Vilnius Union Ships, 1930+: The Good, The Bad, and the Unseaworthy

[The Rock Doctor]

I decided the seaplane cruiser I posted earlier was cool but not sensible, so the 1931 cruiser is just a progression of the 1929 class with DP secondaries and heavier deck armor.


Enter ship name, Enter country Enter ship type laid down 1931

Displacement:
   8,621 t light; 9,054 t standard; 9,948 t normal; 10,663 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (605.26 ft / 590.55 ft) x 58.73 ft x (22.31 / 23.44 ft)
   (184.48 m / 180.00 m) x 17.90 m  x (6.80 / 7.14 m)

Armament:
      8 - 5.91" / 150 mm 50.0 cal guns - 121.25lbs / 55.00kg shells, 250 per gun
     Breech loading guns in turret on barbette mounts, 1931 Model
     4 x 2-gun mounts on centreline ends, evenly spread
      2 raised mounts - superfiring
      8 - 3.94" / 100 mm 45.0 cal guns - 30.77lbs / 13.96kg shells, 400 per gun
     Dual purpose guns in deck mounts, 1931 Model
     4 x Twin mounts on side ends, evenly spread
      12 - 1.97" / 50.0 mm 60.0 cal guns - 4.18lbs / 1.90kg shells, 1,500 per gun
     Anti-air guns in deck mounts, 1931 Model
     6 x Twin mounts on sides, evenly spread
      8 - 0.59" / 15.0 mm 90.0 cal guns - 0.12lbs / 0.05kg shells, 5,000 per gun
     Machine guns in deck mounts, 1931 Model
     4 x Twin mounts on sides, evenly spread
      4 raised mounts
      Weight of broadside 1,267 lbs / 575 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   3.94" / 100 mm   383.86 ft / 117.00 m   16.37 ft / 4.99 m
   Ends:   Unarmoured
     Main Belt covers 100% of normal length
     Main Belt inclined 16.00 degrees (positive = in)

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   5.91" / 150 mm   1.57" / 40 mm      3.94" / 100 mm
   2nd:   0.79" / 20 mm   0.59" / 15 mm            -
   3rd:   0.59" / 15 mm         -               -
   4th:   0.59" / 15 mm         -               -

   - Armoured deck - single deck:
   For and Aft decks: 1.97" / 50 mm
   Forecastle: 1.97" / 50 mm  Quarter deck: 1.97" / 50 mm

   - Conning towers: Forward 3.94" / 100 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 83,110 shp / 62,000 Kw = 32.09 kts
   Range 16,400nm at 10.00 kts
   Bunker at max displacement = 1,609 tons

Complement:
   497 - 647

Cost:
   £3.305 million / $13.220 million

Distribution of weights at normal displacement:
   Armament: 329 tons, 3.3%
      - Guns: 329 tons, 3.3%
   Armour: 2,134 tons, 21.4%
      - Belts: 1,009 tons, 10.1%
      - Armament: 273 tons, 2.7%
      - Armour Deck: 812 tons, 8.2%
      - Conning Tower: 39 tons, 0.4%
   Machinery: 2,485 tons, 25.0%
   Hull, fittings & equipment: 3,396 tons, 34.1%
   Fuel, ammunition & stores: 1,327 tons, 13.3%
   Miscellaneous weights: 277 tons, 2.8%
      - On freeboard deck: 107 tons
      - Above deck: 170 tons

Fittings:
-34 t:  1924 Fire Control (AD)
-25 t:  L/R wireless (AD)
-25 t:  Night-fighting doodads (AD)
-50 t:  Command facilities (AD)
-55 t:  2 armed floatplanes and one catapult with hangers aside aft funnel (FD)
-32 t:  2x4 530mm torpedo carriages (no reloads) (FD)
-20 t + 36 t:  Weight reserve (AD/FD)


Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     11,674 lbs / 5,295 Kg = 113.4 x 5.9 " / 150 mm shells or 1.6 torpedoes
   Stability (Unstable if below 1.00): 1.09
   Metacentric height 2.6 ft / 0.8 m
   Roll period: 15.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 60 %
         - Recoil effect (Restricted arc if above 1.00): 0.35
   Seaboat quality  (Average = 1.00): 1.08

Hull form characteristics:
   Hull has rise forward of midbreak,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.450 / 0.459
   Length to Beam Ratio: 10.06 : 1
   'Natural speed' for length: 24.30 kts
   Power going to wave formation at top speed: 55 %
   Trim (Max stability = 0, Max steadiness = 100): 55
   Bow angle (Positive = bow angles forward): 20.00 degrees
   Stern overhang: 4.92 ft / 1.50 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00%,  26.90 ft / 8.20 m,  21.65 ft / 6.60 m
      - Forward deck:   30.00%,  21.65 ft / 6.60 m,  21.65 ft / 6.60 m
      - Aft deck:   35.00%,  13.78 ft / 4.20 m,  13.78 ft / 4.20 m
      - Quarter deck:   15.00%,  13.78 ft / 4.20 m,  13.78 ft / 4.20 m
      - Average freeboard:      18.14 ft / 5.53 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 93.1%
      - Above water (accommodation/working, high = better): 147.6%
   Waterplane Area: 22,122 Square feet or 2,055 Square metres
   Displacement factor (Displacement / loading): 118%
   Structure weight / hull surface area: 99 lbs/sq ft or 482 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.96
      - Longitudinal: 1.32
      - Overall: 1.00
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room

960nm @ 32 kts
1170nm @ 30 kts
1960nm @ 25 kts
3510nm @ 20 kts
6930nm @ 15 kts

[TacCovert4]

I won't say obsolete.  Not in our meta.  When you get out of Treaty BB ranges, you get into sizes where a BB can be fast, heavily armored, and covered in AA to the point that even a late WW2 carrier would have a rough go of it.  After all, the Iowas were a viable, if expensive, fleet unit in the 80s, and they could have been more heavily refitted to have a viable missile suite if they had pulled the aft turret off and replaced everything back there with missiles.

[The Rock Doctor]

Pondering life-extension options for the Angstrom class battleships.  Laid down between 1913 and 1915, they would ideally be leaving service after 25 years in about 1940-1942.  So they're just at, or approaching, the middle of their careers.

The class is not bad; speed is good, belt and torpedo protection are adequate.  Deck armor is falling behind modern artillery/bomb trends.  The big problem is the armament, because I designed them at a time when I did not remember the difference between a triple turret and a 3-gun turret and went for the former.  This problem was repeated in the following two classes of battlecruiser, too.

The class had a refit a few years back and picked up new AA and torpedo nets, and of course, they'll be in for fire control updates in the future.

Refurbishment options include FC and new 2-gun 100mm DP mountings, which are not hugely consequential to what follows.  Major decisions are needed for the following options:

Engine Room

1)  A basic replacement of the engines would increase hull strength enough that I could add another 30mm (on top of existing 90) of deck armor to the main and quarter decks.  That'd be about 3 BP, roughly speaking.

2)  Alternately, I could increase power to 27 knots, which only allows for the main deck to receive a 20mm topping.  This lets the class keep pace with the Encke and Gadolin classes; seakeeping remains reasonable.  I assume the BP cost would be about equal.

Main Battery

1)  Nothing; retain the 350/45 in a single sleeve in triple turrets and get ~1.5 rounds a minute.  No cost.

2)  Replace with a new model 350/45, shooting the same sized shells and using the same triple turrets and their protection.  Not sure how the newer gun tech would affect ROF or penetration.  Cost is in the range of 2.1 BP

3)  Replace with a new model ~320-325mm gun, shooting smaller but relatively super-heavy shells from a 3-gun turret.  Likely ROF increase but possible modest drop in firepower.  Will need to replace turret armor but not barbette armor.  Magazine weight would be kept unchanged.  Cost bumps to around 2.9 BP

4)  Replace with a new model ~370-380mm gun, shooting heavier projectiles from a 2-gun turret.  Better penetration, but down to 6 barrels overall.  New turret but same barbette.  Unknown ROF, might not be much improved.  Figure cost remains about 2.9 BP.

Additional thoughts

Any re-gunning option delays the refurbishments to at least 1932 because as of 1929 I haven't designed any of the replacement gun options.  At that point, Anders Angstrom is in the yard for the better part of 1932 and has a theoretical ~eight years of service afterward.  Her sisters follow the same schedule at one year intervals.

For context, it is likely that the class would become the core of the Caribbean Fleet for most of their remaining service lives, so that gives a sense of who the potential OPFORs could be.

Thoughts?

Brainfart as I was shoveling the driveway:

-Develop the new 350/45 as planned; the gun weight and shell size mean I'm just swapping out guns and shells of the same size so I'm not replacing main battery armor or messing with magazine dimensions.

-Develop a 2-gun 350/45 turret with the new guns that fits onto the existing triple barbette (size-wise, it's 552 t versus the old 676 t)

-Replace the middle (only!) triple turret so Angstrom comes out with two triples and one two-gun - allowing each triple and one of the two-gun barrels to fire half-salvos.

-I end up with eight guns rather than nine, shooting the same size shell in more effective half-salvos and with newer tech guns.

[Jefgte]

Byzantium will not replace these big guns (343 & 381).
AA light artillery (40 pompom & 12.7MG) has been replaced since 1929.
Remains the secondary with DP 102 or 114 or 133.
--------------

=> Changing the engines to save weight and investing it in deck protection is probably a good choice.

[TacCovert4]

I'm in the same boat.  The 360s and 400s will be there.  Even the 280s aren't being changed.   I considered a triple 240 on those, but it's not worth the expense.

[The Rock Doctor]

Byzantium will not replace these big guns (343 & 381).
AA light artillery (40 pompom & 12.7MG) has been replaced since 1929.
Remains the secondary with DP 102 or 114 or 133.
--------------

=> Changing the engines to save weight and investing it in deck protection is probably a good choice.

At the moment, my notion is:

-Change the guns in turrets A and C to 1925 tech 350/45
-Remove turret B in its entirety and replace it with a new 2-gun 350/45 with similar protection
-Remove the end belt
-Add some 50mm AA
-Use weight savings achieved above, plus weight reserve, to add another 30mm (90 --> 120mm) to the fore/aft deck armor.  It isn't as good as monolithic 120mm, but it's still better than 90mm.

I can do this at a cost of a little over 3 BP.  I can also do this without re-engining, which is not as big a problem as the gunnery; these ships will spend the remainder of their career deployed as a quartet to the Caribbean where range is not huge and the bad guys aren't super fast (so far).

[The Rock Doctor]

Alright, so it's $11.07 and 3.717 BP to get this.

I'd have a triple 350mm and its entire armor set, plus the end belt armor, for scrap - or in the case of the guns, maybe a monitor.



Angstrom, laid down 1913, engine year 1913, refurb 1932

Displacement:
   27,037 t light; 28,453 t standard; 30,005 t normal; 31,247 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (662.78 ft / 651.25 ft) x 95.14 ft x (28.25 / 29.21 ft)
   (202.02 m / 198.50 m) x 29.00 m  x (8.61 / 8.90 m)

Armament:
      8 - 13.78" / 350 mm 45.0 cal guns - 1,319.35lbs / 598.45kg shells, 100 per gun
     Breech loading guns in turret on barbette mounts, 1913 Model
     2 x Triple mounts on centreline, evenly spread
     1 x 2-gun mount on centreline, aft deck forward
      1 raised mount aft
      16 - 5.12" / 130 mm 45.0 cal guns - 67.61lbs / 30.67kg shells, 250 per gun
     Breech loading guns in casemate mounts, 1913 Model
     16 x Single mounts on sides, forward deck aft
      8 - 3.94" / 100 mm 45.0 cal guns - 30.77lbs / 13.96kg shells, 250 per gun
     Anti-air guns in deck mounts, 1913 Model
     8 x Single mounts on side ends, evenly spread
      8 raised mounts
      12 - 1.97" / 50.0 mm 60.0 cal guns - 4.18lbs / 1.89kg shells, 1,500 per gun
     Anti-air guns in deck mounts, 1913 Model
     4 x Twin mounts on side ends, evenly spread
     2 x Twin mounts on centreline, evenly spread
      2 double raised mounts
      12 - 0.59" / 15.0 mm 90.0 cal guns - 0.12lbs / 0.05kg shells, 5,000 per gun
     Machine guns in deck mounts, 1913 Model
     6 x Twin mounts on sides, evenly spread
      6 double raised mounts
      Weight of broadside 11,934 lbs / 5,413 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   13.8" / 350 mm   423.10 ft / 128.96 m   12.47 ft / 3.80 m
   Ends:   Unarmoured
     Main Belt covers 100% of normal length

   - Torpedo Bulkhead - Additional damage containing bulkheads:
      2.95" / 75 mm   423.10 ft / 128.96 m   26.64 ft / 8.12 m
   Beam between torpedo bulkheads 75.46 ft / 23.00 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   15.7" / 400 mm   9.84" / 250 mm      13.8" / 350 mm
   2nd:   0.98" / 25 mm   0.98" / 25 mm      3.94" / 100 mm
   3rd:   0.79" / 20 mm   0.79" / 20 mm            -
   4th:   0.59" / 15 mm         -               -
   5th:   0.59" / 15 mm         -               -

   - Armoured deck - single deck:
   For and Aft decks: 4.72" / 120 mm
   Forecastle: 2.95" / 75 mm  Quarter deck: 2.95" / 75 mm

   - Conning towers: Forward 13.78" / 350 mm, Aft 0.00" / 0 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 75,068 shp / 56,000 Kw = 25.84 kts
   Range 10,000nm at 10.00 kts
   Bunker at max displacement = 2,794 tons

Complement:
   1,139 - 1,481

Cost:
   £2.629 million / $10.517 million

Distribution of weights at normal displacement:
   Armament: 2,160 tons, 7.2%
      - Guns: 2,160 tons, 7.2%
   Armour: 10,902 tons, 36.3%
      - Belts: 3,138 tons, 10.5%
      - Torpedo bulkhead: 1,231 tons, 4.1%
      - Armament: 2,532 tons, 8.4%
      - Armour Deck: 3,714 tons, 12.4%
      - Conning Tower: 287 tons, 1.0%
   Machinery: 2,942 tons, 9.8%
   Hull, fittings & equipment: 10,275 tons, 34.2%
   Fuel, ammunition & stores: 2,969 tons, 9.9%
   Miscellaneous weights: 759 tons, 2.5%
      - Hull above water: 199 tons
      - On freeboard deck: 110 tons
      - Above deck: 450 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     46,668 lbs / 21,168 Kg = 35.7 x 13.8 " / 350 mm shells or 8.2 torpedoes
   Stability (Unstable if below 1.00): 1.14
   Metacentric height 5.9 ft / 1.8 m
   Roll period: 16.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.65
   Seaboat quality  (Average = 1.00): 1.31

Hull form characteristics:
   Hull has rise forward of midbreak,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.600 / 0.604
   Length to Beam Ratio: 6.84 : 1
   'Natural speed' for length: 25.52 kts
   Power going to wave formation at top speed: 51 %
   Trim (Max stability = 0, Max steadiness = 100): 54
   Bow angle (Positive = bow angles forward): 10.00 degrees
   Stern overhang: 6.56 ft / 2.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00%,  28.22 ft / 8.60 m,  24.28 ft / 7.40 m
      - Forward deck:   40.00%,  24.28 ft / 7.40 m,  24.28 ft / 7.40 m
      - Aft deck:   25.00%,  16.40 ft / 5.00 m,  16.40 ft / 5.00 m
      - Quarter deck:   15.00%,  16.40 ft / 5.00 m,  16.40 ft / 5.00 m
      - Average freeboard:      21.44 ft / 6.54 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 82.5%
      - Above water (accommodation/working, high = better): 161.0%
   Waterplane Area: 45,318 Square feet or 4,210 Square metres
   Displacement factor (Displacement / loading): 109%
   Structure weight / hull surface area: 177 lbs/sq ft or 863 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.95
      - Longitudinal: 1.51
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

[The Rock Doctor]

Auxiliaries to be thinking about:

-More oilers and depot ships, obviously

-Another round of salvage tugs would not be amiss; probably just updated Vellamo-class

-Maybe a couple of real-shallow-draft river depot ships to support light craft way up the South American and African riverways

-Maybe some dedicated troopships

-Or maybe some more troop ferries or smaller troop ships.  Are LCTs a thing yet?

-Probably another hospital ship

[The Rock Doctor]

A really shallow draft riverine depot ship.

Notionally, this supports a patrol and policing presence in either the upper reaches of the Orimiri/Niger river and the extensive riverine system of South America.  Some combination of motor torpedo-boats, small river gunboats, patrol craft, or even landing craft with troops could base themselves wherever the depot ship is hanging out.  There's some basic resupply capability, accommodations, and some basic admin/operational space set aside.

The shallow draft precludes any kind of protection, and the ship shouldn't be on the frontlines anyway.  It's well armed for defence against air attack, and the AA guns and machine guns could also be used for direct fire against waterborne or terrestrial threats too. 

This would be built to mercantile specs, probably using the local drydocks since they won't quite fit on my sealift ships.

A non-mercantile version, at 0.75 hull strength, would have another 100 t or so available for stuff on the same hull.


Enter ship name, Enter country Enter ship type laid down 1931

Displacement:
   799 t light; 831 t standard; 851 t normal; 868 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (254.05 ft / 246.06 ft) x 49.21 ft x (3.28 / 3.34 ft)
   (77.43 m / 75.00 m) x 15.00 m  x (1.00 / 1.02 m)

Armament:
      4 - 1.97" / 50.0 mm 60.0 cal guns - 4.18lbs / 1.89kg shells, 1,500 per gun
     Anti-air guns in deck mounts, 1931 Model
     2 x Twin mounts on centreline, evenly spread
      2 raised mounts
      4 - 0.59" / 15.0 mm 90.0 cal guns - 0.12lbs / 0.05kg shells, 4,000 per gun
     Machine guns in deck mounts, 1931 Model
     4 x Single mounts on sides, forward evenly spread
      4 raised mounts
      Weight of broadside 17 lbs / 8 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.79" / 20 mm         -               -
   2nd:   0.59" / 15 mm         -               -

Machinery:
   Diesel Internal combustion generators,
   Electric motors, 2 shafts, 536 shp / 400 Kw = 10.31 kts
   Range 1,000nm at 10.00 kts
   Bunker at max displacement = 37 tons

Complement:
   78 - 102

Cost:
   £0.138 million / $0.552 million

Distribution of weights at normal displacement:
   Armament: 5 tons, 0.5%
      - Guns: 5 tons, 0.5%
   Armour: 5 tons, 0.6%
      - Armament: 5 tons, 0.6%
   Machinery: 16 tons, 1.9%
   Hull, fittings & equipment: 453 tons, 53.2%
   Fuel, ammunition & stores: 53 tons, 6.2%
   Miscellaneous weights: 320 tons, 37.6%
      - Hull below water: 69 tons
      - Hull above water: 60 tons
      - On freeboard deck: 120 tons
      - Above deck: 71 tons

Fittings:
-25 t:  L/R wireless (AD)
-25 t:  Command and operations facilities (AD)
-10 t:  Sickbay (AD)
-10 t:  Crew amenities (AD)
-1 t:  Fire control, such as it is (AD)
-120 t:  Accommodation for sixty (6 for 20 t MTB, 12 for 40 t MTB or HPB, 3 for landing craft, or 30 man naval infantry platoon) (FD)
-60 t:  Machine shop and stores/dry cargo/ammunition (AW)
-60 t:  Fuel for small craft (BW)
-9 t:  Diesel-electric machinery (BW)

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     7,153 lbs / 3,244 Kg = 1,875.4 x 2.0 " / 50 mm shells or 4.0 torpedoes
   Stability (Unstable if below 1.00): 1.41
   Metacentric height 3.2 ft / 1.0 m
   Roll period: 11.6 seconds
   Steadiness   - As gun platform (Average = 50 %): 80 %
         - Recoil effect (Restricted arc if above 1.00): 0.01
   Seaboat quality  (Average = 1.00): 1.16

Hull form characteristics:
   Hull has rise forward of midbreak, raised quarterdeck ,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.750 / 0.751
   Length to Beam Ratio: 5.00 : 1
   'Natural speed' for length: 15.69 kts
   Power going to wave formation at top speed: 22 %
   Trim (Max stability = 0, Max steadiness = 100): 69
   Bow angle (Positive = bow angles forward): 10.00 degrees
   Stern overhang: 4.92 ft / 1.50 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   10.00%,  17.39 ft / 5.30 m,  13.45 ft / 4.10 m
      - Forward deck:   15.00%,  13.45 ft / 4.10 m,  13.45 ft / 4.10 m
      - Aft deck:   25.00%,  5.58 ft / 1.70 m,  5.58 ft / 1.70 m
      - Quarter deck:   50.00%,  13.45 ft / 4.10 m,  13.45 ft / 4.10 m
      - Average freeboard:      11.64 ft / 3.55 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 27.5%
      - Above water (accommodation/working, high = better): 211.3%
   Waterplane Area: 10,142 Square feet or 942 Square metres
   Displacement factor (Displacement / loading): 230%
   Structure weight / hull surface area: 39 lbs/sq ft or 190 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.94
      - Longitudinal: 1.67
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

[The Rock Doctor]

New salvage tug. 

The Vellamo class is pretty good for its job, and this just tweaks the formula.  Slimmer lines, deeper draft and higher freeboard lead to improved seakeeping qualities.  There's a bit of space to take on survivors or specialists and there's an AA gun.  The end armor protects the bow when pushing ships around.  There's a token amount of ASW hardware, enough that it could annoy a submarine for a short time if this were necessary and the ship were not in the process of towing something - fundamentally, this could function as a convoy escort. 

The minimal armament and armor (1.97% of normal tonnage) means the ship can be costed as a merchantile build.

A run of four to six ships will probably happen.  Deployment will probably focus on those parts of the Atlantic with the worst weather conditions, given the improved seakeeping/freeboard aspect of the ship.


Enter ship name, Enter country Enter ship type laid down 1931

Displacement:
   1,001 t light; 1,039 t standard; 1,165 t normal; 1,266 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (201.77 ft / 196.85 ft) x 32.81 ft x (11.48 / 12.27 ft)
   (61.50 m / 60.00 m) x 10.00 m  x (3.50 / 3.74 m)

Armament:
      1 - 3.94" / 100 mm 45.0 cal gun - 30.77lbs / 13.96kg shells, 400 per gun
     Dual purpose gun in deck mount, 1931 Model
     1 x Single mount on centreline, forward deck centre
      2 - 1.97" / 50.0 mm 60.0 cal guns - 4.18lbs / 1.89kg shells, 1,500 per gun
     Anti-air guns in deck mount, 1931 Model
     1 x Twin mount on centreline, aft deck centre
      1 raised mount
      4 - 0.59" / 15.0 mm 45.0 cal guns - 0.10lbs / 0.05kg shells, 5,000 per gun
     Machine guns in deck mounts, 1931 Model
     2 x Twin mounts on sides amidships
      2 raised mounts
      Weight of broadside 40 lbs / 18 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Ends:   0.98" / 25 mm     15.75 ft / 4.80 m   11.81 ft / 3.60 m
     181.10 ft / 55.20 m Unarmoured ends

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.79" / 20 mm   0.59" / 15 mm            -
   2nd:   0.59" / 15 mm         -               -

Machinery:
   Diesel Internal combustion generators,
   Electric motors, 2 shafts, 4,022 shp / 3,000 Kw = 18.24 kts
   Range 9,000nm at 10.00 kts
   Bunker at max displacement = 227 tons

Complement:
   99 - 129

Cost:
   £0.236 million / $0.944 million

Distribution of weights at normal displacement:
   Armament: 8 tons, 0.7%
      - Guns: 8 tons, 0.7%
   Armour: 11 tons, 0.9%
      - Belts: 7 tons, 0.6%
      - Armament: 4 tons, 0.4%
   Machinery: 120 tons, 10.3%
   Hull, fittings & equipment: 352 tons, 30.2%
   Fuel, ammunition & stores: 164 tons, 14.1%
   Miscellaneous weights: 510 tons, 43.8%
      - Hull below water: 81 tons
      - Hull above water: 100 tons
      - On freeboard deck: 300 tons
      - Above deck: 29 tons

Fittings:
-25 t:  L/R wireless (AD)
-1 t:  Fire control (AD)
-2 t:  Searchlights (AD)
-250 t:  Towing and salvage stuff, including two water monitors (FD)
-30 t + 30 t:  Emergency accommodations (FD/AW) 
-4 t:  Depth charges (FD)
-50 t:  Pumps and salvage stuff (AW)
-15 t:  Enhanced hydrophone package (BW)
-66 t:  D-E machinery (BW)
1t + 16 + 20 t:  Weight reserve

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     2,879 lbs / 1,306 Kg = 94.4 x 3.9 " / 100 mm shells or 1.3 torpedoes
   Stability (Unstable if below 1.00): 1.14
   Metacentric height 1.2 ft / 0.4 m
   Roll period: 12.5 seconds
   Steadiness   - As gun platform (Average = 50 %): 60 %
         - Recoil effect (Restricted arc if above 1.00): 0.05
   Seaboat quality  (Average = 1.00): 1.82

Hull form characteristics:
   Hull has rise forward of midbreak,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.550 / 0.559
   Length to Beam Ratio: 6.00 : 1
   'Natural speed' for length: 14.03 kts
   Power going to wave formation at top speed: 63 %
   Trim (Max stability = 0, Max steadiness = 100): 33
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 4.92 ft / 1.50 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00%,  21.65 ft / 6.60 m,  17.72 ft / 5.40 m
      - Forward deck:   30.00%,  17.72 ft / 5.40 m,  17.72 ft / 5.40 m
      - Aft deck:   30.00%,  9.84 ft / 3.00 m,  9.84 ft / 3.00 m
      - Quarter deck:   20.00%,  9.84 ft / 3.00 m,  12.80 ft / 3.90 m
      - Average freeboard:      14.39 ft / 4.39 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 54.5%
      - Above water (accommodation/working, high = better): 119.5%
   Waterplane Area: 4,507 Square feet or 419 Square metres
   Displacement factor (Displacement / loading): 149%
   Structure weight / hull surface area: 41 lbs/sq ft or 202 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.82
      - Longitudinal: 6.10
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Adequate accommodation and workspace room
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

[The Rock Doctor]

Still playing with carrier options for 1931 as I try out fuller hull forms (BC 0.55) compared to the preceding Centaury class. 

As it turns out, the singlest biggest factor bumping size up from the Centaury is not the air group but the torpedo bulkhead; otherwise, I could've put this all on a ~17,500 t hull.

This one's armored against CL fire - but not the hanger deck - and has a similar armament to the Centaury.  The airgroup of 48 modern aircraft would likely consist of two fighter squadrons and one scout/torpedo-bomber squadron, each of 16 aircraft.



Enter ship name, Enter country Enter ship type laid down 1931

Displacement:
   20,541 t light; 21,247 t standard; 22,891 t normal; 24,207 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (747.45 ft / 721.78 ft) x 82.02 ft x (24.61 / 25.72 ft)
   (227.82 m / 220.00 m) x 25.00 m  x (7.50 / 7.84 m)

Armament:
      10 - 5.12" / 130 mm 45.0 cal guns - 67.62lbs / 30.67kg shells, 500 per gun
     Dual purpose guns in deck and hoist mounts, 1931 Model
     4 x 2-gun mounts on sides, evenly spread
     1 x 2-gun mount on centreline, aft deck aft
      16 - 1.97" / 50.0 mm 60.0 cal guns - 4.19lbs / 1.90kg shells, 1,500 per gun
     Anti-air guns in deck mounts, 1931 Model
     8 x Twin mounts on sides, evenly spread
      16 - 0.59" / 15.0 mm 90.0 cal guns - 0.11lbs / 0.05kg shells, 5,000 per gun
     Machine guns in deck mounts, 1931 Model
     8 x Twin mounts on sides, evenly spread
      Weight of broadside 745 lbs / 338 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   3.94" / 100 mm   493.77 ft / 150.50 m   16.37 ft / 4.99 m
   Ends:   Unarmoured
     Main Belt covers 105% of normal length

   - Torpedo Bulkhead - Additional damage containing bulkheads:
      1.97" / 50 mm   493.77 ft / 150.50 m   22.28 ft / 6.79 m
   Beam between torpedo bulkheads 65.62 ft / 20.00 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.97" / 50 mm   1.18" / 30 mm      1.97" / 50 mm
   3rd:   0.79" / 20 mm   0.59" / 15 mm            -
   4th:   0.59" / 15 mm         -               -

   - Armoured deck - single deck:
   For and Aft decks: 1.97" / 50 mm
   Forecastle: 0.98" / 25 mm  Quarter deck: 1.97" / 50 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 136,729 shp / 102,000 Kw = 32.06 kts
   Range 18,000nm at 10.00 kts
   Bunker at max displacement = 2,959 tons

Complement:
   929 - 1,209

Cost:
   £5.941 million / $23.764 million

Distribution of weights at normal displacement:
   Armament: 212 tons, 0.9%
      - Guns: 212 tons, 0.9%
   Armour: 3,678 tons, 16.1%
      - Belts: 1,316 tons, 5.7%
      - Torpedo bulkhead: 801 tons, 3.5%
      - Armament: 87 tons, 0.4%
      - Armour Deck: 1,474 tons, 6.4%
   Machinery: 4,089 tons, 17.9%
   Hull, fittings & equipment: 7,526 tons, 32.9%
   Fuel, ammunition & stores: 2,350 tons, 10.3%
   Miscellaneous weights: 5,037 tons, 22.0%
      - Hull below water: 2,296 tons
      - Hull above water: 2,280 tons
      - On freeboard deck: 161 tons
      - Above deck: 300 tons

Fittings: 
-4560 t:  48 x Post-1933 airgroup (BW/AW)
-16 t:  4 x aft-firing heavyweight 21" torpedoes (BW)
-50 t:  Two steam catapults (FD)
-22 t:  Fire control (AD)
-25 t:  L/R wireless (AD)
-10 t:  Extra S/R wireless (AD)
-200 t:  Command and operations facilities (AD)
-111t + 43 t:  Weight reserve/damage control/whatever (FD/AD)

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     37,696 lbs / 17,099 Kg = 562.3 x 5.1 " / 130 mm shells or 4.8 torpedoes
   Stability (Unstable if below 1.00): 1.22
   Metacentric height 5.3 ft / 1.6 m
   Roll period: 14.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 100 %
         - Recoil effect (Restricted arc if above 1.00): 0.10
   Seaboat quality  (Average = 1.00): 1.78

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.550 / 0.556
   Length to Beam Ratio: 8.80 : 1
   'Natural speed' for length: 26.87 kts
   Power going to wave formation at top speed: 54 %
   Trim (Max stability = 0, Max steadiness = 100): 56
   Bow angle (Positive = bow angles forward): 20.00 degrees
   Stern overhang: 13.12 ft / 4.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   15.00%,  34.45 ft / 10.50 m,  29.53 ft / 9.00 m
      - Forward deck:   40.00%,  29.53 ft / 9.00 m,  29.53 ft / 9.00 m
      - Aft deck:   30.00%,  29.53 ft / 9.00 m,  29.53 ft / 9.00 m
      - Quarter deck:   15.00%,  29.53 ft / 9.00 m,  29.53 ft / 9.00 m
      - Average freeboard:      29.82 ft / 9.09 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 105.0%
      - Above water (accommodation/working, high = better): 250.1%
   Waterplane Area: 41,316 Square feet or 3,838 Square metres
   Displacement factor (Displacement / loading): 130%
   Structure weight / hull surface area: 114 lbs/sq ft or 554 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.93
      - Longitudinal: 1.76
      - Overall: 1.00
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

WP Area allows:  59 planes
48 post-1933 planes

[The Rock Doctor]

My math says this larger carrier could take on 64 aircraft, and it's not a heck of a lot heavier than the 48 plane ship above.



Enter ship name, Enter country Enter ship type laid down 1931

Displacement:
   23,939 t light; 24,795 t standard; 26,598 t normal; 28,040 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (767.13 ft / 741.47 ft) x 88.58 ft x (26.25 / 27.36 ft)
   (233.82 m / 226.00 m) x 27.00 m  x (8.00 / 8.34 m)

Armament:
      14 - 5.12" / 130 mm 45.0 cal guns - 67.61lbs / 30.67kg shells, 500 per gun
     Dual purpose guns in deck and hoist mounts, 1931 Model
     6 x 2-gun mounts on sides, evenly spread
     1 x 2-gun mount on centreline, aft deck aft
      16 - 1.97" / 50.0 mm 60.0 cal guns - 4.18lbs / 1.89kg shells, 1,500 per gun
     Anti-air guns in deck mounts, 1931 Model
     6 x Twin mounts on sides, evenly spread
     2 x Twin mounts on sides, forward deck centre
      2 raised mounts
      16 - 0.59" / 15.0 mm 90.0 cal guns - 0.12lbs / 0.05kg shells, 5,000 per gun
     Machine guns in deck mounts, 1931 Model
     8 x Twin mounts on sides, evenly spread
      Weight of broadside 1,015 lbs / 461 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   3.94" / 100 mm   504.20 ft / 153.68 m   16.37 ft / 4.99 m
   Ends:   Unarmoured
     Main Belt covers 105% of normal length

   - Torpedo Bulkhead - Additional damage containing bulkheads:
      1.97" / 50 mm   504.20 ft / 153.68 m   23.92 ft / 7.29 m
   Beam between torpedo bulkheads 72.18 ft / 22.00 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.97" / 50 mm   1.18" / 30 mm      1.97" / 50 mm
   3rd:   0.79" / 20 mm   0.59" / 15 mm            -
   4th:   0.59" / 15 mm         -               -

   - Armoured deck - single deck:
   For and Aft decks: 1.97" / 50 mm
   Forecastle: 1.97" / 50 mm  Quarter deck: 1.97" / 50 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 4 shafts, 147,453 shp / 110,000 Kw = 32.00 kts
   Range 18,000nm at 10.00 kts
   Bunker at max displacement = 3,245 tons

Complement:
   1,040 - 1,353

Cost:
   £6.768 million / $27.072 million

Distribution of weights at normal displacement:
   Armament: 290 tons, 1.1%
      - Guns: 290 tons, 1.1%
   Armour: 4,006 tons, 15.1%
      - Belts: 1,351 tons, 5.1%
      - Torpedo bulkhead: 878 tons, 3.3%
      - Armament: 110 tons, 0.4%
      - Armour Deck: 1,667 tons, 6.3%
   Machinery: 4,409 tons, 16.6%
   Hull, fittings & equipment: 8,414 tons, 31.6%
   Fuel, ammunition & stores: 2,659 tons, 10.0%
   Miscellaneous weights: 6,820 tons, 25.6%
      - Hull below water: 3,156 tons
      - Hull above water: 3,140 tons
      - On freeboard deck: 224 tons
      - Above deck: 300 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     41,933 lbs / 19,021 Kg = 625.5 x 5.1 " / 130 mm shells or 5.4 torpedoes
   Stability (Unstable if below 1.00): 1.20
   Metacentric height 5.9 ft / 1.8 m
   Roll period: 15.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 100 %
         - Recoil effect (Restricted arc if above 1.00): 0.11
   Seaboat quality  (Average = 1.00): 1.65

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.540 / 0.546
   Length to Beam Ratio: 8.37 : 1
   'Natural speed' for length: 27.23 kts
   Power going to wave formation at top speed: 54 %
   Trim (Max stability = 0, Max steadiness = 100): 62
   Bow angle (Positive = bow angles forward): 20.00 degrees
   Stern overhang: 13.12 ft / 4.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   16.00%,  34.45 ft / 10.50 m,  29.53 ft / 9.00 m
      - Forward deck:   40.00%,  29.53 ft / 9.00 m,  29.53 ft / 9.00 m
      - Aft deck:   28.00%,  29.53 ft / 9.00 m,  29.53 ft / 9.00 m
      - Quarter deck:   16.00%,  29.53 ft / 9.00 m,  29.53 ft / 9.00 m
      - Average freeboard:      29.84 ft / 9.10 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 103.6%
      - Above water (accommodation/working, high = better): 245.6%
   Waterplane Area: 45,411 Square feet or 4,219 Square metres
   Displacement factor (Displacement / loading): 129%
   Structure weight / hull surface area: 121 lbs/sq ft or 592 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.95
      - Longitudinal: 1.56
      - Overall: 1.00
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Excellent seaboat, comfortable, can fire her guns in the heaviest weather

WP Area allows:  64 planes
64 post-1933 planes

[Kaiser Kirk]

...Well....
Technically, I don't see problems except the bow raise.  As written the options are to continue the deck level OR to do a flying off deck. Not a ski ramp. I don't expect it matters much.

The choice to field a 27m beam and 22m inside bulkheads means only a 2.5m deep TDS.
That's not great. Another meter or two depth would be nice.

I will continue to note- as I have in the past-  that for any wars I wind up moderating, the SS listed cruise speed will be assumed to be the speed your ships have gears to economically travel and so default to using. That was, as I understand, what historical cruising speed was. 

They can of course be instructed to maintain higher speeds without an issue – and you've demonstrated the conversion ratio SS is linear.

As a practical matter, subs have trouble making full speeds on the surface except in very good weather, so their ability to move ahead of the fleet, submerge and attack is limited by the defenders speed.  In 1925, only 125t subs can not exceed 10 knots.


Still the ship makes me feel like it's too soon.

Now, my similar ..still smaller...Charmosh was in 1926, and you pointed out it was too early, and .... I agreed. But that was 5 game years... With your vessel, it's less clear here.
It's really a shame we don't have 1929-30 Norse, Roman and Mayan vessels to "drive" that narrative.

But we can judge by your earlier classes.
Your preceding Centaury  class leader was laid down in 1928, so finished in 1929.5,
so it's just a year in service. The second is just finished and on trials.
Yet this doubles the airgroup and increases size by 2/3rds. *
That's a big jump- and a massive investment. What's changed in the strategic situation?

Then there's the budgeting of Misc weight for the future aircraft. On the prior ships you simply list both, which saves you later booking and I envy and wish I did....but I expect I will continue to neglect to do.

But here, at the top of the page you do : 4560 t:  48 x Post-1933 airgroup (BW/AW) – later you lack the weight breakdown, but seem to be budgeting for a full post 1933 airgroup.

Presuming that is what you did, I do object to you using the post 1933 air tech misc weight to budget for the aircraft.

That approach does not seem reasonable until – at the very least- you're researching the tech that unlocks the post-1933 aircraft. ... to me, you don't need and can't Foresee the additional weight until you finish researching the 1934 tech and have access to post 1933 aircraft.

Currently, you just started researching the 1930-1933 aircraft in 1930 HY2.
and so they won't even be ready in 1931 when you propose to lay down this ship.

*Note, your encyclopedia puts it at 15,000 tons, but your warships tab has it at 21,000, so you're paying to much on it.

[The Rock Doctor]

That was more reaction than I anticipated.

Freeboard:  My interpretation was that, for an unarmored carrier, the armor deck = hanger floor = freeboard, so there's another 5.5m to 6 metres of light hanger structure above the 9 metre mark.  The "ski jump" is just a normal rising bow, ending probably 4 metres below the level of the flight deck.


On range:  Fine, I will start changing things.


On aircraft weight:  I disagree.  Aircraft weight has always been rising, perhaps not in a linear progression but rising nonetheless.  They haven't stayed the same from 1915 to 1930.  I think it is entirely reasonable that a carrier designer in 1931 will expect the growth to continue, and have a ballpark sense of minimum aircraft size a mere four years later.

The 1933 tech isn't a breakthrough point.  There's no wild new techIt's just another step in an iterative process.  Historically, the planes didn't make a notable jump in size at this point.  We've simply chosen to impose one - much as the original SS guidelines did for "post WW2" - because it was easier than having to adjust aircraft tech with every single level.

I can change the misc. weight info to also list pre-1933 airgroup composition (57 vs 48, or 76 vs 64).  It doesn't change that I'm designing the ship to handle an airgroup based on the average size of aircraft it will embark for 95% of its service career.


What has changed: By and large, I don't know what has changed; it's nobody's fault, but I have limited insight into what everybody else in Europe is doing right now.  Rome may or may not have 57/44 A/C carriers in service, and it has an enormous amount of land-based airpower.  It is possible that when the Norse and Iberia are caught up, they will have the same.  I don't want to consider myself bound by assumptions about what the rest of Europe may or may not have done.

In the event of a war with either Rome or the Norse, my fleet can only sortie by going around the British Isles, with a significant risk of encountering a lot of that land-based airpower.  Against this, Centaury's airgroup of 35 or 30 planes just isn't going to be enough to defend my surface forces.  I feel a larger complement will be necessary to maintain a sturdy CAP in place at all times.  I have mentioned this perspective, sporadically, for some time now.  It informs Union design, deployment, and fleet structure.

The jump in carrier size from Centaury to the 20,500 t ship is driven by the addition of the torpedo bulkhead.  More than half the size increase is directly the result of adding the bulkhead, its weight, and having to extend the rest of the armor scheme to accommodate the larger volume taken up by vitals. 

And from there, it isn't a huge jump in cost to escalate to the 23,500 t ship.  All other major design points being equal, I gain a 33% increase in airgroup size compared to the 20,500 t ship, but with just a 15% increase in price.  That's a good deal.  I can afford it.  I should be considering it.

[The Rock Doctor]

I appreciate the tip on carrier over-payment.  Obvious somebody is defrauding the government somehow.