IJN, Post-1900

[Walter]

Not so sure about stuffing all those 5 140mm mounts on the centerline. What about adding a sixth and then put all of them on the sides with the pair fore and aft superfiring the 200mm guns? I'm not sure if the beam is wide enough for those end guns then to turn inward and then fire over the other mount to keep a decent broadside if I you know what I mean. That would save length space needed and at the same time give a certain look...

[Logi]

My model of Tenryu shows it's a pretty tight fit with 5x140mm on centerline. I'm going to have to revisit it by either removing a 140mm gun or mounting them along the sides instead.

In the meantime, Kaba kaba kaba. It loses 1.5kn top speed as well as 300nm @ 10kn range compared to the Nowaki it replaces, but it gains a much heavier gun armament (61kg vs 18kg), better seakeeping (1.21 vs 1.01), and a long-range wireless.

The long-range wireless antennae makes the ship appear quite a bit taller than it actually is. The bridge is only 2 floors (5.5m) above deck.

Kaba, Japanese Destroyer laid down 1904 (Engine 1905)

Displacement:
   500 t light; 520 t standard; 630 t normal; 718 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (242.78 ft / 242.78 ft) x 20.34 ft x (10.39 / 11.38 ft)
   (74.00 m / 74.00 m) x 6.20 m  x (3.17 / 3.47 m)

Armament:
      3 - 4.72" / 120 mm 45.0 cal guns - 45.00lbs / 20.41kg shells, 100 per gun
     Quick firing guns in deck mounts, 1904 Model
     3 x Single mounts on centreline ends, majority aft
      1 raised mount aft - superfiring
      Weight of broadside 135 lbs / 61 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.08" / 2 mm         -               -

Machinery:
   Coal and oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 7,788 shp / 5,810 Kw = 25.00 kts
   Range 3,700nm at 10.00 kts
   Bunker at max displacement = 197 tons (90% coal)

Trial Speed: 27.50 kts

Complement:
   62 - 81

Cost:
   £0.070 million / $0.281 million

Distribution of weights at normal displacement:
   Armament: 28 tons, 4.4 %
      - Guns: 28 tons, 4.4 %
   Armour: 1 tons, 0.1 %
      - Armament: 1 tons, 0.1 %
   Machinery: 322 tons, 51.1 %
   Hull, fittings & equipment: 120 tons, 19.0 %
   Fuel, ammunition & stores: 130 tons, 20.6 %
   Miscellaneous weights: 30 tons, 4.8 %
      - On freeboard deck: 30 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     140 lbs / 63 Kg = 2.7 x 4.7 " / 120 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.24
   Metacentric height 0.7 ft / 0.2 m
   Roll period: 10.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.62
   Seaboat quality  (Average = 1.00): 1.21

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.430 / 0.447
   Length to Beam Ratio: 11.94 : 1
   'Natural speed' for length: 15.58 kts
   Power going to wave formation at top speed: 60 %
   Trim (Max stability = 0, Max steadiness = 100): 58
   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:   15.00 %,  8.86 ft / 2.70 m,  8.86 ft / 2.70 m
      - Forward deck:   35.00 %,  8.86 ft / 2.70 m,  8.86 ft / 2.70 m
      - Aft deck:   35.00 %,  8.86 ft / 2.70 m,  8.86 ft / 2.70 m
      - Quarter deck:   15.00 %,  8.86 ft / 2.70 m,  8.86 ft / 2.70 m
      - Average freeboard:      8.86 ft / 2.70 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 176.4 %
      - Above water (accommodation/working, high = better): 84.4 %
   Waterplane Area: 3,101 Square feet or 288 Square metres
   Displacement factor (Displacement / loading): 45 %
   Structure weight / hull surface area: 21 lbs/sq ft or 100 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.51
      - Overall: 0.55
   Cramped machinery, storage, compartmentation space
   Cramped accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

Misc Weight: 30t
   25t - Long-Range Wireless
     6t - 3 x 1 45m TT rotating centerline with one reload each

I've noticed the OTL period IJN destroyers tend to have quite shoddy range, hovering at ~900nm @ 11kn. Even the best of their ship - Sakura class - had only 2,400nm @ 12kn.

[eltf177]

Kaba needs one more ton of miscellaneous weight. Other than that looks good although a pair of 47mm cannons would be nice...

[Logi]

Where would the pair of 47mm guns even fit? They were likely have to be elevated in a superstructure next to the rear smokestack. Even then it wouldn't be very much space.

I also tried a torpedo boat. Replacing the Kotaka isn't nearly as much a concern as replacing the Nowaki though. Quite a lot of range sacrificed for the 33.5kn top speed, although top speed is fairly important relative to range for such a ship.

Yamadori, Japanese Torpedo Boat laid down 1904 (Engine 1905)

Displacement:
   260 t light; 266 t standard; 285 t normal; 300 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (229.66 ft / 229.66 ft) x 19.19 ft x (5.58 / 5.77 ft)
   (70.00 m / 70.00 m) x 5.85 m  x (1.70 / 1.76 m)

Armament:
      1 - 1.97" / 50.0 mm 45.0 cal gun - 3.85lbs / 1.74kg shells, 100 per gun
     Quick firing gun in deck mount, 1904 Model
     1 x Single mount on centreline aft
      Weight of broadside 4 lbs / 2 kg

Machinery:
   Coal and oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 7,746 shp / 5,778 Kw = 28.10 kts
   Range 1,000nm at 10.00 kts
   Bunker at max displacement = 34 tons (90% coal)
     Caution: Delicate, lightweight machinery

Trial Speed: 33.50 kts

Complement:
   34 - 45

Cost:
   £0.033 million / $0.132 million

Distribution of weights at normal displacement:
   Armament: 1 tons, 0.3 %
      - Guns: 1 tons, 0.3 %
   Machinery: 169 tons, 59.5 %
   Hull, fittings & equipment: 82 tons, 28.6 %
   Fuel, ammunition & stores: 25 tons, 8.8 %
   Miscellaneous weights: 8 tons, 2.8 %
      - On freeboard deck: 8 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     66 lbs / 30 Kg = 17.3 x 2.0 " / 50 mm shells or 0.1 torpedoes
   Stability (Unstable if below 1.00): 1.09
   Metacentric height 0.5 ft / 0.2 m
   Roll period: 11.4 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.02
   Seaboat quality  (Average = 1.00): 0.80

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.406 / 0.413
   Length to Beam Ratio: 11.97 : 1
   'Natural speed' for length: 15.15 kts
   Power going to wave formation at top speed: 65 %
   Trim (Max stability = 0, Max steadiness = 100): 88
   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:   15.00 %,  8.53 ft / 2.60 m,  7.87 ft / 2.40 m
      - Forward deck:   35.00 %,  7.87 ft / 2.40 m,  7.55 ft / 2.30 m
      - Aft deck:   35.00 %,  7.55 ft / 2.30 m,  7.55 ft / 2.30 m
      - Quarter deck:   15.00 %,  7.55 ft / 2.30 m,  7.55 ft / 2.30 m
      - Average freeboard:      7.69 ft / 2.34 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 192.6 %
      - Above water (accommodation/working, high = better): 116.3 %
   Waterplane Area: 2,722 Square feet or 253 Square metres
   Displacement factor (Displacement / loading): 22 %
   Structure weight / hull surface area: 17 lbs/sq ft or 82 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.02
      - Overall: 0.53
   Cramped machinery, storage, compartmentation space
   Adequate accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Poor seaboat, wet and uncomfortable, reduced performance in heavy weather

Misc Weight: 8t
     8t - 4 x 1 45m TT rotating centerline with one reload each

[Logi]

I corrected the missing 1t of misc weight on the Kaba and made some changes.

I gave up 1.21 seakeeping (now 1.01) and 200nm @ 10kn range in exchange for a less extreme hull-form and an extra 120mm gun.

Kaba, Japanese Destroyer laid down 1904 (Engine 1905)

Displacement:
   500 t light; 522 t standard; 624 t normal; 705 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (262.47 ft / 262.47 ft) x 22.97 ft x (8.10 / 8.85 ft)
   (80.00 m / 80.00 m) x 7.00 m  x (2.47 / 2.70 m)

Armament:
      4 - 4.72" / 120 mm 45.0 cal guns - 45.00lbs / 20.41kg shells, 100 per gun
     Quick firing guns in deck mounts, 1904 Model
     4 x Single mounts on centreline ends, evenly spread
      2 raised mounts - superfiring
      Weight of broadside 180 lbs / 82 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.08" / 2 mm         -               -

Machinery:
   Coal and oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 7,512 shp / 5,604 Kw = 25.00 kts
   Range 3,500nm at 10.00 kts
   Bunker at max displacement = 183 tons (90% coal)

Trial Speed: 27.50 kts

Complement:
   62 - 81

Cost:
   £0.071 million / $0.285 million

Distribution of weights at normal displacement:
   Armament: 37 tons, 6.0 %
      - Guns: 37 tons, 6.0 %
   Armour: 1 tons, 0.1 %
      - Armament: 1 tons, 0.1 %
   Machinery: 312 tons, 50.0 %
   Hull, fittings & equipment: 119 tons, 19.1 %
   Fuel, ammunition & stores: 124 tons, 19.9 %
   Miscellaneous weights: 31 tons, 5.0 %
      - On freeboard deck: 31 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     146 lbs / 66 Kg = 2.8 x 4.7 " / 120 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.24
   Metacentric height 0.8 ft / 0.2 m
   Roll period: 10.7 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.62
   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): 0.447 / 0.463
   Length to Beam Ratio: 11.43 : 1
   'Natural speed' for length: 16.20 kts
   Power going to wave formation at top speed: 59 %
   Trim (Max stability = 0, Max steadiness = 100): 69
   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:   15.00 %,  8.53 ft / 2.60 m,  8.53 ft / 2.60 m
      - Forward deck:   35.00 %,  8.53 ft / 2.60 m,  8.53 ft / 2.60 m
      - Aft deck:   35.00 %,  8.53 ft / 2.60 m,  8.53 ft / 2.60 m
      - Quarter deck:   15.00 %,  8.53 ft / 2.60 m,  8.53 ft / 2.60 m
      - Average freeboard:      8.53 ft / 2.60 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 176.5 %
      - Above water (accommodation/working, high = better): 100.5 %
   Waterplane Area: 3,836 Square feet or 356 Square metres
   Displacement factor (Displacement / loading): 46 %
   Structure weight / hull surface area: 21 lbs/sq ft or 104 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 0.86
      - Overall: 0.52
   Cramped machinery, storage, compartmentation space
   Adequate accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

Misc Weight: 31t
   25t - Long-Range Wireless
     6t - 3 x 1 45m TT rotating centerline with one reload each

An alternative arrangement in which the long-range wireless is switched out for a short-range set. For that and a lost of 500nm @ 10kn range, top speed goes to 28.5kn and an extra 120mm gun is gained. I'm not sure which one is better.

Kaba, Japanese Destroyer laid down 1904 (Engine 1905)

Displacement:
   500 t light; 524 t standard; 611 t normal; 680 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (262.47 ft / 262.47 ft) x 22.97 ft x (8.17 / 8.81 ft)
   (80.00 m / 80.00 m) x 7.00 m  x (2.49 / 2.68 m)

Armament:
      5 - 4.72" / 120 mm 45.0 cal guns - 45.00lbs / 20.41kg shells, 100 per gun
     Quick firing guns in deck mounts, 1904 Model
     5 x Single mounts on centreline ends, majority aft
      2 raised mounts - superfiring
      Weight of broadside 225 lbs / 102 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.08" / 2 mm         -               -

Machinery:
   Coal and oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 8,586 shp / 6,405 Kw = 25.95 kts
   Range 3,000nm at 10.00 kts
   Bunker at max displacement = 156 tons (90% coal)

Trial Speed: 28.50 kts

Complement:
   60 - 79

Cost:
   £0.074 million / $0.296 million

Distribution of weights at normal displacement:
   Armament: 46 tons, 7.6 %
      - Guns: 46 tons, 7.6 %
   Armour: 1 tons, 0.2 %
      - Armament: 1 tons, 0.2 %
   Machinery: 312 tons, 51.1 %
   Hull, fittings & equipment: 124 tons, 20.3 %
   Fuel, ammunition & stores: 111 tons, 18.2 %
   Miscellaneous weights: 16 tons, 2.6 %
      - On freeboard deck: 16 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     137 lbs / 62 Kg = 2.6 x 4.7 " / 120 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.23
   Metacentric height 0.8 ft / 0.2 m
   Roll period: 10.8 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.77
   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): 0.434 / 0.448
   Length to Beam Ratio: 11.43 : 1
   'Natural speed' for length: 16.20 kts
   Power going to wave formation at top speed: 60 %
   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:   15.00 %,  8.86 ft / 2.70 m,  8.86 ft / 2.70 m
      - Forward deck:   35.00 %,  8.86 ft / 2.70 m,  8.86 ft / 2.70 m
      - Aft deck:   35.00 %,  8.86 ft / 2.70 m,  8.86 ft / 2.70 m
      - Quarter deck:   15.00 %,  8.86 ft / 2.70 m,  8.86 ft / 2.70 m
      - Average freeboard:      8.86 ft / 2.70 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 184.1 %
      - Above water (accommodation/working, high = better): 106.8 %
   Waterplane Area: 3,797 Square feet or 353 Square metres
   Displacement factor (Displacement / loading): 39 %
   Structure weight / hull surface area: 23 lbs/sq ft or 110 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.03
      - Overall: 0.53
   Cramped machinery, storage, compartmentation space
   Adequate accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

Misc Weight: 16t
   10t - Short-Range Wireless
     6t - 3 x 1 45m TT rotating centerline with one reload each

[eltf177]

I like these, although I'm not sure Yamadori can handle 4 single centerline tubes. Maybe two on each beam or twin centerline?

[snip]

How much speed can you get out of the 5x120mm version if you drop a gun?

[Logi]

If I drop from 100 rounds to 80 on the battery as well as that 1x120mm gun, speed goes to 26.4kn (29kn trial). Speed doesn't budge much... if I drop the short-range wireless set, at most I would get an additional 0.5kn increase in trial speed.

At that point, significant combat abilities will have been traded away for 0.5-1kn of speed - something that is of dubious value.


@elft177
Simple math shows that it is more than possible to fit. But here's the Yamadori (quick model) side-by-side with the Kaba. If I remove the ability for the torpedo tubes to rotate 360 degrees, I'ld be able to fit another torpedo tube centerline as well.

Ps: Lifeboats would be mounted on the superstructure. They would be overhanging at the rear and simply sitting on top at the front.

[Walter]

Hmm. I'm not sure if it is caused by the depth of the 3D image but it almost seems as if the 50mm gun on the Yamadori is as big as the 120mm gun on the Kaba... I also do not get the impression that the Yamadori is shorter than the Kaba (but that could also be caused by the depth as well as the angle).

Simple math shows that it is more than possible to fit. But here's the Yamadori (quick model) side-by-side with the Kaba. If I remove the ability for the torpedo tubes to rotate 360 degrees, I'ld be able to fit another torpedo tube centerline as well.

Another centerline tube in the Yamadori? Even if it could fit on the ship, don't you need the 1904 Destroyer and TB tech for 5 tubes? If you go for limited turn radius, I would think that the second TT (between middle and aft smokestack) could be moved to the side and forward a bit so another TT could fit on the other beam facing forward. If you do that with your current layout, you could move the aft superstructure forward a bit and perhaps add a second 50mm gun aft.

[snip]

If I drop from 100 rounds to 80 on the battery as well as that 1x120mm gun, speed goes to 26.4kn (29kn trial).

That sounds like it would clobber any destroyer out there. I think the speed is worth more then the additional 120mm gun because this thing does not have the durability to, IMO, be able to utalise that 5th gun effectively in the majority of scenarios. The speed is going to be a greater asset in keeping the ship an active combatant.

Also, with the drawings, I feel very very strongly that the 5x120mm version is just going to be too cramped. 4x120mm, while cramped, seems workable to me. 3x120mm looks far more workable however, to the point I feel its the best option if 120mm guns are strongly desired. What does going to 3x120mm on that hull buy you?

[Walter]

Looking at that Kaba again, I am kinda doubting the usefulness of the tin foil you have on the guns...

[Logi]

Hmm. I'm not sure if it is caused by the depth of the 3D image but it almost seems as if the 50mm gun on the Yamadori is as big as the 120mm gun on the Kaba... I also do not get the impression that the Yamadori is shorter than the Kaba (but that could also be caused by the depth as well as the angle).

It's foreshortening. If I pick a more shallow angle, it's pretty apparent that the 50mm gun is smaller and the Yamadori is indeed shorter. I chose the high angle because there's some weird anti-aliasing glitch in the midsection that makes it appear as though there's a white line running through the midsection.

Another centerline tube in the Yamadori? Even if it could fit on the ship, don't you need the 1904 Destroyer and TB tech for 5 tubes

My point was that there was such space. That was really the only reason I brought it up. It was not that I would do it or that it was legal with the current tech.

Looking at that Kaba again, I am kinda doubting the usefulness of the tin foil you have on the guns...

They're to protect against water spray. It's not meant to physically protect the crew.

The speed is going to be a greater asset in keeping the ship an active combatant.

We're talking 1kn of top speed though. That is practically no effect on the ship's combat capability, especially since they're already fast ships.

3x120mm looks far more workable however, to the point I feel its the best option if 120mm guns are strongly desired.

3x120mm fits on 74m as I showed. Why would it even be questionable whether an 80m destroyer (6m longer than that) can fit 3x120mm?

At 80m with 5x120mm it would look something like this....

Lifeboats would be overhanging at the front. I'll probably have to move some stuff around as well. The rear and forward TT have firing arcs of ~300 degrees, the middle TT can rotate 360.

Cramped affair, but because it's just a short-range wireless (no radar, etc.) and the ship is short (less need for an extended rear bridge) it fits... kind of. Another factor into why it is so short is because, our tech doesn't allow superfiring guns to fire straight towards the bow or stern, so there's no point in having the spacing away from the muzzle blast that you see in later OTL destroyers.

If we did have such superfiring, I'ld probably need to put another 3m of space behind each gun.... easily getting close to OTL destroyer lengths.
5*3 = 15m, 15+80 = 95m, Mahan was 104m and Minekaze was 102.6m
Neither ships had exactly the most efficient longitudinal layout.

[snip]

I think the blast effect of the guns is being understated here. The Mahan's have fully enclosed mounts, so I think any comparison there is invalid on that the Kaba does not. The Minekaze provides a much better comparison, and it only has four guns on a hull 17m longer (waterline). Given that, I feel really strongly that 5x120mm is way overguned for a hull this size. 4x120mm is still going to outgun every other design I have seen to date, and be far less cramped.

[Logi]

As I said, they don't have particularly efficient layouts. Minekaze has all its guns on the same deck level.

I don't know what you're looking at but the Mahan did not have fully enclosed mounts. The forward mounts were partially enclosed (i.e. the half the side and the whole rear was completely exposed). The rear mounts were completely open. You can easily find pictures and blueprints showing as much.

Most of the muzzle blast from a gun is expended in the 30 degrees angle in front. And though some of the overpressure spills sideways, at the 180 degrees arc, it is very minor. Add to the fact that these are 120mm guns and not larger, and I have little reason to believe the blast effect would impact the gun layout except in the in the 30 degrees arc facing bow or stern.

Period ships can be shorter because they are less capable. The capability to fire astern and directly forwards requires a longer ship, on the order of magnitude of 4-5m longer per gun. And that is exactly the sort of ship lengths we see on ships that could do so. In addition, for every TT that can't rotate the full 360 degrees, add another 1-2m because period destroyers almost all had the ability to turn their TTs 360 degrees.

[Logi]

If 1 gun has to be eliminated, I'ld rather get better seakeeping (1.01 -> 1.21) than 1 kn of speed.

It's a bit of a dubious trade off though. In comparison, the previous 4-gun Kaba had a long (now short) range wireless, 100 rounds (now 80), as well as 500nm @ 10kn more range. What I gained from that was 1 kn of top speed (27.5->28.5) and better seakeeping (1.01->1.21)

Kaba, Japanese Destroyer laid down 1904 (Engine 1905)

Displacement:
   500 t light; 520 t standard; 607 t normal; 676 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (262.47 ft / 262.47 ft) x 22.15 ft x (8.69 / 9.37 ft)
   (80.00 m / 80.00 m) x 6.75 m  x (2.65 / 2.85 m)

Armament:
      4 - 4.72" / 120 mm 45.0 cal guns - 45.00lbs / 20.41kg shells, 80 per gun
     Quick firing guns in deck mounts, 1904 Model
     4 x Single mounts on centreline ends, evenly spread
      2 raised mounts - superfiring
      Weight of broadside 180 lbs / 82 kg

Machinery:
   Coal and oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 8,385 shp / 6,255 Kw = 25.90 kts
   Range 3,000nm at 10.00 kts
   Bunker at max displacement = 156 tons (90% coal)

Trial Speed: 28.50 kts

Complement:
   60 - 79

Cost:
   £0.071 million / $0.286 million

Distribution of weights at normal displacement:
   Armament: 37 tons, 6.1 %
      - Guns: 37 tons, 6.1 %
   Machinery: 313 tons, 51.6 %
   Hull, fittings & equipment: 134 tons, 22.0 %
   Fuel, ammunition & stores: 107 tons, 17.6 %
   Miscellaneous weights: 16 tons, 2.6 %
      - On freeboard deck: 16 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     147 lbs / 66 Kg = 2.8 x 4.7 " / 120 mm shells or 0.2 torpedoes
   Stability (Unstable if below 1.00): 1.28
   Metacentric height 0.8 ft / 0.2 m
   Roll period: 10.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.72
   Seaboat quality  (Average = 1.00): 1.21

Hull form characteristics:
   Hull has a flush deck,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.420 / 0.435
   Length to Beam Ratio: 11.85 : 1
   'Natural speed' for length: 16.20 kts
   Power going to wave formation at top speed: 59 %
   Trim (Max stability = 0, Max steadiness = 100): 58
   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:   15.00 %,  10.30 ft / 3.14 m,  9.51 ft / 2.90 m
      - Forward deck:   35.00 %,  9.51 ft / 2.90 m,  9.19 ft / 2.80 m
      - Aft deck:   35.00 %,  9.19 ft / 2.80 m,  9.19 ft / 2.80 m
      - Quarter deck:   15.00 %,  9.19 ft / 2.80 m,  9.19 ft / 2.80 m
      - Average freeboard:      9.34 ft / 2.85 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 181.7 %
      - Above water (accommodation/working, high = better): 106.7 %
   Waterplane Area: 3,625 Square feet or 337 Square metres
   Displacement factor (Displacement / loading): 41 %
   Structure weight / hull surface area: 22 lbs/sq ft or 108 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.50
      - Longitudinal: 1.32
      - Overall: 0.55
   Cramped machinery, storage, compartmentation space
   Adequate accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

Misc Weight: 16t
   10t - Short-Range Wireless
     6t - 3 x 1 45m TT rotating centerline with one reload each