WesWorld

I-300, Japan Submarine laid down 1940

Displacement:
1,069 t light; 1,099 t standard; 1,456 t normal; 1,742 t full load

Dimensions: Length overall / water x beam x draught
259.19 ft / 259.19 ft x 19.03 ft x 22.97 ft (normal load)
79.00 m / 79.00 m x 5.80 m x 7.00 m

Armament:
2 - 0.98" / 25.0 mm guns in single mounts, 0.57lbs / 0.26kg shells, 1940 Model
Breech loading guns in deck mounts
on centreline ends, evenly spread
Weight of broadside 1 lbs / 1 kg
Shells per gun, main battery: 1,500
4 - 21.0" / 533.4 mm submerged torpedo tubes (all forward)

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Ends: Unarmoured
Upper: 1.69" / 43 mm 180.45 ft / 55.00 m 19.69 ft / 6.00 m (see below)

Machinery:
Oil fired boilers, steam turbines,
Geared drive, 2 shafts, 4,673 shp / 3,486 Kw = 19.00 kts
Range 10,000nm at 14.00 kts
Bunker at max displacement = 643 tons

Complement:
59 - 76

Cost:
£0.330 million / $1.320 million

Distribution of weights at normal displacement:
Armament: 0 tons, 0.0%
Armour: 242 tons, 16.6%
- Belts: 242 tons, 16.6%
- Torpedo bulkhead: 0 tons, 0.0%
- Armament: 0 tons, 0.0%
- Armour Deck: 0 tons, 0.0%
- Conning Tower: 0 tons, 0.0%
Machinery: 125 tons, 8.6%
Hull, fittings & equipment: 702 tons, 48.2%
Fuel, ammunition & stores: 387 tons, 26.6%
Miscellaneous weights: 0 tons, 0.0%

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,592 lbs / 722 Kg = 3,340.3 x 1.0 " / 25 mm shells or 1.2 torpedoes
Stability (Unstable if below 1.00): 1.00
Metacentric height 0.4 ft / 0.1 m
Roll period: 12.5 seconds
Steadiness - As gun platform (Average = 50 %): 0 %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): 0.00

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.450
Length to Beam Ratio: 13.62 : 1
'Natural speed' for length: 16.10 kts
Power going to wave formation at top speed: 40 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 0.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 0.00 ft / 0.00 m
- Forecastle (20%): 0.00 ft / 0.00 m
- Mid (50%): 0.00 ft / 0.00 m
- Quarterdeck (15%): 0.00 ft / 0.00 m
- Stern: 0.00 ft / 0.00 m
- Average freeboard: 0.00 ft / 0.00 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 44.9%
- Above water (accommodation/working, high = better): 0.0%
Waterplane Area: 3,146 Square feet or 292 Square metres
Displacement factor (Displacement / loading): 296%
Structure weight / hull surface area: 102 lbs/sq ft or 496 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 2.82
- Longitudinal: 3.22
- Overall: 2.86
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is extremely poor
Ship has quick, lively roll, not a steady gun platform
Caution: Lacks seaworthiness - very limited seakeeping ability

Upper belt used to sim ballast tank.
Speed (surface): 15.8 knots
Speed (submerged): 19 knots
Actual range (surface): 5,800nm at 14 knots
Range (submerged): 135nm at 3 knots
Diving depth: 286 feet
Test Depth (*): 358 feet
Emergency Depth: 458 feet
Crush Depth: 715 feet

Actual bunker size: 329 tons
10 Type 99 torpedoes: 18 tons (used bunker)
Ninjatousaya System: 10 tons (used bunker)
Increased Battery Capacity: 286 tons (used bunker)

(*) read: Limit of a crew member's life insurance.

Quoted

Originally posted by Rooijen10
I-300, Japan Submarine laid down 1940

Five years is just a wee bit early for this, don't you think?

Which was why I was initially a bit worried about posting it, but considering that the Italians already have 20 such subs already around (10 of them for about 8 sim years), I'm not worried about that.

http://wesworld.jk-clan.de/thread.php?postid=41779#post41779

Quoted

Originally posted by Rooijen10
Which was why I was initially a bit worried about posting it, but considering that the Italians already have 20 such subs already around (10 of them for about 8 sim years), I'm not worried about that.

http://wesworld.jk-clan.de/thread.php?postid=41779#post41779

In other words:
- You're pushing a design five years early "because someone else did it first".
- You're pushing a design five years early despite lacking the historical rationale for the historical design's adoption.
- You're trying to sim an electroboot in Springsharp and basing your submerged performance figures on... what, exactly?

I would strongly suggest that if you wish to push cutting edge submarine designs, you use Subsim rather than Springsharp as it can sim both submerged and surfaced performance.

In any case, the Aduas are hardly comparable; RA at least gave a rationale for his design theory, which you've not rebutted, nor did you provide your own for this design (other than "he started it").

Bzzz. Try again please.

I think concepts like this are why we have the Ship Design board, folks;

On one hand, While Subsim is being used by many players, it is technically /not/ the method required by the board rules, so I think criticising someone for not using it is unwarranted.

On the other, I do notice a couple of questionable elements to Walter's sim; The oil-fired boilers and steam turbines, for example, and how the stats are being derived.

I believe I've mentioned that before, but I'll repeat it again...

I would request that this design (and any other major designs, especially the 'innovative' ones) be posted in Ship Design for the kind of peer review and discussion the board was really founded around, rather than appended to industrial reports.

I've copied this over to the Ship Design folder for further discussion.

Quoted

Originally posted by ShinRa_Inc
I would request that this design (and any other major designs, especially the 'innovative' ones) be posted in Ship Design for the kind of peer review and discussion the board was really founded around, rather than appended to industrial reports.

Agreed.

I´m not a player but i follow Wesworld with interest, i feel that i have to put in a few thoughts.

I-300class is the The Sen Taka (submarine, high speed).

Quoted

The Sen Taka (submarine, high speed), in high bursts of speed, could run faster submerged than on the surface for up to an hour. The only World War II submarine comparable in underwater speed to the I-201 class was the German Type XXI "Elektro-boote" class. The I-201 class had streamlined all-welded hulls, high capacity 4,192 cell batteries and electric motors that provided almost twice the horsepower of their German-designed diesel engines. The I-201 class were fitted with snorkels to allow cruising submerged on their diesels and recharging of their batteries while underwater. They carried 25-mm guns in retractable mounts to maintain streamlining. Eight boats were laid down, but only three were completed before the end of the war. None saw operational use.

Doesn´t this submarine need the German Type XXI "Elektro-boote" class, and its predessors to be designed before it can be built.

The XXI class was designed as an answer to the allied destroyer escorts and frigates.

My 5 cents are since Wesworld havent had a battle of the atlantic nobody have had any reason to think of submarines with fast underwater speed. In WWI our timelane UK had the R class hunterkiller submarines but didn´t develop them further because they had no need for them. Germany chose a few WWI designs to develop their submarine fleet after 1933. But not until the battle of the atlantic begane to turn for them they started to develop submarines with high underwater speed.

In peacetime the development is much slower than in wartime when need goes before costs. In peacetime designers can come up with very innovative designs but they are killed by the costs.

Well my 5 cents bocome a whole dollar.

So no "Submarine No.71" type as a testbed first?

Quoted

Originally posted by thesmilingassassin
So no "Submarine No.71" type as a testbed first?

Not even the IJN started to continue develepment of the No.71 until they had a need for it.

Quoted

[From Wikipedia
By late 1942 it had become apparent to the IJN that conventional submarines were unable to survive the new ASW techniques coming into service, such as radar, HF/DF, sonar, and new depth charge projectors. New submarines were required, with a higher underwater than surface speed, quick-diving capability, quiet underwater running, and a high underwater operational radius.

My question is this has Wesworld IJN deleoped the Submarine No.71, and have they the need for a development, we havent seen the 1942 ASW weapons in large use yet. Often when brilliant new developments come they are killed or put on a shelf because of the cost to develop it. In peacetime it is more secure to use existant tecnology.

Quoted

Originally posted by Johan

Quoted

[From Wikipedia]
By late 1942 it had become apparent to the IJN that conventional submarines were unable to survive the new ASW techniques coming into service, such as radar, HF/DF, sonar, and new depth charge projectors. New submarines were required, with a higher underwater than surface speed, quick-diving capability, quiet underwater running, and a high underwater operational radius.

My question is this has Wesworld IJN deleoped the Submarine No.71, and have they the need for a development, we havent seen the 1942 ASW weapons in large use yet. Often when brilliant new developments come they are killed or put on a shelf because of the cost to develop it. In peacetime it is more secure to use existant tecnology.

No, Japan has not seen new-model ASW weapons in service - that's one of the reasons these submarines need to be challenged.

Bumped.

This design is still being challenged.

I do have a couple of concerns.

1. The Italian designs cited as justification are ordinary diesel-electric boats - they may have a high speed, but it appears to me to be obtained by what one might consider conventional means. As such, citing them as justification to adopt unorthodox methods of propulsions is not appropriate.

2. The current I-300 design would seem to have some sort of air independent propulsion system. I would like to see that defined. Are we talking a Walter-style turbine using hydrogen peroxide or are we talking something more exotic? If a Walter-style turbine, what was the chain of test and development? Is this an operational or a trials boat?

Regarding the "Oil fired boilers, steam turbines", I'm not sure what I was smoking (or perhaps it was the flu) when I entered the Engines tab... It should be the standard "Diesel Internal combustion engines plus batteries, Electric cruising motors plus geared drives".


Italian subs:
Antonio Sciesca (2203 tons), 150 tons batteries = 6.8%
Argonauta (535 tons), 44 tons batteries = 8.2%
Adua (396 tons), 160 tons batteries = 40.4%
Perla (423 tons), 45 tons batteries = 10.6%
T (1062 tons), 100 tons batteries = 9.4 %
U (1656 tons), 120 tons batteries = 7.2%

For comparison: Type XXI (~1870 tons), 236 tons batteries = 12.6% (note: normal displacement is a rough guess working with Spring Sharp, battery weight taken from german wiki page)

With battery weight at 40.4% of its normal displacement, the Adua really sticks out there among those submarines.

Adua has a "more streamlined hull", just like the XXI and the I-201.
Adua's submerged speed is 25% higher than its surfaced speed.
Submerged range is 757nm at 4 knots (with a little bit of calculation, that's about 487nm at 5 knots). Compare to the Type XXI (340nm at 5 knots) and the I-201 (135nm at 3 knots).
The way I see it, for its size the Adua is superior to both historical e-subs for their size as an underwater operating submarine, especially when you consider that with the Adua you're talking about a 1932 design while the XXI is a 1943 design and the I-201 a 1944 design.

Bruce, if you consider the Adua's to be ordinary diesel-electric boats, then you're saying that the XXI and the 201 were that as well. However, I don't see it that way. To me, all three designs are e-subs.

Brock, I really don't care what rationales are being given for the Adua's, that does not change the fact that those are operational e-subs 11 years before the Type XXI. If you want to challenge the I-300, fine. But then you should also have challenged the Adua's.


And then another thing. The Adua's SS file does not match the subsim file. It's a 1932 sub, but SS file indicated 1933, it's top speed is 16.1 knots, but SS indicates 12.8 knots and when dividing the normal displacement by 6, you have 66 tons for the ballast, leaving only 1 ton of miscellaneous weights for the Mililiter device, D3 sonar, 8 torpedoes and the additional weight of the batteries. While I'm not saying that what I am doing is the right thing, at least I try to use other SS aspects to simulate the extra weight of the torpedoes and various other additional things on a submarine and I try to twist SS so it gives a reasonable representation of a historical submarine design (which is not helped by the fact that it is 4 feet higher than it is wide) even if what I do does not match the Spring Style notes for the creation of submarines.

Quoted

So no "Submarine No.71" type as a testbed first?

The original idea was to use the I-300 class for that. Actually, each of the five subs would be focussing on one specific aspect which would be combined in a single slightly bigger sub in the mid 40s. Can't find the list I made. It was electric engines, batteries and pressure hull, but can't remember what the other two were.

Quoted

Originally posted by Rooijen10
Regarding the "Oil fired boilers, steam turbines", I'm not sure what I was smoking (or perhaps it was the flu) when I entered the Engines tab... It should be the standard "Diesel Internal combustion engines plus batteries, Electric cruising motors plus geared drives".

<snippage>

Bruce, if you consider the Adua's to be ordinary diesel-electric boats, then you're saying that the XXI and the 201 were that as well. However, I don't see it that way. To me, all three designs are e-subs.

<more snippage>

Your clarification speaks to a lot of concerns. If you are obtaining these speeds though conventional means - ie. diesels and batteries - it changes a lot of conceptions. I'd like to see an updated SS or subsim file indicating the change.

I use the term "ordinary diesel-electric" boat in the sense of a submarine powered by diesel engines with electric motors running off batteries. Not one powered by a steam turbine or other exotic AIP engine.

In that case the use of "ordinary" threw me off. With "ordinary diesel-electric" boat, I think of the normal standard diesel/electric powered subs that were around such as the Type VII, Type IX, Gato, I-121, etc. To me, it somehow does not seem right to label an e-sub as "ordinary".

Quoted

Not one powered by a steam turbine or other exotic AIP engine.

Like I mentioned, an error on my part. Feel free to punch me, cause I usually don't make a silly mistake like that with submarines.
I'm no expert so I did not know about the Me-style turbine... I mean Walter-style turbine until you mentioned it. Somehow that sounds like something that would required additional weights to be set aside for it in an SS-style sim.

Very well. <Thwack!>

I'm looking forward to seeing a corrected sim to evaluate on its own merits.

Quoted

Originally posted by Rooijen10
Italian subs:
Antonio Sciesca (2203 tons), 150 tons batteries = 6.8%
Argonauta (535 tons), 44 tons batteries = 8.2%
Adua (396 tons), 160 tons batteries = 40.4%
Perla (423 tons), 45 tons batteries = 10.6%
T (1062 tons), 100 tons batteries = 9.4 %
U (1656 tons), 120 tons batteries = 7.2%

With battery weight at 40.4% of its normal displacement, the Adua really sticks out there among those submarines.

For the sake of exactitude, 160 tons is the Adua's weight of fuel plus batteries, not just batteries. The actual figure for batteries alone is 140 tons, so the percentage is 35.4% (not that it disrupts your comparison much).

Quoted

Originally posted by Rooijen10
Brock, I really don't care what rationales are being given for the Adua's, that does not change the fact that those are operational e-subs 11 years before the Type XXI. If you want to challenge the I-300, fine. But then you should also have challenged the Adua's.

If I had been here and been a moderator at the time, then I could and likely would have challenged them; but I was not here nor was I a moderator then, and therefore could not do so. But, I notice, neither did YOU challenge the Adua design back in 2006 when it was introduced, though others did.

But I can help prevent that error from being repeated and perpetuated.

Quoted

The actual figure for batteries alone is 140 tons, so the percentage is 35.4% (not that it disrupts your comparison much).

Gah! Shows you that I need glasses. That or a long holiday break.
-_-;;

Quoted

But, I notice, neither did YOU challenge the Adua design back in 2006 when it was introduced, though others did.

Of course I did not challenge it! I need to think about the IJN's future. Shows you how long I have been plotting to build this submarine class!!
(more seriously, that was due to a lack of knowledge on my part so if you want to punch me for lacking the proper knowledge, feel free to do so)

Quoted

Very well. <Thwack!>

Ouch! That hurts!!! *sues Bruce*

Quoted

I'm looking forward to seeing a corrected sim to evaluate on its own merits.

Well, in SS, going from OFBSTGD propulsion to DICEBECMGD propulsion does not change anything for the sim. However, it did need a minor tweak as I cheated a little with the ballast tank due to stability (weight should really be 243 and not 242)
So you would get *digs through +100 Wesworld submarine files* this:

Sen Taka gata, Japan Submarine laid down 1940

Displacement:
1,069 t light; 1,099 t standard; 1,456 t normal; 1,742 t full load

Dimensions: Length overall / water x beam x draught
259.19 ft / 259.19 ft x 19.03 ft x 22.97 ft (normal load)
79.00 m / 79.00 m x 5.80 m x 7.00 m

Armament:
2 - 0.98" / 25.0 mm guns in single mounts, 0.57lbs / 0.26kg shells, 1940 Model
Breech loading guns in deck mounts
on centreline ends, evenly spread
Weight of broadside 1 lbs / 1 kg
Shells per gun, main battery: 1,500
4 - 21.0" / 533.4 mm submerged torpedo tubes

Armour:
- Belts: Width (max) Length (avg) Height (avg)
Ends: Unarmoured
Upper: 1.69" / 43 mm 181.10 ft / 55.20 m 19.69 ft / 6.00 m

Machinery:
Diesel Internal combustion engines plus batteries,
Electric cruising motors plus geared drives, 2 shafts, 4,582 shp / 3,418 Kw = 18.90 kts
Range 10,000nm at 14.00 kts
Bunker at max displacement = 643 tons

Complement:
117 - 153

Cost:
£0.328 million / $1.312 million

Distribution of weights at normal displacement:
Armament: 0 tons, 0.0%
Armour: 243 tons, 16.7%
- Belts: 243 tons, 16.7%
- Torpedo bulkhead: 0 tons, 0.0%
- Armament: 0 tons, 0.0%
- Armour Deck: 0 tons, 0.0%
- Conning Tower: 0 tons, 0.0%
Machinery: 123 tons, 8.4%
Hull, fittings & equipment: 704 tons, 48.3%
Fuel, ammunition & stores: 387 tons, 26.6%
Miscellaneous weights: 0 tons, 0.0%

Overall survivability and seakeeping ability:
Survivability (Non-critical penetrating hits needed to sink ship):
1,626 lbs / 738 Kg = 3,410.7 x 1.0 " / 25 mm shells or 1.3 torpedoes
Stability (Unstable if below 1.00): 1.00
Metacentric height 0.4 ft / 0.1 m
Roll period: 12.5 seconds
Steadiness - As gun platform (Average = 50 %): 0 %
- Recoil effect (Restricted arc if above 1.00): 0.00
Seaboat quality (Average = 1.00): 0.00

Hull form characteristics:
Hull has a flush deck
Block coefficient: 0.450
Length to Beam Ratio: 13.62 : 1
'Natural speed' for length: 16.10 kts
Power going to wave formation at top speed: 40 %
Trim (Max stability = 0, Max steadiness = 100): 50
Bow angle (Positive = bow angles forward): 0.00 degrees
Stern overhang: 0.00 ft / 0.00 m
Freeboard (% = measuring location as a percentage of overall length):
- Stem: 0.00 ft / 0.00 m
- Forecastle (20%): 0.00 ft / 0.00 m
- Mid (50%): 0.00 ft / 0.00 m
- Quarterdeck (15%): 0.00 ft / 0.00 m
- Stern: 0.00 ft / 0.00 m
- Average freeboard: 0.00 ft / 0.00 m
Ship tends to be wet forward

Ship space, strength and comments:
Space - Hull below water (magazines/engines, low = better): 44.1%
- Above water (accommodation/working, high = better): 0.0%
Waterplane Area: 3,146 Square feet or 292 Square metres
Displacement factor (Displacement / loading): 298%
Structure weight / hull surface area: 102 lbs/sq ft or 497 Kg/sq metre
Hull strength (Relative):
- Cross-sectional: 2.83
- Longitudinal: 3.23
- Overall: 2.87
Hull space for machinery, storage, compartmentation is excellent
Room for accommodation and workspaces is extremely poor
Ship has quick, lively roll, not a steady gun platform
Caution: Lacks seaworthiness - very limited seakeeping ability

Upper belt used to sim ballast tank.
Speed (surface, diesel): 15.8 knots
Speed (submerged, electric): 18.9 knots
Actual range (surface): 5,800nm at 14 knots
Range (submerged): 135nm at 3 knots
Diving depth: 286 feet
Test Depth (*): 358 feet
Emergency Depth: 458 feet
Crush Depth: 715 feet

Actual bunker size: 329 tons
10 Type 99 torpedoes: 18 tons (used bunker)
Ninjatousaya System: 10 tons (used bunker)
Increased Battery Capacity: 286 tons (used bunker)

(*) read: Limit of a crew member's life insurance.


I also realized that part of the bunker represents fixed aspects on the sub so 296 tons need to be added to the 1,069 ton construction cost of each submarine in the report.


BTW, Bruce, I was mistaken regarding the Me-style turbines. I noticed that it was mentioned back then and I even replied to that. Just completely forgot about it.

Quoted

Speed (surface, diesel): 15.8 knots
Speed (submerged, electric): 18.9 knots
Actual range (surface): 5,800nm at 14 knots
Range (submerged): 135nm at 3 knots

Assuming a straight-line extrapolation of speed versus radius, this boat would have a radius of only 23 nm at its maximum speed. This would be a best case scenario - in all likelihood the power required to attain flank submerged speed would reduce the radius significantly. Outside of a very short 'spurt' to get out from under an attack, I see absolutely no value to such speed. Your mileage may vary.

Yes. In that aspect, the Type XXI is definitely the superior sub. (of course, the source of ST's submerged range given above is the always extremely "reliable" *cough cough* wikipedia (though I did look at the jp version for it as well))