SDN World 3 Ship Design Thread

[CmdrWilkens]

Is your belt internal, Wilks?

My belt? Its an angled belt descending at 18 deg from the point where the deck and belt meet for a height of 20' (which oddly enough should cover the entire freeboard to the waterline while the torpedo belt rises above the draft.

[CmdrWilkens]

So something I've noticed that I'm not sure everyone is aware but the number of torpedo hits (on the non-crit survivability section) a ship can sustain is highly dependent on whether or not the ship itself carriers torpedoes.

If the ship does carry torpedoes SpringSharp calculates the number of hits by a similar class torpedo...if it does not then SpringSharp calculates against a default super heavy torpedo (something like a Mk 48 or something). In other words those numbers are non-comparable between ships with and without torpedoes.

[Fingolfin_Noldor]

So something I've noticed that I'm not sure everyone is aware but the number of torpedo hits (on the non-crit survivability section) a ship can sustain is highly dependent on whether or not the ship itself carriers torpedoes.

If the ship does carry torpedoes SpringSharp calculates the number of hits by a similar class torpedo...if it does not then SpringSharp calculates against a default super heavy torpedo (something like a Mk 48 or something). In other words those numbers are non-comparable between ships with and without torpedoes.

Spring Sharp doesn't even bother factoring in the distance between the bulkheads. So I wouldn't put too much stock on it.

[Sea Skimmer]

Yeah, the torpedo resistance figures for Springsharp are pretty much bullshit. Even if you exactly evenly optimally flooded a ship many of the results it claims are just impossible. It’s pretty much just based on how big the ship is and how much the armor weighs. The figures for shell resistance are little better. Rick Robinson threw that in mainly for the hell of it not because he thought it was very accurate, though the figures are 'okay' for heavy cruisers.

I mean that 60,000 ton battleship I designed; Springsharp thought it could survive 48 torpedo hits which is completely preposterous. In reality only one battleship ever made it back home after taking more then one torpedo hit on the open sea, and while ships could be expected to do better anything more then perhaps 5 hits on a battleship of that scale is almost surely going to bring it to a halt if not sink it outright. Especially in the 1920s when no one had unit machinery.

[CmdrWilkens]

So as I've mentioned this is a work in progress. I've decided to shift the construction date back to 1928 both because I want to have more slips available for construction and because I need to procure a new Destroyer and Cruiser class in 1927 so from a points perspective it just wouldn't work otherwise. Anyway these figures are subject to change up until Q2 1928 (assuming construction starts Q1 1928)

Wilkonia, Mexico Battleship laid down 1928

Displacement:
57,394 t light; 60,422 t standard; 64,000 t normal; 66,862 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(881.60 ft / 873.00 ft) x 112.00 ft (Bulges 122.00 ft) x (36.00 / 37.42 ft)
(268.71 m / 266.09 m) x 34.14 m (Bulges 37.19 m) x (10.97 / 11.41 m)

Armament:
10 - 18.00" / 457 mm 45.0 cal guns - 2,940.00lbs / 1,333.56kg shells, 100 per gun
Breech loading guns in turret on barbette mounts, 1925 Model
2 x 2-gun mounts on centreline ends, evenly spread
2 raised mounts - superfiring
2 x 3-gun mounts on centreline ends, evenly spread
12 - 5.00" / 127 mm 38.0 cal guns - 59.33lbs / 26.91kg shells, 120 per gun
Quick firing guns in deck and hoist mounts, 1916 Model
6 x 2-gun mounts on side ends, majority aft
16 - 2.95" / 75.0 mm 39.0 cal guns - 12.28lbs / 5.57kg shells, 600 per gun
Dual purpose guns in deck mounts, 1922 Model
4 x 2 row quad mounts on sides, evenly spread
16 - 0.79" / 20.0 mm 39.0 cal guns - 0.23lbs / 0.11kg shells, 600 per gun
Anti-air guns in deck mounts, 1922 Model
4 x 2 row quad mounts on sides, evenly spread
16 - 0.50" / 12.7 mm 12.0 cal guns - 0.05lbs / 0.02kg shells, 150 per gun
Breech loading guns in deck mounts, 1909 Model
8 x Single mounts on sides, forward deck aft
8 x Single mounts on sides, aft deck aft
Weight of broadside 30,313 lbs / 13,750 kg

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 18.8" / 476 mm 460.00 ft / 140.21 m 20.00 ft / 6.10 m
Ends: Unarmoured
Main Belt covers 81 % of normal length
Main Belt inclined 18.00 degrees (positive = in)

- Torpedo Bulkhead - Strengthened structural bulkheads:
4.00" / 102 mm 850.00 ft / 259.08 m 36.00 ft / 10.97 m
Beam between torpedo bulkheads 112.00 ft / 34.14 m

- Hull Bulges:
1.00" / 25 mm 850.00 ft / 259.08 m 36.00 ft / 10.97 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 18.0" / 457 mm 12.0" / 305 mm 18.0" / 457 mm
2nd: 2.00" / 51 mm 1.00" / 25 mm 1.00" / 25 mm

- Armoured deck - multiple decks:
For and Aft decks: 8.50" / 216 mm
Forecastle: 1.00" / 25 mm Quarter deck: 1.00" / 25 mm

- Conning towers: Forward 16.00" / 406 mm, Aft 16.00" / 406 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 146,708 shp / 109,444 Kw = 28.00 kts
Range 10,000nm at 14.00 kts
Bunker at max displacement = 6,440 tons

Complement:
2,011 - 2,615

Cost:
£20.826 million / $83.306 million

Distribution of weights at normal displacement:
Armament: 5,718 tons, 8.9 %
- Guns: 5,718 tons, 8.9 %
Armour: 29,937 tons, 46.8 %
- Belts: 7,643 tons, 11.9 %
- Torpedo bulkhead: 4,529 tons, 7.1 %
- Bulges: 1,132 tons, 1.8 %
- Armament: 6,323 tons, 9.9 %
- Armour Deck: 9,206 tons, 14.4 %
- Conning Towers: 1,103 tons, 1.7 %
Machinery: 4,567 tons, 7.1 %
Hull, fittings & equipment: 17,172 tons, 26.8 %
Fuel, ammunition & stores: 6,606 tons, 10.3 %
Miscellaneous weights: 0 tons, 0.0 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
81,130 lbs / 36,800 Kg = 27.8 x 18.0 " / 457 mm shells or 17.7 torpedoes
Stability (Unstable if below 1.00): 1.02
Metacentric height 6.2 ft / 1.9 m
Roll period: 20.6 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.69
Seaboat quality (Average = 1.00): 1.11

Hull form characteristics:
Hull has a flush deck,
a normal bow and a cruiser stern
Block coefficient (normal/deep): 0.584 / 0.587
Length to Beam Ratio: 7.16 : 1
'Natural speed' for length: 29.55 kts
Power going to wave formation at top speed: 47 %
Trim (Max stability = 0, Max steadiness = 100): 63
Bow angle (Positive = bow angles forward): 16.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 18.00 %, 30.00 ft / 9.14 m, 19.00 ft / 5.79 m
- Forward deck: 32.00 %, 19.00 ft / 5.79 m, 19.00 ft / 5.79 m
- Aft deck: 32.00 %, 19.00 ft / 5.79 m, 19.00 ft / 5.79 m
- Quarter deck: 18.00 %, 19.00 ft / 5.79 m, 19.00 ft / 5.79 m
- Average freeboard: 19.79 ft / 6.03 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 63.3 %
- Above water (accommodation/working, high = better): 126.8 %
Waterplane Area: 70,463 Square feet or 6,546 Square metres
Displacement factor (Displacement / loading): 97 %
Structure weight / hull surface area: 244 lbs/sq ft or 1,193 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.99
- Longitudinal: 1.02
- Overall: 1.00
Excellent machinery, storage, compartmentation space
Excellent accommodation and workspace room
Ship has slow, easy roll, a good, steady gun platform

Just as a point to what I was saying earlier, I briefly gave the ship two 21"x 8' torpedoes and the torpedo hits result changed to this:

Survivability (Non-critical penetrating hits needed to sink ship):
81,130 lbs / 36,800 Kg = 27.8 x 18.0 " / 457 mm shells or 37.3 torpedoes

[Steve]

18.8" armor now? Honestly, I think 16" would be pushing it. Manufacturing plates that thick will be absolute hell and would realistically also hike the ship's costs greatly.

[Fingolfin_Noldor]

18.8" armor now? Honestly, I think 16" would be pushing it. Manufacturing plates that thick will be absolute hell and would realistically also hike the ship's costs greatly.

I'm not sure about technology then, but from what I read here and there, armor plates aren't that homogeneous, and rather are multilayered.

Of course, riveting the whole lot would be a glorious pain with many riveters cursing the Chief Constructor.

[CmdrWilkens]

18.8" armor now? Honestly, I think 16" would be pushing it. Manufacturing plates that thick will be absolute hell and would realistically also hike the ship's costs greatly.

Its a variant on what was done with the North Carolina class (though with slightly greater thicknesses) with the alternated layers of armor. In this case my design idea is that there is a .8" layer of STS capped by a 16" Class B (or homogeneous) plate capped by a 2" Class A (or Face hardened) plate. The welding and riveting of this scheme is ridiculous but, again by almost brute force she would be immune from both flat and plunging fire over a huge range, during which her heavy guns can tell against almost anybody else's design.

Also $83 mil is certainly the costliest design I've seen (hell my 1925-series BC is only $67 mil by comparison)


As an addendum, making plate of this size IS possible. The turret plates on the Yamato class were 26" of face-hardened non-cemented armor. Also edited to reflect, the face hardened plate is the outermost layer and is designed as an AP cap breaker in addition to normal duties. It should defeat AP caps on all shells of 24" class or below.

[Steve]

Talked about this with one of my naval enthusiast friends:

[23:37] Sunhawk2: the welding and riveting is beyond ridiculous
[23:37] Sunhawk2: in order to do the capping he'd have to be either including mini framing between the layers or penetrating the armored faces for the bolts, which critically weakens the entire plate
[23:38] Sunhawk2: there are reasons WELL beyond the WNT that armor thickness remained a constant
[23:38] sbbigsteve: Both do?
[23:38] sbbigsteve: Well, he seems intent on building it.
[23:39] Sunhawk2: he would need to attach the STS to the Class A, which would require armor bolts or welding penetrating the outer (armored) face of the Class A
[23:39] Sunhawk2: then he'd be bolting to the Class B, which would AGAIN require face penetrations
[23:39] Sunhawk2: there's a reason that on all battleships immense care was taken to NEVER break the outer face of the armor plates with bolts, it compromises the entire plate

[CmdrWilkens]

Fair enough, I'll go with face-hardened, 18 degree angled plate armor. It should be doable as, again, the Japanese produced a 26" plate. So it may suffer from some problems and I may need to go with homogeneous rather than face-hardened but at proper angles this would still be proof against virtually every other shell out there.

Note again for the record: this is WIP so the armor scheme may change.

[Fingolfin_Noldor]

Fair enough, I'll go with face-hardened, 18 degree angled plate armor. It should be doable as, again, the Japanese produced a 26" plate. So it may suffer from some problems and I may need to go with homogeneous rather than face-hardened but at proper angles this would still be proof against virtually every other shell out there.

Note again for the record: this is WIP so the armor scheme may change.

I recall Skimmer mentioning that for the most part, turret armor tends to be thicker, largely because say the front has a habit of being weaker due ot the holes for the guns.

[CmdrWilkens]

Fair enough, I'll go with face-hardened, 18 degree angled plate armor. It should be doable as, again, the Japanese produced a 26" plate. So it may suffer from some problems and I may need to go with homogeneous rather than face-hardened but at proper angles this would still be proof against virtually every other shell out there.

Note again for the record: this is WIP so the armor scheme may change.

I recall Skimmer mentioning that for the most part, turret armor tends to be thicker, largely because say the front has a habit of being weaker due ot the holes for the guns.

Yes but the thicker armor is proof that such plate manufacture is both possible and probable which is what I need. Yes the expense would be huge (again costliest ship anybody has proposed) but its doable, which seemed to be Steve's initial objection.

I may end up doing it as just 18" plate with .8" STS backing plates. The Montana class included tranverse bulkheads up to 18" and forward plates on the turrets of 18" with 4.5" backing plates, in other words I know 18" with STS backing is doable.

[Steve]

Turret plates are also much smaller. It's not so much making a plate thick, 18" or more, it's making it that thick but also 15+ feet high and much, much longer.

[Ma Deuce]

I may end up doing it as just 18" plate with .8" STS backing plates. The Montana class included tranverse bulkheads up to 18" and forward plates on the turrets of 18" with 4.5" backing plates, in other words I know 18" with STS backing is doable.

Yeah, but this is the '20s not the '40s. Armor manufacturing is less advanced in this period, and the quality of a face-hardened plate WILL degrade past 13.5-14 inches. It is certainly possible to make it thicker if you want, but past that thickness the law of diminishing returns will kick in and protection will no longer increase proportionally with thickness. There's a reason why US battleships all the way through the South Dakota (BB49) class never went past 13.5 inch belts, and the Germans never went past 13.8 inches, despite the fact that both nations' navies placed a very heavy emphasis on armor protection at the time. To my knowledge, the only design actually approved for construction that had a thicker belt in this time period was the N3, which was 15 inches.

BTW, I'm pretty sure Springsharp accounts for the backing plate already, since it is part of the hull structure. All you need to enter is the thickness of the armor plate itself.

My belt? Its an angled belt descending at 18 deg from the point where the deck and belt meet for a height of 20' (which oddly enough should cover the entire freeboard to the waterline while the torpedo belt rises above the draft.

Bad idea. The main belt has to be taken a few feet below the waterline (6 feet should be good, though a 20 foot tall belt should have enough excess height to go 8 feet deep) to stop underwater shell hits, which are no small concern. Torpedoes are not going to run at the surface anyway (unless they're malfunctioning), and if they do run shallow enough to hit the main belt will usually prove ineffective, though they might dislodge a belt plate or two.

[Fingolfin_Noldor]

This is one of the 18"/45 gun designs that is currently being considered for construction. I might tweak it some more to extract as much speed as possible, but this may well be the final word on the design.:

John II Komnenos, Byzantine Empire Battleship laid down 1926

Displacement:
51,509 t light; 55,020 t standard; 58,444 t normal; 61,183 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(855.56 ft / 836.61 ft) x 108.27 ft (Bulges 114.83 ft) x (36.09 / 37.55 ft)
(260.77 m / 255.00 m) x 33.00 m (Bulges 35.00 m) x (11.00 / 11.45 m)

Armament:
9 - 18.00" / 457 mm 45.0 cal guns - 3,000.01lbs / 1,360.78kg shells, 100 per gun
Breech loading guns in turret on barbette mounts, 1926 Model
3 x 3-gun mounts on centreline ends, majority forward
1 raised mount - superfiring
16 - 5.00" / 127 mm 38.0 cal guns - 59.33lbs / 26.91kg shells, 1,400 per gun
Dual purpose guns in deck and hoist mounts, 1926 Model
8 x 2-gun mounts on sides, evenly spread
4 raised mounts
40 - 1.57" / 40.0 mm 56.0 cal guns - 2.12lbs / 0.96kg shells, 2,000 per gun
Anti-air guns in deck mounts, 1926 Model
8 x Twin mounts on side ends, evenly spread
4 raised mounts - superfiring
40 - 0.79" / 20.0 mm 39.0 cal guns - 0.22lbs / 0.10kg shells, 2,000 per gun
Anti-air guns in deck mounts, 1926 Model
8 x Quad mounts on side ends, evenly spread
16 - 0.50" / 12.7 mm 12.0 cal guns - 0.05lbs / 0.02kg shells, 500 per gun
Anti-air guns in deck mounts, 1926 Model
16 x Single mounts on centreline, aft deck forward
Weight of broadside 28,044 lbs / 12,720 kg

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 16.0" / 406 mm 500.00 ft / 152.40 m 21.00 ft / 6.40 m
Ends: Unarmoured
Main Belt covers 92 % of normal length
Main Belt inclined 19.00 degrees (positive = in)

- Torpedo Bulkhead - Additional damage containing bulkheads:
4.00" / 102 mm 450.00 ft / 137.16 m 30.00 ft / 9.14 m
Beam between torpedo bulkheads 68.00 ft / 20.73 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 21.0" / 533 mm 16.0" / 406 mm 18.0" / 457 mm
2nd: 2.50" / 64 mm 2.50" / 64 mm 2.50" / 64 mm
3rd: 0.50" / 13 mm - -
4th: 0.50" / 13 mm - -
5th: 0.50" / 13 mm - -

- Armoured deck - multiple decks:
For and Aft decks: 8.50" / 216 mm
Forecastle: 2.00" / 51 mm Quarter deck: 2.00" / 51 mm

- Conning towers: Forward 16.00" / 406 mm, Aft 3.00" / 76 mm

Machinery:
Oil fired boilers, steam turbines,
Electric motors, 4 shafts, 57,041 shp / 42,553 Kw = 22.00 kts
Range 10,000nm at 14.00 kts
Bunker at max displacement = 6,163 tons

Complement:
1,879 - 2,443

Cost:
£15.920 million / $63.681 million

Distribution of weights at normal displacement:
Armament: 5,223 tons, 8.9 %
- Guns: 5,223 tons, 8.9 %
Armour: 24,408 tons, 41.8 %
- Belts: 7,263 tons, 12.4 %
- Torpedo bulkhead: 1,998 tons, 3.4 %
- Armament: 5,608 tons, 9.6 %
- Armour Deck: 8,922 tons, 15.3 %
- Conning Towers: 616 tons, 1.1 %
Machinery: 1,826 tons, 3.1 %
Hull, fittings & equipment: 19,957 tons, 34.1 %
Fuel, ammunition & stores: 6,935 tons, 11.9 %
Miscellaneous weights: 95 tons, 0.2 %
- Hull above water: 20 tons
- On freeboard deck: 75 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
92,829 lbs / 42,106 Kg = 31.8 x 18.0 " / 457 mm shells or 19.1 torpedoes
Stability (Unstable if below 1.00): 1.02
Metacentric height 5.9 ft / 1.8 m
Roll period: 19.9 seconds
Steadiness - As gun platform (Average = 50 %): 71 %
- Recoil effect (Restricted arc if above 1.00): 0.79
Seaboat quality (Average = 1.00): 1.22

Hull form characteristics:
Hull has a flush deck,
an extended bulbous bow and a round stern
Block coefficient (normal/deep): 0.590 / 0.594
Length to Beam Ratio: 7.29 : 1
'Natural speed' for length: 28.92 kts
Power going to wave formation at top speed: 35 %
Trim (Max stability = 0, Max steadiness = 100): 58
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20.00 %, 32.81 ft / 10.00 m, 19.69 ft / 6.00 m
- Forward deck: 30.00 %, 19.69 ft / 6.00 m, 19.69 ft / 6.00 m
- Aft deck: 35.00 %, 19.69 ft / 6.00 m, 19.69 ft / 6.00 m
- Quarter deck: 15.00 %, 19.69 ft / 6.00 m, 19.69 ft / 6.00 m
- Average freeboard: 20.73 ft / 6.32 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 82.4 %
- Above water (accommodation/working, high = better): 131.0 %
Waterplane Area: 65,631 Square feet or 6,097 Square metres
Displacement factor (Displacement / loading): 111 %
Structure weight / hull surface area: 238 lbs/sq ft or 1,162 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.98
- Longitudinal: 1.12
- 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

[Sea Skimmer]

Fair enough, I'll go with face-hardened, 18 degree angled plate armor. It should be doable as, again, the Japanese produced a 26" plate. So it may suffer from some problems and I may need to go with homogeneous rather than face-hardened but at proper angles this would still be proof against virtually every other shell out there.

Note again for the record: this is WIP so the armor scheme may change.

Plate quality .839 compared to typical 1940s US Armor (which was not the best in the world either and which the USN felt sucked too hard to be used above 17in). It would be reasonable to retroactively apply that scaling figure to an exceptionally thick piece of 1920s armor to account for the gap in armor technology improvements, which would mean an 18in belt equivalent to 15in belt with no quality loss. Not so great. But do what you want.

Turret plates are also much smaller. It's not so much making a plate thick, 18" or more, it's making it that thick but also 15+ feet high and much, much longer.

Smaller, and more importantly far less numerous which meant quality control could be tighter without bursting the budget. This isn’t just a matter of the steel quality is not so great, you ran into problems in which you simply had to outright reject large numbers of plates, melt them back then with other scrap and try again. That was very time consuming and costly to do. Still of course those thick plates which got accepted sucked as seen above. Japan also had to spend several tens of millions of dollars to improve its armor facilities machinery to be able to handle the super thick armor slabs Yamato required.

As late as the Iowa class the USN decided that an 18in plate sucked too hard, and so the Iowa’s have a 17in plate on top of a 2.5in plate to create the required 18in effective thickness. Montana used 18in on 4.5in. Obviously such a choice would not be made lightly. As we see on the first South Dakotas, back in WW1 13.5in was felt to be the limit for good belts, by WW2 it had crept up to the point that 16in could be accepted without worrying too much

Making face hardened armor was a complex time consuming process dominated by heating and cooling cycles which had to be controlled as precisely as possible… in an era with zero computer systems to help out. Not a fun thing to do. I’m sure people would rather not get involved with armor quality or shell quality too much, but folks are gonna end up with some really unrealistic battleships really fast with armor thicknesses already inflating past Yamato-Montana-Project 24 standards.

[Evincer]

This is the design for the two Coastal Defense Ships that Germany delivered to the Bolivarian Union in July, 1925.
(Naturally, these stats are not published in-game.)

Simon Bolivar, Germany Coastal Defence Ship laid down 1923

Displacement:
27.981 t light; 30.428 t standard; 31.070 t normal; 31.583 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(604,79 ft / 590,55 ft) x 104,99 ft x (29,53 / 29,93 ft)
(184,34 m / 180,00 m) x 32,00 m x (9,00 / 9,12 m)

Armament:
9 - 18,00" / 457 mm 45,0 cal guns - 2.850,00lbs / 1.292,74kg shells, 120 per gun
Breech loading guns in turret on barbette mounts, 1923 Model
3 x Triple mounts on centreline ends, majority forward
Aft Main mounts separated by engine room
12 - 6,00" / 152 mm 50,0 cal guns - 114,33lbs / 51,86kg shells, 150 per gun
Quick firing guns in turret on barbette mounts, 1923 Model
6 x Twin mounts on sides, evenly spread
12 - 1,57" / 40,0 mm 45,0 cal guns - 1,97lbs / 0,89kg shells, 150 per gun
Dual purpose guns in deck mounts, 1923 Model
6 x Single mounts on sides, evenly spread
Weight of broadside 27.046 lbs / 12.268 kg

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 14,0" / 356 mm 415,00 ft / 126,49 m 15,00 ft / 4,57 m
Ends: Unarmoured
Main Belt covers 108% of normal length

- Torpedo Bulkhead:
1,00" / 25 mm 415,00 ft / 126,49 m 25,00 ft / 7,62 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 12,0" / 305 mm 10,0" / 254 mm 12,0" / 305 mm
2nd: 1,00" / 25 mm 0,50" / 13 mm 0,50" / 13 mm

- Armoured deck - single deck: 5,00" / 127 mm For and Aft decks
Forecastle: 1,00" / 25 mm Quarter deck: 1,00" / 25 mm

- Conning towers: Forward 5,00" / 127 mm, Aft 0,00" / 0 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 30.054 shp / 22.420 Kw = 20,00 kts
Range 2.200nm at 14,00 kts
Bunker at max displacement = 1.155 tons

Complement:
1.169 - 1.521

Cost:
£10,855 million / $43,421 million

Distribution of weights at normal displacement:
Armament: 4.447 tons, 14,3%
Armour: 10.460 tons, 33,7%
- Belts: 3.799 tons, 12,2%
- Torpedo bulkhead: 384 tons, 1,2%
- Armament: 2.593 tons, 8,3%
- Armour Deck: 3.578 tons, 11,5%
- Conning Tower: 106 tons, 0,3%
Machinery: 1.004 tons, 3,2%
Hull, fittings & equipment: 12.069 tons, 38,8%
Fuel, ammunition & stores: 3.089 tons, 9,9%
Miscellaneous weights: 0 tons, 0,0%

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
32.352 lbs / 14.675 Kg = 11,1 x 18,0 " / 457 mm shells or 4,8 torpedoes
Stability (Unstable if below 1.00): 1,26
Metacentric height 8,2 ft / 2,5 m
Roll period: 15,4 seconds
Steadiness - As gun platform (Average = 50 %): 60 %
- Recoil effect (Restricted arc if above 1.00): 0,59
Seaboat quality (Average = 1.00): 1,13

Hull form characteristics:
Hull has a flush deck,
a normal bow and a cruiser stern
Block coefficient (normal/deep): 0,594 / 0,596
Length to Beam Ratio: 5,63 : 1
'Natural speed' for length: 24,30 kts
Power going to wave formation at top speed: 42 %
Trim (Max stability = 0, Max steadiness = 100): 53
Bow angle (Positive = bow angles forward): 15,00 degrees
Stern overhang: 9,84 ft / 3,00 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 20,00%, 16,40 ft / 5,00 m, 14,76 ft / 4,50 m
- Forward deck: 30,00%, 14,76 ft / 4,50 m, 14,76 ft / 4,50 m
- Aft deck: 35,00%, 14,76 ft / 4,50 m, 14,76 ft / 4,50 m
- Quarter deck: 15,00%, 14,76 ft / 4,50 m, 14,76 ft / 4,50 m
- Average freeboard: 14,90 ft / 4,54 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 107,3%
- Above water (accommodation/working, high = better): 108,5%
Waterplane Area: 45.092 Square feet or 4.189 Square metres
Displacement factor (Displacement / loading): 83%
Structure weight / hull surface area: 233 lbs/sq ft or 1.135 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0,96
- Longitudinal: 1,49
- Overall: 1,00
Hull space for machinery, storage, compartmentation is adequate
Room for accommodation and workspaces is adequate

[CmdrWilkens]

Fair enough, I'll go with face-hardened, 18 degree angled plate armor. It should be doable as, again, the Japanese produced a 26" plate. So it may suffer from some problems and I may need to go with homogeneous rather than face-hardened but at proper angles this would still be proof against virtually every other shell out there.

Note again for the record: this is WIP so the armor scheme may change.

Plate quality .839 compared to typical 1940s US Armor (which was not the best in the world either and which the USN felt sucked too hard to be used above 17in). It would be reasonable to retroactively apply that scaling figure to an exceptionally thick piece of 1920s armor to account for the gap in armor technology improvements, which would mean an 18in belt equivalent to 15in belt with no quality loss. Not so great. But do what you want.

The Japanese were also required by nickel shortage to work with a lot of copper for certain properties which meant their steel was always going to rate lower on an inch for inch basis. At the same time now that we are at the point where soft capped AP rounds are likely unbreakable and since obliquity on side hits isn't likely to be greater than 30 deg total I could probably get away with shifting to all Class B plate. Making homogeneous, or near homogeneous, steel means I don't have to engage in the face hardening process at the expense of having a comparative quality level in the .95 range based on the 13" STS tests the US was running in the early 20s. Given we would have almost a decade of additional experience (and a continuation of naval building focusing efforts everywhere) I would anticipate that drop off would likely be to no worse than .9 quality for an effective thickness of just about 17" based on the tentative design.

All of which is going way over and beyond what we are looking in to via using the SpringSharp system for naval design. My intention is for this ship to be Mexico's largest and hardest hitting ship so it needs protection against about the worst I can imagine which would be someone developing the equivalent of the 16"/50 heavy AP round OR Thanas' 18"/45 with 2,940 lbs round which has been kicked around since about 1924. Since this ship wouldn't even get its keel laid until 1928 I think that there is incentive enough for my designers to seek to protect against such super heavy rounds as best as possible.

All that said, Steve/Rogue/Timothy I will keep you appraised of this WIP and I won't lay a keel until it passes basic muster.

[Norseman]

My Large Cruiser design, note these are *not* battlecruisers, they're Large Cruisers, there's a difference.

Code: Select all

Working Class Hero, FSR of Brazil Large Cruiser laid down 1923

Displacement:
	31,956 t light; 33,275 t standard; 36,779 t normal; 39,582 t full load

Dimensions: Length overall / water x beam x draught
	864.38 ft / 848.00 ft x 92.00 ft x 33.00 ft (normal load)
	263.46 m / 258.47 m x 28.04 m  x 10.06 m

Armament:
      9 - 12.00" / 305 mm guns (3x3 guns), 864.00lbs / 391.90kg shells, 1923 Model
	  Breech loading guns in turrets (on barbettes)
	  on centreline ends, majority forward
      12 - 5.00" / 127 mm guns (6x2 guns), 62.50lbs / 28.35kg shells, 1923 Model
	  Dual purpose guns in deck mounts with hoists
	  on side, all amidships
      24 - 1.57" / 40.0 mm guns (12x2 guns), 1.95lbs / 0.88kg shells, 1923 Model
	  Quick firing guns in deck mounts with hoists
	  on side, evenly spread
      24 - 0.50" / 12.7 mm guns (12x2 guns), 0.06lbs / 0.03kg shells, 1923 Model
	  Machine guns in deck mounts 
	  on side, evenly spread
	Weight of broadside 8,574 lbs / 3,889 kg
	Shells per gun, main battery: 120

Armour:
   - Belts:		Width (max)	Length (avg)		Height (avg)
	Main:	9.00" / 229 mm	500.00 ft / 152.40 m	18.00 ft / 5.49 m
	Ends:	Unarmoured
	  Main Belt covers 91 % of normal length

   - Torpedo Bulkhead:
		3.50" / 89 mm	848.00 ft / 258.47 m	25.00 ft / 7.62 m

   - Gun armour:	Face (max)	Other gunhouse (avg)	Barbette/hoist (max)
	Main:	13.0" / 330 mm	5.00" / 127 mm		13.0" / 330 mm
	2nd:	1.50" / 38 mm	1.00" / 25 mm		1.00" / 25 mm
	3rd:	      -		      -			1.00" / 25 mm

   - Armour deck: 5.00" / 127 mm, Conning tower: 12.00" / 305 mm

Machinery:
	Oil fired boilers, steam turbines, 
	Geared drive, 3 shafts, 160,019 shp / 119,374 Kw = 31.69 kts
	Range 11,500nm at 15.00 kts
	Bunker at max displacement = 6,307 tons

Complement:
	1,327 - 1,726

Cost:
	£8.051 million / $32.204 million

Distribution of weights at normal displacement:
	Armament: 1,072 tons, 2.9 %
	Armour: 13,085 tons, 35.6 %
	   - Belts: 3,452 tons, 9.4 %
	   - Torpedo bulkhead: 2,745 tons, 7.5 %
	   - Armament: 1,794 tons, 4.9 %
	   - Armour Deck: 4,808 tons, 13.1 %
	   - Conning Tower: 286 tons, 0.8 %
	Machinery: 5,348 tons, 14.5 %
	Hull, fittings & equipment: 12,401 tons, 33.7 %
	Fuel, ammunition & stores: 4,823 tons, 13.1 %
	Miscellaneous weights: 50 tons, 0.1 %

Overall survivability and seakeeping ability:
	Survivability (Non-critical penetrating hits needed to sink ship):
	  51,196 lbs / 23,222 Kg = 59.3 x 12.0 " / 305 mm shells or 8.5 torpedoes
	Stability (Unstable if below 1.00): 1.18
	Metacentric height 6.0 ft / 1.8 m
	Roll period: 15.8 seconds
	Steadiness	- As gun platform (Average = 50 %): 70 %
			- Recoil effect (Restricted arc if above 1.00): 0.41
	Seaboat quality  (Average = 1.00): 1.21

Hull form characteristics:
	Hull has a flush deck
	Block coefficient: 0.500
	Length to Beam Ratio: 9.22 : 1
	'Natural speed' for length: 29.12 kts
	Power going to wave formation at top speed: 48 %
	Trim (Max stability = 0, Max steadiness = 100): 58
	Bow angle (Positive = bow angles forward): 20.00 degrees
	Stern overhang: 5.00 ft / 1.52 m
	Freeboard (% = measuring location as a percentage of overall length):
	   - Stem:		31.27 ft / 9.53 m
	   - Forecastle (18 %):	19.90 ft / 6.07 m
	   - Mid (50 %):		19.90 ft / 6.07 m
	   - Quarterdeck (18 %):	19.90 ft / 6.07 m
	   - Stern:		19.90 ft / 6.07 m
	   - Average freeboard:	20.70 ft / 6.31 m
	Ship tends to be wet forward

Ship space, strength and comments:
	Space	- Hull below water (magazines/engines, low = better): 89.7 %
		- Above water (accommodation/working, high = better): 148.5 %
	Waterplane Area: 51,980 Square feet or 4,829 Square metres
	Displacement factor (Displacement / loading): 113 %
	Structure weight / hull surface area: 160 lbs/sq ft or 781 Kg/sq metre
	Hull strength (Relative):
		- Cross-sectional: 1.00
		- Longitudinal: 1.01
		- Overall: 1.00
	Hull space for machinery, storage, compartmentation is adequate
	Room for accommodation and workspaces is excellent
	Ship has slow, easy roll, a good, steady gun platform
	Good seaboat, rides out heavy weather easily

[Steve]

A ship my Lightning-class or that a newer battlecruiser can actually successfully chase down? Watch out for Shep's Lexes.

If you're going for a Large Cruiser, don't settle for less than 33 knots and consider lighter armament - Lightning uses 10" guns - which are still plentiful to kill AMCs, cruisers, and anything else it's meant to kill.

[Norseman]

A ship my Lightning-class or that a newer battlecruiser can actually successfully chase down? Watch out for Shep's Lexes.

If you're going for a Large Cruiser, don't settle for less than 33 knots and consider lighter armament - Lightning uses 10" guns - which are still plentiful to kill AMCs, cruisers, and anything else it's meant to kill.

I think it'd actually be faster in practice to be honest, possibly a knot or two more enough to push it into 33 knot. At any rate endurance will generally mean a lot more than a single knot more or less.

[Steve]

Actually, no, it'd be slower. The speed is a max speed that presumed no hull fouling or engine wear. Once in actual conditions her speed will likely be more like 31 knots exact.

[Norseman]

Steve I have a ship of far less tonnage and better lines, mine have 160 000 hp the lexingtons have 180 000. Quite frankly my ships should be a lot faster than the Lexingtons. Indeed I dare you to see how many horsepowers you'll need to get that kind of speed with a Lexington build in Springsharp. Indeed to match the Lexingtons speed Springsharp tells me I'd need 200 000 hp and that's just insane.

[Steve]

Steve I have a ship of far less tonnage and better lines, mine have 160 000 hp the lexingtons have 180 000. Quite frankly my ships should be a lot faster than the Lexingtons. Indeed I dare you to see how many horsepowers you'll need to get that kind of speed with a Lexington build in Springsharp. Indeed to match the Lexingtons speed Springsharp tells me I'd need 200 000 hp and that's just insane.

Someone gives me a formula I'll allow it in revised design... of course, that means my Lightning, with a 180,000hp plant, is even faster.

[Norseman]

I'll be fiddling with the design, when is the transom stern acceptable by the way?