight might be a lesser problem on these designs as they only carry a pair of turrets more then a Dido yet on a larger hull
Interestingly I've never seen a design with single 5,25" mounts or turrets say for a small cruiser or destroyer. (I did see once ages ago a hypothetical carrier model with single 5,25" turrets basically cut in half assymetrical Dido turrets)
Strictly speaking it's height above the centre of buoyancy that matters, which is why weight close to the waterline still causes stability problems.You're right that the larger hull would help, but the problem is not just the weight of the turrets, but their height - the significant factor is their moment arm, so it's weight times height above the waterline.
Strictly speaking it's height above the centre of buoyancy that matters, which is why weight close to the waterline still causes stability problems.
The centre of buoyancy is generally one-third to half the draught below the waterline, but that's a function of the hullform. As is the location of the metacentre, which is also calculated with respect to the centre of buoyancy. Keep the centre of gravity well below the metacentre or else you'll have a bad day at sea!
Because the shape of the immersed hull changes with displacement, weird things can happen sometimes. I've dealt with a barge loading condition where adding topweight actually improved stability by increasing the displaced volume significantly. But that isn't normal, and adding the same weight low down would have an even more beneficial effect.
@smurf, it’s wonderful to see you posting here again. Thanks for the insight and welcome back, I hope you are well.
Had Henderson got K25G* built, and also successfully replaced the last few Didos with L.72 or L.90, roughly how many 5.25 mountings would be required?I've just re-read the Forum rules and noticed that reopening topics with further info is OK. As the latest posts on here are 2010 and 2011, I did write an article for "Warship" 2010, page 43 (AA to AA - the Fijis turn full circle) which discussed the Fijis in detail with emphasis on the various AA variants from the K25's to the Tigers, and various emergency versions between. In it were drawings of all the Fiji preliminary designs, including the K25 AA versions by John Jordan based on Admiralty sketch design drawings. N2, the 1944 AA cruiser got a description as a footnote, but no drawing. There are drawings of N2 in George Moore's book "Building for Victory" though the automatic MkIII rectangular turrets he portrays were not available for a 1944 design, and I don't think he sticks very closely to the written description of "two funnels set close together roughly where the second turret stands" (on Royalist). There are drawings of an earlier automatic twin 5.25 in the Vickers archive in the Brrow library, which looked more like the curved top Mk I and II. I covered Dido's origins in an article on RN interwar small cruisers (Damnable Folly) in Warship 2011, p.130. Scylla and Charybdis had 4x2 4.5in to meet shortages of 5.25s
[D. Murfin]
i wasn't suggesting replacing the 1938 Didos with more 5.25in Fijis, but instead L.72 and L.90, which were preliminary designs for the L class Destroyer, roughly equivalent to the Mogador class contre-torpilleurs.snip
Not all 5" but partial when the RN discovers it could not build the necessary amount of 5,25" turrets
I've never heard of L.72/90 before. Would you mind sharing an image of the ship?Sorry, I misunderstood.
So the additional 5.25" turret requirement drops to 76 (i.e. my original 97 less those for the 1938 Didos (being 5+2 for 3 ships)
Both L.72 and L.90 were to carry 4 twin 4.7" in weatherproof mounts (the Mk.XX from the L&M classes). That mount too was having to be designed at this busy period which is why come March 1940 half the L class were regunned with 4". The lengthened build times on these classes resulted in the second 1939 flotilla being the N class (repeat J/K). The alternative come war is to regun with something. Its a big "destroyer" for the 4". So maybe the twin 4.5" Mk.III UD mount. But I don't really see that option speeding up delivery that much - just look to Scylla & Charybdis which took about the same length of time to complete as the rest of the class.
L.72 2745 tons std 420ft long 35kts deep
L.90 3205 tons std 475ft long 36.5kts deep
Both with 4 twin 4.7" (50 degree elevation) in weatherproof mounts, 2 quad pom-pom, 2 new 0.661 multiple mounts, 8TT
Cost est £1.5m - double an L class and half that of a Dido.
So maybe 6 ships for the cost of the 1938 Didos and probably deliverable in the same timescale, end 1941 - mid 1942 at best. But not even equivalent to a full flotillas worth of destroyers and with an inferior HA armament when compared to a Dido. And it is too big to go to some of the traditional destroyer builders like White & Yarrow.
There is no way that the USN would be supplying that number of twin 5" mounts given the planned build programme for BB, Essex class CV and the massive cruiser programme.
They sound like modernized Tribal class destroyers in specifications.They are preliminary designs of the large L class destroyers. I don't think I've seen official or other drawings of them.