Builders League United designers present...

[Laertes]

Designed as a treaty-cruiser killer, the Invercargill class is fast, expensive, and capable of slugging it out with anything from OTL short of HMS Nelson.

This is my first sim I've shown anyone else, and I'd be grateful for feedback.

Invercargill, BLU Battlecruiser laid down 1918

Displacement:
   31,543 t light; 33,193 t standard; 39,463 t normal; 44,480 t full load

Dimensions: Length overall / water x beam x draught
   810.00 ft / 810.00 ft x 98.00 ft x 30.00 ft (normal load)
   246.89 m / 246.89 m x 29.87 m  x 9.14 m

Armament:
      8 - 13.50" / 343 mm guns (4x2 guns), 1,230.19lbs / 558.00kg shells, 1916 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread, 2 raised mounts - superfiring
      8 - 4.00" / 102 mm guns (4x2 guns), 32.00lbs / 14.51kg shells, 1914 Model
     Quick firing guns in turrets (on barbettes)
     on side, all amidships
      4 - 4.00" / 102 mm guns in single mounts, 32.00lbs / 14.51kg shells, 1914 Model
     Anti-aircraft guns in deck mounts
     on side, evenly spread, all raised mounts
   Weight of broadside 10,226 lbs / 4,638 kg
   Shells per gun, main battery: 150

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   13.0" / 330 mm   540.00 ft / 164.59 m   12.00 ft / 3.66 m
   Ends:   Unarmoured
     Main Belt covers 103 % of normal length

   - Torpedo Bulkhead:
      1.00" / 25 mm   540.00 ft / 164.59 m   40.00 ft / 12.19 m

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   10.0" / 254 mm   4.00" / 102 mm      8.00" / 203 mm
   2nd:   6.00" / 152 mm         -         4.00" / 102 mm
   3rd:   2.00" / 51 mm         -               -

   - Armour deck: 3.20" / 81 mm, Conning tower: 12.00" / 305 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 4 shafts, 185,213 shp / 138,169 Kw = 32.00 kts
   Range 12,000nm at 18.00 kts
   Bunker at max displacement = 11,287 tons

Complement:
   1,399 - 1,819

Cost:
   £6.226 million / $24.905 million

Distribution of weights at normal displacement:
   Armament: 1,278 tons, 3.2 %
   Armour: 9,813 tons, 24.9 %
      - Belts: 3,567 tons, 9.0 %
      - Torpedo bulkhead: 799 tons, 2.0 %
      - Armament: 1,774 tons, 4.5 %
      - Armour Deck: 3,373 tons, 8.5 %
      - Conning Tower: 300 tons, 0.8 %
   Machinery: 6,682 tons, 16.9 %
   Hull, fittings & equipment: 13,551 tons, 34.3 %
   Fuel, ammunition & stores: 7,920 tons, 20.1 %
   Miscellaneous weights: 220 tons, 0.6 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     46,544 lbs / 21,112 Kg = 37.8 x 13.5 " / 343 mm shells or 6.2 torpedoes
   Stability (Unstable if below 1.00): 1.10
   Metacentric height 5.8 ft / 1.8 m
   Roll period: 17.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 76 %
         - Recoil effect (Restricted arc if above 1.00): 0.50
   Seaboat quality  (Average = 1.00): 1.09

Hull form characteristics:
   Hull has raised forecastle
   Block coefficient: 0.580
   Length to Beam Ratio: 8.27 : 1
   'Natural speed' for length: 28.46 kts
   Power going to wave formation at top speed: 53 %
   Trim (Max stability = 0, Max steadiness = 100): 70
   Bow angle (Positive = bow angles forward): -10.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      34.00 ft / 10.36 m
      - Forecastle (20 %):   34.00 ft / 10.36 m (20.00 ft / 6.10 m aft of break)
      - Mid (40 %):      20.00 ft / 6.10 m
      - Quarterdeck (33 %):   20.00 ft / 6.10 m
      - Stern:      20.00 ft / 6.10 m
      - Average freeboard:   22.80 ft / 6.95 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 101.9 %
      - Above water (accommodation/working, high = better): 155.2 %
   Waterplane Area: 56,980 Square feet or 5,294 Square metres
   Displacement factor (Displacement / loading): 117 %
   Structure weight / hull surface area: 167 lbs/sq ft or 818 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 1.00
      - Longitudinal: 1.03
      - Overall: 1.00
   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

[Logi]

No treaty-cruisers here ;)

But my criticism would be: Armament is light for 31.5 kt. Belt is short and TDS is thin. You have too many rounds for the main gun. The legs are a tad long for my taste.

In reverse, the main battery armor is thin (the face and barbette). The second bat. is too armored, and you don't need turrets, yet. Hoist and mount should do, not to mention turreted secondaries is advanced as things go.

All in all, a ship that could be held down by a one several if not 10 kt lighter. It's only merit is it's speed. At 32 kts, it's speed makes the large armament and belt quite useless. Too heavy for light vessels, too light for battleships.

[Laertes]

I was feeling cheeky putting a torpedo bulkhead on her at all, to be honest.

The magazine and bunker were both designed to be large in order to allow long-duration, blue-water operations.

The armament and armour are neither fish nor fowl, I'm aware of this. The idea is that against real battleships she can safely disengage, and against anything other than a BB, a 13" belt and 13.5"/L45 armament mean she's basically invincible.

The points about the turrets are gratefully accepted. I shall resim when it's not midnight.

[TexanCowboy]

Always willing to be assistful!

First off, the bunker is enormous! The US ships in WWII were designed for 15knm at 15 knots, and that was considered very long range. I've found that a lot of people here consider about 18% the max for the fuel catagory, and I'd think it would be a good decision to cut down on the range.

The armour on this ship is pretty low. Comparable OTL ships, like the Ugly Sisters, had up to 40% armour. By the same token, the speed is very high for a cap ship. I'd cut it down to 30 knots, use the weight on more TB, belt, and deck....oh, and Barbette! Golden Twinke, anyone?

The secondary is extrodinarily light, and the 4'' guns don't need to be in turret and barbette. If you insist upon 4'', which I don't recommend, I'd raise the battery up to 20, at least.

Overall, and no offense intended, it appears to be a large ship that's underarmed compared to comparably sized ships, and that would end up being used against capital ships because of the size of it's armerment, at which it would fail/

[Laertes]

Thanks for the feedback, guys. Rather than impose design creep upon the Invercargill, I'll write her off as experimental, and purpose-build something else for its task.

As for the light secondary - TBH, I've never understood the purpose of mid-weight secondaries. A 4" QF will kill a destroyer (not at range, but that's what escorts are for), which is surely the main reason to have secondaries.

[Nobody]

One more thing. As it is the ship is unbuildable, because it exceeds the maximum allowed engine power which is right now 40000 hp per shaft (160000 in total) at best.

[Laertes]

Okay, on a different tack, I've tried building an N-verse style cruiser. Her weapons are excessively large, but she doesn't carry many of them - I see her as comparable to GC's Avenger. (Yes, she only has half as many guns, but then she only has half the price tag - N^2 is an axiom here at BLU.)

Napier, BLU Cruiser laid down 1920

Displacement:
   16,555 t light; 17,272 t standard; 19,491 t normal; 21,266 t full load

Dimensions: Length overall / water x beam x draught
   680.00 ft / 680.00 ft x 76.00 ft x 24.00 ft (normal load)
   207.26 m / 207.26 m x 23.16 m  x 7.32 m

Armament:
     4 - 13.50" / 343 mm guns (2x2 guns), 1,230.19lbs / 558.00kg shells, 1912 Model
     Breech loading guns in turrets (on barbettes)
     on centreline ends, evenly spread
     8 - 5.10" / 130 mm guns (4x2 guns), 66.33lbs / 30.08kg shells, 1920 Model
     Breech loading guns in deck mounts with hoists
     on side, all amidships
     8 - 4.00" / 102 mm guns (4x2 guns), 32.00lbs / 14.51kg shells, 1920 Model
     Dual purpose guns in deck mounts
     on side, evenly spread, 2 raised mounts
   Weight of broadside 5,707 lbs / 2,589 kg
   Shells per gun, main battery: 100

Armour:
  - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   12.0" / 305 mm   437.00 ft / 133.20 m   12.00 ft / 3.66 m
   Ends:   Unarmoured
     Main Belt covers 99 % of normal length

  - Torpedo Bulkhead:
      1.00" / 25 mm   437.00 ft / 133.20 m   12.00 ft / 3.66 m

  - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   12.0" / 305 mm   6.00" / 152 mm      10.0" / 254 mm
   2nd:   6.00" / 152 mm         -               -
   3rd:   1.00" / 25 mm         -               -

  - Armour deck: 2.20" / 56 mm, Conning tower: 12.00" / 305 mm

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 2 shafts, 73,834 shp / 55,080 Kw = 28.00 kts
   Range 9,000nm at 16.00 kts
   Bunker at max displacement = 3,995 tons

Complement:
   824 - 1,072

Cost:
   £3.640 million / $14.561 million

Distribution of weights at normal displacement:
   Armament: 713 tons, 3.7 %
   Armour: 5,519 tons, 28.3 %
      - Belts: 2,657 tons, 13.6 %
      - Torpedo bulkhead: 194 tons, 1.0 %
      - Armament: 1,013 tons, 5.2 %
      - Armour Deck: 1,468 tons, 7.5 %
      - Conning Tower: 187 tons, 1.0 %
   Machinery: 2,582 tons, 13.2 %
   Hull, fittings & equipment: 7,441 tons, 38.2 %
   Fuel, ammunition & stores: 2,935 tons, 15.1 %
   Miscellaneous weights: 300 tons, 1.5 %

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     27,673 lbs / 12,552 Kg = 22.5 x 13.5 " / 343 mm shells or 3.9 torpedoes
   Stability (Unstable if below 1.00): 1.09
   Metacentric height 3.9 ft / 1.2 m
   Roll period: 16.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 83 %
         - Recoil effect (Restricted arc if above 1.00): 0.66
   Seaboat quality  (Average = 1.00): 1.36

Hull form characteristics:
   Hull has raised forecastle
   Block coefficient: 0.550
   Length to Beam Ratio: 8.95 : 1
   'Natural speed' for length: 26.08 kts
   Power going to wave formation at top speed: 49 %
   Trim (Max stability = 0, Max steadiness = 100): 61
   Bow angle (Positive = bow angles forward): -10.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = measuring location as a percentage of overall length):
      - Stem:      29.00 ft / 8.84 m
      - Forecastle (20 %):   29.00 ft / 8.84 m (18.50 ft / 5.64 m aft of break)
      - Mid (50 %):      18.50 ft / 5.64 m
      - Quarterdeck (33 %):   18.50 ft / 5.64 m
      - Stern:      18.50 ft / 5.64 m
      - Average freeboard:   20.60 ft / 6.28 m

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 98.7 %
      - Above water (accommodation/working, high = better): 154.2 %
   Waterplane Area: 36,067 Square feet or 3,351 Square metres
   Displacement factor (Displacement / loading): 117 %
   Structure weight / hull surface area: 139 lbs/sq ft or 677 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.98
      - Longitudinal: 1.19
      - Overall: 1.00
   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

[damocles]

Too few main guns. Need at least six. Dutch 1912 fire control will mean at 12,000 meters that ship will be slaughtered by one of my smaller eight gun frigates.

[maddox]

Thanks for the feedback, guys. Rather than impose design creep upon the Invercargill, I'll write her off as experimental, and purpose-build something else for its task.

I like her, but for a French ship she'll need extensive redesing.  340mm main guns,  more wide beam but slim lines (low BC) and care for seakeeping, stability and misc weight in relation to crew comfort.

As for the light secondary - TBH, I've never understood the purpose of mid-weight secondaries. A 4" QF will kill a destroyer (not at range, but that's what escorts are for), which is surely the main reason to have secondaries.

Wartime experience gives that the secundaries need to be reasonably heavy, with a minimum of  4.5" and up to 6". And in sufficient numbers to achieve enough hits outside torpedo range. 
"N-verse History gives that torpedos are way better than irl".

For France, it means the ubiqtous 5.5" twin mount and hoist is mounted on about any vessel large enough to carry enough of them.
Even French DD's use that 140mm as main guns. And french ship-engineers are devising ways to get even more of those guns on the ships .
Seems that premiers get ,as a welcoming gift, a serious amount of shares in a factory that churns out those guns, and mounts

[Laertes]

Too few main guns. Need at least six. Dutch 1912 fire control will mean at 12,000 meters that ship will be slaughtered by one of my smaller eight gun frigates.

I didn't annotate it, but Napier carries 250t capital ship fire control to compensate for the lower accuracy that fewer guns gives her. We at BLU are aware that the smaller number of guns is a weakness, but considering her size and the power of her armament, we consider this a reasonable tradeoff.

Also, we at BLU wanted to try something fairly different to what everybody else's doing, and see if it lead anywhere.

I like her, but for a French ship she'll need extensive redesing.  340mm main guns,  more wide beam but slim lines (low BC) and care for seakeeping, stability and misc weight in relation to crew comfort.

Can certainly be done. She already has excellent accomodation; to this, we can add wine cellars, climate control and refrigerated concubine storage.

Wartime experience gives that the secundaries need to be reasonably heavy, with a minimum of  4.5" and up to 6". And in sufficient numbers to achieve enough hits outside torpedo range. 
"N-verse History gives that torpedos are way better than irl".

From my reading of threads, I'd have thought the opposite was true. It seems to be received wisdom that torpedo accuracy above ~1km or so is down to divine providence. So much to learn.

For France, it means the ubiqtous 5.5" twin mount and hoist is mounted on about any vessel large enough to carry enough of them.
Even French DD's use that 140mm as main guns. And french ship-engineers are devising ways to get even more of those guns on the ships .

Perhaps, then, a dedicated light cruiser / heavy DD to carry 140mm guns and anti-aircraft weaponry, freeing the large warships for line-of-battle duty, might be a useful addition to a fleet? It could be a useful rebuild for aged hulls...

[damocles]

Too few main guns. Need at least six. Dutch 1912 fire control will mean at 12,000 meters that ship will be slaughtered by one of my smaller eight gun frigates.

I didn't annotate it, but Napier carries 250t capital ship fire control to compensate for the lower accuracy that fewer guns gives her. We at BLU are aware that the smaller number of guns is a weakness, but considering her size and the power of her armament, we consider this a reasonable tradeoff.

Also, we at BLU wanted to try something fairly different to what everybody else's doing, and see if it lead anywhere.

Okay, Admiral Schoepen clashed briefly with an allied fleet at Aden. Lousy shooting on both  sides (fortunately) prevented a naval debacle. The result was that Dutch tacticians confirmed that you need a minimum four shell ladder to score hits using indirect fire on a ship track.     

I like her, but for a French ship she'll need extensive redesing.  340mm main guns,  more wide beam but slim lines (low BC) and care for seakeeping, stability and misc weight in relation to crew comfort.

Can certainly be done. She already has excellent accomodation; to this, we can add wine cellars, climate control and refrigerated concubine storage.

I agree with that French assessment. Dutch desigmers, however, would want eight medium heavies, and heavier secondaries. Dutch combat experience with naval air warfare (we have that now at last, naysayers)  means AAA-lots of machine guns.       

Wartime experience gives that the secundaries need to be reasonably heavy, with a minimum of  4.5" and up to 6". And in sufficient numbers to achieve enough hits outside torpedo range. 
"N-verse History gives that torpedos are way better than irl".

From my reading of threads, I'd have thought the opposite was true. It seems to be received wisdom that torpedo accuracy above ~1km or so is down to divine providence. So much to learn.

There was a major battle in the Second Rift War that indicates massed torpedo fire
beyond 3000+ meters is dangerous.

For France, it means the ubiqtous 5.5" twin mount and hoist is mounted on about any vessel large enough to carry enough of them.
Even French DD's use that 140mm as main guns. And french ship-engineers are devising ways to get even more of those guns on the ships .

Holland prefers the 125mm developed from the ESC 5 inch. Semi-automatic vy 1926. 

Perhaps, then,

a dedicated light cruiser / heavy DD to carry 140mm guns and anti-aircraft weaponry

, freeing the large warships for line-of-battle duty, might be a useful addition to a fleet? It could be a useful rebuild for aged hulls...

That is current Dutch thinking.

[Laertes]

I'm glad that our designers at BLU have arrived at the same philosophy as those at the Koninklijke Marine.

[TexanCowboy]

The 4x13.5'' design is fairly dangerous. What the fire control does is practically increasing the range that you can effectively score hits, not making it so that you can get hits with only four guns. You need more guns so, by the analyzation of shell hits and water plumes, you can figure out where the enemy ship is and aim accordingly.

5'' and 4'' guns on the same ship is redundant, and seems not nessasary.

On a ship that narrow, I'd feel that a TB would be more harm than good. I think that a few of us here find 80' about the minimum for adding one. That should help a lot with cramping.

Damocles, torpedoes aren't really better than IRL. Read the history of the Second Pacific War for more info on that. There have been exceptions, but, in general, they aren't really better. Those torpedoes were effective in the Rift because that's what happens when you launch 400 odd torpedoes at a given target.

[damocles]

The 4x13.5'' design is fairly dangerous. What the fire control does is practically increasing the range that you can effectively score hits, not making it so that you can get hits with only four guns. You need more guns so, by the analyzation of shell hits and water plumes, you can figure out where the enemy ship is and aim accordingly.

5'' and 4'' guns on the same ship is redundant, and seems not nessasary.

On a ship that narrow, I'd feel that a TB would be more harm than good. I think that a few of us here find 80' about the minimum for adding one. That should help a lot with cramping.

Damocles, torpedoes aren't really better than IRL. Read the history of the Second Pacific War for more info on that. There have been exceptions, but, in general, they aren't really better. Those torpedoes were effective in the Rift because that's what happens when you launch 400 odd torpedoes at a given target.

Both MK, Dutch, and RRC MTBs attack by divisions. Dutch/MK TJs also attack by divisions. I dare say from the losses both sides suffered in this war, that the Dutch and both Chinas know what modern 1910 and 1915 torpedoes can do now.  These are not 1905 torpedoes anymore.  

I dare say that all those MTBs I'm replacing as well as all those warship losses the RRC are building to overcome, are because of gunfire? Nope.   

D.

   

[Nobody]

Well if the BLU is looking for a Challenge the ORN (Orange Republic Navy) has a few concepts that still need to be designed.

• 1. A treaty battlecruiser:
  Laid down 1922
  35 kt¹⁾ (light) displacement
  160 k SHP
  six or more 42 cm/45 main guns in three or more twin or triple turrets
  5 or 6 inch secondaries
  40 mm and 3 inch AA
  
• 2. A treaty battleship:
  Laid down 1922
  35 kt¹⁾ (light) displacement
  24 to 25 kn²⁾ top speed
  eight or more 42 cm/45 main guns in three or more twin or triple turrets
  a decent armor
  5 or 6 inch secondaries
  40 mm and 3 inch AA
  
• 3. An armored cruiser:
  Laid down 1920
  ~15 kt¹⁾ (light) displacement
  26+ kn²⁾ top speed
  eight or more 9.2" main guns in three or more twin or triple turrets
  good armor
  5" secondaries
  40 mm and 3 inch AA
  
• 4. A monitor or coastal battleship:
  Laid down 1922
  as small as possible
  two to four 42 cm/45 main guns in twin or triple turrets
  a decent armor
  
• 5. A light cruiser:
  Laid down 1920
  ~6 kt¹⁾ (light) displacement
  as fast as possible (30+)
  eight or more 6" main guns in twin turrets
  armor
  40 mm and 3 inch AA
  
  ¹⁾ kt = kiloton
  ²⁾ kn = knot(s)