Japanese Ship Designs 1915+

[Kaiser Kirk]

I'm not horribly worried about kite balloon tonnage,
going forward though it should be a set amount so we have consistancy ship to ship.
I mean if Nation A puts 15t / balloon, and Nation B 5t, while Nation C has 25t..... do they have the same utility?

The minimal tonnage for 1 aircraft is 25t..., that's already in effect,  so let's use that.

As for the MTBs - the problem is 20t MTBs can be loaded and launched with no modification.  The difference between a research one and a "off the shelf" is minimal.
So - compromise - drop the weight of the MTBs to 19t,  total 76t for two - that way you can't be loading the 20t MTBs, but you can still replicate your research concept.

I used signals as an example, as it's possible we'll add some techs to the late trees to cover things that are missing.
As for the technology, if there is none that covers it, then it will not be successful in operational use.
We all know there were radio controlled target ships, but I can't think of a single case of a radio guided drone ship used in combat successfully- either to ram or to fire torps.

[Desertfox]

I'm not horribly worried about kite balloon tonnage,
going forward though it should be a set amount so we have consistancy ship to ship.
I mean if Nation A puts 15t / balloon, and Nation B 5t, while Nation C has 25t..... do they have the same utility?

Looking thru my ships, I've used 10t, 20t, and 40t. I can live with 20t (and a grandfather clause).

As for the MTBs - the problem is 20t MTBs can be loaded and launched with no modification.  The difference between a research one and a "off the shelf" is minimal.
So - compromise - drop the weight of the MTBs to 19t,  total 76t for two - that way you can't be loading the 20t MTBs, but you can still replicate your research concept.

That's a problem for a lot of other auxiliaries as well. Can't we just do the whole "paid as aux - cannot do combat launches"? Its a simple yes/no check.

We all know there were radio controlled target ships, but I can't think of a single case of a radio guided drone ship used in combat successfully- either to ram or to fire torps.

Most likely a case of developed too late for WWI and OBE by the time of WWII. The British quite clearly demonstrated the capability to remotely maneuver up to 8 MTBs at a time from an aircraft in 1918. The technology is available in this time period and the extensive usage of MTBs would make it more likely for such a track to be followed compared to say tanks, where the lack of trench warfare has stalled development.

[Kaiser Kirk]

Balloons - past is grandfathered in, no problem.  Future, I'd like to match the base Aircraft and move that future point to 25t.  Look at it this way, eventually you'd be able to replace them with a floatplane.

Combat launches - that's already there. List them as just their weight and they just deck cargo. It's listing them as twice that weight and thus eligible for combat launch that triggers this consideration.

Yes, we know there were RC ships.  But there was no actual combat implementation. Trials, experiments, creative storytelling - sure go ahead.

But I don't want to have the argument later that these experimental items can be used in a conflict and a special carve out made for them.
I'm stating very very clearly that without a supporting Technology they will not be operational useful.

[Desertfox]

This is the problem:

Aikoku Maru, Japan AMC/Troop Transport laid down 1910

200t - 4 x 25-ton landing boats

The ships where designed before 20t MTBs were an option. But overnight they gained the ability to carry and combat launch them. If davits can handle 25t they can handle 20t without a problem. And the Aikokus are not the only ships with this capability (Aztec LSS-1 etc). All I'm saying is there are legitimate auxiliary reasons for ships to be capable of conducting a "combat" load and unload of a MTB that don't actually involve combat. The Toph Maru III itself is designed to pick up MTBs for repairs. I don't mind adding a "non-combat" disclaimer, but just saying "twice the weight = automatic combat launch" is opening a whole can of worms, as suddenly ANY ship that is designed to with the "twice the weight" rule for 20t or larger boats is now no longer an auxiliary whether it was designed for combat or not.

[Kaiser Kirk]

In the example it's specified as 25t landing craft. That's all it gets to carry.
The question of if the davits for a shorter beamier landing craft can handle a longer slimmer MTB is irrelevant,
you are tied to the miscellaneous weight specified.

If you want to convert it to launch 20t MTBs, then you have to refit it,
at which point it will be disallowed.

[Kaiser Kirk]

I should also make clear :
I do not have time to look at the ship design thread often.
I wish I did,  I like seeing what others are doing, but generally not.
I wandered by the Vilnus thread the other day, but that's unusual.

Ship review is usually the purview of the players.
So, an existing design is not necessarily precedent

If there's a question, send me a PM and I'll make time to come look.
That was the case here, I was asked to take a look.

Overall the easiest solution would be to declare a vessel can't have more than 2% weight allocated to launchable (as opposed to deck cargo) craft.
That would take care of your landing craft -> MTB's example.
It's actually cheaper to call them Deck Cargo, so making that choice to making them combat launchable is a bit of a heads ups up.

But I'd rather be more specific to the individual vessel. Which unfortunately means I have to spend time on these discussions.

[Desertfox]

The issue is that I may want to have a capability equivalent to "combat launchable" for a completely non-combat related reason. Case in point the Toph Maru III is designed specifically to be capable of recovering MTBs away from port facilities, this is 100% an auxiliary role (and not "deck cargo") and there is zero intent for it to conduct combat launches, but the necessary equipment is the same. What I don't understand is why we can't just add a "no combat launches allowed" disclaimer? That way I can keep the necessary auxiliary capability while at the same time making it clear, the ship won't be used in a combat role.

[Desertfox]

Made drawings of the Furutakas, Kitakamis, and Oi.

[Desertfox]

Japan is starting 1910 ASW Tech in H1/1917. As part of that a couple of improved Kaibokans will be built as testbeds for ASW equipment and tech. Main change other than the misc weight is the addition of electric drive.

Kaibokan II, Japan ASW Testbed laid down 1917

Displacement:
   299 t light; 307 t standard; 374 t normal; 427 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (172.12 ft / 170.00 ft) x 27.00 ft x (5.70 / 6.33 ft)
   (52.46 m / 51.82 m) x 8.23 m  x (1.74 / 1.93 m)

Armament:
      1 - 2.00" / 50.8 mm 45.0 cal gun - 4.03lbs / 1.83kg shells, 100 per gun
     Quick firing gun in deck mount, 1917 Model
     1 x Single mount on centreline, forward deck centre
      Weight of broadside 4 lbs / 2 kg

Machinery:
   Oil fired boilers, steam turbines,
   Electric motors, 1 shaft, 1,558 shp / 1,162 Kw = 17.00 kts
   Range 3,000nm at 14.00 kts
   Bunker at max displacement = 120 tons

Complement:
   42 - 55

Cost:
   £0.034 million / $0.136 million

Distribution of weights at normal displacement:
   Armament: 1 tons, 0.2 %
      - Guns: 1 tons, 0.2 %
   Machinery: 57 tons, 15.3 %
   Hull, fittings & equipment: 145 tons, 38.7 %
   Fuel, ammunition & stores: 74 tons, 19.9 %
   Miscellaneous weights: 97 tons, 26.0 %
      - Hull below water: 14 tons
      - On freeboard deck: 83 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1,217 lbs / 552 Kg = 304.2 x 2.0 " / 51 mm shells or 1.0 torpedoes
   Stability (Unstable if below 1.00): 1.24
   Metacentric height 1.0 ft / 0.3 m
   Roll period: 11.1 seconds
   Steadiness   - As gun platform (Average = 50 %): 71 %
         - Recoil effect (Restricted arc if above 1.00): 0.01
   Seaboat quality  (Average = 1.00): 1.20

Hull form characteristics:
   Hull has low quarterdeck ,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.500 / 0.514
   Length to Beam Ratio: 6.30 : 1
   'Natural speed' for length: 13.04 kts
   Power going to wave formation at top speed: 58 %
   Trim (Max stability = 0, Max steadiness = 100): 59
   Bow angle (Positive = bow angles forward): 10.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   31.00 %,  12.00 ft / 3.66 m,  10.00 ft / 3.05 m
      - Forward deck:   20.00 %,  10.00 ft / 3.05 m,  10.00 ft / 3.05 m
      - Aft deck:   14.00 %,  10.00 ft / 3.05 m,  10.00 ft / 3.05 m
      - Quarter deck:   35.00 %,  7.00 ft / 2.13 m,  7.00 ft / 2.13 m
      - Average freeboard:      9.20 ft / 2.80 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 55.4 %
      - Above water (accommodation/working, high = better): 133.3 %
   Waterplane Area: 2,940 Square feet or 273 Square metres
   Displacement factor (Displacement / loading): 175 %
   Structure weight / hull surface area: 32 lbs/sq ft or 157 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.90
      - Longitudinal: 2.60
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

25t - Experimental Radar
20t - Observation Balloon Equipment
20t - Basic + Enhanced Hydrophone Suite
10t - Minesweeping Gear
8t - Misc ASW Weapons

[Desertfox]

Fast transport capable of carrying and landing 120 marines or 250t of supplies anywhere.

Matsu, Japan Fast Transport/Dispatch Boat laid down 1917

Displacement:
   1,700 t light; 1,764 t standard; 2,029 t normal; 2,241 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (342.64 ft / 340.00 ft) x 47.00 ft x (10.10 / 10.83 ft)
   (104.44 m / 103.63 m) x 14.33 m  x (3.08 / 3.30 m)

Armament:
      3 - 5.00" / 127 mm 45.0 cal guns - 63.03lbs / 28.59kg shells, 200 per gun
     Quick firing guns in deck mounts, 1917 Model
     3 x Single mounts on centreline ends, majority forward
      2 raised mounts - superfiring
      6 - 2.00" / 50.8 mm 45.0 cal guns - 4.03lbs / 1.83kg shells, 200 per gun
     Quick firing guns in deck mounts, 1917 Model
     2 x Single mounts on sides amidships
      Weight of broadside 213 lbs / 97 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.20" / 5 mm         -               -

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 12,674 shp / 9,454 Kw = 24.00 kts
   Range 5,000nm at 14.00 kts
   Bunker at max displacement = 477 tons

Complement:
   150 - 196

Cost:
   £0.245 million / $0.981 million

Distribution of weights at normal displacement:
   Armament: 38 tons, 1.9 %
      - Guns: 38 tons, 1.9 %
   Armour: 2 tons, 0.1 %
      - Armament: 2 tons, 0.1 %
   Machinery: 465 tons, 22.9 %
   Hull, fittings & equipment: 780 tons, 38.5 %
   Fuel, ammunition & stores: 329 tons, 16.2 %
   Miscellaneous weights: 415 tons, 20.5 %
      - Hull below water: 100 tons
      - Hull above water: 150 tons
      - On freeboard deck: 135 tons
      - Above deck: 30 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     3,289 lbs / 1,492 Kg = 52.6 x 5.0 " / 127 mm shells or 1.0 torpedoes
   Stability (Unstable if below 1.00): 1.30
   Metacentric height 2.6 ft / 0.8 m
   Roll period: 12.3 seconds
   Steadiness   - As gun platform (Average = 50 %): 72 %
         - Recoil effect (Restricted arc if above 1.00): 0.07
   Seaboat quality  (Average = 1.00): 1.05

Hull form characteristics:
   Hull has rise forward of midbreak,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.440 / 0.453
   Length to Beam Ratio: 7.23 : 1
   'Natural speed' for length: 18.44 kts
   Power going to wave formation at top speed: 56 %
   Trim (Max stability = 0, Max steadiness = 100): 69
   Bow angle (Positive = bow angles forward): 10.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   30.00 %,  15.00 ft / 4.57 m,  14.00 ft / 4.27 m
      - Forward deck:   30.00 %,  14.00 ft / 4.27 m,  14.00 ft / 4.27 m
      - Aft deck:   25.00 %,  9.00 ft / 2.74 m,  9.00 ft / 2.74 m
      - Quarter deck:   15.00 %,  9.00 ft / 2.74 m,  9.00 ft / 2.74 m
      - Average freeboard:      12.12 ft / 3.69 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 93.7 %
      - Above water (accommodation/working, high = better): 150.6 %
   Waterplane Area: 10,112 Square feet or 939 Square metres
   Displacement factor (Displacement / loading): 140 %
   Structure weight / hull surface area: 58 lbs/sq ft or 282 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.96
      - Longitudinal: 1.43
      - Overall: 1.00
   Adequate machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

5t - 1908 Fire Control
25t - LR Wireless
20t - Observation Balloon
15t - Minesweeping Gear
100t - 2 x 25t Boats
250t - Supplies/Marines

[Desertfox]

Updated the fast transport, now cheaper and with a nice round 420t of misc weight for all of your drug smuggling needs... Do like how it looks a lot more now.

Matsu Maru, Japan Fast Transport/Dispatch Boat laid down 1917

Displacement:
   1,327 t light; 1,379 t standard; 1,711 t normal; 1,977 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (342.47 ft / 340.00 ft) x 44.00 ft x (9.10 / 10.08 ft)
   (104.38 m / 103.63 m) x 13.41 m  x (2.77 / 3.07 m)

Armament:
      2 - 5.00" / 127 mm 45.0 cal guns - 63.03lbs / 28.59kg shells, 180 per gun
     Quick firing guns in deck mounts, 1917 Model
     2 x Single mounts on centreline ends, evenly spread
      1 raised mount - superfiring
      12 - 2.00" / 50.8 mm 45.0 cal guns - 4.03lbs / 1.83kg shells, 200 per gun
     Quick firing guns in deck mounts, 1917 Model
     4 x Single mounts on sides, evenly spread
      Weight of broadside 174 lbs / 79 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   0.10" / 3 mm         -               -

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 6,705 shp / 5,002 Kw = 21.00 kts
   Range 7,000nm at 14.00 kts
   Bunker at max displacement = 598 tons

Complement:
   132 - 172

Cost:
   £0.163 million / $0.651 million

Distribution of weights at normal displacement:
   Armament: 32 tons, 1.9 %
      - Guns: 32 tons, 1.9 %
   Armour: 1 tons, 0.0 %
      - Armament: 1 tons, 0.0 %
   Machinery: 246 tons, 14.4 %
   Hull, fittings & equipment: 628 tons, 36.7 %
   Fuel, ammunition & stores: 385 tons, 22.5 %
   Miscellaneous weights: 420 tons, 24.5 %
      - Hull below water: 90 tons
      - Hull above water: 170 tons
      - On freeboard deck: 130 tons
      - Above deck: 30 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     3,554 lbs / 1,612 Kg = 56.9 x 5.0 " / 127 mm shells or 1.3 torpedoes
   Stability (Unstable if below 1.00): 1.43
   Metacentric height 2.7 ft / 0.8 m
   Roll period: 11.2 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.05
   Seaboat quality  (Average = 1.00): 1.28

Hull form characteristics:
   Hull has raised forecastle,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.440 / 0.459
   Length to Beam Ratio: 7.73 : 1
   'Natural speed' for length: 18.44 kts
   Power going to wave formation at top speed: 47 %
   Trim (Max stability = 0, Max steadiness = 100): 55
   Bow angle (Positive = bow angles forward): 10.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   30.00 %,  14.00 ft / 4.27 m,  14.00 ft / 4.27 m
      - Forward deck:   30.00 %,  9.00 ft / 2.74 m,  9.00 ft / 2.74 m
      - Aft deck:   25.00 %,  9.00 ft / 2.74 m,  9.00 ft / 2.74 m
      - Quarter deck:   15.00 %,  9.00 ft / 2.74 m,  9.00 ft / 2.74 m
      - Average freeboard:      10.50 ft / 3.20 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 69.4 %
      - Above water (accommodation/working, high = better): 122.9 %
   Waterplane Area: 9,466 Square feet or 879 Square metres
   Displacement factor (Displacement / loading): 172 %
   Structure weight / hull surface area: 51 lbs/sq ft or 250 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.99
      - Longitudinal: 1.07
      - Overall: 1.00
   Excellent machinery, storage, compartmentation space
   Excellent accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform
   Good seaboat, rides out heavy weather easily

5t - 1908 Fire Control
25t - LR Wireless
20t - Observation Balloon
10t - Minesweeping Gear
120t - 4 x 15t Boats
240t - Supplies/Marines

[TacCovert4]

I'd chop the gun shields.  3mm of plating would just cause more splinters to come flying at the gunner.....if it was hit with rifle rounds.  I wouldn't hold much confidence that 3mm of steel could stop pistol rounds at combat ranges.  Might as well have the mounts wholly open and save the weight.

[Desertfox]

Oh it's not so much armor as weather shielding, in reality I was feeling lazy and didn't feel like drawing a 5" gun without a shield.

[Desertfox]

Potential upgrade of the Tenryus. Adds bigger torpedoes, 2" Gatlings, and MTB capability, does lose its observation balloon capability.

Improved Tenryu, Japan Littoral Combattant  laid down 1917

Displacement:
   1,397 t light; 1,459 t standard; 1,741 t normal; 1,967 t full load

Dimensions: Length (overall / waterline) x beam x draught (normal/deep)
   (342.64 ft / 340.00 ft) x 42.00 ft x (9.70 / 10.57 ft)
   (104.44 m / 103.63 m) x 12.80 m  x (2.96 / 3.22 m)

Armament:
      5 - 5.00" / 127 mm 45.0 cal guns - 63.03lbs / 28.59kg shells, 140 per gun
     Quick firing guns in deck and hoist mounts, 1917 Model
     3 x Single mounts on centreline ends, majority aft
      1 raised mount aft - superfiring
     2 x Single mounts on sides amidships
      6 - 2.00" / 50.8 mm 45.0 cal guns - 4.03lbs / 1.83kg shells, 200 per gun
     Quick firing guns in deck mounts, 1917 Model
     2 x Triple mounts on sides amidships
      Weight of broadside 339 lbs / 154 kg

Armour:
   - Gun armour:   Face (max)   Other gunhouse (avg)   Barbette/hoist (max)
   Main:   1.00" / 25 mm         -         1.00" / 25 mm

Machinery:
   Oil fired boilers, steam turbines,
   Direct drive, 2 shafts, 11,328 shp / 8,451 Kw = 24.00 kts
   Range 5,900nm at 14.00 kts
   Bunker at max displacement = 508 tons

Complement:
   134 - 175

Cost:
   £0.252 million / $1.007 million

Distribution of weights at normal displacement:
   Armament: 89 tons, 5.1 %
      - Guns: 89 tons, 5.1 %
   Armour: 13 tons, 0.8 %
      - Armament: 13 tons, 0.8 %
   Machinery: 415 tons, 23.8 %
   Hull, fittings & equipment: 624 tons, 35.9 %
   Fuel, ammunition & stores: 344 tons, 19.8 %
   Miscellaneous weights: 255 tons, 14.6 %
      - Hull above water: 200 tons
      - On freeboard deck: 20 tons
      - Above deck: 35 tons

Overall survivability and seakeeping ability:
   Survivability (Non-critical penetrating hits needed to sink ship):
     1,741 lbs / 790 Kg = 27.9 x 5.0 " / 127 mm shells or 0.7 torpedoes
   Stability (Unstable if below 1.00): 1.19
   Metacentric height 1.9 ft / 0.6 m
   Roll period: 12.9 seconds
   Steadiness   - As gun platform (Average = 50 %): 70 %
         - Recoil effect (Restricted arc if above 1.00): 0.24
   Seaboat quality  (Average = 1.00): 1.02

Hull form characteristics:
   Hull has raised forecastle,
     a normal bow and a cruiser stern
   Block coefficient (normal/deep): 0.440 / 0.456
   Length to Beam Ratio: 8.10 : 1
   'Natural speed' for length: 18.44 kts
   Power going to wave formation at top speed: 54 %
   Trim (Max stability = 0, Max steadiness = 100): 69
   Bow angle (Positive = bow angles forward): 10.00 degrees
   Stern overhang: 0.00 ft / 0.00 m
   Freeboard (% = length of deck as a percentage of waterline length):
            Fore end,    Aft end
      - Forecastle:   37.00 %,  15.00 ft / 4.57 m,  15.00 ft / 4.57 m
      - Forward deck:   30.00 %,  9.00 ft / 2.74 m,  9.00 ft / 2.74 m
      - Aft deck:   18.00 %,  9.00 ft / 2.74 m,  9.00 ft / 2.74 m
      - Quarter deck:   15.00 %,  9.00 ft / 2.74 m,  9.00 ft / 2.74 m
      - Average freeboard:      11.22 ft / 3.42 m
   Ship tends to be wet forward

Ship space, strength and comments:
   Space   - Hull below water (magazines/engines, low = better): 106.7 %
      - Above water (accommodation/working, high = better): 115.6 %
   Waterplane Area: 9,036 Square feet or 839 Square metres
   Displacement factor (Displacement / loading): 125 %
   Structure weight / hull surface area: 53 lbs/sq ft or 259 Kg/sq metre
   Hull strength (Relative):
      - Cross-sectional: 0.87
      - Longitudinal: 1.16
      - Overall: 0.90
   Adequate machinery, storage, compartmentation space
   Adequate accommodation and workspace room
   Ship has slow, easy roll, a good, steady gun platform

10t - 1908 Fire Control
25t - LR Wireless
20t - 6 x 21" Torpedo Tubes
80t - 2 x 20t MTBs
120t - Mines/Supplies/Marines

[eltf177]

Just out of curiosity where is the original Tenryu design?