Treaty Cruiser Design Challenge

[Hood]

The Yoshinos look great and its a great idea to use those surplus turrets and how you have maximised their use to get four pretty good cruisers from them.

[Navybrat85]

My entry, the Kalimantan class Cruiser of the Tequilapolian Navy.



SS Report

Kalimantan, Tequilapoli Light Cruiser laid down 1936

Displacement:
9,456 t light; 9,844 t standard; 10,247 t normal; 10,569 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(587.52 ft / 575.00 ft) x 60.00 ft x (21.00 / 21.49 ft)
(179.08 m / 175.26 m) x 18.29 m x (6.40 / 6.55 m)

Armament:
15 - 6.10" / 155 mm 45.0 cal guns - 114.59lbs / 51.98kg shells, 150 per gun
Breech loading guns in turret on barbette mounts, 1936 Model
5 x Triple mounts on centreline ends, majority forward
2 raised mounts - superfiring
8 - 5.00" / 127 mm 38.0 cal guns - 59.90lbs / 27.17kg shells, 150 per gun
Anti-air guns in deck mounts, 1936 Model
8 x Single mounts on sides, evenly spread
8 raised mounts
8 - 0.50" / 12.7 mm 45.0 cal guns - 0.06lbs / 0.03kg shells, 150 per gun
Breech loading guns in deck mounts, 1936 Model
8 x Single mounts on centreline, evenly spread
1 raised mount
Weight of broadside 2,199 lbs / 997 kg
Main Torpedoes
10 - 21.0" / 533 mm, 23.00 ft / 7.01 m torpedoes - 1.544 t each, 15.443 t total
In 2 sets of deck mounted side rotating tubes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 5.00" / 127 mm 376.63 ft / 114.80 m 9.30 ft / 2.83 m
Ends: Unarmoured
Main Belt covers 101 % of normal length
Main Belt inclined 9.00 degrees (positive = in)

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 5.00" / 127 mm 2.00" / 51 mm 4.00" / 102 mm

- Armoured deck - multiple decks:
For and Aft decks: 2.00" / 51 mm

- Conning towers: Forward 4.00" / 102 mm, Aft 0.00" / 0 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 67,066 shp / 50,031 Kw = 30.00 kts
Range 3,000nm at 15.00 kts
Bunker at max displacement = 725 tons

Complement:
508 - 661

Cost:
£4.098 million / $16.391 million

Distribution of weights at normal displacement:
Armament: 499 tons, 4.9 %
- Guns: 468 tons, 4.6 %
- Weapons: 31 tons, 0.3 %
Armour: 1,847 tons, 18.0 %
- Belts: 720 tons, 7.0 %
- Armament: 394 tons, 3.8 %
- Armour Deck: 693 tons, 6.8 %
- Conning Tower: 41 tons, 0.4 %
Machinery: 1,882 tons, 18.4 %
Hull, fittings & equipment: 5,202 tons, 50.8 %
Fuel, ammunition & stores: 791 tons, 7.7 %
Miscellaneous weights: 25 tons, 0.2 %
- On freeboard deck: 20 tons
- Above deck: 5 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
14,421 lbs / 6,541 Kg = 126.9 x 6.1 " / 155 mm shells or 1.8 torpedoes
Stability (Unstable if below 1.00): 1.08
Metacentric height 2.7 ft / 0.8 m
Roll period: 15.3 seconds
Steadiness - As gun platform (Average = 50 %): 52 %
- Recoil effect (Restricted arc if above 1.00): 0.53
Seaboat quality (Average = 1.00): 1.04

Hull form characteristics:
Hull has a flush deck,
a straight bulbous bow and a round stern
Block coefficient (normal/deep): 0.495 / 0.499
Length to Beam Ratio: 9.58 : 1
'Natural speed' for length: 23.98 kts
Power going to wave formation at top speed: 54 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 21.00 degrees
Stern overhang: 3.50 ft / 1.07 m
Freeboard (% = length of deck as a percentage of waterline length):
Fore end, Aft end
- Forecastle: 17.00 %, 23.50 ft / 7.16 m, 20.50 ft / 6.25 m
- Forward deck: 30.00 %, 20.50 ft / 6.25 m, 16.00 ft / 4.88 m
- Aft deck: 35.50 %, 16.00 ft / 4.88 m, 16.00 ft / 4.88 m
- Quarter deck: 17.50 %, 16.00 ft / 4.88 m, 16.00 ft / 4.88 m
- Average freeboard: 17.64 ft / 5.38 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 77.1 %
- Above water (accommodation/working, high = better): 142.1 %
Waterplane Area: 22,882 Square feet or 2,126 Square metres
Displacement factor (Displacement / loading): 139 %
Structure weight / hull surface area: 151 lbs/sq ft or 738 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1.40
- Longitudinal: 1.83
- Overall: 1.44
Excellent machinery, storage, compartmentation space
Excellent accommodation and workspace room

Edit Note: Changed secondaries to 5"/38s, since that's what I actually used.

[Keisser]

Using your advices, I recalculate with SpringSharp 3.0 Beta 2. I kept the 6 in armoured belt:

You lengthened the hull even more and reduced draft - quite the contrary to what you have to do in order to increase the overall strength of the ship. And the largest flaw of your design is that you still want to make a full-scale Washington cruiser, even better then Exeter, in 9000 tons of displacent. You see, the closest similar ship to yours is ARA Almirante Brown, and she is much weaker in terms of everything - like, she has no belt armor at all and her deck is only 25 millimiters, while she is armed with much lighter 190 mm guns. Whats the point of complaining about incorrect gun weights if your ships is too much overloaded in general?
Here is what I came up with trying to calculate your ship - https://pastebin.com/3W1c24jE.

[Charguizard]

I'm very glad we're getting a lot of excellent entries and I want to congratulate Navybrat because I think he hasn't posted in the forum for a while and it's a great job he's done.

Garlic, can you tell me about the colours you chose for your ships? I think I've heard how every arsenal had a different colour but I wonder how you chose these in particular and if you have any references.

[Garlicdesign]

Hi Charguizard

A long time ago, I googled Gunze Sangyo modelling colours, who offer Kure grey (the lighter bluish one, used on Otowa), Yokosuka grey (the darker bluish one, used on Yoshino and Shirane) and Sasebo grey (the one without any hue, used on Unebi), plus Maizuru grey (actually a very dark blue with a bit of purple in it; seems to have been used only on submarines). They had to be grayed down a little to match colour illustrations in the intenet, but that was largely an approximation based on gut feeling. Another indicator used to be the plastic colour used in the 1980s for Japanese waterline ship models; Tamiya used Yokosuka grey, Fujimi and Aoshima Kure grey and Hasegawa used Sasebo grey (as a general rule). This is what I have read anyway; I remember them somewhat different, but it's long long ago, and nowadays, they don't use these colours any more.

Greetings
GD

[BB1987]

AS an extra trivia on the matter. I got the mix for Kure gray from the Janus Skulsky books on the Cruiser Takao and IJN Fuso around the same time I switched from the standard shipbucket red to the IJN red for underwater paint. When I converted it into SB I ended up with a shade a tad darker than the standard gray I'm still using, yet at the same time a tad lighter than the shaded gray. Not only much lighter that I thought, but so close to the palette I'm still using that (maybe also out of a bit of layness) I eventually chose to not switch over such a subtle difference.

[Charguizard]

Thanks for the information to both of you, consider your colours "acquired".

[Garlicdesign]

Hi Charguizard!

I've rummaged through my old files and realized I've mixed up Sasebo and Maizuru; Unebi thus is painted Maizuru grey, and Sasebo grey is the very dark blue I did not use. What I do not know is which colours the private yards used when they painted newly built ships; sources also don't seem to be entirely trustworthy. If BB1987 indeed has a book that says Takao - which was built, modernized and repaired only at Yokosuka throughout her career (according to Wikipedia) - was painted in a light grey tone very similar to Shipbucket standard grey, that can't have been Yokosuka grey with its (accoording to the colour table I once saw and now can't find anymore) distinctly blue-green hue. Since I rarely do real-life IJN ships and the rules say 'use standard SB colours if you are not perfectly sure you know better', BB1987 probably has it right.

GreetingsGD

[reytuerto]

Very interesting designs, guys! Your dark shades of japanese grays are very impressive, GD (as Ian's Measure 1, and WW1 RN dark grays!).

[Garlicdesign]

Hi everyone!

OK, last time, promise.

I googled around a little and found IJN colour chips from an US company, who were obviously totally wrong (their Sasebo grey was nearly black and everything else too dark as well), and new Tamiya modelling colours, who had somewhat different - usually lighter - shades than the old Gunze Sangyo I used. Assuming the newer ones are based on better research, I recoloured the Yoshinos, one in each tone: Yoshino in Yokosuka grey, Otowa in Kure grey, Unebi in Maizuru grey and Shirane in Sasebo grey. That's as good as I can do with the sources at hand. I also - courtesy of BB1987 - made some changes to radars and fire control arrangements.

Greetings
GD