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

The Rock Doctor · October 29, 2024, 05:48:21 AM

I hadn't thought about the Furutaka, thanks for the reminder.

Kaiser Kirk · October 29, 2024, 11:51:13 AM

Happy to helpful for once,
... it'll throw people off the track

The Rock Doctor · October 29, 2024, 02:48:51 PM

Furutaka does seem to work. I have to think that foremost turret would be wet, given how close to the bow it is. I'll have to do more reading on that.

Jefgte · October 29, 2024, 04:50:13 PM

Byzantium uses this 6T2x191 layout on its 8000t - 166m x 18.8m cruisers with a more modest speed of 30kts.

I note heavy armor (120mm belt), too much for 150mm guns, I think.
For me, 100mm belt & 6T2x150 is better.

The Rock Doctor · October 29, 2024, 07:12:56 PM

The belt might be heavy for a CL, but I suppose the other consideration is that she might be fighting at close range in crappy north Atlantic weather.

Revised sketch - played with the forward superstructure and funnel to get a more modern look, very vaguely based on the historical Nurnberg.

The Rock Doctor · November 01, 2024, 08:32:27 PM

Although I now find myself leaning towards the small six-gun CL I posted a few pages back. Why? Cost. Last I checked, I reckoned I wanted ten CL for "guard" functions in colonial waters - trade protection, leading torpedo-boat divisions, etc.

And right now I'm scrapping a few of those cruisers, and the rest are all pre-1910 designs that just can't keep up with torpedo-boats or travel long ranges. So I need a bunch of replacements, and pretty quickly.

A group of six lets me put probably two each in North America, Africa, and the Azores, while the South American territories continue to get by with old stuff.

Enter ship name, Enter country Enter ship type laid down 1935

Displacement:
5,998 t light; 6,342 t standard; 7,175 t normal; 7,841 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(545.64 ft / 531.17 ft) x 52.49 ft x (20.01 / 21.29 ft)
(166.31 m / 161.90 m) x 16.00 m x (6.10 / 6.49 m)

Armament:
6 - 5.91" / 150 mm 50.0 cal guns - 121.25lbs / 55.00kg shells, 250 per gun
Quick firing guns in turret on barbette mounts, 1935 Model
3 x 2-gun mounts on centreline ends, majority forward
1 raised mount - superfiring
8 - 3.94" / 100 mm 45.0 cal guns - 30.78lbs / 13.96kg shells, 400 per gun
Anti-air guns in deck mounts, 1935 Model
4 x Twin mounts on side ends, evenly spread
12 - 1.97" / 50.0 mm 60.0 cal guns - 4.19lbs / 1.90kg shells, 1,500 per gun
Anti-air guns in deck mounts, 1935 Model
6 x Twin mounts on sides, evenly spread
2 raised mounts
8 - 0.59" / 15.0 mm 90.0 cal guns - 0.11lbs / 0.05kg shells, 5,000 per gun
Machine guns in deck mounts, 1935 Model
4 x Twin mounts on sides, evenly spread
4 raised mounts
Weight of broadside 1,025 lbs / 465 kg

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 3.54" / 90 mm 345.28 ft / 105.24 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: 5.12" / 130 mm 1.97" / 50 mm 3.54" / 90 mm
2nd: 0.59" / 15 mm 0.12" / 3 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 3.54" / 90 mm, Aft 0.00" / 0 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 65,013 shp / 48,500 Kw = 32.04 kts
Range 8,000nm at 15.00 kts
Bunker at max displacement = 1,499 tons

Complement:
389 - 506

Cost:
£2.817 million / $11.267 million

Distribution of weights at normal displacement:
Armament: 258 tons, 3.6 %
- Guns: 258 tons, 3.6 %
Armour: 1,706 tons, 23.8 %
- Belts: 819 tons, 11.4 %
- Armament: 190 tons, 2.7 %
- Armour Deck: 668 tons, 9.3 %
- Conning Tower: 28 tons, 0.4 %
Machinery: 1,847 tons, 25.7 %
Hull, fittings & equipment: 1,892 tons, 26.4 %
Fuel, ammunition & stores: 1,176 tons, 16.4 %
Miscellaneous weights: 294 tons, 4.1 %
- On freeboard deck: 94 tons
- Above deck: 200 tons

Fittings:
-26 t: 1930 fire control (AD)
-25 t: L/R wireless (AD)
-25 t: Nightfighting doodads (AD)
-25 t: Huelsmeyer device (AD)
-50 t: Command facilities (AD)
-30 t: Armed floatplane and catapult, no hanger (FD)
-24 t: 2x3 530mm torpedo carriages, no reloads (FD)
-49 + 40 t: Weight reserve (AD/FD)

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
6,415 lbs / 2,910 Kg = 62.3 x 5.9 " / 150 mm shells or 1.3 torpedoes
Stability (Unstable if below 1.00): 1.08
Metacentric height 2.2 ft / 0.7 m
Roll period: 14.9 seconds
Steadiness - As gun platform (Average = 50 %): 60 %
- Recoil effect (Restricted arc if above 1.00): 0.41
Seaboat quality (Average = 1.00): 1.08

Hull form characteristics:
Hull has rise forward of midbreak,
a normal bow and small transom stern
Block coefficient (normal/deep): 0.450 / 0.462
Length to Beam Ratio: 10.12 : 1
'Natural speed' for length: 24.80 kts
Power going to wave formation at top speed: 57 %
Trim (Max stability = 0, Max steadiness = 100): 56
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 %, 26.25 ft / 8.00 m, 21.33 ft / 6.50 m
- Forward deck: 30.00 %, 21.33 ft / 6.50 m, 21.33 ft / 6.50 m
- Aft deck: 35.00 %, 13.45 ft / 4.10 m, 13.45 ft / 4.10 m
- Quarter deck: 15.00 %, 13.45 ft / 4.10 m, 13.45 ft / 4.10 m
- Average freeboard: 17.78 ft / 5.42 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 96.8 %
- Above water (accommodation/working, high = better): 152.3 %
Waterplane Area: 18,199 Square feet or 1,691 Square metres
Displacement factor (Displacement / loading): 110 %
Structure weight / hull surface area: 68 lbs/sq ft or 330 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.71
- Longitudinal: 1.15
- Overall: 0.75
Caution: Hull subject to strain in open-sea
Adequate machinery, storage, compartmentation space
Excellent accommodation and workspace room

The Rock Doctor · November 07, 2024, 04:58:08 PM

The Wrona class carriers currently operate 15 modern aircraft, which makes for not-quite-ideal airgroups - usually 8 fighters and 6 or 7 scout-bombers.

A simple refurbishment would see the end armor yanked off and some of the weight reserve used to allow for a bump to 16 aircraft. I'd probably tweak the armament as well. Cost would be in the ballpark of $2.50 and maybe 0.2 BP.

A more elaborate refurbishment would leave the end armor in place but re-engine her as well as re-arming her and allowing some additional topside weight for sensors or comms. The airgroup would increase to 20 modern aircraft. Cost here would be in the ballpark of $5.50 and 3.2 BP.

Enter ship name, Enter country Enter ship type laid down 1925 (Engine 1936)

Displacement:
   11,083 t light; 11,433 t standard; 12,452 t normal; 13,266 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (545.08 ft / 529.20 ft) x 75.79 ft x (22.64 / 23.72 ft)
   (166.14 m / 161.30 m) x 23.10 m x (6.90 / 7.23 m)

Armament:
6 - 5.12" / 130 mm 45.0 cal guns - 67.62lbs / 30.67kg shells, 250 per gun
     Dual purpose guns in deck and hoist mounts, 1925 Model
     1 x 2-gun mount on centreline, aft deck aft
     2 x 2-gun mounts on sides amidships
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, 1925 Model
     6 x Twin mounts on side ends, majority forward
12 - 0.59" / 15.0 mm 90.0 cal guns - 0.11lbs / 0.05kg shells, 4,000 per gun
     Machine guns in deck mounts, 1925 Model
     4 x Single mounts on sides, evenly spread
     4 x Twin mounts on sides, evenly spread
Weight of broadside 457 lbs / 207 kg

Armour:
- Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   2.95" / 75 mm   371.72 ft / 113.30 m   11.81 ft / 3.60 m
   Ends:   1.18" / 30 mm     78.74 ft / 24.00 m   11.81 ft / 3.60 m
     78.74 ft / 24.00 m Unarmoured ends
     Main Belt covers 108 % of normal length

- Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.97" / 50 mm   1.18" / 30 mm      1.97" / 50 mm
   2nd:   0.59" / 15 mm   0.12" / 3 mm        -
   3rd:   0.59" / 15 mm     -           -

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

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 107,238 shp / 80,000 Kw = 32.04 kts
   Range 18,000nm at 10.00 kts
   Bunker at max displacement = 1,833 tons

Complement:
   589 - 766

Cost:
   £2.789 million / $11.154 million

Distribution of weights at normal displacement:
   Armament: 130 tons, 1.0 %
     - Guns: 130 tons, 1.0 %
   Armour: 1,110 tons, 8.9 %
     - Belts: 583 tons, 4.7 %
     - Armament: 45 tons, 0.4 %
     - Armour Deck: 482 tons, 3.9 %
   Machinery: 3,009 tons, 24.2 %
   Hull, fittings & equipment: 4,539 tons, 36.5 %
   Fuel, ammunition & stores: 1,369 tons, 11.0 %
   Miscellaneous weights: 2,295 tons, 18.4 %
     - Hull below water: 962 tons
     - Hull above water: 950 tons
     - On freeboard deck: 113 tons
     - Above deck: 270 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     19,158 lbs / 8,690 Kg = 285.8 x 5.1 " / 130 mm shells or 2.0 torpedoes
   Stability (Unstable if below 1.00): 1.22
   Metacentric height 4.8 ft / 1.4 m
   Roll period: 14.6 seconds
   Steadiness   - As gun platform (Average = 50 %): 89 %
         - Recoil effect (Restricted arc if above 1.00): 0.09
   Seaboat quality (Average = 1.00): 1.48

Hull form characteristics:
   Hull has low forecastle,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.480 / 0.488
   Length to Beam Ratio: 6.98 : 1
   'Natural speed' for length: 23.00 kts
   Power going to wave formation at top speed: 63 %
   Trim (Max stability = 0, Max steadiness = 100): 60
   Bow angle (Positive = bow angles forward): 20.00 degrees
   Stern overhang: 6.56 ft / 2.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
     - Forecastle:   10.00 %, 25.59 ft / 7.80 m, 19.69 ft / 6.00 m
     - Forward deck:   40.00 %, 29.53 ft / 9.00 m, 29.53 ft / 9.00 m
     - Aft deck:   40.00 %, 29.53 ft / 9.00 m, 29.53 ft / 9.00 m
     - Quarter deck:   10.00 %, 29.53 ft / 9.00 m, 29.53 ft / 9.00 m
     - Average freeboard:      28.78 ft / 8.77 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 99.2 %
      - Above water (accommodation/working, high = better): 250.6 %
   Waterplane Area: 26,247 Square feet or 2,438 Square metres
   Displacement factor (Displacement / loading): 127 %
   Structure weight / hull surface area: 103 lbs/sq ft or 502 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.87
      - Longitudinal: 3.38
      - Overall: 1.00
   Adequate 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

WP area = 2438/77 = 31.6
Original airgroup was 18/15
Revised airgroup would be 23.75/20

The Rock Doctor · November 09, 2024, 03:57:59 PM

What the Union is calling a "turtle carrier" but we'd call an armored box carrier. The notion is that she's primarily operating in the North Sea, providing air cover to the battleline but "turtling" under her armor when necessary to endure air attack.

The flight deck itself is the whole 3" armor deck, with armored hanger walls, side, and belt armor from +12 meters to ~-2.4 metres below water. This protection is...mostly...adequate to withstand DD/CL fire, and the main battery will give out a nice number of shells to hit back at surface attackers.

On the other hand, she is slower than enemy cruisers. On the gripping hand, her seakeeping is such that she'd be running pretty well in stormy Atlantic weather compared to the much smaller, lower-freeboard cruisers in question, so I dunno. The 16t of weight in "void" is four fixed-tube 530mm torpedoes, firing aft, as further dis-incentive for enemy attackers to follow her.

Miscellaneous weight would be about the same distribution as the Hydry class carriers - flight ops, flag facilities, comms and sensors.

Enter ship name, Enter country Enter ship type laid down 1936

Displacement:
26,989 t light; 27,898 t standard; 30,401 t normal; 32,403 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(829.62 ft / 789.04 ft) x 95.14 ft x (26.25 / 27.56 ft)
(252.87 m / 240.50 m) x 29.00 m x (8.00 / 8.40 m)

Armament:
16 - 5.12" / 130 mm 45.0 cal guns - 67.62lbs / 30.67kg shells, 400 per gun
Dual purpose guns in deck and hoist mounts, 1936 Model
8 x 2-gun mounts on sides, evenly spread
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, 1936 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 - 0.11lbs / 0.05kg shells, 5,000 per gun
Machine guns in deck mounts, 1936 Model
8 x Twin mounts on sides, evenly spread
Weight of broadside 1,151 lbs / 522 kg

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 2.95" / 75 mm 512.89 ft / 156.33 m 16.37 ft / 4.99 m
Ends: Unarmoured
Upper: 2.95" / 75 mm 512.89 ft / 156.33 m 31.50 ft / 9.60 m
Main Belt covers 100 % of normal length

- Torpedo Bulkhead - Additional damage containing bulkheads:
1.97" / 50 mm 512.89 ft / 156.33 m 23.92 ft / 7.29 m
Beam between torpedo bulkheads 65.62 ft / 20.00 m

- Hull void:
0.00" / 0 mm 0.00 ft / 0.00 m 0.00 ft / 0.00 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: 0.59" / 15 mm - -
4th: 0.59" / 15 mm - -

- Armoured deck - single deck:
For and Aft decks: 2.95" / 75 mm
Forecastle: 0.98" / 25 mm Quarter deck: 0.98" / 25 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 128,686 shp / 96,000 Kw = 31.00 kts
Range 10,000nm at 15.00 kts
Bunker at max displacement = 4,505 tons

Complement:
1,150 - 1,496

Cost:
£8.219 million / $32.876 million

Distribution of weights at normal displacement:
Armament: 328 tons, 1.1 %
- Guns: 328 tons, 1.1 %
Armour: 6,611 tons, 21.7 %
- Belts: 3,049 tons, 10.0 %
- Torpedo bulkhead: 893 tons, 2.9 %
- Armament: 103 tons, 0.3 %
- Armour Deck: 2,565 tons, 8.4 %
Machinery: 3,611 tons, 11.9 %
Hull, fittings & equipment: 11,358 tons, 37.4 %
Fuel, ammunition & stores: 3,412 tons, 11.2 %
Miscellaneous weights: 5,081 tons, 16.7 %
- Hull below water: 2,280 tons
- Hull void weights: 16 tons
- Hull above water: 2,280 tons
- On freeboard deck: 205 tons
- Above deck: 300 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
84,986 lbs / 38,549 Kg = 1,267.8 x 5.1 " / 130 mm shells or 12.1 torpedoes
Stability (Unstable if below 1.00): 1.29
Metacentric height 7.3 ft / 2.2 m
Roll period: 14.8 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.09
Seaboat quality (Average = 1.00): 2.00

Hull form characteristics:
Hull has a flush deck,
a normal bow and small transom stern
Block coefficient (normal/deep): 0.540 / 0.548
Length to Beam Ratio: 8.29 : 1
'Natural speed' for length: 30.32 kts
Power going to wave formation at top speed: 51 %
Trim (Max stability = 0, Max steadiness = 100): 35
Bow angle (Positive = bow angles forward): 20.00 degrees
Stern overhang: 26.25 ft / 8.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00 %, 39.37 ft / 12.00 m, 39.37 ft / 12.00 m
- Forward deck: 30.00 %, 39.37 ft / 12.00 m, 39.37 ft / 12.00 m
- Aft deck: 35.00 %, 39.37 ft / 12.00 m, 39.37 ft / 12.00 m
- Quarter deck: 15.00 %, 39.37 ft / 12.00 m, 39.37 ft / 12.00 m
- Average freeboard: 39.37 ft / 12.00 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 86.9 %
- Above water (accommodation/working, high = better): 346.8 %
Waterplane Area: 53,177 Square feet or 4,940 Square metres
Displacement factor (Displacement / loading): 152 %
Structure weight / hull surface area: 126 lbs/sq ft or 613 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.88
- Longitudinal: 2.89
- 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

48 post-1933 planes by weight
64 by waterplane

The Rock Doctor · November 09, 2024, 03:58:56 PM

For the sake of comparison, a similar-sized vessel built to non-box conventions has 72 planes and 32 knots, and a 100mm belt.

The Rock Doctor · November 09, 2024, 05:39:01 PM

And with a 229 x 29 x 8.4 hull, and a 50mm upper belt, I can get 56 planes and 32 knots.

Though the upper belt isn't going to keep out cruiser shells.

The Rock Doctor · November 17, 2024, 06:40:00 PM

This is a semi-turtle, an armored box carrier with armored flight deck but unarmored sides.

The flight deck is 75mm, and the lower splinter deck is level with the top of the main belt. So around 2.4 - 3.0 metres above water, I dunno.

The hanger is thus vulnerable to shallow shell fire, but with a good top speed, the usual stern-mounted torpedoes, a reasonable airgroup and - oh yes - escorts, the risk of surface engagement in the North Sea is judged to be lower than the risk of aircraft or mines/submarines.

56 aircraft is 3.5 Union squadrons, so probably two full squadrons of fighters and then maybe two 12-plane squadrons of torpedo and scout bombers.

A 29,000 t variant embarks 64 aircraft and a modestly heavier TDS thickness. Eight extra planes for 2,000 tonnes is kind of pricey, I admit.

Enter ship name, Enter country Enter ship type laid down 1936

Displacement:
   26,995 t light; 27,904 t standard; 30,394 t normal; 32,387 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (812.32 ft / 751.31 ft) x 95.14 ft x (27.56 / 28.94 ft)
   (247.60 m / 229.00 m) x 29.00 m x (8.40 / 8.82 m)

Armament:
16 - 5.12" / 130 mm 45.0 cal guns - 67.62lbs / 30.67kg shells, 400 per gun
     Dual purpose guns in deck and hoist mounts, 1936 Model
     8 x 2-gun mounts on sides, evenly spread
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, 1936 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 - 0.11lbs / 0.05kg shells, 5,000 per gun
     Machine guns in deck mounts, 1936 Model
     8 x Twin mounts on sides, evenly spread
Weight of broadside 1,151 lbs / 522 kg

Armour:
- Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   3.94" / 100 mm   488.35 ft / 148.85 m   16.37 ft / 4.99 m
   Ends:   Unarmoured
     Main Belt covers 100 % of normal length

- Torpedo Bulkhead - Additional damage containing bulkheads:
      1.97" / 50 mm   488.35 ft / 148.85 m   25.13 ft / 7.66 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:   0.59" / 15 mm     -           -
   4th:   0.59" / 15 mm     -           -

- Armoured deck - single deck: No this is multiple decks.
   For and Aft decks: 3.94" / 100 mm (75mm flight deck, 25mm above vitals.
   Forecastle: 0.98" / 25 mm Quarter deck: 0.98" / 25 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 4 shafts, 148,793 shp / 111,000 Kw = 32.05 kts
   Range 10,000nm at 15.00 kts
   Bunker at max displacement = 4,483 tons

Complement:
   1,150 - 1,496

Cost:
   £8.637 million / $34.547 million

Distribution of weights at normal displacement:
   Armament: 328 tons, 1.1 %
     - Guns: 328 tons, 1.1 %
   Armour: 5,528 tons, 18.2 %
     - Belts: 1,332 tons, 4.4 %
     - Torpedo bulkhead: 894 tons, 2.9 %
     - Armament: 103 tons, 0.3 %
     - Armour Deck: 3,199 tons, 10.5 %
   Machinery: 4,175 tons, 13.7 %
   Hull, fittings & equipment: 10,958 tons, 36.1 %
   Fuel, ammunition & stores: 3,399 tons, 11.2 %
   Miscellaneous weights: 6,006 tons, 19.8 %
     - Hull below water: 2,676 tons
     - Hull above water: 2,660 tons
     - On freeboard deck: 270 tons
     - Above deck: 400 tons

-2660/2660 t: 56 post-1933 planes BW/AW
-16 t: 4x1 530mm heavyweight torpedoes - I might move these to above water
-670 t: All the usual carrier fixings - catapults, flag and operations, sensors.

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     73,238 lbs / 33,220 Kg = 1,092.5 x 5.1 " / 130 mm shells or 9.6 torpedoes
   Stability (Unstable if below 1.00): 1.34
   Metacentric height 7.8 ft / 2.4 m
   Roll period: 14.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.09
   Seaboat quality (Average = 1.00): 2.00

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and small transom stern
   Block coefficient (normal/deep): 0.540 / 0.548
   Length to Beam Ratio: 7.90 : 1
   'Natural speed' for length: 29.65 kts
   Power going to wave formation at top speed: 55 %
   Trim (Max stability = 0, Max steadiness = 100): 35
   Bow angle (Positive = bow angles forward): 25.00 degrees
   Stern overhang: 42.65 ft / 13.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
     - Forecastle:   20.00 %, 39.37 ft / 12.00 m, 39.37 ft / 12.00 m
     - Forward deck:   30.00 %, 39.37 ft / 12.00 m, 39.37 ft / 12.00 m
     - Aft deck:   35.00 %, 39.37 ft / 12.00 m, 39.37 ft / 12.00 m
     - Quarter deck:   15.00 %, 39.37 ft / 12.00 m, 39.37 ft / 12.00 m
     - Average freeboard:      39.37 ft / 12.00 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 90.4 %
      - Above water (accommodation/working, high = better): 330.2 %
   Waterplane Area: 50,634 Square feet or 4,704 Square metres
   Displacement factor (Displacement / loading): 145 %
   Structure weight / hull surface area: 126 lbs/sq ft or 617 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.87
      - Longitudinal: 3.19
      - 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

56 post-1933 planes by weight
62 by waterplane

Kaiser Kirk · November 18, 2024, 01:04:43 PM

Hmm, I commented how much I dislike this notion, but it seems to have wandered off.

Basically - the high unarmored sides and ends around the citadel would allow a substantive portion of shells and bombs to simply go around the armor.

We have this concept that only a small % of shells will hit a main belt. Which is correct as the main belts are a couple meters above water and several below. But in a battleship those unarmored areas are designed to be non-mission critical, that is not the case in a carrier.

The carrier has 12m high walls that make great targets at long range. While a dive bomber along the axis that hits the stern could easily have the bomb pass 'below' the flight deck and detonate. Same for bombs from the sides.

Meanwhile the 25mm splinter deck would not be dealing with mere splinters and ejecta from a penetrated main deck, but rather directly exposed and inadequate against all but the smaller rounds.

The last note is interior TDS beam. 29-22=7/2 = 3.5m on each side. Not bad, but for a big expensive ship if it could be 4,4.5 or 5+, that would be nice.

The Rock Doctor · November 19, 2024, 06:47:14 PM

The march of technology means that I can make incremental improvements to the 1931 harbour patrol boat. Lighter machinery means more bunkerage, slightly greater freeboard, and a proper AA gun with more ammunition.

Same displacement and length, so that keeps the construction logistics simple enough.

I toggled transom sterns to see what would happen and both large and small options made things worse. So the cruiser stern stayed.

Enter ship name, Enter country Enter ship type laid down 1935

Displacement:
   53 t light; 57 t standard; 58 t normal; 59 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (84.41 ft / 78.74 ft) x 13.12 ft x (3.94 / 3.99 ft)
   (25.73 m / 24.00 m) x 4.00 m x (1.20 / 1.22 m)

Armament:
1 - 1.97" / 50.0 mm 60.0 cal gun - 4.18lbs / 1.89kg shells, 1,000 per gun
     Anti-air gun in deck mount, 1935 Model
     1 x Single mount on centreline forward
2 - 0.59" / 15.0 mm 90.0 cal guns - 0.12lbs / 0.05kg shells, 4,000 per gun
     Machine guns in deck mounts, 1935 Model
     1 x Single mount on centreline, aft deck centre
     1 x Single mount on centreline, forward deck aft
      1 raised mount
Weight of broadside 4 lbs / 2 kg

Armour:
- Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.59" / 15 mm   0.12" / 3 mm        -
   2nd:   0.59" / 15 mm     -           -

- Conning towers: Forward 0.79" / 20 mm, Aft 0.00" / 0 mm

Machinery:
   Diesel Internal combustion motors,
   Electric cruising motors plus geared drives, 2 shafts, 402 shp / 300 Kw = 14.78 kts
   Range 400nm at 10.00 kts
   Bunker at max displacement = 2 tons

Complement:
   9 - 13

Cost:
   £0.020 million / $0.079 million

Distribution of weights at normal displacement:
   Armament: 1 tons, 2.6 %
     - Guns: 1 tons, 2.6 %
   Armour: 3 tons, 4.9 %
     - Armament: 3 tons, 4.4 %
     - Conning Tower: 0 tons, 0.4 %
   Machinery: 11 tons, 19.6 %
   Hull, fittings & equipment: 19 tons, 32.8 %
   Fuel, ammunition & stores: 5 tons, 9.2 %
   Miscellaneous weights: 18 tons, 31.0 %
     - Hull below water: 11 tons - D-E machinery and basic hydrophones
     - On freeboard deck: 6 tons - ASW and/or marines
     - Above deck: 1 tons - a searchlight

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     81 lbs / 37 Kg = 21.3 x 2.0 " / 50 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.20
   Metacentric height 0.3 ft / 0.1 m
   Roll period: 9.6 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.13
   Seaboat quality (Average = 1.00): 1.49

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.500 / 0.502
   Length to Beam Ratio: 6.00 : 1
   'Natural speed' for length: 8.87 kts
   Power going to wave formation at top speed: 71 %
   Trim (Max stability = 0, Max steadiness = 100): 47
   Bow angle (Positive = bow angles forward): 20.00 degrees
   Stern overhang: 1.97 ft / 0.60 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
     - Forecastle:   25.00 %, 10.17 ft / 3.10 m, 8.20 ft / 2.50 m
     - Forward deck:   25.00 %, 8.20 ft / 2.50 m, 6.23 ft / 1.90 m
     - Aft deck:   35.00 %, 6.23 ft / 1.90 m, 6.23 ft / 1.90 m
     - Quarter deck:   15.00 %, 6.23 ft / 1.90 m, 6.23 ft / 1.90 m
     - Average freeboard:      7.17 ft / 2.19 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 95.9 %
      - Above water (accommodation/working, high = better): 96.8 %
   Waterplane Area: 688 Square feet or 64 Square metres
   Displacement factor (Displacement / loading): 122 %
   Structure weight / hull surface area: 13 lbs/sq ft or 61 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.56
      - Longitudinal: 11.29
      - Overall: 0.75
   Caution: Hull subject to strain in open-sea
   Adequate machinery, storage, compartmentation space
   Adequate accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

Kaiser Kirk · November 19, 2024, 07:23:26 PM

I should see what I can do with my 60ton Motor Gun Boat. :)

The Rock Doctor · November 19, 2024, 08:05:07 PM

The small slow stuff's still worth tweaking every 4-5 years.