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Re: Treaty Cruiser Design Challenge

Posted: March 31st, 2018, 4:05 pm
by Keisser
pepembr_mb wrote: March 31st, 2018, 3:48 pm 8,390 long tons
That results in 9400 short tons. And your standard displacement in SS report is (insert drumroll here) 8 328 tons - thats like 1000 tons less then original Exeter. And then you add some length, additional four meters of beam with same draft (though to make ship retain her strength all measures should be changed proportionally), put 6 inch belt (Exeter had only three inches), 100 mm bulges for absolutely no reason (as a result, that gives you 3.600 tons of armor). After that, well, you try to blame springsharp and its developers...

Re: Treaty Cruiser Design Challenge

Posted: April 1st, 2018, 11:42 am
by MihoshiK
Keisser wrote: March 31st, 2018, 4:05 pm
pepembr_mb wrote: March 31st, 2018, 3:48 pm 8,390 long tons
That results in 9400 short tons. And your standard displacement in SS report is (insert drumroll here) 8 328 tons - thats like 1000 tons less then original Exeter. And then you add some length, additional four meters of beam with same draft (though to make ship retain her strength all measures should be changed proportionally), put 6 inch belt (Exeter had only three inches), 100 mm bulges for absolutely no reason (as a result, that gives you 3.600 tons of armor). After that, well, you try to blame springsharp and its developers...
Ladies, please, you're both pretty. Now take it to PM, allright?

Re: Treaty Cruiser Design Challenge

Posted: April 3rd, 2018, 3:24 am
by Charguizard
Hood, I'm very glad you have revisited this concept. Not only does a real project lend considerable credibility to the arrangement, I also think it's a gorgeous looking ship!

Re: Treaty Cruiser Design Challenge

Posted: April 3rd, 2018, 4:11 pm
by BB1987
My take on the challenge, maybe not 100% original but based on background stuff of my AU:

Starting in 1929, while the two ships of the Saimei class were still under construction Kokoan designers were already working on a new class of heavy cruisers. The new design lengthened the hull to 194,59m overall (192,43m at the waterline). beam and draft increased accordingly to 19 and 6,5m for a standard displacement of 10.000t standard and 11.527t at full load. To abide treaty limitations in light of the overweight issues of contemporary Japanese cruisers like the Myoko and Takaos the armament was increased with the addition of one extra 203mm (8-ich) twin turret instead of two, for a total of eight main battery guns in four twin turrets, a number still considered to be acceptable by the naval staff. Secondary armament remained at four single 120mm (4.7inch) guns in shielded mounts, which were however moved on raised platforms to free space on the weather deck for two quadruple 610mm torpedo launchers and the armoured reload boxes (which contained another four warheads each). This allowed to move the torpedo armament out of the hull, freeing extra space for crew and machinery space. two single 40mm machine guns for anti-air defense completed the ship's planned armament. The armor protection called for a 12° inclined belt 102mm thick to protect both magazine and machinery spaces, with diagonal bulkheads 74mm thick to connect the belt to the forwardmost and aftmost barbettes. Torpedo bulkheads were to be 29mm. Deck thichness was split between a 35mm lower and 16mm upper deck with 38 to 48mm thick plates protecting the boiler uptakes. Steering gear was to be protected by 38mm plates on sides, 25mm fore and aft and 19mm on top. Turrets were protected by 25mm of armor and barbettes by 76mm plates. Finally the conning tower and steering wheelhouse were armored with 21mm thick plates on sides and 14mm ones on top.
The machinery space retained the twelve oil-firing-boilers and four geared tubrines of the Saimei class but increased output to 120.000shp which together with a new propeller shaft layout would have led to a planned top speed of 35,5 to 36 knots. Endurance was estimated at 7.000 nautical miles at 14 knots. Aircraft handling was expanded in size by fitting a larger hangar and two catapults with the capacity of operating two to three seaplanes. The bridge size was also slightly increased in order to house the latest fire-control setups. Complement was planned somewhere between 630 and 690 officers and men.
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Design was all fleshed out by January 1931, but at that point, the London Naval Treaty had literaly limited the Kokoan heavy cruiser force to just the two ships of the Saimei Class. the new design was thus scrapped, and work proceded on a new light cruiser type.


By late 1933 the new treaty cruiser design for Koko no Kaigun had evolved from the one for the Japanese Mogami class. Designers cut the length of the ship to 195,48m overall (192,43m on the waterline) while beam and draft remained at 20,6 (18 at the waterline) and 5,5m. The shorter hull was the result of ditching the forwardmost turret decreasing the main armament to a still respectable 12 guns. this allowed to drop the planned standard displacement from 8.500 to 7.750t to better exploit the tonnage allowances, planned full load displacement was 10.132t. The twelve main guns were to be 152mm (6.inch) ones with slightly modified triple turrets when compared to the Japanese units which planned to use 155mm (6.1inch). Kokoan designers thus preferred to maintain caliber commonality within the fleet instead of seeking a minimal increase of caliber to exploit the treaty. Secondary armament was still planned at eight 127mm (5.inch) dual-purpose guns in four mounts, with four single 40mm machine-guns to make up for the light anti-air duties. Torpedo armament was planned at four triple rotating sets for 610mm warheads with 12 reloads carried.
The armor belt was inclined 20° and had a maximum thickness of 102mm on both machinery and magazines. The magazine section of the belt tapered down to 30mm, while the part over machinery went down to 25mm, with the lower half (from 60 to the aforementioned 25mm) doubling up as torpedo bulkhead. Diagonal bulkheads tapering from 102 to 65mm would have connected the belt to the forward and aftmost barbettes. The deck protection was on a single 35mm plate above machinery spaces, inceasing to 40mm above magazines. Boiler uptakes were also to be protected by 70 to 95mm plates. In addition, ventilation uptakes for boilers 3 to 8 had a 60mm protection as well. Steering gear was enclosed by 100mm plates on sides, 35mm on ends and 30mm on top. Main gun turets had planned 50mm thick faces, 25mm sides and roofs. Barbettes were to be 25mm thick below the armor deck and 75mm above. Secondary guns had 25mm shields and 75mm of armor protecting the ammunition hoists. Finally, conning tower and steering wheelhouse would have been armored with 100mm thick plates on sides and 50mm ones on top. Machinery-wise, the number of boilers was to be reduced from 12 to 10 for a power output of 120.000shp, enough to reach at least 36knots according to designers. Endurance was planned at 8.000 nm at 14knots. Aircraft-handling space allowed to operate three floatplanes with two catapults. Complement would have been around 635-693 officers and men.
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Despite superseeded by a new desing in late 1933 (which would ultimately become the Senjo class), the original 12-gunned CL plan remained alive for another year, being tweaked aorund to reflect weight issues emerging from the Tomozoru incident. Like the Japanese Mogami class, the bridge and superstructure layout was modified to reduce top-heavyness. Eventually, the design was finally ditched when Koko denounced naval treaties and planned on building even more heavy cruisers. Acccording to historians, even tough this light cruiser project would have probably suffered from some of the overload and overweight issues of the Japanese Mogamis, the as built displacement would have been still within treaty limitations, at 10.000t standard and 11.700t full load. top speed would have probably dropped to 35knots as well.

An "artist impression" on how the cruisers could have looked late in WWII:
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Re: Treaty Cruiser Design Challenge

Posted: April 3rd, 2018, 8:02 pm
by Charguizard
So none of them get built? D:

Shame because they really look the part and would've liked to see late refits.

Re: Treaty Cruiser Design Challenge

Posted: April 5th, 2018, 3:27 pm
by pepembr_mb
Keisser wrote: March 31st, 2018, 4:05 pm
pepembr_mb wrote: March 31st, 2018, 3:48 pm 8,390 long tons
That results in 9400 short tons. And your standard displacement in SS report is (insert drumroll here) 8 328 tons - thats like 1000 tons less then original Exeter. And then you add some length, additional four meters of beam with same draft (though to make ship retain her strength all measures should be changed proportionally), put 6 inch belt (Exeter had only three inches), 100 mm bulges for absolutely no reason (as a result, that gives you 3.600 tons of armor). After that, well, you try to blame springsharp and its developers...
If you are part of SpringSharp design group, I'm suggesting a good and simple enhancement. Add an armament database could ease the designing work a lot. Brasil design uses three Mk. II turrets weighting 166 tonnes each and four 5 Mk. 38 twin turrets weighting 21.32 tonnes each. If you can place it and the intended hull position you have a realistic preview.

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

Brasil, Brazil Heavy Cruiser laid down 1935

Displacement:
8.513 t light; 8.988 t standard; 11.000 t normal; 12.610 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(590.69 ft / 577.43 ft) x 65.62 ft x (17.39 / 19.45 ft)
(180.04 m / 176.00 m) x 20.00 m x (5.30 / 5.93 m)

Armament:
6 - 8.00" / 203 mm 50.0 cal guns - 271.01lbs / 122.93kg shells, 150 per gun
Breech loading guns in turret on barbette mounts, 1935 Model
2 x Twin mounts on centreline, forward deck forward
1 raised mount - superfiring
1 x Twin mount on centreline, aft evenly spread
1 hull mount in lower deck - Limited use in all but light seas
8 - 5,00" / 127 mm 38.0 cal guns - 59.33lbs / 26.91kg shells, 450 per gun
Breech loading guns in deck mounts, 1935 Model
8 x Twin mounts on side ends, evenly spread
4 raised mounts - superfiring
Weight of broadside 2,101 lbs / 953 kg

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 6.00" / 152 mm 150.00 ft / 45.72 m 5.00 ft / 1,52 m
Ends: Unarmoured
Main Belt covers 40% of normal length
Main belt does not fully cover magazines and engineering spaces

- Torpedo Bulkhead:
5.00" / 127 mm 150.00 ft / 45.72 m 3.00 ft / 0.91 m

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 5.00" / 127 mm 5.00" / 127 mm 5.00" / 127 mm
2nd: 5.00" / 127 mm 5,00" / 127 mm -

- Armoured deck - multiple decks: 4.00" / 102 mm For and Aft decks
Forecastle: 4.00" / 102 mm Quarter deck: 4.00" / 102 mm

- Conning towers: Forward 5.00" / 127 mm, Aft 0.00" / 0 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 96,950 shp / 72,325 Kw = 32,00 kts
Range 10,000nm at 18.00 kts
Bunker at max displacement = 3,622 tons

Complement:
536 - 698

Cost:
£4.440 million / $17.759 million

Distribution of weights at normal displacement:
Armament: 457 tons, 4.2%
Armour: 3.042 tons, 27.7%
- Belts: 233 tons, 2.1%
- Torpedo bulkhead: 83 tons, 0,8%
- Armament: 635 tons, 5.8%
- Armour Deck: 2.037 tons, 18.5%
- Conning Tower: 53 tons, 0.5%
Machinery: 2.754 tons, 25.0%
Hull, fittings & equipment: 2.260 tons, 20.5%
Fuel, ammunition & stores: 2.487 tons, 22.6%
Miscellaneous weights: 0 tons, 0.0%

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
9.751 lbs / 4,423 Kg = 38.1 x 8,0 " / 203 mm shells or 1.8 torpedoes
Stability (Unstable if below 1.00): 1.46
Metacentric height 5,1 ft / 1,5 m
Roll period: 12,2 seconds
Steadiness - As gun platform (Average = 50 %): 51 %
- Recoil effect (Restricted arc if above 1.00): 0.26
Seaboat quality (Average = 1.00): 1.02

Hull form characteristics:
Hull has rise forward of midbreak,
a normal bow and a cruiser stern
Block coefficient (normal/deep): 0.584 / 0.599
Length to Beam Ratio: 8.80 : 1
'Natural speed' for length: 24.03 kts
Power going to wave formation at top speed: 60 %
Trim (Max stability = 0, Max steadiness = 100): 50
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%, 22.97 ft / 7.00 m, 22.97 ft / 7.00 m
- Forward deck: 55.00%, 22.97 ft / 7.00 m, 22.97 ft / 7.00 m
- Aft deck: 10.00%, 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: 21.33 ft / 6.50 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 141.5%
- Above water (accommodation/working, high = better): 213.1%
Waterplane Area: 27,309 Square feet or 2,537 Square metres
Displacement factor (Displacement / loading): 106%
Structure weight / hull surface area: 61 lbs/sq ft or 299 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.55
- Longitudinal: 0.76
- Overall: 0.57
Caution: Hull subject to strain in open-sea
Hull space for machinery, storage, compartmentation is cramped
Room for accommodation and workspaces is excellent

Re: Treaty Cruiser Design Challenge

Posted: April 5th, 2018, 3:36 pm
by pepembr_mb
My idea about Brazil heavy cruiser was something that could fight the Argentinian Almirante Brown Class with more armour and equivalent firepower. This is the revised drawn:

Image

Re: Treaty Cruiser Design Challenge

Posted: April 5th, 2018, 3:39 pm
by pepembr_mb
This could be her appearance after a complete refit in 1943:

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Re: Treaty Cruiser Design Challenge

Posted: April 5th, 2018, 9:29 pm
by Garlicdesign
Hello again!

OK, here's a more serious attempt to compete for the second place after Charguizard has definitely carried this competition:

Yoshino-Class: Economy cruisers

By the time the European war had commenced, Japan had just started to rebuild her light cruiser fleet with the Agano class, of which eight were laid down in 1939 and 1940. For larger cruisers, the Japanese fleet wanted something that would not even pretend to observe any size limits, ordering four 30.000-ton Naniwa-class large cruisers with nine 305mm guns each and four 18.000-ton Ibuki-Class heavy cruisers with twelve 203mm guns each. Both heavy guns and engines (the former were to have 180.000 SHP for 34 knots) would prove production bottlenecks, and a March 1939 Admiral Staff study estimated that these vessels would not be available before 1944/5 – and even these late dates could only be met at the expense of aircraft carrier production. The study proposed postponing the Naniwas and cancelling the Ibukis in favour of a much smaller and less powerful type which could be armed with stockpiled guns and would be available in 1942/3. Admiral Yamamoto, who had no interest in any delays to the carrier programme (three Zuilaku- and three Taiho-class ships were to be laid down between 1938 and 1941 and completed within no more than three years per hull) strongly endorsed the proposal, and the four hulls were included in the 1939 programme.

The design was a straightforward downsize of the existing Tone-hull, with superstructure resembling a mix between Mogami (full-length shelter deck, aviation and torpedo arrangements) and Agano (Bridge and funnel shape, mast and crane arrangement). Although by that time the LNT was dead and buried, and the Japanese designers paid no regard to any size limits when drawing up this type, they came out at 9,970 tons standard more or less by coincidence; weights were calculated in a much more realistic fashion than previously, and the final plans were presented less than a month after the ministerial go-ahead. Engine power was reduced to 104.000 SHP for a design speed of 33 kts – a third less engine weight and space compared with Mogami, paid for with only two knots less speed, which struck everyone involved as a good deal – and range was calculated to be 10.000 nm at 14 knots. Armour protection consisted of an internal 100mm belt and a 50mm deck; the main guns had 120mm shields, 50mm sides and 70mm barbettes. Armament varied between the class ship and her three sisters: The first unit was equipped with 8 203mm Type 3 No.1 guns in four twin turrets; these turrets and their guns were less powerful than the newer weapons of the Mogamis and Tones, but they came free of charge, because they had been removed from the aircraft carriers Akagi and Amagi during their recent complete refits. Four twin 127mm DP guns, arranged as on Mogami, and six twin 25mm mounts completed the designed gunnery. Sixteen 609mm torpedo tubes in four quad mounts were added; no torpedo reloads were provided. Two catapults were installed, served by a single very large crane attached to the main mast. Three F1M aircraft could be carried, but only two in an assembled state. The class ship was named Yoshino and laid down in August 1939 at the Yokosuka Navy Yard, less than five months after the first proposal. By using material already stockpiled for the cancelled Ibuki-class, Yoshino could be completed in little more than three years and was commissioned in December 1942. Design speed was easily secured at regular full power; on flank speed trials, 34,05 knots were attained at 114.989 shp.
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Yoshino used up all 203mm twin turrets still in stock; for her sisters, a lighter armament was provided. Of the 28 155mm triple turrets originally built for the Mogamis and Tones, 16 were to be re-used as secondary armament for the four Yamato-class battleships. The remaining 12 were earmarked for the other three Yoshino-Class ships; all other particulars were to remain as per the class ship. They were named Shirane (laid down in November 1939 by Mitsubishi at Nagasaki), Otowa (laid down June 1940 by the Kure Navy Yard) and Unebi (laid down August 1940 by Kawasaki at Kobe). Late in 1940, the decision was made to cut armament to three 155mm triples in Otowa and Unebi and replace their heavy flak by ten of the superb new 100mm/60 guns in five twin mounts; the two 155mm turrets were later issued to the new light cruiser Oyodo. The second pair also differed from the first two by more modern AA fire control (rangefinders with integral directors), the lack of the aft main director, which was replaced by an additional AA director, and a bulbous bow; the speed gain was however marginal. As construction proceeded, the decision was made to change Shirane’s armament likewise (approved May 1941); this was done when new calculations showed that Otowa and Unebi could be fitted with a 140mm belt and a 60mm deck due to the lower weight of their armament, resulting in a more balanced and survivable design. Turrets and barbettes were likewise up-armoured (140mm shields, 70mm sides, 120mm barbettes). These changes, which were implemented early in Otowa and Unebi without much loss of time, delayed Shirane’s completion and placed her last of her class when she was delivered in August 1944, after a construction time of nearly four years. Otowa was commissioned in October 1943, Unebi in December. By the time Otowa was ready, her 25mm twins had been replaced by triples, and a fourth pair of these was added for a total of 24 barrels; while Yoshino had been delivered without radars, the other three had Type 13 (one at the mainmast) and 22 (two abreast of the main director) radar from the outset.
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Unebi was identical to Otowa when she was commissioned. Light flak on all ships was rapidly augmented; by late 1944, Unebi had received a total of 60 25mm barrels (17 triple mounts and 9 single mounts). She also now embarked new E16A floatplanes, whose number was reduced to 2.
Image

Shirane differed from Otowa and Unebi by her older-fashioned fire control fit (she had AA directors with integral rangefinders, but only two of them, and retained the aft main gun director) and bow shape; her armament was identical. In 1945, she was fitted with an additional Type 21 radar in the foretop and a much enlargened radar office between bridge and foremast.
Image

This quartet of cruisers was generally rated as very satisfactory; the only quibbles were the short space between the catapults and the mainmast, which made operating any floatplane bigger than the F1M difficult (the catapult had to be trained outward to 60° and the plane on the other catapult moved to its forward end in order to launch an E16A) and the lack of deckspace for even more light AA. Their two-knot speed deficit compared with older japanese cruisers usually was no problem, because their sustained sea speed was only marginally slower. Like all Japanese cruisers, they were indifferent sea boats due to their rather low freeboard, but under pacific conditions, this was not much of a problem either.

Although brief, war service of these ships was intense. Yoshino was present at the offensive against Fiji/New Caledonia and the bloody battle of Rotuma; she was one of the last IJN ships to escape from Truk and fought at Leyte with Nishimura’s squadron, where she was lost to US battleship gunnery after repulsing a destroyer attack and sinking an US destroyer; she was credited with another at New Caledonia. Shirane, the luckiest of the quartet, survived the war after sinking an US escort carrier and an escort destroyer at Leyte; she became a British prize and was scrapped in 1950 after use in various trials. Unebi and Otowa both were present in the battle of the Philippine Sea and accompanied Ozawa’s carriers at Leyte; Otowa was sunk by US carrier planes in that battle, Unebi escaped to Japan and was sunk in shallow water by US airstrikes in 1946.

For those who care: Springsharp for the heavy cruiser Version

Yoshino, Japan Heavy Cruiser laid down 1939

Displacement:
9.536 t light; 9.968 t standard; 11.059 t normal; 11.932 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(634,19 ft / 623,36 ft) x 63,98 ft x (18,70 / 19,83 ft)
(193,30 m / 190,00 m) x 19,50 m x (5,70 / 6,04 m)

Armament:
8 - 7,99" / 203 mm 50,0 cal guns - 270,21lbs / 122,57kg shells, 120 per gun
Breech loading guns in turret on barbette mounts, 1939 Model
4 x 2-gun mounts on centreline ends, evenly spread
8 - 5,00" / 127 mm 50,0 cal guns - 66,16lbs / 30,01kg shells, 200 per gun
Anti-air guns in deck and hoist mounts, 1939 Model
4 x Twin mounts on sides, forward evenly spread
18 - 0,98" / 25,0 mm 72,0 cal guns - 0,54lbs / 0,24kg shells, 1.500 per gun
Machine guns in deck mounts, 1939 Model
6 x Triple mounts on side ends, majority forward
Weight of broadside 2.701 lbs / 1.225 kg
Main Torpedoes
16 - 24,0" / 609 mm, 26,25 ft / 8,00 m torpedoes - 2,220 t each, 35,513 t total
In 4 sets of deck mounted side rotating tubes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 3,94" / 100 mm 437,99 ft / 133,50 m 9,61 ft / 2,93 m
Ends: Unarmoured
Main Belt covers 108% of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 4,70" / 120 mm 1,97" / 50 mm 2,76" / 70 mm
2nd: 1,97" / 50 mm 0,79" / 20 mm -

- Protected deck - single deck:
For and Aft decks: 1,97" / 50 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 104.000 shp / 77.584 Kw = 33,23 kts
Range 10.000nm at 14,00 kts
Bunker at max displacement = 1.963 tons

Complement:
538 - 700

Cost:
£5,879 million / $23,516 million

Distribution of weights at normal displacement:
Armament: 875 tons, 7,9%
- Guns: 804 tons, 7,3%
- Weapons: 71 tons, 0,6%
Armour: 1.746 tons, 15,8%
- Belts: 672 tons, 6,1%
- Armament: 266 tons, 2,4%
- Armour Deck: 808 tons, 7,3%
Machinery: 2.814 tons, 25,4%
Hull, fittings & equipment: 3.951 tons, 35,7%
Fuel, ammunition & stores: 1.523 tons, 13,8%
Miscellaneous weights: 150 tons, 1,4%
- On freeboard deck: 100 tons
- Above deck: 50 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
12.100 lbs / 5.488 Kg = 47,4 x 8,0 " / 203 mm shells or 0,9 torpedoes
Stability (Unstable if below 1.00): 1,26
Metacentric height 3,9 ft / 1,2 m
Roll period: 13,6 seconds
Steadiness - As gun platform (Average = 50 %): 45 %
- Recoil effect (Restricted arc if above 1.00): 0,38
Seaboat quality (Average = 1.00): 0,79

Hull form characteristics:
Hull has a flush deck,
a normal bow and a cruiser stern
Block coefficient (normal/deep): 0,519 / 0,528
Length to Beam Ratio: 9,74 : 1
'Natural speed' for length: 24,97 kts
Power going to wave formation at top speed: 57 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 23,00 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%, 25,52 ft / 7,78 m, 17,39 ft / 5,30 m
- Forward deck: 30,00%, 17,39 ft / 5,30 m, 16,99 ft / 5,18 m
- Aft deck: 35,00%, 16,99 ft / 5,18 m, 16,99 ft / 5,18 m
- Quarter deck: 15,00%, 16,99 ft / 5,18 m, 14,50 ft / 4,42 m
- Average freeboard: 17,60 ft / 5,36 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 106,1%
- Above water (accommodation/working, high = better): 159,1%
Waterplane Area: 27.039 Square feet or 2.512 Square metres
Displacement factor (Displacement / loading): 108%
Structure weight / hull surface area: 111 lbs/sq ft or 540 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1,00
- Longitudinal: 1,03
- Overall: 1,00
Adequate machinery, storage, compartmentation space
Excellent accommodation and workspace room
Poor seaboat, wet and uncomfortable, reduced performance in heavy weather

And Springsharp for the light cruiser version:

Unebi, Japan Light Cruiser laid down 1940

Displacement:
9.596 t light; 9.978 t standard; 11.059 t normal; 11.924 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
(634,19 ft / 623,36 ft) x 63,98 ft x (18,70 / 19,82 ft)
(193,30 m / 190,00 m) x 19,50 m x (5,70 / 6,04 m)

Armament:
9 - 6,10" / 155 mm 60,0 cal guns - 124,45lbs / 56,45kg shells, 150 per gun
Breech loading guns in turret on barbette mounts, 1940 Model
3 x 3-gun mounts on centreline ends, majority forward
10 - 3,94" / 100,0 mm 65,0 cal guns - 33,83lbs / 15,35kg shells, 300 per gun
Anti-air guns in deck and hoist mounts, 1940 Model
4 x Twin mounts on sides, forward evenly spread
1 x Twin mount on centreline, aft deck centre
1 raised mount
24 - 0,98" / 25,0 mm 72,0 cal guns - 0,54lbs / 0,24kg shells, 1.500 per gun
Machine guns in deck mounts, 1940 Model
8 x Triple mounts on sides, evenly spread
6 raised mounts
Weight of broadside 1.471 lbs / 667 kg
Main Torpedoes
16 - 24,0" / 609 mm, 26,25 ft / 8,00 m torpedoes - 2,220 t each, 35,513 t total
In 4 sets of deck mounted side rotating tubes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Main: 5,51" / 140 mm 437,99 ft / 133,50 m 9,61 ft / 2,93 m
Ends: Unarmoured
Main Belt covers 108% of normal length

- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 5,51" / 140 mm 2,76" / 70 mm 4,72" / 120 mm
2nd: 1,97" / 50 mm 0,79" / 20 mm -

- Protected deck - single deck:
For and Aft decks: 2,36" / 60 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 104.000 shp / 77.584 Kw = 33,23 kts
Range 10.000nm at 14,00 kts
Bunker at max displacement = 1.946 tons

Complement:
538 - 700

Cost:
£5,493 million / $21,972 million

Distribution of weights at normal displacement:
Armament: 609 tons, 5,5%
- Guns: 538 tons, 4,9%
- Weapons: 71 tons, 0,6%
Armour: 2.204 tons, 19,9%
- Belts: 944 tons, 8,5%
- Armament: 291 tons, 2,6%
- Armour Deck: 970 tons, 8,8%
Machinery: 2.781 tons, 25,1%
Hull, fittings & equipment: 3.852 tons, 34,8%
Fuel, ammunition & stores: 1.463 tons, 13,2%
Miscellaneous weights: 150 tons, 1,4%
- On freeboard deck: 100 tons
- Above deck: 50 tons

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
14.031 lbs / 6.364 Kg = 123,5 x 6,1 " / 155 mm shells or 1,0 torpedoes
Stability (Unstable if below 1.00): 1,29
Metacentric height 4,0 ft / 1,2 m
Roll period: 13,4 seconds
Steadiness - As gun platform (Average = 50 %): 45 %
- Recoil effect (Restricted arc if above 1.00): 0,21
Seaboat quality (Average = 1.00): 0,83

Hull form characteristics:
Hull has a flush deck,
a straight bulbous bow and a cruiser stern
Block coefficient (normal/deep): 0,519 / 0,528
Length to Beam Ratio: 9,74 : 1
'Natural speed' for length: 24,97 kts
Power going to wave formation at top speed: 57 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 23,00 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%, 25,52 ft / 7,78 m, 17,39 ft / 5,30 m
- Forward deck: 30,00%, 17,39 ft / 5,30 m, 16,99 ft / 5,18 m
- Aft deck: 35,00%, 16,99 ft / 5,18 m, 16,99 ft / 5,18 m
- Quarter deck: 15,00%, 16,99 ft / 5,18 m, 14,50 ft / 4,42 m
- Average freeboard: 17,60 ft / 5,36 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 97,9%
- Above water (accommodation/working, high = better): 159,1%
Waterplane Area: 27.039 Square feet or 2.512 Square metres
Displacement factor (Displacement / loading): 114%
Structure weight / hull surface area: 104 lbs/sq ft or 509 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 1,02
- Longitudinal: 0,99
- Overall: 1,00
Adequate machinery, storage, compartmentation space
Excellent accommodation and workspace room
Poor seaboat, wet and uncomfortable, reduced performance in heavy weather


Greetings
GD

Re: Treaty Cruiser Design Challenge

Posted: April 5th, 2018, 10:49 pm
by BB1987
Charguizard wrote: April 3rd, 2018, 8:02 pm So none of them get built? D:

Shame because they really look the part and would've liked to see late refits.
Unfortunately yes. Maybe I'm rigging myself between too many restrictions, but I do try to stick within the footprint of my AU with nearly everything I'm drawing that it is not real life. This unfortunately means those two never left the papers :(


@Garlicdesign: splendid job on those Japanese cruisers :D