Cruiser Ideas

[The Rock Doctor]

It's an interesting contrast with my new Ironside.

You have three Moltkes already - how many ships in this size range do you reckon you need?

[Sachmle]

It's an interesting contrast with my new Ironside.

You have three Moltkes already - how many ships in this size range do you reckon you need?

Well, Moltke's are 3kts slower, and have 2 less 11" guns. These are more like Improved Moltke's. Scharnhorst and Gneisenau are basically relagated to 2nd line Battleships now as they're too slow (24kts) to be BCs and to weak armed to be 1st line BBs (6x12), but still pretty well protected (12" belt, 2" deck).

[P3D]

Would it be a one-off design, or you plan to build more?

[Sachmle]

I'm not planning anymore one-off designs. That doesn't mean changing world situations wouldn't make that happen, but as of now I'm looking for at least a class of 2, 4 preferably. Unfortunately I need to expand my shipbuilding infrastructure, as I don't have enough Type 3 slip or drydocks right now.

[Sachmle]

Possible Large Light Cruiser

Kruezer 15/5a, Duetsche Reich Klein Kruezer laid down 1920

Displacement:
   8,650 t light; 8,970 t standard; 10,010 t normal; 10,842 t full load

Dimensions: Length overall / water x beam x draught
   557.76 ft / 551.18 ft x 55.12 ft x 22.97 ft (normal load)
   170.00 m / 168.00 m x 16.80 m  x 7.00 m

Armament:
     10 - 5.91" / 150 mm guns (5x2 guns), 99.21lbs / 45.00kg shells, 1920 Model
     Breech loading guns in deck mounts with hoists
     on centreline ends, majority aft, 3 raised mounts - superfiring
     2 - 3.46" / 88.0 mm guns in single mounts, 22.05lbs / 10.00kg shells, 1920 Model
     Anti-aircraft guns in deck mounts
     on side, all amidships
     4 - 1.46" / 37.0 mm guns (2x2 guns), 1.55lbs / 0.70kg shells, 1920 Model
     Anti-aircraft guns in deck mounts
     on side, all amidships, all raised mounts - superfiring
     6 - 0.30" / 7.7 mm guns in single mounts, 0.02lbs / 0.01kg shells, 1920 Model
     Machine guns in deck mounts
     on side ends, evenly spread, all raised mounts - superfiring
   Weight of broadside 1,042 lbs / 473 kg
   Shells per gun, main battery: 204
   8 - 23.6" / 600 mm above water torpedoes

Armour:
  - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   3.15" / 80 mm   459.32 ft / 140.00 m   10.01 ft / 3.05 m
   Ends:   Unarmoured
     Main Belt covers 128 % of normal length

  - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   3.15" / 80 mm   1.57" / 40 mm      3.15" / 80 mm
   2nd:   0.98" / 25 mm         -               -
   3rd:   0.59" / 15 mm         -               -
   4th:   0.39" / 10 mm         -               -

  - Armour deck: 1.57" / 40 mm, Conning tower: 3.15" / 80 mm

Machinery:
   Oil fired boilers, steam turbines,
   Geared drive, 4 shafts, 100,000 shp / 74,600 Kw = 33.08 kts
   Range 8,500nm at 14.00 kts
   Bunker at max displacement = 1,872 tons

Complement:
   499 - 650

Cost:
   £2.140 million / $8.560 million

Distribution of weights at normal displacement:
   Armament: 135 tons, 1.3 %
   Armour: 1,299 tons, 13.0 %
      - Belts: 581 tons, 5.8 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 96 tons, 1.0 %
      - Armour Deck: 591 tons, 5.9 %
      - Conning Tower: 32 tons, 0.3 %
   Machinery: 3,497 tons, 34.9 %
   Hull, fittings & equipment: 3,469 tons, 34.7 %
   Fuel, ammunition & stores: 1,360 tons, 13.6 %
   Miscellaneous weights: 250 tons, 2.5 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     7,157 lbs / 3,246 Kg = 69.5 x 5.9 " / 150 mm shells or 1.0 torpedoes
   Stability (Unstable if below 1.00): 1.13
   Metacentric height 2.6 ft / 0.8 m
   Roll period: 14.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.43
   Seaboat quality  (Average = 1.00): 1.12

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.502
   Length to Beam Ratio: 10.00 : 1
   'Natural speed' for length: 23.48 kts
   Power going to wave formation at top speed: 60 %
   Trim (Max stability = 0, Max steadiness = 100): 62
   Bow angle (Positive = bow angles forward): 13.90 degrees
   Stern overhang: -6.56 ft / -2.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      26.57 ft / 8.10 m
      - Forecastle (20 %):   20.01 ft / 6.10 m
      - Mid (50 %):      20.01 ft / 6.10 m
      - Quarterdeck (15 %):   20.01 ft / 6.10 m
      - Stern:      20.01 ft / 6.10 m
      - Average freeboard:   20.54 ft / 6.26 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 126.7 %
      - Above water (accommodation/working, high = better): 119.4 %
   Waterplane Area: 20,281 Square feet or 1,884 Square metres
   Displacement factor (Displacement / loading): 104 %
   Structure weight / hull surface area: 94 lbs/sq ft or 461 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.94
      - Longitudinal: 1.90
      - 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

100t 1912 FC
25t LR W/T
24t 8 3t Torpedoes
50t Mines
51t Reserve

[Jefgte]

IMO, 1920 techno is not enough for 33kts

" Main Belt covers 128 % of normal length"
&
" Machinery: 3,497 tons, 34.9 %"


1920 engines cost too much for high speed.


Jef  ;)

[Guinness]

Using SS at least, we won't be seeing a marked improvement in machinery output for quite some time after 1920.

This is the sort of ship that may illustrate the need for a WW style reduced strength cruiser rule though.

[Carthaginian]

This is the sort of ship that may illustrate the need for a WW style reduced strength cruiser rule though.

To build really competitive cruisers and destroyers, we will need some modifications to the rules starting about now.

[Sachmle]

IMO, 1920 techno is not enough for 33kts

" Main Belt covers 128 % of normal length"
&
" Machinery: 3,497 tons, 34.9 %"


1920 engines cost too much for high speed.


Jef  ;)

Using SS at least, we won't be seeing a marked improvement in machinery output for quite some time after 1920.

This is the sort of ship that may illustrate the need for a WW style reduced strength cruiser rule though.

This is the sort of ship that may illustrate the need for a WW style reduced strength cruiser rule though.

To build really competitive cruisers and destroyers, we will need some modifications to the rules starting about now.

Thank all 3 of you for pointing out the flaw in SpringSharp, again. Now, aside from the fact that the engines weight more than the hull, whatcha think of the actual cruiser?

[Guinness]

I think 8500 tons and 10x150mm might be too much for a light fleet cruiser. What's the mission an what ships might we expect it to operate with?

[Logi]

What is the role of this ship? I see multi-role as a possibility with it's varied armament.

[Sachmle]

Anti DD escorts for the battleline. Being 10kts faster than the Battleships will allow them to range ahead and still be able to quickly recall if needed. They pack enough punch to let anything short of a real BC know they're there, and the 8 60cm torpedoes would great anything to big. At 33kts they can run from pretty much anything.

[Guinness]

Let's say you take ~33 knots to be the major design parameter, and can accept slightly less armor (particularly the deck, where 1 inch ought to be enough). How small can you make it and how many guns would a smaller ship have?

In this role, you still need some numbers, I think, so savings might mean one or two extra ships (depending on how many you build). I suspect your expected role is similar to what the OTL RN had in mind with their post WW1 6" cruisers like Arethusa... 33 knots, 6 guns, on ~5000 tons standard.

[Sachmle]

I could settle for 32kts, but it has to have at least 8 guns. My last CLs are 5,475t light w/ 10 singles, but only 7 at most can bare on any one angle.
The biggest problem with comparisons to OTL is we're now in the WNT/LNT dead zone. After the Emeralds in 1918 the RN didn't lay down a new CL until 1931's Leanders (7,000t std, 4x2x6", 32.5kts).

[Guinness]

Everyone is going to have to endure DK Brown tidbits from me for the next few days...

RN wargames, it seems, revealed the greatest danger from DDs to be in the forward quarter, presumable because torpedos fired from ahead of the target's beam would have the greatest closing speed, etc. So some emphasis on end-on fire is warranted it seems, especially in ships or batteries meant to deal with the DD threat. Just thought I'd throw that out there as a possible argument for wing mounts. It also brings me to:

Why 8 guns? Enough barrels in broadside was certainly important for capital ships to be able to hit their target at long range, but the engagement distances of 150mm armed cruisers vs. DDs will be appreciably shorter, making splash spotting and salvo fire less important. What is important is bring maximum RoF to bear on the target(s), which given the idea that the most danger is forward of the enemy's target, would mean forward fire. So in that respect, a 6 gun ship is as good as an 8 gun ship for this mission (at least, that's the argument the RN made I suspect, I haven't read that far).

I think the DKB's recent battle experience might support this conclusion as well. In the Banda Sea for instance, your light cruisers had few opportunities to fire on the broadside.

Later the RN and USN adopted 12 or 15 6" guns on their "light" cruisers, but that was mostly a product of building up to the treaty maximums, I think, not a product of real mission requirements. By that point, given the proliferation of treaty cruisers, cruisers seemed to be meant to fight other cruisers in fleet engagements, not necessarily just for battleline screening.