Logi's Design Studies

[Delta Force]

Why is the entire ship armored, and why are you using quad turrets? Don't those usually have problems with rate of fire? Usually nothing large than a 40mm cannon had more than 3 guns.

[Jefgte]

Remember the Yupanqui study with 6T2x6" on a 557" hull
Remove one of the aft turret & affect this free space to the quad turrets installations.
Superstructures are not too cramped



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Jef

[Logi]

Why is the entire ship armored,

Why not? Should not a cruiser/destroyer/TB killer be armored against the shells of it's expected enemies? Even if I sacrifice bow and stern armor for an AoN scheme, that grants me only 5-6" of armor, hardly enough to withstand the next class of weaponry. In addition, a high speed ship should have armor not only over vital areas but also bow and shafts. Last thing you would want is a stray cruiser or destroyer shell opening a hole in the forward bulkhead or dislocating a shaft.

In other words, the tonnage is required to keep the rest of the ship aspects in check and there is nothing a heavier belt will do, so why not a longer belt? There is no inherent disadvantage of total belt coverage.

and why are you using quad turrets? Don't those usually have problems with rate of fire? Usually nothing large than a 40mm cannon had more than 3 guns.

Not at all, I associate those problems with teething issues, quads typically being a new gun rushed into production. There is no basic engineering problem that quads would suffer from that triples and twins would not suffer from as well. Similarly, there no unsolvable problem a quad would suffer from that a twin or triple would suffer from as well. There is no inherent reason that a quad ought to have a lower RoF than another gun. OTL most quads suffered not from the quads themselves, but from improper crew training, teething issues, (optional) complicated loading mechanisms, etc.

Quad is a simple solution to deck space and protection. More guns in one turret means there needs to be less turrets for the same number of guns and less armor weight for the same protection over the guns. It's a natural solution. That's the same reason the French decided to use quads, similar firepower in less weight.

Think about it this way, if I wanted to mount 20 guns on a cruiser with triples, I would need 7 mounts. For twins I would need ten mounts, how would I possible hope to fit that in 550ft? As Jefgte shows, the Yupanqui study fits 6 mounts, anymore would require a bigger dock.

[ctwaterman]

Not at all, I associate those problems with teething issues, quads typically being a new gun rushed into production. There is no basic engineering problem that quads would suffer from that triples and twins would not suffer from as well. Similarly, there no unsolvable problem a quad would suffer from that a twin or triple would suffer from as well. There is no inherent reason that a quad ought to have a lower RoF than another gun. OTL most quads suffered not from the quads themselves, but from improper crew training, teething issues, (optional) complicated loading mechanisms, etc.

Quad is a simple solution to deck space and protection. More guns in one turret means there needs to be less turrets for the same number of guns and less armor weight for the same protection over the guns. It's a natural solution. That's the same reason the French decided to use quads, similar firepower in less weight.

I think some of the problems the Quads had was trying to fit 4 guns in the smallest possible turret to try and save space and weight.  The result was a crowded gun room and complicated loading gear.   The solution to more guns less weight resulted in other problems that had not been addressed before some of these ships KGV class so combat.

Some of Early Twin turrets had these problems as well..

And lastly what you have just done and why I wont build an 8 gun ship with only 2 quad turrets is put barrels of your weapons into 1 armored egg shell.  If the turrets is hit and even jammed not destroyed you loose 4 barrels not 2... same problem with the tripples.

Its a balancing act but 4 quads is no more inherently dangerous then 4 twins so go with it.

Charles

[ledeper]

The problem is that you cant mount triples or quadruple mounts ,unless you have mastered the:

Light Cruiser Architecture - Main battery in deck mounts/casemates .
1920:  No restriction (high or low) on caliber of turreted guns

the same problem I had regarding the Esc designs as shown below:

http://www.navalism.org/index.php?topic=5319.0

[Kaiser Kirk]

There is a greater inherent challange because of the extra shell hoists and fitting crews in, and Edinburgh never mounted Quads apparently because the Brits couldn't get the turret to work acceptably. By time Jean Bart was finished, her Quads worked fine*, and by time of DoY's engagement with Scharnhorst, they worked fairly well, but there was a long teething process.    Rate of fire on the quads apparently never got to where they were designed for the Brits, and didn't until post war for the French- again a long teething process. 

Quads save weight, so for max gun power, why not. It is more "eggs in one basket", and
They impose greater beam, but with the weight savings you can have more machinery and come out ahead.

Functionally, the only limit I can think of is that if a Quad 6" turret weighs the same as an 8" twin, then it should be expected to train at that rate, which only matters in short range actions like Savo Island. And of course the poor appearance :) 

Lastly, I think those using Quads may find some MOD-random design error crop up- we can't expect that all our systems work right because they certainly didn't IRL.

*There is some thought that French shells suffered high dispersion, but I can't recall if that was because the dual twins had each pair mounted close, or because of the shell/MV. Here, SS seems to go with the PoW style 4- across rather than the French Dual Twins anyhow.

[P3D]

I borrowed Jeftge's drawing, and sketched how the quads could be fit the design. Red line is the 314' occupied by the machinery, put the quads (20' barbettes) then copypasted the Yupanqui bow/stern on the ends. I ended up with a 194m hull.

[Logi]

I could probably fit it in 167.64m. I'll work on that.

[Jefgte]

If you want realy 5T4 on a 170m hull...
Reduce the engines spaces by a little slower speed: 30kts


Jef

[Logi]

Reduces machinery space to ~283 ft. Used extra strength for a slightly thicker belt, more misc weight (for more FCS directors), and longer legs.

I could adjust to 70 stability, but requires 70 trim. 70 trim is too high, no?

CL22,  Light Cruiser laid down 1922

Displacement:
   10,000 t light; 10,547 t standard; 11,861 t normal; 12,912 t full load

Dimensions: Length overall / water x beam x draught
   557.00 ft / 557.00 ft x 68.00 ft x 20.00 ft (normal load)
   169.77 m / 169.77 m x 20.73 m  x 6.10 m

Armament:
      20 - 6.00" / 152 mm guns (5x4 guns), 108.00lbs / 48.99kg shells, 1922 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, majority forward, 2 raised mounts - superfiring
      4 - 3.00" / 76.2 mm guns in single mounts, 13.50lbs / 6.12kg shells, 1922 Model
     Anti-aircraft guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 2,214 lbs / 1,004 kg
   Shells per gun, main battery: 250
   6 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   4.00" / 102 mm   557.00 ft / 169.77 m   16.00 ft / 4.88 m
   Ends:   Unarmoured
     Main Belt covers 154 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   3.00" / 76 mm   2.00" / 51 mm      2.00" / 51 mm
   2nd:   1.00" / 25 mm   1.00" / 25 mm            -

   - Armour deck: 1.50" / 38 mm, Conning tower: 3.00" / 76 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 78,249 shp / 58,374 Kw = 30.00 kts
   Range 14,000nm at 12.00 kts
   Bunker at max displacement = 2,365 tons

Complement:
   567 - 738

Cost:
   £2.602 million / $10.408 million

Distribution of weights at normal displacement:
   Armament: 277 tons, 2.3 %
   Armour: 2,374 tons, 20.0 %
      - Belts: 1,319 tons, 11.1 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 289 tons, 2.4 %
      - Armour Deck: 732 tons, 6.2 %
      - Conning Tower: 34 tons, 0.3 %
   Machinery: 2,654 tons, 22.4 %
   Hull, fittings & equipment: 4,202 tons, 35.4 %
   Fuel, ammunition & stores: 1,861 tons, 15.7 %
   Miscellaneous weights: 493 tons, 4.2 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     14,503 lbs / 6,578 Kg = 134.3 x 6.0 " / 152 mm shells or 1.8 torpedoes
   Stability (Unstable if below 1.00): 1.19
   Metacentric height 3.9 ft / 1.2 m
   Roll period: 14.5 seconds
   Steadiness   - As gun platform (Average = 50 %): 60 %
         - Recoil effect (Restricted arc if above 1.00): 0.36
   Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.548
   Length to Beam Ratio: 8.19 : 1
   'Natural speed' for length: 23.60 kts
   Power going to wave formation at top speed: 58 %
   Trim (Max stability = 0, Max steadiness = 100): 60
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      23.00 ft / 7.01 m
      - Forecastle (15 %):   20.00 ft / 6.10 m
      - Mid (50 %):      18.00 ft / 5.49 m
      - Quarterdeck (15 %):   18.00 ft / 5.49 m
      - Stern:      18.00 ft / 5.49 m
      - Average freeboard:   18.83 ft / 5.74 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 96.6 %
      - Above water (accommodation/working, high = better): 146.1 %
   Waterplane Area: 26,384 Square feet or 2,451 Square metres
   Displacement factor (Displacement / loading): 114 %
   Structure weight / hull surface area: 108 lbs/sq ft or 528 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.96
      - Longitudinal: 1.32
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is excellent

[mentat]

  If the objective is mounting 20 x 6 inch - which is pretty impressive firepower vs. CLs + DDs - then by far the most practical apptoach is 4 x 3 ABXY and 4 x single turrets each side amidships

- it only gives broadside of 16 - but no one can say it doesn't fit/causes big problems - and 10 years on - you need the midships space for good heavy AA 

    I posted a Heavy Escort Cruiser design allong these lines a while back.

[Logi]

That is a bad idea. Side mountings need additional support from the keel and only cover one arc. Which, is not good at all.

Also, single turrets? What use would those be? If they are in turrets, you just increased the amount of weight in our ship. If they are casemate, you just limited the arcs of fire even more than just having them on the side.

I would find such a design as regressing back rather than a forward movement in design. Not only is the system of mounting archaic but very inefficient. What you run into then is not a length issue, but a NEDS issue.

[Logi]

HH&LM Modern,  Armoured Cruiser laid down 1921

Displacement:
   16,000 t light; 16,973 t standard; 17,974 t normal; 18,775 t full load

Dimensions: Length overall / water x beam x draught
   555.00 ft / 555.00 ft x 84.00 ft x 25.10 ft (normal load)
   169.16 m / 169.16 m x 25.60 m  x 7.65 m

Armament:
      10 - 11.00" / 279 mm guns (3 mounts), 666.00lbs / 302.09kg shells, 1921 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, majority forward, 2 raised guns - superfiring
      16 - 4.13" / 105 mm guns (8x2 guns), 35.32lbs / 16.02kg shells, 1921 Model
     Quick firing guns in deck mounts with hoists
     on side, evenly spread, 2 raised mounts
      8 - 0.50" / 12.7 mm guns (4x2 guns), 0.06lbs / 0.03kg shells, 1921 Model
     Machine guns in deck mounts
     on centreline, evenly spread
   Weight of broadside 7,226 lbs / 3,277 kg
   Shells per gun, main battery: 150
   6 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   9.00" / 229 mm   360.00 ft / 109.73 m   16.00 ft / 4.88 m
   Ends:   Unarmoured
     Main Belt covers 100 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   11.0" / 279 mm   5.00" / 127 mm      10.0" / 254 mm
   2nd:   2.00" / 51 mm   1.00" / 25 mm      1.00" / 25 mm
   3rd:   1.00" / 25 mm         -               -

   - Armour deck: 1.50" / 38 mm, Conning tower: 3.00" / 76 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 78,479 shp / 58,545 Kw = 28.00 kts
   Range 8,000nm at 12.00 kts
   Bunker at max displacement = 1,801 tons

Complement:
   776 - 1,009

Cost:
   £4.318 million / $17.274 million

Distribution of weights at normal displacement:
   Armament: 903 tons, 5.0 %
   Armour: 4,757 tons, 26.5 %
      - Belts: 2,251 tons, 12.5 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 1,569 tons, 8.7 %
      - Armour Deck: 892 tons, 5.0 %
      - Conning Tower: 44 tons, 0.2 %
   Machinery: 2,702 tons, 15.0 %
   Hull, fittings & equipment: 7,306 tons, 40.6 %
   Fuel, ammunition & stores: 1,974 tons, 11.0 %
   Miscellaneous weights: 332 tons, 1.8 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     21,113 lbs / 9,577 Kg = 31.7 x 11.0 " / 279 mm shells or 2.5 torpedoes
   Stability (Unstable if below 1.00): 1.09
   Metacentric height 4.5 ft / 1.4 m
   Roll period: 16.6 seconds
   Steadiness   - As gun platform (Average = 50 %): 53 %
         - Recoil effect (Restricted arc if above 1.00): 0.59
   Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.538
   Length to Beam Ratio: 6.61 : 1
   'Natural speed' for length: 23.56 kts
   Power going to wave formation at top speed: 58 %
   Trim (Max stability = 0, Max steadiness = 100): 53
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      23.00 ft / 7.01 m
      - Forecastle (15 %):   21.00 ft / 6.40 m
      - Mid (50 %):      20.00 ft / 6.10 m
      - Quarterdeck (10 %):   20.00 ft / 6.10 m
      - Stern:      20.00 ft / 6.10 m
      - Average freeboard:   20.45 ft / 6.23 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 89.9 %
      - Above water (accommodation/working, high = better): 145.6 %
   Waterplane Area: 32,161 Square feet or 2,988 Square metres
   Displacement factor (Displacement / loading): 101 %
   Structure weight / hull surface area: 158 lbs/sq ft or 771 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.93
      - Longitudinal: 1.82
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is excellent

Misc Weight (332 t):
250t FCS
25t Radar
25t Long Range Wireless
24t 21" Torpedoes
8t Construction Reserve

KGV arrangement, no TDS. Vertical Belt. High Velocity 11"/54 naval gun. Normandie was to fit quad 13.5"s on 27m, this should fit quad 11"s on 25.6m.

[Kaiser Kirk]

Why bother providing barbettes and belts which can withstand 9-10" fire, but a deck only good for 6"?  Unless you're expecting short range fights ?

[Logi]

Because the Battle of Shangdong shows the threat of a turret explosion is worth the extra armor. ;D Also, I expect a short range knife duel with this sort of ship.

Something like this then?

HH&LM Modern,  Armoured Cruiser laid down 1921

Displacement:
   16,000 t light; 16,973 t standard; 17,974 t normal; 18,775 t full load

Dimensions: Length overall / water x beam x draught
   555.00 ft / 555.00 ft x 84.00 ft x 25.10 ft (normal load)
   169.16 m / 169.16 m x 25.60 m  x 7.65 m

Armament:
      10 - 11.00" / 279 mm guns (3 mounts), 666.00lbs / 302.09kg shells, 1921 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, majority forward, 2 raised guns - superfiring
      16 - 4.13" / 105 mm guns (8x2 guns), 35.32lbs / 16.02kg shells, 1921 Model
     Quick firing guns in deck mounts with hoists
     on side, evenly spread, 2 raised mounts
      8 - 0.50" / 12.7 mm guns (4x2 guns), 0.06lbs / 0.03kg shells, 1921 Model
     Machine guns in deck mounts
     on centreline, evenly spread
   Weight of broadside 7,226 lbs / 3,277 kg
   Shells per gun, main battery: 150
   6 - 21.0" / 533.4 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   8.50" / 216 mm   360.00 ft / 109.73 m   16.00 ft / 4.88 m
   Ends:   Unarmoured
     Main Belt covers 100 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   10.0" / 254 mm   5.00" / 127 mm      7.00" / 178 mm
   2nd:   2.00" / 51 mm   1.00" / 25 mm      1.00" / 25 mm
   3rd:   0.25" / 6 mm         -               -

   - Armour deck: 2.50" / 64 mm, Conning tower: 3.00" / 76 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 78,479 shp / 58,545 Kw = 28.00 kts
   Range 8,000nm at 12.00 kts
   Bunker at max displacement = 1,801 tons

Complement:
   776 - 1,009

Cost:
   £4.318 million / $17.274 million

Distribution of weights at normal displacement:
   Armament: 903 tons, 5.0 %
   Armour: 4,886 tons, 27.2 %
      - Belts: 2,126 tons, 11.8 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 1,228 tons, 6.8 %
      - Armour Deck: 1,487 tons, 8.3 %
      - Conning Tower: 44 tons, 0.2 %
   Machinery: 2,702 tons, 15.0 %
   Hull, fittings & equipment: 7,168 tons, 39.9 %
   Fuel, ammunition & stores: 1,974 tons, 11.0 %
   Miscellaneous weights: 341 tons, 1.9 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     20,990 lbs / 9,521 Kg = 31.5 x 11.0 " / 279 mm shells or 2.4 torpedoes
   Stability (Unstable if below 1.00): 1.09
   Metacentric height 4.5 ft / 1.4 m
   Roll period: 16.6 seconds
   Steadiness   - As gun platform (Average = 50 %): 58 %
         - Recoil effect (Restricted arc if above 1.00): 0.60
   Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.538
   Length to Beam Ratio: 6.61 : 1
   'Natural speed' for length: 23.56 kts
   Power going to wave formation at top speed: 58 %
   Trim (Max stability = 0, Max steadiness = 100): 57
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      21.00 ft / 6.40 m
      - Forecastle (15 %):   20.00 ft / 6.10 m
      - Mid (50 %):      20.00 ft / 6.10 m
      - Quarterdeck (10 %):   20.00 ft / 6.10 m
      - Stern:      20.00 ft / 6.10 m
      - Average freeboard:   20.06 ft / 6.11 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 90.0 %
      - Above water (accommodation/working, high = better): 143.9 %
   Waterplane Area: 32,161 Square feet or 2,988 Square metres
   Displacement factor (Displacement / loading): 101 %
   Structure weight / hull surface area: 156 lbs/sq ft or 760 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.93
      - Longitudinal: 1.81
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is excellent

Misc Weight (341 t):
250t FCS
25t Radar
25t Long Range Wireless
24t 21" Torpedoes
17t Construction Reserve