NUS planned light forces for 1914

[Sachmle]

Unless that is two sets of triple launchers side-by-side amidships me thinks you have to many torpedo tubes listed. If it is two sets of side-by-side triples, why? You can still only fire 3 TT at once to any side, and they would have to be mounted out towards the sides, which interferes w/ the firing arc of the Q 6" gun.

[RAM]

eough. No, the ship is intended to carry a single triple torpedo launcher, in the spot seen in the pic. Initially I modelled the ship with 2 torpedo launchers, 2nd in place of the Q turret, and a tad more speed. Then I Came with the idea of the 10 gun CL, put the turret there, but forgot to change the torpedo stats in the design and report.

HEre you go:

A-Class, NUS Light Cruiser laid down 1915 (Engine 1912)

Displacement:
   5.483 t light; 5.710 t standard; 6.521 t normal; 7.169 t full load

Dimensions: Length overall / water x beam x draught
   465,82 ft / 459,32 ft x 46,92 ft x 19,69 ft (normal load)
   141,98 m / 140,00 m x 14,30 m  x 6,00 m

Armament:
      8 - 6,00" / 152 mm guns (4x2 guns), 108,00lbs / 48,99kg shells, 1915 Model
     Quick firing guns in deck mounts with hoists
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      2 - 6,00" / 152 mm guns (1x2 guns), 108,00lbs / 48,99kg shells, 1915 Model
     Quick firing guns in a deck mount with hoist
     on centreline amidships
      6 - 2,00" / 50,8 mm guns in single mounts, 4,00lbs / 1,81kg shells, 1915 Model
     Quick firing guns in deck mounts
     on side, evenly spread
      4 - 1,00" / 25,4 mm guns in single mounts, 0,50lbs / 0,23kg shells, 1915 Model
     Quick firing guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 1.106 lbs / 502 kg
   Shells per gun, main battery: 150
   3 - 21,0" / 533,4 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   3,54" / 90 mm   360,89 ft / 110,00 m   9,84 ft / 3,00 m
   Ends:   1,97" / 50 mm     98,10 ft / 29,90 m   7,71 ft / 2,35 m
     Main Belt covers 121 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   3,15" / 80 mm   0,98" / 25 mm            -
   2nd:   3,15" / 80 mm   0,98" / 25 mm            -
   3rd:   0,79" / 20 mm         -               -
   4th:   0,79" / 20 mm         -               -

   - Armour deck: 1,57" / 40 mm, Conning tower: 2,76" / 70 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 3 shafts, 46.654 shp / 34.804 Kw = 28,60 kts
   Range 9.000nm at 12,00 kts
   Bunker at max displacement = 1.459 tons

Complement:
   362 - 471

Cost:
   £0,827 million / $3,307 million

Distribution of weights at normal displacement:
   Armament: 138 tons, 2,1 %
   Armour: 1.096 tons, 16,8 %
      - Belts: 566 tons, 8,7 %
      - Torpedo bulkhead: 0 tons, 0,0 %
      - Armament: 76 tons, 1,2 %
      - Armour Deck: 433 tons, 6,6 %
      - Conning Tower: 21 tons, 0,3 %
   Machinery: 1.860 tons, 28,5 %
   Hull, fittings & equipment: 2.251 tons, 34,5 %
   Fuel, ammunition & stores: 1.037 tons, 15,9 %
   Miscellaneous weights: 138 tons, 2,1 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     5.656 lbs / 2.566 Kg = 52,4 x 6,0 " / 152 mm shells or 1,0 torpedoes
   Stability (Unstable if below 1.00): 1,11
   Metacentric height 2,0 ft / 0,6 m
   Roll period: 14,1 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0,67
   Seaboat quality  (Average = 1.00): 1,20

Hull form characteristics:
   Hull has raised forecastle
   Block coefficient: 0,538
   Length to Beam Ratio: 9,79 : 1
   'Natural speed' for length: 21,43 kts
   Power going to wave formation at top speed: 58 %
   Trim (Max stability = 0, Max steadiness = 100): 59
   Bow angle (Positive = bow angles forward): 15,00 degrees
   Stern overhang: 0,00 ft / 0,00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      24,28 ft / 7,40 m
      - Forecastle (22 %):   24,28 ft / 7,40 m (16,08 ft / 4,90 m aft of break)
      - Mid (67 %):      16,08 ft / 4,90 m
      - Quarterdeck (14 %):   16,08 ft / 4,90 m
      - Stern:      16,08 ft / 4,90 m
      - Average freeboard:   17,88 ft / 5,45 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 111,4 %
      - Above water (accommodation/working, high = better): 113,7 %
   Waterplane Area: 14.871 Square feet or 1.382 Square metres
   Displacement factor (Displacement / loading): 108 %
   Structure weight / hull surface area: 83 lbs/sq ft or 406 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,93
      - Longitudinal: 2,01
      - Overall: 1,00
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is adequate
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

Misc weight:
100 tons FC
12 tons 3 torps+3 reloads
25 tons LR Marconi
1 tons extra accomodation for the captain.

[The Rock Doctor]

I gotta ask - has NUS developed a twin mount for the main battery?

[ledeper]

No,not when I looked the last time

[RAM]

I gotta ask - has NUS developed a twin mount for the main battery?

nope, but the two first ships of this class will be laid down 1st HY 1916. And I have yet to post 1915 HY reports. And a dual mount is 2 HYs worth of development...

hope you get my drift ;)

[The Rock Doctor]

I smell what you're cooking.

[RAM]

Revising the HYs spreadsheets I'm working on, I just stuck on the fact that if I hold the build start until HY2/16 I'll have both the dual 6'' mounts and the 1916 turbines ready for the design.

So the first Altairs will be laid down in HY2, not HY1, 1916.

Stats as follows (drawing is identical). Only change over the previously posted ship is that speed is 29.5 knots instead of 28.6. Seakeeping and steadiness are a bit low but well within acceptable parameters anyway.

Altair Class, NUS Light Cruiser laid down 1916

Displacement:
   5.603 t light; 5.830 t standard; 6.521 t normal; 7.073 t full load

Dimensions: Length overall / water x beam x draught
   465,82 ft / 459,32 ft x 46,92 ft x 19,69 ft (normal load)
   141,98 m / 140,00 m x 14,30 m  x 6,00 m

Armament:
      8 - 6,00" / 152 mm guns (4x2 guns), 108,00lbs / 48,99kg shells, 1916 Model
     Quick firing guns in deck mounts with hoists
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      2 - 6,00" / 152 mm guns (1x2 guns), 108,00lbs / 48,99kg shells, 1916 Model
     Quick firing guns in a deck mount with hoist
     on centreline amidships
      6 - 2,00" / 50,8 mm guns in single mounts, 4,00lbs / 1,81kg shells, 1916 Model
     Quick firing guns in deck mounts
     on side, evenly spread
      4 - 1,00" / 25,4 mm guns in single mounts, 0,50lbs / 0,23kg shells, 1916 Model
     Quick firing guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 1.106 lbs / 502 kg
   Shells per gun, main battery: 150
   3 - 21,0" / 533,4 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   3,54" / 90 mm   360,89 ft / 110,00 m   9,84 ft / 3,00 m
   Ends:   1,97" / 50 mm     98,10 ft / 29,90 m   7,71 ft / 2,35 m
     Main Belt covers 121 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   3,15" / 80 mm   0,98" / 25 mm            -
   2nd:   3,15" / 80 mm   0,98" / 25 mm            -
   3rd:   0,79" / 20 mm         -               -
   4th:   0,79" / 20 mm         -               -

   - Armour deck: 1,57" / 40 mm, Conning tower: 2,76" / 70 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 53.001 shp / 39.539 Kw = 29,50 kts
   Range 9.000nm at 12,00 kts
   Bunker at max displacement = 1.244 tons

Complement:
   362 - 471

Cost:
   £0,963 million / $3,853 million

Distribution of weights at normal displacement:
   Armament: 138 tons, 2,1 %
   Armour: 1.096 tons, 16,8 %
      - Belts: 566 tons, 8,7 %
      - Torpedo bulkhead: 0 tons, 0,0 %
      - Armament: 76 tons, 1,2 %
      - Armour Deck: 433 tons, 6,6 %
      - Conning Tower: 21 tons, 0,3 %
   Machinery: 1.975 tons, 30,3 %
   Hull, fittings & equipment: 2.256 tons, 34,6 %
   Fuel, ammunition & stores: 918 tons, 14,1 %
   Miscellaneous weights: 138 tons, 2,1 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     5.200 lbs / 2.359 Kg = 48,2 x 6,0 " / 152 mm shells or 0,9 torpedoes
   Stability (Unstable if below 1.00): 1,15
   Metacentric height 2,1 ft / 0,6 m
   Roll period: 13,7 seconds
   Steadiness   - As gun platform (Average = 50 %): 60 %
         - Recoil effect (Restricted arc if above 1.00): 0,59
   Seaboat quality  (Average = 1.00): 1,11

Hull form characteristics:
   Hull has raised forecastle
   Block coefficient: 0,538
   Length to Beam Ratio: 9,79 : 1
   'Natural speed' for length: 21,43 kts
   Power going to wave formation at top speed: 60 %
   Trim (Max stability = 0, Max steadiness = 100): 54
   Bow angle (Positive = bow angles forward): 15,00 degrees
   Stern overhang: 0,00 ft / 0,00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      24,28 ft / 7,40 m
      - Forecastle (22 %):   24,28 ft / 7,40 m (16,08 ft / 4,90 m aft of break)
      - Mid (67 %):      16,08 ft / 4,90 m
      - Quarterdeck (14 %):   16,08 ft / 4,90 m
      - Stern:      16,08 ft / 4,90 m
      - Average freeboard:   17,88 ft / 5,45 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 117,0 %
      - Above water (accommodation/working, high = better): 113,7 %
   Waterplane Area: 14.871 Square feet or 1.382 Square metres
   Displacement factor (Displacement / loading): 104 %
   Structure weight / hull surface area: 83 lbs/sq ft or 407 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,92
      - Longitudinal: 2,01
      - Overall: 1,00
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is adequate

[P3D]

A bit too deep draught for the beam.
There's no real reason to have the narrow and thin end belts. Either have no end belt or just extend the main belt.
The belts themselves reach only 60cm below the waterline - in normal load conditions.

OTOH I think you could decrease freeboard by ~0.5m and lengthen+widen the ship if you want preserve seakeeping number. Then your belt should be ~3.5m wide.

Gun face armor should be limited to 2" (I might be mistaken here, though).

FYI, there id a New Swiss heavy cruiser NSS Atair (same star, different spelling).
http://www.navalism.org/index.php?topic=638.0

[RAM]

draught is not a concern for the type. It's a CL which will sail with the fleet, meaning capital ships. And those have much deeper draughts. And a 6m draught for a 6500t cruiser isn't that terrible anyway, the Toreador class CLs already in service within the NUS navy are quite a bit lighter, and have a 5.5m draught...

About the belt protection. Yes, 3m coverage might seem too shallow. It is not when you see most CLs out there have 1/3 or more of it's belt under the water. This one has most of it over the water, so the 3m belt is enough (more on this later), the design of this ship stems out of several doctrines the NUS navy is adopting (as why, I already said there's a big mouthy guy in charge of the naval design bureau, and who has political contacts strong enough to stop and scrap an already laid down BB)

Following this doctrine: There is a reason to have end belts: a degree of protection against light projectiles and splinters. For a cruiser, speed is important. If you let your ends free of armor, and you're likely to be facing light combatants with fast firing light guns, you risk potential floodings you could avoid by a relatively thin armor plate.

The same principle is followed with the main belt. It actually is intended to be around 70 cm under the water (slightly more than 2 feet). The drawing I take as being of the ship on normal condition (meaning 6500tons)...and this is a ship that under full load displaces 7000 tons.  That belt is going to be deeper then.

Regardless of that, it's also part of doctrine of CL design  the fact that CLs are designed to fight it out against other CLs and DDs. Chances are that such fights happen at quite low distances (helped by the fact that the common FC out there is 1912's), and it's unlikely that guns of calibers over 6'' are involved.
At low distances shells tend to ricochet off the water rather than going into the water. With lighter shells this is even more usual, and their underwater performance is abysmal (small shells=small weights=small kinetic energy, which is easily lost if the shell hits the water and goes under). Heavier shells could fall short, sink, and keep enough energy to penetrate clearly. But heavier shells will come from AC, BC or BBs. Not from CLs and DDs...no CL can stand hits from those classes of ships so why putting protection there, if it's going to be defeated anyway?.

In other words, underwater hits coming from the shells the ship's armor is intended to defeat (6 inch and lower) are quite unlikely to happen. And so, designing an armor belt to cover too much below the water is a waste of tonnage. There're at least 80cm of belt under the water. If a shell is to hit 1m under the waterline, coming from short distances (the distances this ship is expected to fight at) it has to do a long trip underwater (and that if the shell does not ricochet vs the water), light shells won't keep kinetic energy, and won't penetrate the hull.

Well, that says NUS doctrine at least ;)


As for names, it was not strange OTL to have ships called by similar names. Usually language made a difference, just not in this case as star names are common for all languages :).


About the gun protection,though, you're dead right. According to the rules, twin gun mounts can't have more than 1'' of protection. I'd have to work on that and change the design accordingly, but IIRC there are already some CLs around in the N-verse with twin mounts which doen't comply with this rule and have more armor than 1'' aswell...

[The Rock Doctor]

The 1910 CL tech has been amended to allow for heavier armor on constructon since then (applied retroactively, if necessary, from construction reserve weight).  This was part of the recent changes - we Mods will endeavour to get it into the rules sections promptly.

[P3D]

About the draught. Most real world ships has a D:B between 2.5 and 3. SS2 thinks even deeper draught makes the hull much stronger, but something prevented RL navies to go that way. Think about it as some reality check.

The problem with not having adequate belt below water is that the waves would expose unarmored sections of the hull. Even moderately high speeds (as in 15kts+) would do that too, not only rough seas.

[RAM]

Well, not much use in discussing with someone who knows much more than me about this details, so I'll simply take your advice in consideration
;)

Last iteration, 29,1 knots, wider belt coverage and reduced draught.



Altair Class, NUS Light Cruiser laid down 1916

Displacement:
   5.601 t light; 5.827 t standard; 6.518 t normal; 7.070 t full load

Dimensions: Length overall / water x beam x draught
   465,82 ft / 459,32 ft x 46,92 ft x 18,86 ft (normal load)
   141,98 m / 140,00 m x 14,30 m  x 5,75 m

Armament:
      8 - 6,00" / 152 mm guns (4x2 guns), 108,00lbs / 48,99kg shells, 1916 Model
     Quick firing guns in deck mounts with hoists
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      2 - 6,00" / 152 mm guns (1x2 guns), 108,00lbs / 48,99kg shells, 1916 Model
     Quick firing guns in a deck mount with hoist
     on centreline amidships
      6 - 2,00" / 50,8 mm guns in single mounts, 4,00lbs / 1,81kg shells, 1916 Model
     Quick firing guns in deck mounts
     on side, evenly spread
      4 - 1,00" / 25,4 mm guns in single mounts, 0,50lbs / 0,23kg shells, 1916 Model
     Quick firing guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 1.106 lbs / 502 kg
   Shells per gun, main battery: 150
   3 - 21,0" / 533,4 mm above water torpedoes

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   3,54" / 90 mm   360,89 ft / 110,00 m   11,48 ft / 3,50 m
   Ends:   1,97" / 50 mm     98,10 ft / 29,90 m   7,71 ft / 2,35 m
     Main Belt covers 121 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   3,54" / 90 mm   0,98" / 25 mm      0,98" / 25 mm
   2nd:   3,54" / 90 mm   0,98" / 25 mm      0,98" / 25 mm
   3rd:   0,79" / 20 mm         -               -
   4th:   0,79" / 20 mm         -               -

   - Armour deck: 1,57" / 40 mm, Conning tower: 2,76" / 70 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 2 shafts, 50.613 shp / 37.757 Kw = 29,10 kts
   Range 9.000nm at 12,00 kts
   Bunker at max displacement = 1.243 tons

Complement:
   362 - 471

Cost:
   £0,943 million / $3,771 million

Distribution of weights at normal displacement:
   Armament: 138 tons, 2,1 %
   Armour: 1.198 tons, 18,4 %
      - Belts: 652 tons, 10,0 %
      - Torpedo bulkhead: 0 tons, 0,0 %
      - Armament: 83 tons, 1,3 %
      - Armour Deck: 443 tons, 6,8 %
      - Conning Tower: 21 tons, 0,3 %
   Machinery: 1.886 tons, 28,9 %
   Hull, fittings & equipment: 2.241 tons, 34,4 %
   Fuel, ammunition & stores: 917 tons, 14,1 %
   Miscellaneous weights: 138 tons, 2,1 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     5.480 lbs / 2.486 Kg = 50,7 x 6,0 " / 152 mm shells or 1,0 torpedoes
   Stability (Unstable if below 1.00): 1,07
   Metacentric height 1,8 ft / 0,6 m
   Roll period: 14,5 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0,68
   Seaboat quality  (Average = 1.00): 1,11

Hull form characteristics:
   Hull has raised forecastle
   Block coefficient: 0,561
   Length to Beam Ratio: 9,79 : 1
   'Natural speed' for length: 21,43 kts
   Power going to wave formation at top speed: 60 %
   Trim (Max stability = 0, Max steadiness = 100): 63
   Bow angle (Positive = bow angles forward): 15,00 degrees
   Stern overhang: 0,00 ft / 0,00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      24,28 ft / 7,40 m
      - Forecastle (22 %):   24,28 ft / 7,40 m (16,08 ft / 4,90 m aft of break)
      - Mid (67 %):      16,08 ft / 4,90 m
      - Quarterdeck (14 %):   16,08 ft / 4,90 m
      - Stern:      16,08 ft / 4,90 m
      - Average freeboard:   17,88 ft / 5,45 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 112,7 %
      - Above water (accommodation/working, high = better): 116,2 %
   Waterplane Area: 15.198 Square feet or 1.412 Square metres
   Displacement factor (Displacement / loading): 105 %
   Structure weight / hull surface area: 83 lbs/sq ft or 403 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0,93
      - Longitudinal: 1,92
      - Overall: 1,00
   Hull space for machinery, storage, compartmentation is cramped
   Room for accommodation and workspaces is adequate
   Ship has slow, easy roll, a good, steady gun platform