Submarine Data - not RHS

[Dixie]

ORIGINAL: JWE

ORIGINAL: Dixie
Curses! Foiled again [:D] As to your other point, what penguin? [&:] Now I'm confused (no change there...), is this some sort of in-joke that I don't understand? [&:][:D]

Monty Python

John

Ah-ha. Now I remember. Well, I say remember, you told me so it probably doesn't count [:D] I only watched that sketch a fe days ago as well [8|] I'm never at my best after a night shift [>:]

[JWE]

ORIGINAL: Dixie
Ah-ha. Now I remember. Well, I say remember, you told me so it probably doesn't count [:D] I only watched that sketch a fe days ago as well [8|] I'm never at my best after a night shift [>:]

Oh! Intercourse the Penguin!

Ciao. John

[Monter_Trismegistos]

Do you have data for Dutch subs?

[JWE]

ORIGINAL: Monter_Trismegistos

Do you have data for Dutch subs?

Yes. Let me collect that and put it up, while I'm waiting for the Japanese records.

Ciao. John

[JWE]

Holla, sorry for the delay, I've been busy with AE duties. Dutch will be up very soon.

IJN records are at Pendleton. Going to have to spend a couple days down south; then compare the IJN records to the Mitsubishi records in Japan. Won't take more than a week total. Thanks for ya'lls patience.

Ciao. John

[JWE]

Golly! The IJN records are very interesting, but they very often refer to the Mitsubishi build-outs for detail. I have also noticed that the commercial yard specs are considerably more detailed and informative as to implementation of a class of ship. All of the dinky build details are defined in the commercial yard records, while the IJN specs are more in the nature of “design bureau” numerics. Maybe that’s why service parameters were so often deficient.

Another thing is the difference in specificity. The commercial yards have literally tons of records, going back to 1904, relating to everything they built. Their warship build specs are more extensive than the IJN’s and many of the instabilities, inherent in IJN designs, were obviated by constructors in the commercial yards.

One can only wonder what might have happened, if the IJN General Staff had consulted the industrial base.

[el cid again]

There are interesting features of Japanese commercial yard records: for example (mentioned in Conways) - ten Kaidai type subs were built to the same job numbers by THREE DIFFERENT shipyards. What does that mean? Are we to believe 30 subs were built insteald of 10? Are we to believe the yard records are lies? How you interpret this matters - if the yard records are right - we have unit counts wrong. If they are not right - can we trust them for any purpose?

The yards were the places detail design was worked out. See Shinano for a detail description of this process (a book title).

[el cid again]

ORIGINAL: JWE

Woof! Finally tracked down the IJN records of their sub tech specs; mind boggling. Ya’ll will have to wait a few days for the Japanese subs, till this gets digested.

The RAN Historical Section made it happen – they sent me a copy of a 1997 letter, on the same subject, from Capt. T. Yamamoto, JMSDF, Defence Attache, Embassy of Japan, to Cmdr. M. J. Gregory (RAN, R’td) detailing confiscation of records and documents by allied forces after the war. BTW, Gregory was a newly minted Sub-Lieutenant, who joined HMAS Canberra just in time for Savo.

Okey dokey, commo the Japanese Naval Attache in Washington, with a copy of the letter, and voila! Not only that, but there are compilations from the records and several monographs based on the records, done by serving officers; Naval Historical Section was taking a cue from what the Army was doing with the German Generals, post war.

Arranged for interlibrary loan from Monterey to Carney Mainside, at Pendleton. The NWC records collection is “vast” and only available in the Secure Collection reading room .. ah, well .. maybe someday.

And, here they are.

Dudley Knox Library, Naval Post Graduate School, Monterey CA.
NWC Main Library, Naval War College, Hewett Hall, Newport RI
Naval Historical Collection, Naval War College, Mahan Hall, Newport RI

Record Compilations
Fukuda, Ichiro, “Sensuikan”, Tokyo: Showa17-18 [1942-1943], 2 v. (author of “Shashin Nihon Gunkanshi”, (Konnichi no wadaisha))

Fukunaga, Kyosuke, “Sensuikan”, Tokyo: Arusu, Showa 16 [1941] (Showa 18 [1943] printing). (Arusu bunka sosho; 6).

Kaigunsho Kuroshiokai, “Kesshi senko juyushi”, Showa 18 [1943].

Monographs
Hori, Motoyoshi, “Sensuikan”, 1959. (head of Kure NSY Shipbuilding section during the war)

John

An IJN naval architect wrote - by hand - in engineering block lettering style - a report on all captured vessels - with fine notes. This is combined with a photographic section - in a book by USNI called something like The Imperial Japanese Navy at the End of WWII.
It isn't very big - and it isn't complete - if a ship was not captured it isn't in there - but it is original documentation - by a Japanese technical expert at the time who had spent his life working with the ships. And it is universally available - unclassified since about 1960.

[JWE]

Ok, so here be Dutchness. A lot of this is from http://www.dutchsubmarines.com/. Gotta say the Dutch know what they are doing. The values are all in the ballpark; surprise, surprise, the motors are all Sulzers! We got ‘K’ values well within the windows, and everything fits well within HP/wt. Damn, the Dutch really know what they are doing.

KV----------570----13k----8k-----4800-----73-----165’
KVIII-------583----15k----8k-----4950-----77-----165’
KXI---------688----17k----8k-----3500-----46-----198’
KXIV-------865----17k---12k----10000---159-----265’
O16---------984----18k----12k---10000---202-----265’
O19---------998----19k----12k---10000---256-----330’
O21---------934----19k----12k---10000---238-----330’

Ciao. John

[JWE]

M'kay, finding out some interesting factoids about doctrinal implementation of Japan subs vs ours. 'Endurance' is how far you can go with 'fuel' at the nominal cruise speed, but what was the nominal cruise speed?

We (the US) kept cruise speed low (10 knot neighborhood) so as to have sufficient reserve fuel for a meaningful patroll. Japan, on the other hand, didn't consider patrol endurance as a metric, but rather stepped their boats out at a significantly higher cruise speed in support of fleet operations.

The difference in fuel consumption between a 10 knot cruise speed and a 15 knot cruise speed is large. Accordingly, the difference in 'endurance' using a 10 knot cruise speed and a 15 knot cruise speed, is equally large.

So, knowing the engine parameters, it's not hard to develop a delta 'endurance' as a function of cruise speed. The Japanese subs will have these dual values, as appropriate, for your modding convenience. It's a matter of speed/distance/fuel consumption. One size does not fit all; you have to pick one or the other.

Ciao. John

[JeffroK]

Well done JWE, some of it even makes sense[8D]
 
Its good to see that solid research is going into AE rather than the SWAG of vanilla WITP.
 
Once you have the data together, can you explain how this made any class better than another and the differences between Nations?
 
jeff

[JWE]

ORIGINAL: JeffK
Well done JWE, some of it even makes sense[8D]
Its good to see that solid research is going into AE rather than the SWAG of vanilla WITP.

Well thanks Jeff. Oh yeah, we are digging deep; maybe too deep, but then we can always back off. That’s a lot better position than having to run & catch up.

Once you have the data together, can you explain how this made any class better than another and the differences between Nations?
jeff

Only in a meaningful way with respect to the game engine. I’m just an old doggie cannon cocker and the closest I ever got to a sub was a partner in my very first law firm, who was a Rickover Nuke – Lt. Willian P. Christie (anybody out there know Bill?? He would have been a 60s kinda guy). I used to think I had gonads of hard refractory metals, but the more I learn about dolphins, the more I learn about respect; lordy .. lordy .. lordy!

Ok, class differences. The “real” differences aren’t included in the game model. How do you account for a difference in habitability? A lot of our (US) power went into habitability. Our guys had air conditioning, ice cream, steaks, and if you don’t think that’s worth a world of efficiency, just talk to any combat pilot (shoot, just talk to any doggie whose world is wrapped up in his next good meal). Ok, so our subs had half the range of a Japanese J1, but so what? They had sufficient range to carry out the mission, and sufficient reserve power to care for, and feed, the crew while doing so. Don’t know about you, but I’m certainly willing to burn about 10%-12% of range to put power to the air conditioners, and steak and ice cream reefers, for these pukes. The game does not account for this sort of power utilization.

Japan tried a number of diesel configurations. There were 12, at last count. Many of the long range subs used MAN-type double acting motors that got them a 9% efficiency increase. We tried them, in the Hooven, Owens, Rentschler (H.O.R.) configuration in the Salmon, Sargo, Seadragon classes. We called them HORs, and we did not pronounce the initials. They were a bit$h to maintain and noisy as #ell. The word was that you could hear a Jap sub working up off Yokohama, in San Diego.

The game is just interested in “endurance”, “speed”, “diving depth” (durability), and “fuel”. So here’s the raw numbers for Japan.

J1---------2135---18k---10k---~24k---745t---260’
------------2135---18k---15k---11000---745t---260’
J1M-------2245---18k---10k---~24k---745t---260’
------------2245---18k---15k---11000---745t---260’
J2---------2245---20k---10k---~20k---687t---260’
J3---------2525---23k---15k---~14k---831t---330’
A1--------2920---23k---15k---~16k---844t---330’
A2--------2935---18k---12k---~22k---896t---330’
AM-------3605---17k---12k---~21k---852t---330’
B1--------2585---23k---15k---~14k---827t---330’
B2--------2625---23k---15k---~14k---817t---330’
B3/4------2610---18k---15k---~21k---879t---330’
C1--------2555---23k---15k---~14k---847t---330’
C2--------2560---23k---15k---~14k---847t---330’
C3/4------2565---18k---15k---~21k---879t---330’
KRS------1385---14k---10k---8500---225t---230’
KD2------1500---22k---15k---6150---336t---200’
KD3------1735---20k---10k---6150---242t---200’
KD4------1720---20k---10k---10800---440t---200’
KD5------1705---20k---10k---10800---440t---230’
KD6A----1785---23k---15k---10000---341t---250’
------------1785---23k---10k---14000---341t---250’
KD6B----1810---23k---15k---10000---350t---250’
------------1810---23k---10k---14000---350t---250’
KD7------1835---23k---15k---8020---418t---265’
D1--------1780---13k---10k---15000---172t---245’
D2--------1925---13k---10k---10000---136t---330’
------------1925---13k---13k---5020---136t---330’

[el cid again]

ORIGINAL: JWE

ORIGINAL: JeffK
Well done JWE, some of it even makes sense[8D]
Its good to see that solid research is going into AE rather than the SWAG of vanilla WITP.

Well thanks Jeff. Oh yeah, we are digging deep; maybe too deep, but then we can always back off. That’s a lot better position than having to run & catch up.

Once you have the data together, can you explain how this made any class better than another and the differences between Nations?
jeff

Only in a meaningful way with respect to the game engine. I’m just an old doggie cannon cocker and the closest I ever got to a sub was a partner in my very first law firm, who was a Rickover Nuke – Lt. Willian P. Christie (anybody out there know Bill?? He would have been a 60s kinda guy). I used to think I had gonads of hard refractory metals, but the more I learn about dolphins, the more I learn about respect; lordy .. lordy .. lordy!

I am a 60s sort of guy who joined the Navy in the nuclear field to begin with. This is a name I remember - but I cannot remember why?

[el cid again]

Japanese subs didn't really have more range in many cases - nor ever as much as it seems.

While most navies experimented with "fleet submarines" pre war - and we always called our big boats that -
they really did it. Operating at high speeds meant the effective ranges were reduced. This was more effective
earlier in the war - later subs could not survive on the surface. USS Yorktown was specifically sunk after an
order to do so from Adm Yamamoto during the battle of Midway. Subs did not often function well in fleet
engagements - and more often operated alone. But the Japanese really tried for this.

At PH the Japanese had high hopes for the subs - expected MORE damage by subs than planes -
and in fact the ONLY carrier to be damaged by the overall force was in fact hit by a submarine of the Advance Force -
but since it was not on the same day as the initial attack we don't usually understand it is the same force engaging.

Japanese submarines were intended to sail in the 15, 18 or 20 knot range - until mid war - when engines were reduced
and fuel was increased - and subs were expected to engage in long range recon and raiding and "yanagi" operations.

[JWE]

ORIGINAL: JeffK
Well done JWE, some of it even makes sense[8D]

Its good to see that solid research is going into AE rather than the SWAG of vanilla WITP.

Once you have the data together, can you explain how this made any class better than another and the differences between Nations?

jeff

Okey, dokey. much of the early and mid war subs are in the box. Obviously, Japanese subs are just like everybody else's. Sure, they had great range, but it took almost 1000 tons o' gas to get them there; Duh !!

Late war stuff is a bit more tricky, but in the greater scheme o' things, is actually simpler. Simpler, because the numbers are way more uniform and understandable; more tricky, because they suck, really suck, and way way way suck, with respect to contemporary power plant implementations. If you are a JFB, this will hurt you.

So .. you guys want the bitter end .. ??

[el cid again]

If you use real fuel concumption at realistic speeds, the engine will work fine. Just rate the Japanese subs for cruising at 15 knots - they have a lot less range then - except for the vessels which were smaller and cruise at 10 - and it will work out fine = greater fuel consumption. This because you have real fuel values and real ranges at a good enough cruising speed.

Late war subs will not suck for fuel efficiency - they will have very low cruising speeds of probably only 5 knots (due to snorkel limitations) -
but they will be effective because they dive so deep (deeper than any US sub) = higher durability - the engine will work for them just fine.

I suggesst using actual design depth data instead of recommended operating depth data. This is more uniform - and it works fine - and it solves a big WITP engine problem - i.e. subs are too easy to sink. Using real sub data and confining DC to one die roll per pattern solves this substantially - or completely.

[JWE]

ORIGINAL: JeffK
Well done JWE, some of it even makes sense[8D]
Its good to see that solid research is going into AE rather than the SWAG of vanilla WITP.
Once you have the data together, can you explain how this made any class better than another and the differences between Nations?
jeff

Howdy folks, thanks for the pm’s. I have the green, sewage treatment button turned on, so I can’t respond directly, but from the thrust of your comments, here’s my take.

The Japanese raw numbers are organized by std tonnage, full speed, cruise speed, range, fuel, and diving depth. So the really long range guys have two metrics; 10 knots and 15 knots, with a big difference in endurance betwixt the two. The real booger in the woodpile is developed horsepower.

F(root lwl) is the max speed a hull can go in a displacement mode configuration without serious (power law) implications to applied power; simple physics. To get a hull to a corresponding cruise speed is a function of horsepower; simple physics. To get to horsepower, you need only look at the flat-band values of your chosen power plant; simple physics.

The early Japanese subs had very big plants; 112000, 124000 HP installations; quite sufficient to drive a hull at cruise speeds of 15 knots, at an 80% power push from a diesel. This took a lot of fuel, but, what the hey … the Japanese designed them that way. That’s the basis of the data.

Some of it is from IJN records, as indicated, more is actually from Mitsubishi records. Thing is, Japanese, British, Dutch, US, subs all follow the very simple physical parameters defined by hydrodynamics.

Ciao. John

[JWE]

Agree. I think the eventual AE forum is going to be moderated, so we won’t have to put up with nonsense or spam, in that context. Ok, pm, with your data request, is coming at you.

That's it for this thread.

Ciao. John