WesWorld

Quoted

I hope we're not in danger of overcomplicating simming these ships though with considerations about ballast and wet and dry sims etc.

Well, the one thing you have to remember is that the actual speed and range are higher than you sim. That is also a 'problem' I encountered with submarines in SS where I originally thought "It must have that speed" only to realize years later "Hey! We sim the sub 'in awash condition, just about to go under' meaning in reality the submarine will be higher in the water with the ballast tanks empty thus speed and range are a bit higher than is simmed".

When something like an LSD is underway, the well deck is empty and so are the ballast tanks, so for the actual speed and range you need to resim the ship but then lying higher in the water to get the correct speed for the given amount of power and the correct range for the given amount of bunkerage.

Quoted

I've always assumed the boats on the boat were paid for as misc weight allowances for such craft in the report. I think there was an agreement to that effect somewhere at some time.

Yes. While I could not find the original mentioning of that agreement, I did see Hooman mention it in a thread discussing the LST rule. To me it only makes sense.



Below a test of the USS Ashland. There are two sims: one empty and one that takes the water in the well deck and in the ballast tanks into account. I actually went from the empty one to the loaded one which was kinda of a mistake as I just kept making changes over and over and over and over again altering the draught and freeboard values. The best way is probably to do it the other way around. The empty sim is purely there to calculate the amount of power needed for 17 knots and the amount of bunkerage for 8000nm at 15 knots. Ideally I would think that the empty displacements for both sims should be the same but I got tired of working on it so it is not perfect...


USS Ashland (empty), USN LSD laid down 1942

Displacement:
5,938 t light; 6,111 t standard; 6,806 t normal; 7,362 t full load

Dimensions: Length overall / water x beam x draught
457.97 ft / 453.33 ft x 72.18 ft x 14.56 ft (normal load)
139.59 m / 138.18 m x 22.00 m x 4.44 m

Armament:
1 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1942 Model
Dual purpose gun in a deck mount with hoist
on centreline forward, 1 raised gun
8 - 1.57" / 40.0 mm guns (2x4 guns), 1.95lbs / 0.89kg shells, 1942 Model
Anti-aircraft guns in deck mounts
on side, all aft, all raised mounts - superfiring
4 - 1.57" / 40.0 mm guns (2x2 guns), 1.95lbs / 0.89kg shells, 1942 Model
Anti-aircraft guns in deck mounts
on side, all forward, all raised mounts - superfiring
16 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1942 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 90 lbs / 41 kg
Shells per gun, main battery: 600

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 6,216 shp / 4,637 Kw = 17.00 kts
Range 8,000nm at 15.00 kts
Bunker at max displacement = 1,252 tons

Complement:
374 - 487

Cost:
£1.527 million / $6.109 million

Distribution of weights at normal displacement:
Armament: 11 tons, 0.2%
Machinery: 162 tons, 2.4%
Hull, fittings & equipment: 2,614 tons, 38.4%
Fuel, ammunition & stores: 868 tons, 12.8%
Miscellaneous weights: 3,150 tons, 46.3%

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
19,111 lbs / 8,669 Kg = 305.8 x 5.0 " / 127 mm shells or 3.1 torpedoes
Stability (Unstable if below 1.00): 1.13
Metacentric height 3.9 ft / 1.2 m
Roll period: 15.4 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.02
Seaboat quality (Average = 1.00): 2.00

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.500
Length to Beam Ratio: 6.28 : 1
'Natural speed' for length: 25.30 kts
Power going to wave formation at top speed: 34 %
Trim (Max stability = 0, Max steadiness = 100): 35
Bow angle (Positive = bow angles forward): 8.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 32.99 ft / 10.06 m
- Forecastle (20%): 23.22 ft / 7.08 m
- Mid (50%): 23.22 ft / 7.08 m
- Quarterdeck (15%): 23.22 ft / 7.08 m
- Stern: 23.22 ft / 7.08 m
- Average freeboard: 24.00 ft / 7.32 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 60.7%
- Above water (accommodation/working, high = better): 268.1%
Waterplane Area: 22,672 Square feet or 2,106 Square metres
Displacement factor (Displacement / loading): 191%
Structure weight / hull surface area: 81 lbs/sq ft or 397 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.91
- Longitudinal: 2.36
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather



USS Ashland (loaded), USN LSD laid down 1942

Displacement:
5,985 t light; 6,222 t standard; 10,019 t normal; 13,056 t full load

Dimensions: Length overall / water x beam x draught
457.97 ft / 454.15 ft x 72.18 ft x 21.39 ft (normal load)
139.59 m / 138.42 m x 22.00 m x 6.52 m

Armament:
1 - 5.00" / 127 mm guns in single mounts, 62.50lbs / 28.35kg shells, 1942 Model
Dual purpose gun in a deck mount with hoist
on centreline forward, 1 raised gun
8 - 1.57" / 40.0 mm guns (2x4 guns), 1.95lbs / 0.89kg shells, 1942 Model
Anti-aircraft guns in deck mounts
on side, all aft, all raised mounts - superfiring
4 - 1.57" / 40.0 mm guns (2x2 guns), 1.95lbs / 0.89kg shells, 1942 Model
Anti-aircraft guns in deck mounts
on side, all forward, all raised mounts - superfiring
16 - 0.79" / 20.0 mm guns in single mounts, 0.24lbs / 0.11kg shells, 1942 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 90 lbs / 41 kg
Shells per gun, main battery: 600

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 6,216 shp / 4,637 Kw = 16.04 kts
Range 37,315nm at 15.00 kts
Bunker at max displacement = 6,835 tons

Complement:
499 - 650

Cost:
£1.538 million / $6.151 million

Distribution of weights at normal displacement:
Armament: 11 tons, 0.1%
Machinery: 162 tons, 1.6%
Hull, fittings & equipment: 2,661 tons, 26.6%
Fuel, ammunition & stores: 4,034 tons, 40.3%
Miscellaneous weights: 3,150 tons, 31.4%

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
27,612 lbs / 12,525 Kg = 441.8 x 5.0 " / 127 mm shells or 4.8 torpedoes
Stability (Unstable if below 1.00): 1.27
Metacentric height 4.7 ft / 1.4 m
Roll period: 14.0 seconds
Steadiness - As gun platform (Average = 50 %): 70 %
- Recoil effect (Restricted arc if above 1.00): 0.01
Seaboat quality (Average = 1.00): 2.00

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.500
Length to Beam Ratio: 6.29 : 1
'Natural speed' for length: 25.32 kts
Power going to wave formation at top speed: 33 %
Trim (Max stability = 0, Max steadiness = 100): 35
Bow angle (Positive = bow angles forward): 8.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 27.16 ft / 8.28 m
- Forecastle (20%): 16.39 ft / 4.99 m
- Mid (50%): 16.39 ft / 4.99 m
- Quarterdeck (15%): 16.39 ft / 4.99 m
- Stern: 16.39 ft / 4.99 m
- Average freeboard: 17.25 ft / 5.26 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 41.9%
- Above water (accommodation/working, high = better): 142.1%
Waterplane Area: 22,713 Square feet or 2,110 Square metres
Displacement factor (Displacement / loading): 281%
Structure weight / hull surface area: 84 lbs/sq ft or 408 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.94
- Longitudinal: 1.63
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather

Actual range: 8000nm @ 15 knots (empty well deck and ballast tanks)
Actual bunker at max displacement 1252 tons
Actual speed 17 knots (empty well deck and ballast tanks)

Well deck = 101.8x13.41m Forward part 16.87 meters from 13.41m wide to minimum of 7.32m. Depth max 2 meters.

Well deck volume 3080 cubic meters (= 3080 tons)
Water in ballast tanks = 2503 tons

I am with Hood on this matter. For better or worse a methodology was agreed upon by the player-base on how such ships might be simmed; it has two options. Is it perfect? No. But I see no reason for anyone to have to resim a vessel that has been built or to abandon the methodology agreed upon. We are not naval architects, and we are getting ourselves too wrapped around technical wheels to the detriment of the game.

Quoted from "Rooijen10"

Quoted

I've always assumed the boats on the boat were paid for as misc weight allowances for such craft in the report. I think there was an agreement to that effect somewhere at some time.

Yes. While I could not find the original mentioning of that agreement, I did see Hooman mention it in a thread discussing the LST rule. To me it only makes sense.

You don't pay for the embarked boats if you pay 100% displacement for a design, but if it's a mercantile conversion, then you pay separately for any landing craft included.

I-402 Japanese Submarine
Date: 1946
Type: Oceanic
Length: 125.00m
Beam: 13.00m
Draft: 10.10m
Crush depth: 317.5m
Light Displacement 5098t
Loaded Displacement 7662t
Full Displacement 8206t
wt fuel&batts: 3750t
Reserve buoyancy: 7%
Armament:
- 8 x 533mm (bow)
- 3x3 + 4x2 25mm MGs (1 from sim, 16 from misc weights)
- 64 tons for mines or reload torpedoes
ElecHP: 22800hp
DieselHP: 11000hp
Speed:
- Max Surf Speed: 16.0 knots
- Max Sub Speed: 19.9 knots
Range:
- Surfaced: 32,395nm@12 knots
- Submerged: 566nm@5 knots
Tons Oil: 2500.0t
Tons Battery: 1250.0t
Miscellaneous Weight: 600 tons
Crew: 162

- 38 Type 3 torpedoes (= 8 in the tubes + 32 from the 64 tons for 'mines or reload torpedoes', 16 in the upper room and 16 in the lower room), 4 idle positions to permit withdrawal of torpedoes from tubes for servicing (8 tons miscellaneous).
- Diesel-electric drive.
- Main electric engines output: 22,000 shp.
- Silent running engines output: 800 shp.
- Surface speed: (diesel-electric) 16.0 knots, (battery-electric) 20.3 knots.
- Submerged speed: (silent running engines) 6.5 knots, (battery-electric) 19.6 knots, (diesel-electric + Ninjatousaya) 9.9 knots.
- Range Surfaced (diesel-Electric): 57,591nm@9 knots, 46,649nm@10 knots, 32,395nm@12 knots, 20,733nm@15 knots.
- Range Submerged (batteries, silent running engines): 1,613nm@3 knots, 566nm@5 knots, 323nm@6.5 knots.
- Range Submerged (batteries, main engines): 201nm@8 knots, 116nm@10 knots, 34nm@15 knots.
- Range Submerged (diesel-electric + Ninjatousaya): 57,100nm@6 knots, 32,020nm@8 knots, 20,300@10 knots
- Endurance: (surfaced) 194 days and 9 hour @ 10 knots, (submerged, batteries) 4 days and 17 hours @ 5 knots
- Diving depth: 417 feet
- Emergency Depth: 667 feet
- Crush Depth: 1042 feet


- 600 tons Miscellaneous weights breakdown:
--- 75 tons for 3 aircraft or 10 MXY7B
--- 20 tons for catapult and crane
--- 10 tons for rocket launch rail fitted over the catapult.
--- 30 tons for electric torpedo reloading system
--- 5 tons for torpedo service material
--- 16 ton for 16 extra 25mm machineguns
--- 10 tons for Ninjatousaya System
--- 80 tons for 2x sonar, hydrophones, air search radar, air/surface radar and radar warning receiver
--- 60 tons for defense countermeasures and 'camouflage'
--- 51 tons for air condition system
--- 10 tons for 200 oxygen bottles (50 l, 150 atm).
--- 10 tons for CO2 removal system + Soda lime
--- 51 tons for damage control and fire suppression systems
--- 20 tons for demagnetization cables
--- 15 tons for safety and rescue equipment
--- 15 tons for yatai mobile food stall (well, mobile since the sub moves around)
--- 20 tons for pachinko parlor
--- 15 tons for karaoke facilities + Kobe Cola vending machines
--- 20 tons for officer's lounge
--- 10 tons for deep freeze unit
--- 8 tons for 4 idle torpedo positions in the torpedo rooms (2 upper, 2 lower) for torpedo servicing
--- 30 tons for secondary CT starboard to counter the underwater drag effects of the main CT offset to port
--- 5 tons for desalinization gear
--- 14 tons for various

I-402's new motto: "Continuing Japanese excellence in excessively overindulgent engineering."

You forgot to add "and useless extras"

Nope, I covered that with "Overindulgent". :P

How many days is one of these boats expected to remain at sea?

*Checks ranges*
Don't you mean months?

When patrolling at 9 knots, it could go for 266 days with the available diesel fuel, more when varying it with the rechargeable battery power. It is all mission dependent I would say. While it is based on the I-400 design, it has less fuel range than that submarine due to the more powerful electric engines and the space required for the batteries. I-400 range was 37,500nm @ 14 knots while this one's range is 32,395 @ 12 knots, so less range for a lower speed.

Quoted from "Rooijen10"

*Checks ranges*
Don't you mean months? :D

No, I mean days. :rolleyes:

While we all know that Japanese submariners can live on fish-heads and rice they can't live without drinking water.

Allowing for 1 kg of rations per man per day and 4 liters of water per man per day your submarine's crew will consume at least 810 kg of food and water per day; and those would be close to starvation rations. I did not note any desalinization gear aboard the boat, so I'm wondering where you've stowed nine months worth of food and water - which would amount to more than 200 tons.

Quoted

I did not note any desalinization gear aboard the boat

Did they have them aboard submarines in the mid/late 1940s? Cause if they did, I could assign some of the miscellaneous weights to add something like that to the submarine. Even if they did not, did desalinization gear exist around that time and if it did was it compact enough to fit into a fairly large submarine like that?

Quoted

so I'm wondering where you've stowed nine months worth of food and water - which would amount to more than 200 tons.

Stowed as simmed? I think that the bit regarding the Balao here could apply to that range:

Quoted

Patrol endurance: 75 days. (Or when torpedoes or food ran out.)

Still, I think that food and water could be gotten from Japanese ships around the world. A small supply vessel like those of the Kinesaki class could do that as no fuel would be needed to be pumped aboard. Also it could easily resupply at a remote Pacific station where there is plenty of food and water but a limited/non-existing supply of fuel.

The endurance using the simmed range would give you ~112 days which is a little bit more than the ~111 days of the historical I-400. The I-402 has more crew than the I-400 but it is slightly bigger thus can hold more stores than the I-400. In the end it is not that difficult to add miscellaneous weights for stores (which I'll probably do), but I would have to take a look with SS to indicate how much stores would be in the sub in the first place.

Throwing the dimensions of the sub into SS and alter the BC so it matches Subsim's loaded displacement, I get 153 tons for stores. So when looking at your numbers and keeping a simple 1 ton of food and water per day for the crew (= 6.27 kg of food and water per person per day which should probably be okay for a Japanese-sized person), there would be enough food for 153 days on the submarine based on the SS data. So for 270 days I would need an additional 117 tons of stores for the crew (based on the 1 ton per day). Shouldn't be too hard, though I am not sure as to how high I should keep the reserve buoyancy...

The answer to your question is here

I had not realized the necessity of topping up the cooling system for the diesel engines or the batteries.

We do often take habitability for granted; Japan historically never bothered with it.

Thanks for that link.

So based on the typical war patrol consumption given on wiki ("hotel services"? Really??), for 266 days a total of 4,027,240 liters of water would be needed which is almost 4,000 tons.

Desalinization gear is definitely useful to have on a sub like this then. Also, looking at the photo of the vapor-compression distiller aboard the USS Pampanito, it isn't that big either so 5 tons could be enough for a pair + all the plumbing for getting water to and from those distillers.

Quoted

We do often take habitability for granted; Japan historically never bothered with it.

Yes I read about that on the I-400 page:

Quoted

Like other Japanese submarines, crew members in Japanese subs had no air conditioning to control temperatures in tropic waters and no flush toilets. Lack of cold storage and inadequate sleeping quarters greatly limited the crew's diet and forced some of the crew to sleep on the decks or in passageways.

Interesting stuff.
Threads like these do turn up interesting gems. I'd never even thought about this factor before (at least not as additional to whatever SS calculates is necessary).

Quoted from "Hood"

Interesting stuff.
Threads like these do turn up interesting gems. I'd never even thought about this factor before (at least not as additional to whatever SS calculates is necessary).

I am certain that Springsharp, and Subsim, have some level of provision for habitability and stores; however, the I-400 design presented is so unusual, and with a very large crew, that I felt the question should be considered, particularly if you are asking any crew to remain submerged for nine months.

Quoted

I am certain that Springsharp, and Subsim, have some level of provision for habitability and stores

I know SS does. If you just enter dimensions into Springstyle, the value for "Fuel, ammunition & stores" are for the stores alone. That is how I got to the 153 tons of stores mentioned above.

Not sure with subsim. When you add miscellaneous crew, it adds 15 tons per crew member which is a lot for a guy that is probably 70 kg or so. However it is added to both kerb and light weight and I do not think stores are included in the light weight so it seems more like internal structure added to accommodate the extra crew member. No idea how it works with stores.

Quoted

however, the I-400 design presented is so unusual, and with a very large crew

I-402 only has slightly more than the historical I-400 and is a little bit bigger than that submarine...

OTL I-400 (based on length and the wiki line drawing)
Length: 122 m
Beam: 11.14 m
Depth (deck to keel): 8.71 m
Crew: 144

I-402
Length: 125 m
Beam: 13 m
Depth (deck to keel): 10.1 m
Crew: 162
Crew according to Spring Sharp: 409-532 (corrected to 205 according to springstyle notes)


With the bit about subs in the springstyle notes ("Specify crew as about half the listed minimum"), that means that the 153 tons of stores SS gave me for a I-402 sized hull and that is originally calculated for a crew of 409-532 is, after correcting the SS crew value, now for a crew of 205. So that is already double the endurance (when it comes to supplies) compared to a surface vessel with the same baseline crew as the sub. Unfortunately SS does not indicate how long those stores would last.

Quoted

particularly if you are asking any crew to remain submerged for nine months.

That is actually a wrong assumption there Bruce. That 266 days was based on the 57,591nm@9 knots surface range. The crew does not remain submerged for 9 months. Remaining submerged the whole time, the endurance at 9 knots would be about 118 days. If the sub wants to remain submerged for ~57,000nm, it would have to travel at about 6 knots and then it would take them more than 396 days to cover that distance.

Made a small change to add extra stores for long range patrols. For this size hull, SS gives me 165 tons for the stores. Adding the 150 tons of the miscellaneous weights that would be a total of 315 tons for stores aboard this submarine. I feel more comfortable now to send a sub like this around the world.


I-402 Japanese Submarine
Date: 1946
Type: Oceanic
Length: 130.00m
Beam: 13.50m
Draft: 10.48m
Crush depth: 317.5m
Light Displacement 5493t
Loaded Displacement 8257t
Full Displacement 9196t
wt fuel&batts: 4050t
Reserve buoyancy: 10%
Armament:
- 8 x 533mm (bow)
- 3x3 + 4x2 25mm MGs (1 from sim, 16 from misc weights)
- 64 tons for mines or reload torpedoes
ElecHP: 24800hp
DieselHP: 12000hp
Speed:
- Max Surf Speed: 16.1 knots
- Max Sub Speed: 19.9 knots
Range:
- Surfaced: 32,469nm@12 knots
- Submerged: 567nm@5 knots
Tons Oil: 2700.0t
Tons Battery: 1350.0t
Miscellaneous Weight: 800 tons
Crew: 164

13709

- 38 Type 3 torpedoes (= 8 in the tubes + 32 from the 64 tons for 'mines or reload torpedoes', 16 in the upper room and 16 in the lower room), 4 idle positions to permit withdrawal of torpedoes from tubes for servicing (8 tons miscellaneous).
- Diesel-electric drive.
- Main electric engines output: 24,000 shp.
- Silent running engines output: 800 shp.
- Surface speed: (diesel-electric) 16.1 knots, (battery-electric) 20.6 knots.
- Submerged speed: (silent running engines) 6.3 knots, (battery-electric) 19.7 knots, (diesel-electric + Ninjatousaya) 9.9 knots.
- Range Surfaced (diesel-Electric): 57,723nm@9 knots, 46,756nm@10 knots, 32,469nm@12 knots, 20,780nm@15 knots.
- Range Submerged (batteries, silent running engines): 1,615nm@3 knots, 567nm@5 knots, 346nm@6.3 knots.
- Range Submerged (batteries, main engines): 202nm@8 knots, 116nm@10 knots, 34nm@15 knots.
- Range Submerged (diesel-electric + Ninjatousaya): 57,150nm@6 knots, 32,080nm@8 knots, 20,350@10 knots
- Endurance: (surfaced) 194 days and 19 hour @ 10 knots, (submerged, batteries) 4 days and 17 hours @ 5 knots
- Diving depth: 417 feet
- Emergency Depth: 667 feet
- Crush Depth: 1042 feet


- 800 tons Miscellaneous weights breakdown:
--- 30 tons for secondary CT starboard to counter the underwater drag effects of the main CT offset to port
--- 75 tons for 3 aircraft or 10 MXY7B
--- 20 tons for catapult and crane
--- 10 tons for rocket launch rail fitted over the catapult.
--- 30 tons for electric torpedo reloading system
--- 5 tons for torpedo service material
--- 8 tons for 4 idle torpedo positions in the torpedo rooms (2 upper, 2 lower) for torpedo servicing
--- 16 ton for 16 extra 25mm machineguns
--- 10 tons for Ninjatousaya System
--- 80 tons for 2x sonar, hydrophones, air search radar, air/surface radar and radar warning receiver
--- 70 tons for defense countermeasures and 'camouflage'
--- 55 tons for air condition system
--- 10 tons for 200 oxygen bottles (50 l, 150 atm).
--- 10 tons for CO2 removal system + Soda lime
--- 55 tons for damage control and fire suppression systems
--- 20 tons for demagnetization cables
--- 15 tons for safety and rescue equipment
--- 15 tons for yatai mobile food stall (well, mobile since the sub moves around)
--- 20 tons for pachinko parlor
--- 15 tons for karaoke facilities + Kobe Cola vending machines
--- 20 tons for officer's lounge
--- 10 tons for deep freeze unit
--- 5 tons for desalinization gear
--- 150 tons for extra stores for long range patrols
--- 35 tons for crew comforts (toilets, showers, board games, puzzles, playing cards, dice games, etc.)
--- 11 tons for various

Current CAV version after having made numerous changes since I posted the previous one. I'll just post it due to the lack of activity these last few days.

CAV-1 Coast Assault Vessel, Japan Landing Ship Dock laid down 1947

Displacement:
20,585 t light; 21,448 t standard; 35,802 t normal; 47,285 t full load

Dimensions: Length overall / water x beam x draught
722.78 ft / 700.00 ft x 108.00 ft x 25.50 ft (normal load)
220.30 m / 213.36 m x 32.92 m x 7.77 m

Armament:
8 - 2.95" / 75.0 mm guns (4x2 guns), 12.00lbs / 5.44kg shells, 1947 Model
Automatic rapid fire guns in deck mounts with hoists
on side, evenly spread, all raised mounts
Aft Main mounts separated by engine room
24 - 1.57" / 40.0 mm guns (4x6 guns), 2.00lbs / 0.91kg shells, 1947 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
16 - 0.98" / 25.0 mm guns (4x4 guns), 0.57lbs / 0.26kg shells, 1947 Model
Anti-aircraft guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 153 lbs / 69 kg
Shells per gun, main battery: 1,380

Armour:
- Gun armour: Face (max) Other gunhouse (avg) Barbette/hoist (max)
Main: 1.00" / 25 mm - 1.00" / 25 mm
2nd: 1.00" / 25 mm - -
3rd: 1.00" / 25 mm - -

Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 20,524 shp / 15,311 Kw = 18.00 kts
Range 65,000nm at 15.00 kts
Bunker at max displacement = 25,836 tons

Complement:
1,300 - 1,691

Cost:
£5.892 million / $23.568 million

Distribution of weights at normal displacement:
Armament: 22 tons, 0.1 %
Armour: 16 tons, 0.0 %
- Belts: 0 tons, 0.0 %
- Torpedo bulkhead: 0 tons, 0.0 %
- Armament: 16 tons, 0.0 %
- Armour Deck: 0 tons, 0.0 %
- Conning Tower: 0 tons, 0.0 %
Machinery: 507 tons, 1.4 %
Hull, fittings & equipment: 9,739 tons, 27.2 %
Fuel, ammunition & stores: 15,218 tons, 42.5 %
Miscellaneous weights: 10,300 tons, 28.8 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
123,232 lbs / 55,897 Kg = 9,573.5 x 3.0 " / 75 mm shells or 10.0 torpedoes
Stability (Unstable if below 1.00): 1.26
Metacentric height 8.5 ft / 2.6 m
Roll period: 15.6 seconds
Steadiness - As gun platform (Average = 50 %): 100 %
- Recoil effect (Restricted arc if above 1.00): 0.01
Seaboat quality (Average = 1.00): 1.82

Hull form characteristics:
Hull has low quarterdeck
and transom stern
Block coefficient: 0.650
Length to Beam Ratio: 6.48 : 1
'Natural speed' for length: 30.79 kts
Power going to wave formation at top speed: 31 %
Trim (Max stability = 0, Max steadiness = 100): 55
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 2.00 ft / 0.61 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 36.00 ft / 10.97 m
- Forecastle (20 %): 28.00 ft / 8.53 m
- Mid (50 %): 28.00 ft / 8.53 m
- Quarterdeck (40 %): 17.00 ft / 5.18 m (28.00 ft / 8.53 m before break)
- Stern: 17.00 ft / 5.18 m
- Average freeboard: 24.24 ft / 7.39 m

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 38.1 %
- Above water (accommodation/working, high = better): 247.9 %
Waterplane Area: 60,421 Square feet or 5,613 Square metres
Displacement factor (Displacement / loading): 311 %
Structure weight / hull surface area: 125 lbs/sq ft or 613 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.98
- Longitudinal: 1.17
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is excellent
Ship has slow, easy roll, a good, steady gun platform
Excellent seaboat, comfortable, can fire her guns in the heaviest weather



Actual shells per gun (total magazine weight 148 tons)
75mm = 1500 = 80 tons
40mm = 2000 = 53 tons
25mm = 3000 = 15 tons

Actual range with empty well deck and ballast tanks = 10000nm@15
Actual speed with empty well deck and ballast tanks = 18.85 knots
Actual max bunker for ship's fuel = 3,761 tons
Actual normal draught with empty well deck and ballast tanks = 17.59 feet
Actual max draught with empty well deck and ballast tanks = 19.43 feet
Max draught with fully flooded well deck and filled ballast tanks = 33.68 feet
Normal displacement with empty well deck and ballast tanks: 25,613 tons
Normal displacement with fully flooded well deck and ballast tanks: 44,691 tons
Height of the well deck bottom above waterline with empty well deck and ballast tanks (at normal displacement): 6.25 feet
Height of the well deck bottom above waterline with empty well deck and ballast tanks (at full load displacement): 4.41 feet
Depth of well deck with fully flooded well deck and ballast tanks (at standard displacement): 5.68 feet
Depth of well deck with fully flooded well deck and ballast tanks (at normal displacement): 7.99 feet

- 10200 tons for water in 170x20x3m well deck (simmed as part of bunker) 557.74x65.62x9.84ft
- 9800 tons for water in the ballast tanks (simmed as part of bunker)
- 90 tons for 10x6x1.5m swimming pool (simmed as part of bunker)
- 1200 tons for extra fresh water (simmed as part of bunker)
- 785 tons for extra gasoline (simmed as part of bunker)

10300t
- 50 tons for two catapults (forecastle).
- 20 tons for 2 cranes.
- 300 tons for 12 Aichi E16A or Aichi M6A floatplanes.
- 300 tons for flying boat platform over quarterdeck.
- 20 tons fo 1 large crane.
- 100 tons for 2 Kawanishi H8K flying boats (usually H8K2-L).
- 48 tons for aircraft spare parts.
- 50 tons for aircraft repair shop.
- 200 tons for vehicle/small boat repair shop + crane.
- 150 tons for vehicle, tank, and landing craft spares.
- 2400 tons for 1200 Troops.
- 1584 tons for 8x Heavy Landing Craft (dock).
- 133 tons for 14x Daihatsu (dock).
- 140 tons for 8x Toku-Daihatsu (dock).
- 100 tons for Shohatsu launch deck + cranes (on quarterdeck, underneath flying boat platform, above aft part of the well deck).
- 75 tons for 20x Shohatsu landing craft.
- 600 tons for 15 tanks @40 tons.
- 400 tons for 40 vehicles @10 tons.
- 60 tons for two sets of high-capacity pumps (to flood or drain well deck).
- 100 tons for radar, sonar and electronics.
- 210 tons for damage control and fire suppression systems.
- 55 tons for emergency diesel generators.
- 210 tons for air condition system.
- 145 tons for degaussing coils.
- 1000 tons for combat-loaded supplies.
- 40 tons for 75mm loading, training and elevation systems.
- 8 tons for 40mm loading, training and elevation systems.
- 6 tons for 25mm loading, training and elevation systems.
- 100 tons for command center.
- 75 tons for operations center.
- 75 tons for briefing room.
- 100 tons for fire control and fire control center.
- 525 tons for 150 medical personnel (3.5 tons per person).
- 350 tons for 100 patient beds (3.5 t per patient).
- 200 t for 2 operating rooms and triage center.
- 20 t for water purification system.
- 15 tons for yatai mobile food stall.
- 30 tons for pachinko parlor.
- 15 tons for karaoke facilities + Kobe Cola vending machines.
- 40 tons for officer's lounge.
- 10 tons for deep freeze unit.
- 50 tons for Onsen and Sauna.
- 30 tons for Shinto Shrine.
- 161 tons for various.

And also played around with the old 200 ton landing craft design for 1947...

HLC, Japan Landing Craft laid down 1947

Displacement:
198 t light; 204 t standard; 211 t normal; 216 t full load

Dimensions: Length overall / water x beam x draught
83.18 ft / 80.00 ft x 23.75 ft x 4.85 ft (normal load)
25.35 m / 24.38 m x 7.24 m x 1.48 m

Armament:
2 - 0.98" / 25.0 mm guns (1x2 guns), 0.48lbs / 0.22kg shells, 1947 Model
Anti-aircraft guns in deck mount
on centreline forward, all raised guns - superfiring
4 - 0.52" / 13.2 mm guns (2x2 guns), 0.07lbs / 0.03kg shells, 1947 Model
Machine guns in deck mounts
on side, all amidships, all raised mounts - superfiring
4 - 0.30" / 7.7 mm guns in single mounts, 0.01lbs / 0.01kg shells, 1947 Model
Breech loading guns in deck mounts
on side, evenly spread, all raised mounts
Weight of broadside 1 lbs / 1 kg
Shells per gun, main battery: 2,000

Machinery:
Diesel Internal combustion motors,
Geared drive, 2 shafts, 74 shp / 55 Kw = 8.00 kts
Range 2,000nm at 8.00 kts
Bunker at max displacement = 12 tons

Complement:
26 - 35

Cost:
£0.053 million / $0.213 million

Distribution of weights at normal displacement:
Armament: 0 tons, 0.1 %
Machinery: 2 tons, 0.9 %
Hull, fittings & equipment: 46 tons, 21.7 %
Fuel, ammunition & stores: 13 tons, 6.1 %
Miscellaneous weights: 150 tons, 71.2 %

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
261 lbs / 118 Kg = 547.4 x 1.0 " / 25 mm shells or 0.4 torpedoes
Stability (Unstable if below 1.00): 1.06
Metacentric height 0.6 ft / 0.2 m
Roll period: 12.4 seconds
Steadiness - As gun platform (Average = 50 %): 51 %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): 1.21

Hull form characteristics:
Hull has a flush deck
and transom stern
Block coefficient: 0.800
Length to Beam Ratio: 3.37 : 1
'Natural speed' for length: 10.93 kts
Power going to wave formation at top speed: 53 %
Trim (Max stability = 0, Max steadiness = 100): 42
Bow angle (Positive = bow angles forward): 30.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 5.50 ft / 1.68 m
- Forecastle (20 %): 4.20 ft / 1.28 m
- Mid (50 %): 4.20 ft / 1.28 m
- Quarterdeck (15 %): 4.20 ft / 1.28 m
- Stern: 4.20 ft / 1.28 m
- Average freeboard: 4.30 ft / 1.31 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 82.3 %
- Above water (accommodation/working, high = better): 53.4 %
Waterplane Area: 1,737 Square feet or 161 Square metres
Displacement factor (Displacement / loading): 136 %
Structure weight / hull surface area: 22 lbs/sq ft or 109 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 0.90
- Longitudinal: 2.41
- Overall: 1.00
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is cramped
Good seaboat, rides out heavy weather easily