Rohirrim Battle Cruiser design: 1916

Started by Ithekro, November 21, 2008, 05:30:25 PM

Previous topic - Next topic

Ithekro

In light of the increasing speeds and weapon sizes (the the fact that the first class of Rohan's Battle Cruisers will be ten years old), the Mark has designs for a larger, faster, and more heavily armed Battle Cruiser for long distance oceanic patrols and showing the flag at distant ports.

It is assumed there will be three in this class, one laid down each year (1916, 17, and 18).  It is possible the third ship will be reorded to a different class specifications, depending on the engine technology and what is going on in the rest of the world.  Also it is possible that the follow on class will have either four turrets, or the new 15.5 inch guns.  That class may require a Type 4 class slip to build.

Boromir

Rohan Battle Cruiser laid down 1916 (Engine 1912)

Displacement:
   27,982 t light; 29,547 t standard; 32,000 t normal; 33,834 t full load

Dimensions: Length overall / water x beam x draught
   718.00 ft / 710.00 ft x 90.00 ft x 27.00 ft (normal load)
   218.85 m / 216.41 m x 27.43 m  x 8.23 m

Armament:
      9 - 14.00" / 356 mm guns (3x3 guns), 1,372.00lbs / 622.33kg shells, 1916 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, majority forward, 1 raised mount - superfiring
      12 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1916 Model
     Quick firing guns in casemate mounts
     on side, evenly spread
      6 - 1.50" / 38.1 mm guns in single mounts, 1.69lbs / 0.77kg shells, 1916 Model
     Anti-aircraft guns in deck mounts
     on centreline, evenly spread, all raised mounts
      6 - 0.75" / 19.1 mm guns in single mounts, 0.21lbs / 0.10kg shells, 1916 Model
     Machine guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 13,655 lbs / 6,194 kg
   Shells per gun, main battery: 120

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   9.00" / 229 mm   465.00 ft / 141.73 m   11.00 ft / 3.35 m
   Ends:   3.00" / 76 mm   245.00 ft / 74.68 m   11.00 ft / 3.35 m
   Upper:   5.00" / 127 mm   465.00 ft / 141.73 m   11.00 ft / 3.35 m
     Main Belt covers 101 % of normal length

   - Torpedo Bulkhead:
      2.00" / 51 mm   465.00 ft / 141.73 m   27.00 ft / 8.23 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   11.0" / 279 mm   9.00" / 229 mm      9.00" / 229 mm
   2nd:   5.00" / 127 mm         -               -

   - Armour deck: 3.00" / 76 mm, Conning tower: 11.00" / 279 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric cruising motors plus geared drives, 4 shafts, 80,000 shp / 59,680 Kw = 26.17 kts
   Range 10,000nm at 12.00 kts (Bunkerage = 4,415 tons)

Complement:
   1,196 - 1,555

Cost:
   £4.680 million / $18.718 million

Distribution of weights at normal displacement:
   Armament: 1,707 tons, 5.3 %
   Armour: 9,669 tons, 30.2 %
      - Belts: 3,364 tons, 10.5 %
      - Torpedo bulkhead: 929 tons, 2.9 %
      - Armament: 2,460 tons, 7.7 %
      - Armour Deck: 2,676 tons, 8.4 %
      - Conning Tower: 240 tons, 0.7 %
   Machinery: 3,190 tons, 10.0 %
   Hull, fittings & equipment: 13,016 tons, 40.7 %
   Fuel, ammunition & stores: 4,018 tons, 12.6 %
   Miscellaneous weights: 400 tons, 1.3 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     35,073 lbs / 15,909 Kg = 25.6 x 14.0 " / 356 mm shells or 4.4 torpedoes
   Stability (Unstable if below 1.00): 1.09
   Metacentric height 5.0 ft / 1.5 m
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.99
   Seaboat quality  (Average = 1.00): 1.42

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.649
   Length to Beam Ratio: 7.89 : 1
   'Natural speed' for length: 26.65 kts
   Power going to wave formation at top speed: 48 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 14.94 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      30.00 ft / 9.14 m
      - Forecastle (20 %):   28.00 ft / 8.53 m
      - Mid (50 %):      28.00 ft / 8.53 m (20.00 ft / 6.10 m aft of break)
      - Quarterdeck (15 %):   20.00 ft / 6.10 m
      - Stern:      20.00 ft / 6.10 m
      - Average freeboard:   24.16 ft / 7.36 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 96.0 %
      - Above water (accommodation/working, high = better): 182.0 %
   Waterplane Area: 48,222 Square feet or 4,480 Square metres
   Displacement factor (Displacement / loading): 106 %
   Structure weight / hull surface area: 186 lbs/sq ft or 909 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 1.00
      - Longitudinal: 1.38
      - Overall: 1.03
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is excellent
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily


Tanthalas

"He either fears his fate too much,
Or his desserts are small,
Who dares not put it to the touch,
To win or lose it all!"

James Graham, 5th Earl of Montrose
1612 to 1650
Royalist General during the English Civil War

The Rock Doctor

Seems quite capable...are you sure you want to build them?

Ithekro

Competition-wise, they are outclassed before they are laid down.  They are better than the Mark's current two classes of Battle Cruisers, but under gunned, under armored, and not as fast as some other powers Battlecruisers or large armored cruisers/frigates in some cases.  using the 15.5" guns might help in the out gunned part of the problem.

My internal debate in them is the time/materials needed to build them while also trying to complete the regular Battleship construction runs.

The old plan was to built two classes of two ships each laid down one per year from 1916-1919.  One would have had 6 x 14" guns and the next 8 x 14" guns.  The follow on to those woud have been fast battleships in the 1920s I image.   With the design changes and other improvements, Rohan is staying with triple turrets for the 14" guns on battlecruisers, or going to fit a class with twin 15.5" guns before the 1917 battleships are laid down. 

The basic problem with this design is the 80,000 shp limit of the 1912 engine technology that Rohan currently uses.  They are now slightly behind in this field and won't have the 1916 level technology until at least 1917 or 1918.  This does nothing to the battleship construction because the battle line concept of 21 knots or so fits in easily, and this design shows that Rohan could go up to 25 or even 26 knots if it wanted.  But for a battlecruiser that is designed to outrun what it can't outfight, or catch anything larger than a destroyer....Rohan's are decidedly underpowered.

However as a force projection tool across oceans, it works quite well until it runs into a fast battleship or another battlecruiser.

Ithekro

15.5" gun twin mount version (more armor and shells)

Boromir

Rohan Battle Cruiser laid down 1916 (Engine 1912)

Displacement:
   27,849 t light; 29,547 t standard; 32,000 t normal; 33,834 t full load

Dimensions: Length overall / water x beam x draught
   718.00 ft / 710.00 ft x 90.00 ft x 27.00 ft (normal load)
   218.85 m / 216.41 m x 27.43 m  x 8.23 m

Armament:
      6 - 15.50" / 394 mm guns (3x2 guns), 1,861.94lbs / 844.56kg shells, 1916 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, majority forward, 1 raised mount - superfiring
      12 - 6.00" / 152 mm guns in single mounts, 108.00lbs / 48.99kg shells, 1916 Model
     Quick firing guns in casemate mounts
     on side, evenly spread
      6 - 1.50" / 38.1 mm guns in single mounts, 1.69lbs / 0.77kg shells, 1916 Model
     Anti-aircraft guns in deck mounts
     on centreline, evenly spread, all raised mounts
      6 - 0.75" / 19.1 mm guns in single mounts, 0.21lbs / 0.10kg shells, 1916 Model
     Machine guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 12,479 lbs / 5,660 kg
   Shells per gun, main battery: 150

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   11.0" / 279 mm   465.00 ft / 141.73 m   11.00 ft / 3.35 m
   Ends:   3.00" / 76 mm   245.00 ft / 74.68 m   11.00 ft / 3.35 m
   Upper:   5.00" / 127 mm   465.00 ft / 141.73 m   11.00 ft / 3.35 m
     Main Belt covers 101 % of normal length

   - Torpedo Bulkhead:
      2.00" / 51 mm   465.00 ft / 141.73 m   27.00 ft / 8.23 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   11.0" / 279 mm   9.00" / 229 mm      11.0" / 279 mm
   2nd:   5.00" / 127 mm         -               -

   - Armour deck: 3.00" / 76 mm, Conning tower: 11.00" / 279 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric cruising motors plus geared drives, 4 shafts, 80,000 shp / 59,680 Kw = 26.17 kts
   Range 10,000nm at 12.00 kts (Bunkerage = 4,415 tons)

Complement:
   1,196 - 1,555

Cost:
   £4.470 million / $17.879 million

Distribution of weights at normal displacement:
   Armament: 1,560 tons, 4.9 %
   Armour: 10,152 tons, 31.7 %
      - Belts: 3,803 tons, 11.9 %
      - Torpedo bulkhead: 929 tons, 2.9 %
      - Armament: 2,504 tons, 7.8 %
      - Armour Deck: 2,676 tons, 8.4 %
      - Conning Tower: 240 tons, 0.7 %
   Machinery: 3,190 tons, 10.0 %
   Hull, fittings & equipment: 12,547 tons, 39.2 %
   Fuel, ammunition & stores: 4,151 tons, 13.0 %
   Miscellaneous weights: 400 tons, 1.3 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     36,158 lbs / 16,401 Kg = 19.4 x 15.5 " / 394 mm shells or 4.6 torpedoes
   Stability (Unstable if below 1.00): 1.10
   Metacentric height 5.1 ft / 1.6 m
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.87
   Seaboat quality  (Average = 1.00): 1.40

Hull form characteristics:
   Hull has rise forward of midbreak
   Block coefficient: 0.649
   Length to Beam Ratio: 7.89 : 1
   'Natural speed' for length: 26.65 kts
   Power going to wave formation at top speed: 48 %
   Trim (Max stability = 0, Max steadiness = 100): 50
   Bow angle (Positive = bow angles forward): 14.94 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      30.00 ft / 9.14 m
      - Forecastle (20 %):   28.00 ft / 8.53 m
      - Mid (50 %):      28.00 ft / 8.53 m (19.00 ft / 5.79 m aft of break)
      - Quarterdeck (15 %):   19.00 ft / 5.79 m
      - Stern:      19.00 ft / 5.79 m
      - Average freeboard:   23.66 ft / 7.21 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 92.5 %
      - Above water (accommodation/working, high = better): 177.8 %
   Waterplane Area: 48,222 Square feet or 4,480 Square metres
   Displacement factor (Displacement / loading): 109 %
   Structure weight / hull surface area: 180 lbs/sq ft or 880 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 1.00
      - Longitudinal: 1.32
      - Overall: 1.03
   Hull space for machinery, storage, compartmentation is adequate
   Room for accommodation and workspaces is excellent
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily


Ithekro

I will probably tweek the design later to use the 14" guns and the 11" of armor.  Or not bother with it and focus on constructing a more balanced force.