WesWorld

Bromista, Iberia CL laid down 1925

she specifically has a low draught in order to get into my more obscure harbours.

Displacement:
6,993 t light; 7,238 t standard; 8,471 t normal; 9,423 t full load
Loading submergence 579 tons/feet

Dimensions:
524.93 ft x 59.06 ft x 18.04 ft (normal load)
160.00 m x 18.00 m x 5.50 m

Armament:
8 - 6.00" / 152 mm guns (2 Main turrets x 4 guns)
8 - 2.24" / 57 mm DP guns
12 - 0.53" / 14 mm guns
Weight of broadside 910 lbs / 413 kg
8 - 23.6" / 600 mm above water torpedoes

Armour:
Belt 1.57" / 40 mm, ends unarmoured
Belts cover 116 % of normal area
Main turrets 2.36" / 60 mm
Armour deck 1.18" / 30 mm, Conning tower 3.15" / 80 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 83,287 shp / 62,132 Kw = 32.00 kts
Range 10,000nm at 15.00 kts

Complement:
441 - 573

Cost:
£2.353 million / $9.411 million

Distribution of weights at normal displacement:
Armament: 114 tons, 1.3 %
Armour: 836 tons, 9.9 %
Belts: 238 tons, 2.8 %, Armament: 127 tons, 1.5 %, Armour Deck: 443 tons, 5.2 %
Conning Tower: 28 tons, 0.3 %, Torpedo bulkhead: 0 tons, 0.0 %
Machinery: 2,704 tons, 31.9 %
Hull, fittings & equipment: 3,238 tons, 38.2 %
Fuel, ammunition & stores: 1,478 tons, 17.4 %
Miscellaneous weights: 100 tons, 1.2 %

Metacentric height 3.4

Remarks:
Hull space for machinery, storage & compartmentation is cramped
Room for accommodation & workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1.25
Shellfire needed to sink: 8,860 lbs / 4,019 Kg = 82.0 x 6.0 " / 152 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 1.2
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 70 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0.28
Relative quality as seaboat: 1.20

Hull form characteristics:
Block coefficient: 0.530
Sharpness coefficient: 0.35
Hull speed coefficient 'M': 7.87
'Natural speed' for length: 22.91 kts
Power going to wave formation at top speed: 61 %
Trim: 58
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 115.4 %
Relative accommodation and working space: 148.6 %
(Average = 100%)
Displacement factor: 117 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0.94
(Structure weight / hull surface area: 96 lbs / square foot or 467 Kg / square metre)
Relative longitudinal hull strength: 1.77
(for 21.92 ft / 6.68 m average freeboard, freeboard adjustment 7.27 ft)
Relative composite hull strength: 1.00

TT are 4*2
57 mm are twins
13.5 mm are twins
carries 1 floatplane

She looks quite balanced when browsing through her stats and I like her margin of stability best. She also has a very good range.

One the other hand I question the value of quads on a light cruiser. What is her duty? Fleet action? Commerce protection? With two main turret - both of which will have a slower rate of fire and turning - she might not be flexible enough for actions against fast and manoverable units. She also has 50% of her armament concentrated in one basket which is easily to destroy or put out of order. If you really want to go for quads I proposed twice that much armor for the turrets - at least.

Her 57mm guns seem to be quite useful but I question the value of 14mm guns.

Her size of 7,2kts makes it interesting to compare her to the british LEANDER-class and honestly, I´d prefer the latter. The LEANDERs had 4 turrets (even though they feature only paperthin armor) but were faster and their hull carried more armor. Being faster too they fall behind only in range.

I also wonder about this comment: "she specifically has a low draught in order to get into my more obscure harbours."

Actually I couldn´t find a single british cruiser with a draught as deep or deeper than 5,5m. Some french had but the one most comparable (LA GALISSONNIERE - 7,6kts) only had 5,35m - accourding to Whitley that is. LEIPZIG and NÜRNBERG - both of similar size as well - also had draughts lower than 5m.

I hardly think that a draught of 5,5m is exceptional low but maybe that´s just me and things are different in Wesworld.... :o)

Cheers,

HoOmAn

hm. draught at least as compared to some of my other cruiser designs ... I am not sure why but SS makes it easier to design balanced ships with a deep draught.

well, the Armada is going with quads at the mom, no way to cure it ;-)

cheers

Bernhard

You could trade the good seakeeping comment and 2000nm range against a lower draught, 4 main turrets and thicker armor.

Kreuzer Kategory B, South African Light Cruiser laid down 1925

Displacement:
7.049 t light; 7.290 t standard; 8.265 t normal; 9.012 t full load
Loading submergence 605 tons/feet

Dimensions:
580,71 ft x 57,25 ft x 17,06 ft (normal load)
177,00 m x 17,45 m x 5,20 m

Armament:
8 - 5,98" / 152 mm guns (4 Main turrets x 2 guns, 2 superfiring turrets)
8 - 2,24" / 57 mm AA guns
12 - 0,79" / 20 mm guns
Weight of broadside 905 lbs / 411 kg
12 - 21,0" / 533 mm above water torpedoes

Armour:
Belt 2,95" / 75 mm, ends unarmoured
Belts cover 110% of normal area
Main turrets 2,95" / 75 mm, AA gun shields 0,98" / 25 mm
Armour deck 1,18" / 30 mm, Conning tower 3,15" / 80 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 4 shafts, 76.098 shp / 56.769 Kw = 32,00 kts
Range 8.000nm at 15,00 kts

Complement:
433 - 563

Cost:
£2,251 million / $9,002 million

Distribution of weights at normal displacement:
Armament: 113 tons, 1,4%
Armour: 1.195 tons, 14,5%
Belts: 456 tons, 5,5%, Armament: 249 tons, 3,0%, Armour Deck: 463 tons, 5,6%
Conning Tower: 28 tons, 0,3%, Torpedo bulkhead: 0 tons, 0,0%
Machinery: 2.471 tons, 29,9%
Hull, fittings & equipment: 3.170 tons, 38,4%
Fuel, ammunition & stores: 1.216 tons, 14,7%
Miscellaneous weights: 100 tons, 1,2%

Metacentric height 2,7

Remarks:
Hull space for machinery, storage & compartmentation is adequate
Room for accommodation & workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1,13
Shellfire needed to sink: 8.465 lbs / 3.840 Kg = 79,0 x 6,0 " / 152 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 1,3
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 72 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0,28
Relative quality as seaboat: 1,02

Hull form characteristics:
Block coefficient: 0,510
Sharpness coefficient: 0,33
Hull speed coefficient 'M': 8,78
'Natural speed' for length: 24,10 kts
Power going to wave formation at top speed: 56 %
Trim: 70
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 109,1%
Relative accommodation and working space: 125,2%
(Average = 100%)
Displacement factor: 116%
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0,99
(Structure weight / hull surface area: 94 lbs / square foot or 458 Kg / square metre)
Relative longitudinal hull strength: 1,05
(for 17,88 ft / 5,45 m average freeboard, freeboard adjustment 3,30 ft)
Relative composite hull strength: 1,00

I took the technical data off warships1 and came up with this (freeboard is taken from the drawing). Anybody have more information and can do a better sim? pay special attention to the BC folks ...

Karlsruhe, Germany CL laid down 1926

Displacement:
7,277 t light; 7,533 t standard; 8,171 t normal; 8,648 t full load
Loading submergence 646 tons/feet

Dimensions:
554.46 ft x 49.87 ft x 13.98 ft (normal load)
169.00 m x 15.20 m x 4.26 m

Armament:
9 - 5.91" / 150 mm guns (3 Main turrets x 3 guns, 1 superfiring turret)
Superfiring turret is aft
8 - 3.46" / 88 mm guns
8 - 1.46" / 37 mm AA guns
8 - 0.79" / 20 mm guns
Weight of broadside 1,107 lbs / 502 kg

Armour:
Belt 3.46" / 88 mm, ends unarmoured
Belts cover 122 % of normal area
Main turrets 1.97" / 50 mm, 2nd gun shields 0.79" / 20 mm
AA gun shields 0.79" / 20 mm
Armour deck 1.97" / 50 mm, Conning tower 2.99" / 76 mm

Machinery:
Oil fired boilers, steam turbines plus diesel motors,
Geared drive, 3 shafts, 85,110 shp / 63,492 Kw = 32.00 kts
Range 5,500nm at 14.50 kts

Complement:
429 - 558

Cost:
£2.599 million / $10.397 million

Distribution of weights at normal displacement:
Armament: 138 tons, 1.7 %
Armour: 1,519 tons, 18.6 %
Belts: 524 tons, 6.4 %, Armament: 146 tons, 1.8 %, Armour Deck: 823 tons, 10.1 %
Conning Tower: 26 tons, 0.3 %, Torpedo bulkhead: 0 tons, 0.0 %
Machinery: 2,724 tons, 33.3 %
Hull, fittings & equipment: 2,875 tons, 35.2 %
Fuel, ammunition & stores: 894 tons, 10.9 %
Miscellaneous weights: 20 tons, 0.2 %

Metacentric height 2.7

Remarks:
Caution: Hull subject to strain in open-sea
Hull space for machinery, storage & compartmentation is cramped
Room for accommodation & workspaces is excellent
Caution: Lacks seaworthiness - very limited seakeeping ability

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1.27
Shellfire needed to sink: 5,959 lbs / 2,703 Kg = 57.9 x 5.9 " / 150 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 1.0
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 44 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0.34
Relative quality as seaboat: 0.64

Hull form characteristics:
Block coefficient: 0.740
Sharpness coefficient: 0.39
Hull speed coefficient 'M': 8.42
'Natural speed' for length: 23.55 kts
Power going to wave formation at top speed: 61 %
Trim: 61
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 121.5 %
Relative accommodation and working space: 160.0 %
(Average = 100%)
Displacement factor: 101 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 1.04
(Structure weight / hull surface area: 87 lbs / square foot or 425 Kg / square metre)
Relative longitudinal hull strength: 0.79
(for 15.94 ft / 4.86 m average freeboard, freeboard adjustment 1.40 ft)
Relative composite hull strength: 0.85

Karlsruhe, Germany CL laid down 1926

Displacement:
7,277 t light; 7,533 t standard; 8,171 t normal; 8,648 t full load
Loading submergence 646 tons/feet

Dimensions:
554.46 ft x 49.87 ft x 13.98 ft (normal load)
169.00 m x 15.20 m x 4.26 m

Armament:
9 - 5.91" / 150 mm guns (3 Main turrets x 3 guns, 1 superfiring turret)
Superfiring turret is aft
8 - 3.46" / 88 mm guns
8 - 1.46" / 37 mm AA guns
8 - 0.79" / 20 mm guns
Weight of broadside 1,107 lbs / 502 kg

Armour:
Belt 3.46" / 88 mm, ends unarmoured
Belts cover 122 % of normal area
Main turrets 1.97" / 50 mm, 2nd gun shields 0.79" / 20 mm
AA gun shields 0.79" / 20 mm
Armour deck 1.97" / 50 mm, Conning tower 2.99" / 76 mm

Machinery:
Oil fired boilers, steam turbines plus diesel motors,
Geared drive, 3 shafts, 85,110 shp / 63,492 Kw = 32.00 kts
Range 5,500nm at 14.50 kts

Complement:
429 - 558

Cost:
£2.599 million / $10.397 million

Distribution of weights at normal displacement:
Armament: 138 tons, 1.7 %
Armour: 1,541 tons, 18.9 %
Belts: 524 tons, 6.4 %, Armament: 168 tons, 2.1 %, Armour Deck: 823 tons, 10.1 %
Conning Tower: 26 tons, 0.3 %, Torpedo bulkhead: 0 tons, 0.0 %
Machinery: 2,724 tons, 33.3 %
Hull, fittings & equipment: 2,853 tons, 34.9 %
Fuel, ammunition & stores: 894 tons, 10.9 %
Miscellaneous weights: 20 tons, 0.2 %

Metacentric height 2.4

Remarks:
Caution: Hull subject to strain in open-sea
Hull space for machinery, storage & compartmentation is cramped
Room for accommodation & workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1.18
Shellfire needed to sink: 7,222 lbs / 3,276 Kg = 70.1 x 5.9 " / 150 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 1.0
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 70 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0.60
Relative quality as seaboat: 1.24

Hull form characteristics:
Block coefficient: 0.740
Sharpness coefficient: 0.39
Hull speed coefficient 'M': 8.42
'Natural speed' for length: 23.55 kts
Power going to wave formation at top speed: 61 %
Trim: 57
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 121.5 %
Relative accommodation and working space: 215.6 %
(Average = 100%)
Displacement factor: 101 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0.87
(Structure weight / hull surface area: 80 lbs / square foot or 390 Kg / square metre)
Relative longitudinal hull strength: 1.10
(for 21.49 ft / 6.55 m average freeboard, freeboard adjustment 6.95 ft)
Relative composite hull strength: 0.89

Are you sure about those numbers? Whiltey's book Cruisers of World War Two: An International Encyclopedia gives standard displacement as 6,650 tons, and full load displacement as 8,130 tons. Mean draught is given as 18ft 4 in / 5.56 metres.

using: http://www.german-navy.de/kriegsmarine/s…sruhe/tech.html

and allowing for the fact that SS works with normal displacement I come up with:

Karlsruhe, Germany CL laid down 1926

Displacement:
6,130 t light; 6,364 t standard; 7,111 t normal; 7,680 t full load
Loading submergence 473 tons/feet

Dimensions:
554.46 ft x 49.87 ft x 19.36 ft (normal load)
169.00 m x 15.20 m x 5.90 m

Armament:
9 - 5.91" / 150 mm guns (3 Main turrets x 3 guns, 1 superfiring turret)
Superfiring turret is aft
8 - 3.46" / 88 mm guns
8 - 1.46" / 37 mm AA guns
8 - 0.79" / 20 mm guns
Weight of broadside 1,107 lbs / 502 kg

Armour:
Belt 2.36" / 60 mm, ends unarmoured
Belts cover 119 % of normal area
Main turrets 1.18" / 30 mm, 2nd gun shields 0.79" / 20 mm
AA gun shields 0.79" / 20 mm
Armour deck 1.57" / 40 mm, Conning tower 3.94" / 100 mm

Machinery:
Oil fired boilers, steam turbines plus diesel motors,
Geared drive, 3 shafts, 69,072 shp / 51,528 Kw = 32.10 kts
Range 7,300nm at 14.50 kts

Complement:
387 - 503

Cost:
£2.212 million / $8.849 million

Distribution of weights at normal displacement:
Armament: 138 tons, 1.9 %
Armour: 958 tons, 13.5 %
Belts: 348 tons, 4.9 %, Armament: 96 tons, 1.4 %, Armour Deck: 482 tons, 6.8 %
Conning Tower: 31 tons, 0.4 %, Torpedo bulkhead: 0 tons, 0.0 %
Machinery: 2,211 tons, 31.1 %
Hull, fittings & equipment: 2,772 tons, 39.0 %
Fuel, ammunition & stores: 981 tons, 13.8 %
Miscellaneous weights: 50 tons, 0.7 %

Metacentric height 2.3

Remarks:
Hull space for machinery, storage & compartmentation is cramped
Room for accommodation & workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1.16
Shellfire needed to sink: 6,176 lbs / 2,802 Kg = 60.0 x 5.9 " / 150 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 1.0
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 70 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0.53
Relative quality as seaboat: 1.20

Hull form characteristics:
Block coefficient: 0.465
Sharpness coefficient: 0.31
Hull speed coefficient 'M': 8.82
'Natural speed' for length: 23.55 kts
Power going to wave formation at top speed: 55 %
Trim: 58
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 116.7 %
Relative accommodation and working space: 147.0 %
(Average = 100%)
Displacement factor: 109 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0.97
(Structure weight / hull surface area: 92 lbs / square foot or 448 Kg / square metre)
Relative longitudinal hull strength: 1.38
(for 18.04 ft / 5.50 m average freeboard, freeboard adjustment 3.90 ft)
Relative composite hull strength: 1.00

applying this to my design I get:

Bromista, Iberia CL laid down 1925

Displacement:
7,083 t light; 7,330 t standard; 8,451 t normal; 9,314 t full load
Loading submergence 551 tons/feet

Dimensions:
590.55 ft x 54.13 ft x 19.69 ft (normal load)
180.00 m x 16.50 m x 6.00 m

Armament:
8 - 6.00" / 152 mm guns (2 Main turrets x 4 guns)
12 - 2.24" / 57 mm guns
12 - 0.53" / 14 mm guns
Weight of broadside 933 lbs / 423 kg
8 - 23.6" / 600 mm above water torpedoes

Armour:
Belt 2.36" / 60 mm, ends unarmoured
Belts cover 117 % of normal area
Main turrets 1.57" / 40 mm
Armour deck 1.57" / 40 mm, Conning tower 3.15" / 80 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 84,085 shp / 62,728 Kw = 33.00 kts
Range 9,000nm at 15.00 kts

Complement:
440 - 572

Cost:
£2.383 million / $9.531 million

Distribution of weights at normal displacement:
Armament: 117 tons, 1.4 %
Armour: 1,046 tons, 12.4 %
Belts: 381 tons, 4.5 %, Armament: 76 tons, 0.9 %, Armour Deck: 562 tons, 6.6 %
Conning Tower: 28 tons, 0.3 %, Torpedo bulkhead: 0 tons, 0.0 %
Machinery: 2,730 tons, 32.3 %
Hull, fittings & equipment: 3,090 tons, 36.6 %
Fuel, ammunition & stores: 1,368 tons, 16.2 %
Miscellaneous weights: 100 tons, 1.2 %

Metacentric height 2.9

Remarks:
Hull space for machinery, storage & compartmentation is cramped
Room for accommodation & workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1.22
Shellfire needed to sink: 7,338 lbs / 3,329 Kg = 67.9 x 6.0 " / 152 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 1.1
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 70 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0.31
Relative quality as seaboat: 1.07

Hull form characteristics:
Block coefficient: 0.470
Sharpness coefficient: 0.31
Hull speed coefficient 'M': 8.87
'Natural speed' for length: 24.30 kts
Power going to wave formation at top speed: 55 %
Trim: 65
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 116.9 %
Relative accommodation and working space: 115.6 %
(Average = 100%)
Displacement factor: 112 %
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0.98
(Structure weight / hull surface area: 92 lbs / square foot or 451 Kg / square metre)
Relative longitudinal hull strength: 1.18
(for 17.72 ft / 5.40 m average freeboard, freeboard adjustment 3.07 ft)
Relative composite hull strength: 1.00

TT are 4*2
57 mm are twins
13.5 mm are twins
carries 1 floatplane

Wasn´t one of the main aspects of the original design to get a ship that can enter most if not all harbors? Now you´ve one with a draught of 6m - hardly an improvement over the 5,5m of your original design. From this point of view I would call your new one a design failure.

Are you power-playing to get the best out of spring* or are you favouring roleplaying and thus aiming for a shallow hull but a sub-optimal ship?

Two schools of thought I guess...

Just curious,

HoOmAn

hmm. learning that the K's normal displacement was 5.9 m basically led me to decide that 6 m should od the job, especially since I wanted her fast with a secondary role as fleet scout. And a meaningful design with that speed and 5 m draught is nearly impossible as far as I can see.

Bernhard

I still think the design doesn´t fir your needs if you´re looking for a cruiser that can use small ports as well.

Accourding to Whitley the only cruisers that had an average draught of 6 or more meters at normal load are:

The french CAs (all 10+kts standard).
The japanese TAKAO and TONE-class units (all 10+kts)
The russian CAPAJEV-class (~11,5kts).
The US-PORTLAND-class CAs and all following CAs and CLs (all 10+kts) except the ATLANTAs and their derivates.

The K´s had an exceptional deep draught for a cruiser of their size. Not a good example.

I can´t find a single 7kts cruiser with a draught of 6m.

So again: if you ask for a cruiser that fit your ports you better choose a different design.

Also note that your design will gain an additional 1,57 feet at full load. You might never be able to equipe/supply your ship with everything it needs for a long cruise during war times. Not a good idea.

Just my thoughts...

HoOmAn

according to http://www.german-navy.de/kriegsmarine/s…ipzig/tech.html Leipzig also had 5.69 m normal draught, not less that 5 m. I am getting rather cautious about figures like that ...

Bernhard

Leipzig accourding to

Whitley: average draught 4,88m

Gröner: at maximal tonnage of 8100ts 5,69m; at CWL (6830t - not ts!) 4,75m; at standard displ. 4,88m

Warships1: 4,26m or 14´

The problem with pages like the one you´re linking to or like this one

http://warships.web4u.cz/indexlode.php?l…L&trida=Leipzig

is that you´ll never know their sources. Thus I stick to my books.

Another example: In "Kreuzer Nürnberg" by Harnack and Sonntag you´ll find very detailed information about different tonnage and draught but those 5,74m given on

http://www.german-navy.de/kriegsmarine/s…nberg/tech.html

cannot be found. What does this tell us? A book that offers a half-dozan draughts for a half-dozan displacements and one can´t find 5,74m among them? It´s really difficult because if we look at Gröners we´ll learn that Nürnberg is rated at 5,74m for her max. displ. of 9040t (and 4,75m on CWL and 4,9m on standard displ.).

Anyway, 6m is a lot for normal or standard displacement and surely too much if one needs a cruiser for shallow waters. Even the Hippers had only 5,7-5,9m on normal displacement (14050ts - 14680ts from Hipper to PE).

Cheers,

HoOmAn

Just to add to your confusion on the subject I too have several sorces that state different drafts for Leipzig/Nurnburg. In my little pocket book "collins/janes warships of WW2" it states them as having a 6.4m draft, while in my "encyclopedia of weapons and warfare" it states them as having a 6.63m draft. As you can see quite a few sorces are far over the 4.88/5m of Leipzig/Nurnburg.
The problem with these sorces is that the Collins/Janes book lumps in Karlsruhe and Konigsberg in with the Leipzig and Nurnberg when they are essentially two class's of ships with the pair of Liepzig class differing enough to be separate class's as well. The "Encyclopedia of weapons and warfare" makes the un-bearable mistake of using a picture of Deutschland in place of leipzig. These two mistakes lead me to beleave that not enough research was done by the authors to take the info as true fact, so as Hooman says "I'll stick to my whitleys thank you very much!"
I find a few mistakes in the "Encyclopedia of weapons and warfare" set but on a whole the 24 book set is for the most part accurate and gives me tons of referance for all sorts of weapons, and to think someone sold this to some corner store selling magazines!!!

the problem with those low draughts is that at least for normal displacement they lead to unrealistically high BCs.

Can you sim Leipzig, Nuernberg or a K in such a manner that these low draughts actually work? I can't.

If you can: fair enough, I've learned something. If you can't we must conclude one of two things:

1) our sources are severly flawed
2) SpringSharp sucks as regards light cruisers.

as we have defined SS to define the physics of our game, we have to make our sims work here ...

looking forward to your designs :-)

Bernhard

To be honest, I had no problem to sim Königsberg realistically with springsharp.

I worked from Gröner Vol. 1, page 147 (german edition, 2., unveränderte Auflage). Stats given for her are:

length: 169m (on CWL)
beam: 15,2m
displacement: 6750ts (on CWL)
draught: 5,42m (on CWL)
speed 32,1kn (at 68200wPS and at 371n)
range: 7300nm at 17kn

First I interpreted the remark "normal load" behind her dimensions as "on CWL". This turned out to be an easy one. I got a slightly higher speed (similar to Köln which made 32,5kn with 68485wPS) with a much higher output than Königsberg. Further more it was in no way a dance on the string regarding hull strength (still some reserve) and I also got those beloved remarks (stable gun platform and good seaship - and we all know that at least the latter was not true historically).

Next I interpreted the remark "normal load" behind her dimensions as linked to her "normal displacement" as simed by springsharp. In this case I had to skip both remarks and reduce her bc to 0,48 and thus her standard displacement to a mere 5700ts. I also slowed her down a bit using her historical output. Ceterus paribus it was impossible to get a hs of 1,00 or higher. Given the K-class´ historical problems with hull cracks due to insufficient hull strength this seems to be quite realistic.

I will not propose to use variant A or B but those 5700ts normal displacement (variant B) seem too low even though the rest turned out to be realistic. I leave it to you...

Enjoy,

HoOmAn


Variant A:

KÖNIGSBERG, German Light Cruiser laid down 1926

Displacement:
6.531 t light; 6.775 t standard; 7.937 t normal; 8.835 t full load
Loading submergence 539 tons/feet

Dimensions:
554,46 ft x 49,87 ft x 17,78 ft (standard load)
169,00 m x 15,20 m x 5,42 m

Armament:
9 - 5,91" / 150 mm guns (3 Main turrets x 3 guns, 1 superfiring turret)
Superfiring turret is aft
4 - 3,46" / 88 mm guns
8 - 1,46" / 37 mm AA guns
8 - 0,79" / 20 mm guns
Weight of broadside 1.024 lbs / 465 kg
12 - 21,0" / 533 mm above water torpedoes

Armour:
Belt 1,97" / 50 mm, ends unarmoured
Belts cover 121% of normal area
Main turrets 1,18" / 30 mm, 2nd gun shields 0,98" / 25 mm
Armour deck 0,98" / 25 mm, Conning tower 3,94" / 100 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 81.475 shp / 60.780 Kw = 32,50 kts
Range 7.300nm at 17,00 kts

Complement:
420 - 546

Cost:
£2,423 million / $9,690 million

Distribution of weights at normal displacement:
Armament: 128 tons, 1,6%
Armour: 767 tons, 9,7%
Belts: 295 tons, 3,7%, Armament: 95 tons, 1,2%, Armour Deck: 343 tons, 4,3%
Conning Tower: 34 tons, 0,4%, Torpedo bulkhead: 0 tons, 0,0%
Machinery: 2.608 tons, 32,9%
Hull, fittings & equipment: 2.953 tons, 37,2%
Fuel, ammunition & stores: 1.406 tons, 17,7%
Miscellaneous weights: 75 tons, 0,9%

Metacentric height 2,4

Remarks:
Hull space for machinery, storage & compartmentation is cramped
Room for accommodation & workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform
Good seaboat, rides out heavy weather easily

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1,19
Shellfire needed to sink: 7.021 lbs / 3.185 Kg = 68,2 x 5,9 " / 150 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 1,0
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 70 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0,50
Relative quality as seaboat: 1,20

Hull form characteristics:
Block coefficient: 0,565
Sharpness coefficient: 0,34
Hull speed coefficient 'M': 8,50
'Natural speed' for length: 23,55 kts
Power going to wave formation at top speed: 59 %
Trim: 58
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 120,1%
Relative accommodation and working space: 118,1%
(Average = 100%)
Displacement factor: 112%
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0,97
(Structure weight / hull surface area: 91 lbs / square foot or 442 Kg / square metre)
Relative longitudinal hull strength: 1,34
(for 19,69 ft / 6,00 m average freeboard, freeboard adjustment 5,23 ft)
Relative composite hull strength: 1,01

2 floatplanes, 1 catapult

Variant B:

KÖNIGSBERG, German Light Cruiser laid down 1926

Displacement:
5.477 t light; 5.698 t standard; 6.757 t normal; 7.578 t full load
Loading submergence 484 tons/feet

Dimensions:
554,46 ft x 49,87 ft x 17,78 ft (normal load)
169,00 m x 15,20 m x 5,42 m

Armament:
9 - 5,91" / 150 mm guns (3 Main turrets x 3 guns, 1 superfiring turret)
Superfiring turret is aft
4 - 3,46" / 88 mm guns
8 - 1,46" / 37 mm AA guns
8 - 0,79" / 20 mm guns
Weight of broadside 1.024 lbs / 465 kg
12 - 21,0" / 533 mm above water torpedoes

Armour:
Belt 1,97" / 50 mm, ends unarmoured
Belts cover 125% of normal area
Main turrets 1,18" / 30 mm, 2nd gun shields 0,98" / 25 mm
Armour deck 0,98" / 25 mm, Conning tower 3,94" / 100 mm

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 68.240 shp / 50.907 Kw = 32,20 kts
Range 7.300nm at 17,00 kts

Complement:
372 - 484

Cost:
£2,090 million / $8,361 million

Distribution of weights at normal displacement:
Armament: 128 tons, 1,9%
Armour: 731 tons, 10,8%
Belts: 305 tons, 4,5%, Armament: 87 tons, 1,3%, Armour Deck: 308 tons, 4,6%
Conning Tower: 30 tons, 0,4%, Torpedo bulkhead: 0 tons, 0,0%
Machinery: 2.184 tons, 32,3%
Hull, fittings & equipment: 2.359 tons, 34,9%
Fuel, ammunition & stores: 1.280 tons, 18,9%
Miscellaneous weights: 75 tons, 1,1%

Metacentric height 2,4

Remarks:
Caution: Hull subject to strain in open-sea
Hull space for machinery, storage & compartmentation is cramped
Room for accommodation & workspaces is adequate
Ship has slow, easy roll, a good, steady gun platform

Estimated overall survivability and seakeeping ability:
Relative margin of stability: 1,17
Shellfire needed to sink: 4.942 lbs / 2.242 Kg = 48,0 x 5,9 " / 150 mm shells
(Approx weight of penetrating shell hits needed to sink ship excluding critical hits)
Torpedoes needed to sink: 0,9
(Approx number of typical torpedo hits needed to sink ship)
Relative steadiness as gun platform: 70 %
(Average = 50 %)
Relative rocking effect from firing to beam: 0,45
Relative quality as seaboat: 1,01

Hull form characteristics:
Block coefficient: 0,481
Sharpness coefficient: 0,31
Hull speed coefficient 'M': 8,97
'Natural speed' for length: 23,55 kts
Power going to wave formation at top speed: 56 %
Trim: 69
(Maximise stabilty/flotation = 0, Maximise steadiness/seakeeping = 100)

Estimated hull characteristics & strength:
Underwater volume absorbed by magazines and engineering spaces: 120,7%
Relative accommodation and working space: 99,8%
(Average = 100%)
Displacement factor: 109%
(Displacement relative to loading factors)
Relative cross-sectional hull strength: 0,89
(Structure weight / hull surface area: 81 lbs / square foot or 396 Kg / square metre)
Relative longitudinal hull strength: 1,03
(for 16,40 ft / 5,00 m average freeboard, freeboard adjustment 2,40 ft)
Relative composite hull strength: 0,91

2 floatplanes, 1 catapult

now, the second one seems more believable to me, output, hull cracks and all. Also this means that 0.9 on aship this size is actually feasible if one is prepared to pay the price - interesting. Seems we were being a bit to conservative here in the wesworld :-)

You sure about that 25 mm deck armour? every thing I have seen states higher - but that may be max thickness again.

My main argument was with the claim of 4.3 or so draughts anyway. clearly unfeasible IMHO. The second design ties in pretty much with my experiences, it seems the German designers were qilling to pay the price in lack of strength.

cheers

Bernhard

Quoted

Originally posted by LordArpad

My main argument was with the claim of 4.3 or so draughts anyway. clearly unfeasible IMHO. The second design ties in pretty much with my experiences, it seems the German designers were qilling to pay the price in lack of strength.

cheers

Bernhard

Well, I can´t remember to have claimed 4,3m for the K´s, have I? What I said is

"LEIPZIG and NÜRNBERG - both of similar size as well - also had draughts lower than 5m."

and that´s true AFAIK - at least when not talking about max. displacement.

On the other hand 4,3m isn´t that far off too. The british ARETHUSAs for example had an average draught of 4,21m accourding to Whitley.

Cheers,

HoOmAn