IJN, Post-1900

[eltf177]

Now I'm seeing a "Mogami"-type layout fore and aft, which makes much more sense...

[Walter]

The reason is that as given by Kirk.

I think that one should just use KISS and assume that all that stuff will be below the protected deck and that the average height of the protected deck will be at the waterline. If it is more than 154% (= the length of the ship) then yes I can understand that, but 100%? 100%  "Space - Hull below water" is the length of the ship, not the draught of the ship. If it goes above 100%, it will not stick above the deck, but will be spread out more along the length of the ship (although there is a limit to that of course).

With the ICNS Fuding I tried to sim HMS Apollo. It's about half a knot slower than what is given for HMS Apollo. Its "Space - Hull below water" value is 149.8% and that is based on a historical ship... and it is not even entirely accurate as I did not take into account the additional bit of weight of the sloped sides of the deck, especially that extreme bit aft over the machinery (at least I assume that is over the machinery).

Having drawn a quick, single line on that linedrawing in paint, everything of the protected deck, with exception of that hump aft, is below the waterline. If I enter the historical data of a ship into SS and it gives me a "Space - Hull below water" value of 147.5% (the value I get when I remove all shells) while it all fitted historically below the protected deck, I am fairly sure that there would be no need for a belt on your design (or any of our PC designs) if the "Space - Hull below water" value is in the 100-150% range.

... and if you are curious, if I take my design and go to the 20 knots, the speed that is given for the Apollo class, then "Space - Hull below water" is 161.4% (including magazines).

The bulge is a mistake - I design by displacement and forgot to switch back to Cb before adding the bulge. The reshaping hull and protected deck all follow from that so, not an issue once I correct it. That was a first estimate in any case - 1909 is a far far time away.

Whoever in the IJN who came up with that estimate should be fired immediately before he does more damage to the navy. ;D


After that post of mine, I looked through the rules a bit. There is no indication in the rules that the block coefficient can be changed in either refurbishment or reconstruction so eventhough there might be a little bit of a change in BC when you raise/lower the waterline or add a piece of ship or add bulges, I think we should just keep it simple and not change BC at all.

[snip]

After that post of mine, I looked through the rules a bit. There is no indication in the rules that the block coefficient can be changed in either refurbishment or reconstruction so eventhough there might be a little bit of a change in BC when you raise/lower the waterline or add a piece of ship or add bulges, I think we should just keep it simple and not change BC at all.

Agreed.

[Tanthalas]

God I hate to be the one to bring it up.... Realy Realy REALY hate it, but I think most of these are suffering from NEDS.  KJ3000 and the other 393' ships being the exception (im only talking about the warships obviously), and one minor issue (realy hate even more bringing it up since your a mod mate) don't 7 inch + guns require turret and barbete not mount and hoist (im sure thats in the rules somewhere cause I once wanted to use 8" twins in mount and hoist and got told NO)?

AH HA found it...

Any ship with main guns larger than 7 inches is generally built to the BB/AC "architecture" meaning the technology rules for BBs and/or ACs apply. Any ship with guns 7 inches or less may be built to the Light Cruiser "architecture". Ships may be built to the TB/DD "architecture" rules, provided they meet the minimum requirements for such ships.

so your 7.87/200mm definetly would fit in the BB/AC class I would think anyway (like I said I only rememberd cause I got slapped down for wanting to use mount and hoist on twin 8" guns)

oh and GAH I just realised I sounded like Borys... NEDS... FRACK.

[snip]

I think there is a key difference between twin M&H and a single. Also, this is a replication of a historical ship AFAIK. That being said, in a prolonged engagement those guns are going to not be able to keep up a RoF like they would in a turret due to lack of much mechanical assistance.

[Kaiser Kirk]

so your 7.87/200mm definetly would fit in the BB/AC class I would think anyway (like I said I only rememberd cause I got slapped down for wanting to use mount and hoist on twin 8" guns)

Just as a practical matter, the weight of mounting of a mount & hoist 8" gun would be extremely high, lending itself to slow rates of rotation and train, and imposing considerable strains on the hull members supporting them. Remember, part of the point of a barbette is to transfer that weight down to the keel. Ostensibly one of the reasons the IJN wanted an 8" limit on heavy cruisers was that size of a round requires power assist, regardless of the nationality, thus compensating for the smaller average size of japanese sailors.

I am of the opinion there is a practical weight limit for mount & hoist, which can be inferred from historical mountings and discussion of their performance...and what they were followed with. Take the 6"/53 twin mount on the Omaha class, at 52 tons and weakly armored, I've seen it described as slow to train and inadequate. The 7.5" single mount on the Hawkin's class was 46tons, and also described as slow, even with power assist. The 5.25"/50 on KGV seems to be the very top end of the scale, and the 77ton handworked Type 1 mounts were basically inadequate. The later mountings were "semi-stalked", not quite barbette, but probably distributing those stresses over more deck members and with more power help- I'd call them turret and barbette.  So I'd put that breakpoint at ~55t  - just over Omaha's weight.
*steps off soap box*
And now I return you to your regular programming

[Tanthalas]

Yeah, I got the idea from an OTL ship, Olympia if you look at the pictures of her "barbettes" they are actualy mount and Hoist (atleast by our definition of them).  I could never make her work with turret and Barb, but when I made that switch BANG it worked.  But alas I was told it was forbiden  :'( .  Not that im complaining I was just pointing out a problem I noticed (im runing around looking at everyones "Light Cruisers" cause I decided I didnt like any of the ones I came up with for 1900)

I think there is a key difference between twin M&H and a single. Also, this is a replication of a historical ship AFAIK. That being said, in a prolonged engagement those guns are going to not be able to keep up a RoF like they would in a turret due to lack of much mechanical assistance.

[Logi]

The cruiser that is being built is the last 3,000t KJ project. I highly doubt it has any NEDs issue, seeing as it was based on a less crowded Naniwa-class, which itself is a replicate of the historical Naniwa-class. Compared to the Naniwa-class, it has much smaller and fewer armament whilst being longer - I'm really not seeing the NEDS issue. Even more explicitly is probably the comparison to the ship this design is directly related to - the historical Kasagi-class cruiser. This design is 6 meters longer while having fewer guns in general.

KJ3000, Japan Cruiser laid down 1900

Displacement:
   3,000 t light; 3,132 t standard; 3,806 t normal; 4,345 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (393.70 ft / 393.70 ft) x 39.70 ft x (17.06 / 18.87 ft)
   (120.00 m / 120.00 m) x 12.10 m  x (5.20 / 5.75 m)

Armament:
      2 - 7.87" / 200 mm 45.0 cal guns - 242.51lbs / 110.00kg shells, 60 per gun
     Breech loading guns in deck and hoist mounts, 1900 Model
     2 x Single mounts on centreline ends, evenly spread
      4 - 5.98" / 152 mm 45.0 cal guns - 108.07lbs / 49.02kg shells, 150 per gun
     Quick firing guns in deck and hoist mounts, 1900 Model
     4 x Single mounts on centreline, evenly spread
      2 raised mounts
      4 - 2.24" / 57.0 mm 40.0 cal guns - 5.51lbs / 2.50kg shells, 300 per gun
     Quick firing guns in deck mounts, 1898 Model
     4 x Single mounts on sides, evenly spread
      Weight of broadside 939 lbs / 426 kg

I could never make her work with turret and Barb, but when I made that switch BANG it worked.  But alas I was told it was forbidden

I... I don't recall me or Snip every saying something to this effect in this iteration. What post was that?

[snip]

Its hard mentioned in the rN3 rules, and I think we didnt alter that. Maybe an alteration to clarify "Its not a absolute, but just know that guns larger then 7" are just going to suffer in combat if they are not in T&B".

Regarding the KJ3000 class specifically vs OTL Olympia. The key difference here is that the KJ3000 does not have a fully enclosed gunhouse, or even armor on the hoists where the Olympia does. As such, the only way to sim such a mounting is M&H. I don't think that anyone is under the assumption that these guns will not have a major disadvantage in prolonged combat over the same in T&B.

[Logi]

Oh that portion. I was thrown off a bit by the wording "I was told it was forbidden", since I didn't recall either of us ever saying something to that effect overtly.

As snip states, that section was carried over from N3 and as far as I remember, the understanding was always that you can put guns larger than 7" on a mount&hoist instead of turret&barbette - but the penalties in combat grow exponentially with size. As such, it's never a good idea to do so - but the Japanese fleet here is modeled somewhat on the historical fleet, which is not exactly the shining beacon of good design.

As snip mentions, the intention here is a ship with partially enclosed, not fully enclosed mounts. Look at the historical Takasogo and Kasagi classes for reference. (You should notice the mounts look nothing alike.)

[Tanthalas]

@Logi
Oh I dont think the KJ3000 has NEDS (it should all fit fairly well honestly), at around 400' you have plenty of room (you might even be able to go down to like 350') as to my Olympia knock off, that would have been during N3 I think (I know Mario was the one that slapped me down)

@Snip
Olympia is hard, her mounts were neither fish nor foul, just going by the pictures online anyway... She had full turrets, but the "barbette" was itty bitty (basicly just big enough to get a shell up from the pictures), and very lightly armored.  Like I said if you sim her with mount and hoist weight wise it works but turret and barb no matter how you tryed to armor it just didnt (admitedly that was in SS2 not SS3 havnt tryed it in SS3)

[Kaiser Kirk]

On Olympia, from the line drawings, yes it looks like just the hoist was armored. All the references I find refer to "turrets" though.
however, if you look at an actual picture https://www.flickr.com/photos/24736216@N07/4666996227/ there's clearly a at least an abbreviated structure that supports the rotating gun house. It's possible that there was no trunk structure down to the keel and so not a barbette, but some other means of reinforcing that deck area.

Another aspect is that  8"/35s are shorter and so lighter than later weapons. NavWeaps doesn't have a twin weight for the 8"/35, but gives the gun weight for the 8"/35 on Olympia as about 13 (naval) tons, the 8"/35 on Admiral Nakhimov as 13tons, while the weight of the Hawkin's 7.5/45 was 13.8 tons, while the gun weight of the Omaha's 6"/53 is 10.11 .

So the 8"/35 is heavier and larger, but not completely out of range of the Omaha's twin 6" mount rotating weight. So they may have tried some hybrid structure with a turret ring supported by reinforced hull members. NavWeaps does note that the turrets were not balanced - so an early form with lower weight, and the Mark 6 mounting on the Olympia sounds like it might have lacked power assist.

Interesting, Wikipedia's entry lists 4.5" of barbette armor for Olympia. Albeit that could be a wiki-error, the hoist armor, or the deck structure on which the turret rotates.
The other vessels using a twin mount of this weapon seem to have had barbettes as well, with USS Brooklyn specifically having armor there.

Anyhow, Interesting to poke around.
Can't clearly say one way or another, the 8"/35 is light enough it's possible they felt some lesser structure could work, but it's not something that seems to have been repeated.

Me, I'm still going to pitch that about 40 naval tons or less is the cap for guaranteed success with mount and hoist, and that we should end "successful" mount & hoist at an installed weight of 50-55tons.

[Tanthalas]

here Kirk admitedly they are drawings, but they are period drawings of how the ships were actualy built.  These are why I have always said Olympia didnt realy have turret and Barb as we define it in the Nverse (or as SS2/SS3 Defines it).

Cutaway showing Olympias foreward mount and amunition hoist
http://www.ctomscott.com/Olympia/CrosSect.JPG
see how the structure ends at the main deck and it is just a hoist below that. It is honestly neither turret and barb or mount and hoist IMHO.

and BB1 Indiana (since it is roughly the same period)
http://www.navsource.org/archives/01/010118.jpg
see how the structure extends through the main deck and down it looks like one more deck atleast (proly to about the waterline given the low freeboard on them) that is turret and barb as we define it.

Olympia had steam powerd mounts for its main guns (seriously I read that somewhere), but they were not very eficient or smooth in operation.

[Kaiser Kirk]

Interesting. Agreed, a bit of both, a little like that 5.25" "semi-stalked"...which seems to be about the same weight class. Reminds me of a coles-erricson turret but elevated.

Nav weaps had the steam powered note for the Mk 5 turret, but didn't show anything for Olympia's mk 6.

The "Turret & spindle" I'll call it; that armored hoist looks to transfer forces down to the protected deck.
From wiki that would be a 4.5" thick cylinder.  If you look, there seems to be a flange at the top of that structure, on which the gun cradle rests. So I'm guessing that Hoist armored tube is structural in effect.
On the first deck down adjacent, you can also see hull members shown flaring out to support the Turret "ring" structure, and they presumably support the rotating weight of the armor. 

In the end, if we were forcing it into SS's definitions, presuming my intepretation of the transfer of forces to supporting structures is reasonable,  then it would be a Turret & Barbette.

[Logi]

Since it's been getting close to the time the first Asama-class heavy cruiser will be laid down, I've revisited the design:

Disp: 9,000t -> 10,500t
Belt Thk: 150mm -> 280mm
Belt Hgt: 3m -> 4m
Range: 9000nm -> 4500nm

Most of the range can be cut down since Underway Recoaling will be coming online soon and Japan has several coilers and is projected to have 6 by the time the first Asama hits the waters.

Asama, Japan Heavy Cruiser laid down 1902 (Engine 1900)

Displacement:
   10,500 t light; 11,044 t standard; 11,714 t normal; 12,250 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (393.70 ft / 393.70 ft) x 63.65 ft x (29.53 / 30.60 ft)
   (120.00 m / 120.00 m) x 19.40 m  x (9.00 / 9.33 m)

Armament:
      6 - 9.84" / 250 mm 45.0 cal guns - 440.92lbs / 200.00kg shells, 100 per gun
     Breech loading guns in turret on barbette mounts, 1902 Model
     3 x Twin mounts on centreline, evenly spread
      12 - 5.98" / 152 mm 45.0 cal guns - 108.07lbs / 49.02kg shells, 200 per gun
     Quick firing guns in casemate mounts, 1902 Model
     12 x Single mounts on sides, evenly spread
      8 - 2.24" / 57.0 mm 40.0 cal guns - 5.42lbs / 2.46kg shells, 400 per gun
     Quick firing guns in deck mounts, 1902 Model
     8 x Single mounts on sides, evenly spread
      40 - 1.00" / 25.4 mm 35.0 cal guns - 0.47lbs / 0.21kg shells, 800 per gun
     Machine guns in deck mounts, 1902 Model
     10 x Quad mounts on sides, evenly spread
      40 - 0.43" / 11.0 mm 35.0 cal guns - 0.04lbs / 0.02kg shells, 1,000 per gun
     Breech loading guns in deck mounts, 1902 Model
     4 x 2 row decuple mounts on sides, evenly spread
      Weight of broadside 4,006 lbs / 1,817 kg

Armour:
   - Belts:      Width (max)   Length (avg)      Height (avg)
   Main:   11.0" / 280 mm   311.68 ft / 95.00 m   13.12 ft / 4.00 m
   Ends:   2.95" / 75 mm     82.02 ft / 25.00 m   13.12 ft / 4.00 m
     Main Belt covers 122 % of normal length

   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   12.0" / 305 mm   3.94" / 100 mm      6.69" / 170 mm
   2nd:   2.95" / 75 mm   1.97" / 50 mm      2.95" / 75 mm
   3rd:   0.59" / 15 mm         -               -
   4th:   0.20" / 5 mm         -               -

   - Protected deck - single deck:
   For and Aft decks: 2.95" / 75 mm
   Forecastle: 1.97" / 50 mm  Quarter deck: 1.97" / 50 mm

   - Conning towers: Forward 11.02" / 280 mm, Aft 0.00" / 0 mm

Machinery:
   Coal and oil fired boilers, complex reciprocating steam engines,
   Direct drive, 2 shafts, 21,959 ihp / 16,381 Kw = 21.00 kts
   Range 4,500nm at 10.00 kts
   Bunker at max displacement = 1,206 tons (90% coal)

Complement:
   562 - 731

Cost:
   £1.178 million / $4.712 million

Distribution of weights at normal displacement:
   Armament: 874 tons, 7.5 %
      - Guns: 874 tons, 7.5 %
   Armour: 3,583 tons, 30.6 %
      - Belts: 1,999 tons, 17.1 %
      - Armament: 555 tons, 4.7 %
      - Armour Deck: 907 tons, 7.7 %
      - Conning Tower: 122 tons, 1.0 %
   Machinery: 3,397 tons, 29.0 %
   Hull, fittings & equipment: 2,546 tons, 21.7 %
   Fuel, ammunition & stores: 1,214 tons, 10.4 %
   Miscellaneous weights: 100 tons, 0.9 %
      - Hull above water: 50 tons
      - On freeboard deck: 25 tons
      - Above deck: 25 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     6,437 lbs / 2,920 Kg = 13.5 x 9.8 " / 250 mm shells or 1.1 torpedoes
   Stability (Unstable if below 1.00): 1.12
   Metacentric height 3.1 ft / 1.0 m
   Roll period: 15.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.49
   Seaboat quality  (Average = 1.00): 1.01

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.554 / 0.559
   Length to Beam Ratio: 6.19 : 1
   'Natural speed' for length: 19.84 kts
   Power going to wave formation at top speed: 54 %
   Trim (Max stability = 0, Max steadiness = 100): 70
   Bow angle (Positive = bow angles forward): 0.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   20.00 %,  12.47 ft / 3.80 m,  12.47 ft / 3.80 m
      - Forward deck:   35.00 %,  12.47 ft / 3.80 m,  12.47 ft / 3.80 m
      - Aft deck:   30.00 %,  12.47 ft / 3.80 m,  12.47 ft / 3.80 m
      - Quarter deck:   15.00 %,  12.47 ft / 3.80 m,  12.47 ft / 3.80 m
      - Average freeboard:      12.47 ft / 3.80 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 121.1 %
      - Above water (accommodation/working, high = better): 74.2 %
   Waterplane Area: 17,555 Square feet or 1,631 Square metres
   Displacement factor (Displacement / loading): 86 %
   Structure weight / hull surface area: 111 lbs/sq ft or 541 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.92
      - Longitudinal: 2.07
      - Overall: 1.00
   Cramped machinery, storage, compartmentation space
   Cramped accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform