Swiss Concepts for the Twenties...

[Desertfox]

Yup the return of the super destroyer... And yes everything fits, she is longer than all my light cruisers, except for the Ospreys.


Kidd class, New Switzerland Super Destroyer laid down 1922

Displacement:
   1,500 t light; 1,573 t standard; 1,849 t normal; 2,069 t full load

Dimensions: Length overall / water x beam x draught
   400.00 ft / 400.00 ft x 34.00 ft x 12.20 ft (normal load)
   121.92 m / 121.92 m x 10.36 m  x 3.72 m

Armament:
      10 - 4.00" / 102 mm guns (5x2 guns), 32.00lbs / 14.51kg shells, 1922 Model
     Breech loading guns in deck mounts with hoists
     on centreline, evenly spread, 2 raised mounts
      8 - 1.57" / 40.0 mm guns (4x2 guns), 1.95lbs / 0.89kg shells, 1922 Model
     Quick firing guns in deck mounts
     on side, evenly spread
      4 - 0.50" / 12.7 mm guns in single mounts, 0.06lbs / 0.03kg shells, 1922 Model
     Breech loading guns in deck mounts
     on side, evenly spread
   Weight of broadside 336 lbs / 152 kg
   Shells per gun, main battery: 190
   9 - 19.7" / 500.38 mm above water torpedoes

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.50" / 13 mm         -         0.50" / 13 mm

Machinery:
   Oil fired boilers, steam turbines plus diesel motors,
   Electric motors, 4 shafts, 32,415 shp / 24,181 Kw = 32.00 kts
   Range 5,400nm at 15.00 kts
   Bunker at max displacement = 496 tons

Complement:
   140 - 183

Cost:
   £0.576 million / $2.304 million

Distribution of weights at normal displacement:
   Armament: 42 tons, 2.3 %
   Armour: 10 tons, 0.5 %
      - Belts: 0 tons, 0.0 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 10 tons, 0.5 %
      - Armour Deck: 0 tons, 0.0 %
      - Conning Tower: 0 tons, 0.0 %
   Machinery: 882 tons, 47.7 %
   Hull, fittings & equipment: 487 tons, 26.3 %
   Fuel, ammunition & stores: 349 tons, 18.9 %
   Miscellaneous weights: 79 tons, 4.3 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     443 lbs / 201 Kg = 13.8 x 4.0 " / 102 mm shells or 0.3 torpedoes
   Stability (Unstable if below 1.00): 1.24
   Metacentric height 1.5 ft / 0.4 m
   Roll period: 11.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.54
   Seaboat quality  (Average = 1.00): 1.00

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.390
   Length to Beam Ratio: 11.76 : 1
   'Natural speed' for length: 20.00 kts
   Power going to wave formation at top speed: 59 %
   Trim (Max stability = 0, Max steadiness = 100): 70
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      17.00 ft / 5.18 m
      - Forecastle (30 %):   12.00 ft / 3.66 m
      - Mid (50 %):      12.00 ft / 3.66 m
      - Quarterdeck (20 %):   12.00 ft / 3.66 m
      - Stern:      10.00 ft / 3.05 m
      - Average freeboard:   12.40 ft / 3.78 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 176.5 %
      - Above water (accommodation/working, high = better): 81.4 %
   Waterplane Area: 8,328 Square feet or 774 Square metres
   Displacement factor (Displacement / loading): 70 %
   Structure weight / hull surface area: 33 lbs/sq ft or 162 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 0.83
      - Overall: 0.53
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is cramped
   Ship has slow, easy roll, a good, steady gun platform

[Guinness]

8x40mm?? That's a heavier AA battery than any destroyer in the world had in 1939.

[TexanCowboy]

Yes, but they had DP guns to rely on.

[Desertfox]

They are not AA guns, but rather last ditch anti-torpedoboat weapons. The 40mm sucks in this time period as an AA weapon, having a slow RoF and unable to use fused shells. That said the ship does have enough space and reserve weight to ship a couple of 3" AA guns.

[Desertfox]

Pic and another concept. Once enough new destroyers come online, there is a proposal to rearm the Saipans with 4 6" guns and convert them into fast minelayers. The Johann Wys is also there, and yes everything fits with room to spare. 

[Guinness]

The only naval powers with effective DP batteries in 1939 were the US and to a much lesser extent Japan.

To give some perspective: typical AA battery of an RN destroyer was 2x4barreled 0.50in machine guns or 2xsingle 2-pounder pom-poms.  Some dedicated AA ships carried the twin 4in HA (including sloops, Hunt class light destroyers, and some retrofits).

German ships had much heavier AA batteries: 2x37mm and 7x20mm in the Type 36's, for instance. No DP main battery though.

French DDs carried only 2x37mm and 2x13mm.

Italian ships carried only 12x13.2mm machine guns.

The Japanese Kageros, commissioned starting in 1939 carried 6x5in DP and 4x25mm. The 5in guns apparently had very slow training and no power ramming, limiting their real usefulness in AA fire.

The US Benhams, commissioned starting 1939 carried 4x5inL38's in single mountings, and 4x0.50in MGs. No heavier AA was shipped as designed.

The US and RN ships of the immediate pre-war period all later landed torpedo tubes to free weight up for additional light AA (40mm in the case of the US ships, 12-pounder single AA mountings for the RN).

It also deserves noting that guns of 4+ inches serve a very different AA purpose compared with large caliber autocannon. Both shoot at aircraft, yes, but their intended range and altitude of engagement are quite different.

If these guns are intended as anti-tb weapons, my suggestion is that they're better mounted singly, so they can be hand trained and engage more targets at once. Shipping something slightly bigger, like the 5 barrelled Hotchkiss 3-pounder might be worthwhile instead, since it could fire an HE round.

[Guinness]

Pic and another concept. Once enough new destroyers come online, there is a proposal to rearm the Saipans with 4 6" guns and convert them into fast minelayers. The Johann Wys is also there, and yes everything fits with room to spare. 

What's the scale of that illustration? The Rhys class SS says it's 320 feet long (both overall and at the waterline, so that needs fixing for the raked bow). Your illustration of it is 341 pixels long.

[Desertfox]

Scale is 1 pix to 1 ft. The updated SS2 for the Wys class is 342 ft. I don't bother with bow angles in SS2 since it doesn't do anything.

[The Rock Doctor]

The Kidds - like those Dutch designs with ten guns, and like the 200 t RRC boats with nine torpedoes - are non-sensical.  Those armaments will not fit.  

If it could have been done historically, it would have been - I defy you to show me a single destroyer class of equivalent fire power on similar deck space.

[TexanCowboy]

Rocky.... It's about the size of a Town class, minus 30 feet. If that could fit 10 5.5'' guns in single mountings, I have very little doubt that this could fit 10 4'' guns in double mounting....Now, if this is or is not a floating fireball is a very different question.

[Desertfox]

Oh, I know. But the rules allow it and the Dutch have them. And the Dutch are enemigo number uno of the Swiss.

But as far as deck space goes, well the Kidds are pretty close to your own Puerta Espana class and historical ships such as the British C class cruisers (5x6", 4x4", 8x21" TT)

[Guinness]

Ok, well, first of all your guns are probably too long. The RN's 4"L40 was 13.8 feet long overall, the US 4"L50 was 17 feet. Your's are 21. So you can actually save length there. This is good, because I don't think you have nearly enough room behind those guns to work them. The US 4"L50 had an 11 foot working circle (from center of the mount), and 27.5 inches of recoil. So things would be tight. Also, I'm not sure that your TTs actually have enough room to traverse, but that shouldn't be a difficult fix, particularly since you don't need all those funnels necessarily. 17,000 odd SHP ought to be easily doable with three boilers in 1920, and two of those could have their funnels trunked together.

However, there still are issues. If these boats have wireless, in 1920 they really need taller stronger foremasts, and a mainmast of some sort to hold the aerials up. Q mounting is sitting right on top of the forward boiler room, it seems. 4in guns needed structural support below them. The RN, for instance, when mounting a gun amidships would try to mount it above the strong bulkhead between boiler rooms, or on a column that run up the middle of a large boiler room (which had two boilers in it, facing each other). That's a quibble though, as the machinery spaces can be arranged to put the gun wherever, if the designer is willing to make other compromises.

No, my issue is still BC. The bows on both Rhys and Kidd will be very very fine. I sincerely believe there won't be enough flotation under the superimposed guns forward to allow the bow to rise with the seas. Instead, they'll likely "burrow", which will result in shipping lots of water and damage forward, as well as an uncomfortable ride.

Again diving into the OTL world (because that's what we've got). RN officers who sailed both during WW1 and immediately afterward considered the S class better seaboats who's bows rose more easily, and which could steam more ably into the sea than the V class. The difference? The S-class were a development of the earlier Rs (and therefore of the Ms), and had only one gun forward. The V's had two, and therefore more weight. You also see similar complaints about the Sumners and Gearings of the USN when compared to the Fletchers.

In all these cases, the BC was considerably higher than yours. .537 for the S-class, .55 or so for the Vs, 0.499 for Fletcher, 0.52 for Gearing, and 0.54 for Sumner.

Foxy: I'm not trying to pick on you personally here. You've just provided me an opportunity to get up on my soapbox. Almost all DDs and TBs in the Nverse have this problem, including some I've designed. Frankly, I think some of these ships need to start having accidents at sea so Nverse naval architects can start learning some of these lessons.

[The Rock Doctor]

The rules aren't going to allow it much longer if you guys keep pushing into Alien Space Bat territory.  I'm quite willing to ret-con those Dutch boats if need be.

Puerta Espana has 50% more area at the waterline, and a half-metre more freeboard.  She has only 40% of the machinery, sixty percent of the guns, and half the torpedo battery.

Sim out a C class or a Town and let's compare waterline area, freeboard, and so forth.

[miketr]

Mike is in favor of killing 10 gun cruiser wannabe destoyers.

[Sachmle]

Mike is in favor of killing 10 gun cruiser wannabe destoyers.

Sam is too. Those things Korpen designed were nuts. There is no way 10 guns, ammo, crew, torpedoes, engines, boilers, stearing, stowage, food, mess, officers quarters, crew quarters, ect.. fit on those ships. And Guinness is right about the BC thing...we've all (myself included) undercut the BC on most of our ships way to far. Even some of the BB are in the mid to low 5's (I.e. 0.520-0.530) which is insane.