Logi's Design Studies

[miketr]

Its not a bad design but there are some "issues" with it...  A Sextuple turret isn't pratical even if you are trying to make some downsized Tillman knock of.

I would suggest a pair of twins and some quick firing secondaries 5" as anti TB protection.

Michael

[Korpen]

Its not a bad design but there are some "issues" with it...  A Sextuple turret isn't pratical even if you are trying to make some downsized Tillman knock of.

I would suggest a pair of twins and some quick firing secondaries 5" as anti TB protection.

Michael

It is not a six-gun turret, it is six single-gun turrets. Which is just as weird I think, so your points are true.

[Logi]

AH! My bad, I realized I forgot to change the turret number.
Here's the corrected version.

???, RRC Small Battleship laid down 1916 (Engine 1912)

Displacement:
   12,748 t light; 13,416 t standard; 15,067 t normal; 16,388 t full load

Dimensions: Length overall / water x beam x draught
   450.00 ft / 450.00 ft x 75.00 ft x 25.00 ft (normal load)
   137.16 m / 137.16 m x 22.86 m  x 7.62 m

Armament:
      6 - 13.00" / 330 mm guns (2x3 guns), 1,098.50lbs / 498.27kg shells, 1916 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread
   Weight of broadside 6,591 lbs / 2,990 kg
   Shells per gun, main battery: 100

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   12.0" / 305 mm   300.00 ft / 91.44 m   18.00 ft / 5.49 m
   Ends:   6.00" / 152 mm   150.00 ft / 45.72 m   18.00 ft / 5.49 m
     Main Belt covers 103 % of normal length

   - Torpedo Bulkhead:
      2.00" / 51 mm   300.00 ft / 91.44 m   30.00 ft / 9.14 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   12.0" / 305 mm   7.00" / 178 mm      10.0" / 254 mm

   - Armour deck: 3.00" / 76 mm, Conning tower: 16.00" / 406 mm

Machinery:
   Coal fired boilers, ERROR: no steam engines,
   No drive to shaft, 2 shafts, 13,891 shp / 10,363 Kw = 18.00 kts
   Range 8,000nm at 12.00 kts
   Bunker at max displacement = 2,973 tons (100% coal)

Complement:
   679 - 883

Cost:
   £1.863 million / $7.450 million

Distribution of weights at normal displacement:
   Armament: 824 tons, 5.5 %
   Armour: 6,625 tons, 44.0 %
      - Belts: 3,444 tons, 22.9 %
      - Torpedo bulkhead: 666 tons, 4.4 %
      - Armament: 902 tons, 6.0 %
      - Armour Deck: 1,402 tons, 9.3 %
      - Conning Tower: 210 tons, 1.4 %
   Machinery: 0 tons, 0.0 %
   Hull, fittings & equipment: 4,899 tons, 32.5 %
   Fuel, ammunition & stores: 2,319 tons, 15.4 %
   Miscellaneous weights: 400 tons, 2.7 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     28,351 lbs / 12,860 Kg = 25.8 x 13.0 " / 330 mm shells or 7.1 torpedoes
   Stability (Unstable if below 1.00): 1.08
   Metacentric height 3.8 ft / 1.2 m
   Roll period: 16.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.55
   Seaboat quality  (Average = 1.00): 1.24

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.625
   Length to Beam Ratio: 6.00 : 1
   'Natural speed' for length: 21.21 kts
   Power going to wave formation at top speed: 44 %
   Trim (Max stability = 0, Max steadiness = 100): 56
   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:      13.00 ft / 3.96 m
      - Forecastle (20 %):   13.00 ft / 3.96 m
      - Mid (50 %):      13.00 ft / 3.96 m
      - Quarterdeck (15 %):   13.00 ft / 3.96 m
      - Stern:      13.00 ft / 3.96 m
      - Average freeboard:   13.00 ft / 3.96 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 61.0 %
      - Above water (accommodation/working, high = better): 92.1 %
   Waterplane Area: 25,265 Square feet or 2,347 Square metres
   Displacement factor (Displacement / loading): 111 %
   Structure weight / hull surface area: 142 lbs/sq ft or 694 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.95
      - Longitudinal: 1.57
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is adequate
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

[Carthaginian]

There are no engines in that ship... other than that, it's a mighty respectable coastal defense ship. ;)

[The Rock Doctor]

It will defend its anchorage quite well, I'm sure.

[Logi]

Fixed

???, RRC Small Battleship laid down 1916 (Engine 1912)

Displacement:
   13,660 t light; 14,423 t standard; 16,146 t normal; 17,524 t full load

Dimensions: Length overall / water x beam x draught
   450.00 ft / 450.00 ft x 75.00 ft x 26.00 ft (normal load)
   137.16 m / 137.16 m x 22.86 m  x 7.92 m

Armament:
      6 - 13.00" / 330 mm guns (2x3 guns), 1,320.00lbs / 598.74kg shells, 1916 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread
   Weight of broadside 7,920 lbs / 3,592 kg
   Shells per gun, main battery: 100

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   12.0" / 305 mm   300.00 ft / 91.44 m   18.00 ft / 5.49 m
   Ends:   4.00" / 102 mm   150.00 ft / 45.72 m   18.00 ft / 5.49 m
     Main Belt covers 103 % of normal length

   - Torpedo Bulkhead:
      2.00" / 51 mm   300.00 ft / 91.44 m   31.00 ft / 9.45 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   13.0" / 330 mm   8.00" / 203 mm      11.0" / 279 mm

   - Armour deck: 3.00" / 76 mm, Conning tower: 15.00" / 381 mm

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 2 shafts, 14,548 shp / 10,853 Kw = 18.00 kts
   Range 8,000nm at 12.00 kts
   Bunker at max displacement = 3,101 tons (100% coal)

Complement:
   716 - 931

Cost:
   £2.061 million / $8.244 million

Distribution of weights at normal displacement:
   Armament: 824 tons, 5.1 %
   Armour: 6,571 tons, 40.7 %
      - Belts: 3,248 tons, 20.1 %
      - Torpedo bulkhead: 688 tons, 4.3 %
      - Armament: 1,001 tons, 6.2 %
      - Armour Deck: 1,427 tons, 8.8 %
      - Conning Tower: 206 tons, 1.3 %
   Machinery: 638 tons, 4.0 %
   Hull, fittings & equipment: 5,228 tons, 32.4 %
   Fuel, ammunition & stores: 2,486 tons, 15.4 %
   Miscellaneous weights: 400 tons, 2.5 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     24,406 lbs / 11,070 Kg = 22.2 x 13.0 " / 330 mm shells or 5.4 torpedoes
   Stability (Unstable if below 1.00): 1.10
   Metacentric height 3.9 ft / 1.2 m
   Roll period: 16.0 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.64
   Seaboat quality  (Average = 1.00): 1.27

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.644
   Length to Beam Ratio: 6.00 : 1
   'Natural speed' for length: 21.21 kts
   Power going to wave formation at top speed: 45 %
   Trim (Max stability = 0, Max steadiness = 100): 55
   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:      13.00 ft / 3.96 m
      - Forecastle (20 %):   13.00 ft / 3.96 m
      - Mid (50 %):      13.00 ft / 3.96 m
      - Quarterdeck (15 %):   13.00 ft / 3.96 m
      - Stern:      13.00 ft / 3.96 m
      - Average freeboard:   13.00 ft / 3.96 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 75.0 %
      - Above water (accommodation/working, high = better): 88.9 %
   Waterplane Area: 25,712 Square feet or 2,389 Square metres
   Displacement factor (Displacement / loading): 109 %
   Structure weight / hull surface area: 148 lbs/sq ft or 723 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.94
      - Longitudinal: 1.66
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is cramped
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

[The Rock Doctor]

It's a good start - I would suggest perhaps reducing the main belt height to ~4.5 metres, and using the weight saving for a secondary and AA battery, and a bit more freeboard.

[Guinness]

The uniformly straight flush deck looks odd to me. I suspect there are weight savings to be had there as well. If you need to find weight somewhere, this ship could probably get by with either a little bit thinner or a shorter torpedo bulkhead as well.

[Tanthalas]

shave the Main belt to 16' instead of 18', reduce the TB to 1.5" instead of 2" should save you enough weight to add some secondaries.

[Logi]

@Guiness
I design all my ships as straight flush decks - the majority are uniformly straight flush decks. I'm not aware of any weight savings that can be made in such as area, care to inform me?

???, RRC Small Battleship laid down 1916 (Engine 1912)

Displacement:
   13,284 t light; 14,075 t standard; 15,770 t normal; 17,126 t full load

Dimensions: Length overall / water x beam x draught
   450.00 ft / 450.00 ft x 75.00 ft x 26.00 ft (normal load)
   137.16 m / 137.16 m x 22.86 m  x 7.92 m

Armament:
      6 - 13.00" / 330 mm guns (2x3 guns), 1,320.00lbs / 598.74kg shells, 1916 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread
      8 - 5.12" / 130 mm guns in single mounts, 67.03lbs / 30.41kg shells, 1916 Model
     Quick firing guns in casemate mounts
     on side, all amidships
   Weight of broadside 8,456 lbs / 3,836 kg
   Shells per gun, main battery: 100

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   12.0" / 305 mm   300.00 ft / 91.44 m   16.00 ft / 4.88 m
   Ends:   4.00" / 102 mm   150.00 ft / 45.72 m   18.00 ft / 5.49 m
     Main Belt covers 103 % of normal length

   - Torpedo Bulkhead:
      1.50" / 38 mm   300.00 ft / 91.44 m   31.00 ft / 9.45 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   13.0" / 330 mm   8.00" / 203 mm      11.0" / 279 mm
   2nd:   3.00" / 76 mm   2.00" / 51 mm      2.00" / 51 mm

   - Armour deck: 3.00" / 76 mm, Conning tower: 15.00" / 381 mm

Machinery:
   Coal fired boilers, steam turbines,
   Direct drive, 2 shafts, 14,274 shp / 10,648 Kw = 18.00 kts
   Range 8,000nm at 12.00 kts
   Bunker at max displacement = 3,051 tons (100% coal)

Complement:
   703 - 914

Cost:
   £2.129 million / $8.515 million

Distribution of weights at normal displacement:
   Armament: 891 tons, 5.6 %
   Armour: 6,128 tons, 38.9 %
      - Belts: 2,929 tons, 18.6 %
      - Torpedo bulkhead: 516 tons, 3.3 %
      - Armament: 1,073 tons, 6.8 %
      - Armour Deck: 1,407 tons, 8.9 %
      - Conning Tower: 203 tons, 1.3 %
   Machinery: 626 tons, 4.0 %
   Hull, fittings & equipment: 5,239 tons, 33.2 %
   Fuel, ammunition & stores: 2,486 tons, 15.8 %
   Miscellaneous weights: 400 tons, 2.5 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     22,112 lbs / 10,030 Kg = 20.1 x 13.0 " / 330 mm shells or 4.7 torpedoes
   Stability (Unstable if below 1.00): 1.09
   Metacentric height 3.8 ft / 1.2 m
   Roll period: 16.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.67
   Seaboat quality  (Average = 1.00): 1.26

Hull form characteristics:
   Hull has a flush deck
   Block coefficient: 0.629
   Length to Beam Ratio: 6.00 : 1
   'Natural speed' for length: 21.21 kts
   Power going to wave formation at top speed: 44 %
   Trim (Max stability = 0, Max steadiness = 100): 56
   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:      13.00 ft / 3.96 m
      - Forecastle (20 %):   13.00 ft / 3.96 m
      - Mid (50 %):      13.00 ft / 3.96 m
      - Quarterdeck (15 %):   13.00 ft / 3.96 m
      - Stern:      13.00 ft / 3.96 m
      - Average freeboard:   13.00 ft / 3.96 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 80.7 %
      - Above water (accommodation/working, high = better): 89.3 %
   Waterplane Area: 25,359 Square feet or 2,356 Square metres
   Displacement factor (Displacement / loading): 106 %
   Structure weight / hull surface area: 150 lbs/sq ft or 733 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.94
      - Longitudinal: 1.68
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is cramped
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

[Guinness]

Well, there's a reason that OTL ships often have higher stems than sterns, step downs or "breaks" in hulls, etc. It has a lot to do with the mechanics of moving a ship through the sea, etc. P3D could explain a lot better than me, I'm sure.

As an experiment though, you might consider experimenting with the freeboard numbers, by (for instance) raising the stem a bit, and lowering the stern, so that that the freeboard deck runs at a slant instead of parallel to a calm sea. You might find that you can keep an acceptable freeboard number, while also getting more weight to use for other things.

The common BB hull of the period OTL often had three decks (aka approx 24 feet) forward, and two decks (approx 16 feet aft), with a "break" somewhere in the middle.

Your 13 feet of freeboard all the way across may work fine from springsharp's point of view, but I suspect that it's less than optimal for a real ship. For one thing, when the ship rolls in a sea, it's more likely that the deck might become awash toward the low part of the roll, which is less desirable.

One last thing to consider too is this: with a 26 foot draft, and 13 feet of freeboard, your total hull depth is 39 feet. It may be (and not being a structural engineer, I don't have the knowledge to calculate this, but rather am going on feel here) that the hull gurder, ie the overall structure of the hull in this case, is less than optimal for distributing the loads of the hull. Generally making a ship deeper, meaning the whole structure not just the draft adds to the load carrying capability of the ship, at least up to a point. Food for thought, at least.

I don't think there is anything wrong with a uniform 13 foot freeboard, at least from the perspective of our game and it's rules. It's just that I know there are reasons why ships weren't usually designed that way OTL.

[The Rock Doctor]

Adidng to that - it's not just rolling that will have the deck awash - damage-induced listing will do the same.  Then you've got to worry about water getting inside through openings on the deck.

[Logi]

Just a design study but feed back would be appreciated

North Wind, RRC Battlecruiser laid down 1917 (Engine 1916)

Displacement:
   24,627 t light; 25,872 t standard; 27,883 t normal; 29,492 t full load

Dimensions: Length overall / water x beam x draught
   778.86 ft / 765.00 ft x 85.00 ft x 28.00 ft (normal load)
   237.40 m / 233.17 m x 25.91 m  x 8.53 m

Armament:
      9 - 13.00" / 330 mm guns (3x3 guns), 1,320.00lbs / 598.74kg shells, 1917 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, majority forward, 1 raised mount - superfiring
      12 - 4.00" / 102 mm guns (6x2 guns), 32.00lbs / 14.51kg shells, 1917 Model
     Breech loading guns in deck mounts with hoists
     on side, all amidships, all raised mounts - superfiring
   Weight of broadside 12,264 lbs / 5,563 kg
   Shells per gun, main battery: 100

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   12.0" / 305 mm   500.00 ft / 152.40 m   15.00 ft / 4.57 m
   Ends:   3.00" / 76 mm   200.00 ft / 60.96 m   15.00 ft / 4.57 m
     65.00 ft / 19.81 m Unarmoured ends
   Upper:   3.00" / 76 mm   700.00 ft / 213.36 m   5.00 ft / 1.52 m
     Main Belt covers 101 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   13.0" / 330 mm   6.00" / 152 mm      10.0" / 254 mm
   2nd:   1.00" / 25 mm   1.00" / 25 mm            -

   - Armour deck: 3.00" / 76 mm, Conning tower: 4.00" / 102 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 4 shafts, 80,000 shp / 59,680 Kw = 27.30 kts
   Range   3,300nm at 20.00 kts
   Range 10,000nm at 12.00 kts
   Range   1,482nm at 27.30 kts
   Bunker at max displacement = 3,620 tons

Complement:
   1,078 - 1,402

Cost:
   £4.287 million / $17.147 million

Distribution of weights at normal displacement:
   Armament: 1,284 tons, 4.6 %
   Armour: 8,784 tons, 31.5 %
      - Belts: 4,534 tons, 16.3 %
      - Torpedo bulkhead: 0 tons, 0.0 %
      - Armament: 1,685 tons, 6.0 %
      - Armour Deck: 2,486 tons, 8.9 %
      - Conning Tower: 79 tons, 0.3 %
   Machinery: 2,981 tons, 10.7 %
   Hull, fittings & equipment: 11,179 tons, 40.1 %
   Fuel, ammunition & stores: 3,255 tons, 11.7 %
   Miscellaneous weights: 400 tons, 1.4 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     36,166 lbs / 16,405 Kg = 32.9 x 13.0 " / 330 mm shells or 3.5 torpedoes
   Stability (Unstable if below 1.00): 1.10
   Metacentric height 4.7 ft / 1.4 m
   Roll period: 16.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 60 %
         - Recoil effect (Restricted arc if above 1.00): 0.76
   Seaboat quality  (Average = 1.00): 1.15

Hull form characteristics:
   Hull has rise aft of midbreak
   Block coefficient: 0.536
   Length to Beam Ratio: 9.00 : 1
   'Natural speed' for length: 27.66 kts
   Power going to wave formation at top speed: 44 %
   Trim (Max stability = 0, Max steadiness = 100): 52
   Bow angle (Positive = bow angles forward): 30.00 degrees
   Stern overhang: -5.00 ft / -1.52 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      24.00 ft / 7.32 m
      - Forecastle (20 %):   20.00 ft / 6.10 m
      - Mid (50 %):      15.00 ft / 4.57 m (18.00 ft / 5.49 m aft of break)
      - Quarterdeck (15 %):   15.00 ft / 4.57 m
      - Stern:      15.00 ft / 4.57 m
      - Average freeboard:   17.60 ft / 5.36 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 71.7 %
      - Above water (accommodation/working, high = better): 134.2 %
   Waterplane Area: 44,790 Square feet or 4,161 Square metres
   Displacement factor (Displacement / loading): 110 %
   Structure weight / hull surface area: 175 lbs/sq ft or 855 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 1.01
      - Longitudinal: 0.99
      - Overall: 1.00
   Hull space for machinery, storage, compartmentation is excellent
   Room for accommodation and workspaces is excellent

[mentat]

Strikes me as a nicely balanced design - i.e. very dual purpose - can effectively support light forces or stand in the battle line - good BCs should be very useful in being able to do both

A few minor points:

No Torpedo bulkhead - there isn't a lot of scope on an 85' beam - but some prot'n here seems in order - possibly more valuable than the thin upper belt? - which won't stop anything serious at effective battle ranges

? - impact on speed of 95' beam which will allow more TDS?

- really depends on the threat environment you envisage - but as a large, capable and pretty fast ship she will be useful for 20+ years - so this will evolve ...

Secondaries - only 12 x 4 " seems a bit light for her size, 16 guns is better and 4.7"- 5.5" is best to stop TBDs

Small detail - no 'close in' or AA guns are specified - but easily sorted

Any chance of a Pic - I imagine she deserves one and would really like to see  :) ...

[The Rock Doctor]

Two notes -

There's no need for the secondary battery to be all-raised.  In fact, with the hull that long, there's probably enough room for all of the secondaries to be at deck level.

Since your cross-sectional hull strength exceeds your longitudinal hull strength, you could probably raise the freeboard a bit.  Shouldn't cost you any hull strength, and would gain you a bit of seakeeping.