Babes Aux Ships - Details

[Symon]

Looking at stuff for the SF Scen, and ... Oh, Holly Shimoly !!! Found a vein of the Mother Lode !!! This one has listings, details, specs, and photos of virtually all the Japanese auxiliary “Babes” types; xPC/PB, xAMc, xCMC, ACM, you name it. It dials down to the ultimate nitty gritty detail. There is an English set of pages that are excellent, but the Japanese pages are out of this world.

For example (in English), click on Tokusetsukansen. Under Tokusetsu Tokumutei, click on Tokusetsu Sokaitei, and you get detail on the 120 civilian hulls (trawlers, and such) that were converted to xAMc from 1939 to 1945 (with photos of 90% of them). The Data page has: Name, Gross T, Net T, L, B, D, Main Dates, Hull Type, Propulsion, Nominal HP, even has their Call Signs; WOOF !!!

http://www.geocities.jp/tokusetsukansen/E/index.html

There were 393 Tokusetsu Kanshitei (xPC/PB) 90% of which were between 60 and 120 GTs (the largest was 268 GT). They were fishing boats whose role was to patrol on a picket line. Mostly wood and with minimal weaponry (1-2 MGs only) they should probably use the Babes ‘seatruck’ stats and art.

There were 94 Tokusetsu Hokan (xPG/PB), mostly 1000-1500 GT. Babes models these pretty well with the Ansyu (and the photos match as well). Their role was to patrol, transport, minimal minelaying.

There were 296 Tokusetsu Kusentei (xSC) pretty much split between 100 GT and 300 GT types. It just goes on-and-on. I’m getting dizzy just looking at all this.

Main utility was in Guard Districts and areas subordinate to Base Forces. Indeed, they “belonged” to a Base Force, or Guard Force, rather than to a “Fleet”. They were administratively IJN, but did not belong to Combined Fleet. Indeed, most were manned by their civilian crews, and some were actually Army vessels. Some of the larger, and more capable, may have had a small Naval component (2-4 ratings and a PO, maybe) to operate guns, DCs, sweeping gear, laying gear, etc, and do makee-learnee with the poor schlob civilians.

Fun stuff. And, yes Don, I know you are coming. I’m waiting with baited breath. There’s a few boats in there that Matt and I have bets on, as which ones you are gonna want art and stats for [8D] Bring it, my friend.

Ciao. JWE

[Symon]

This guy's bibliography and source list is utterly beyond belief: Senshi Sosho, v18/33, Bessatsu Shashincho, and more Sempaku Gijutsu Kyokai of mercantile stats, than I even knew existed.

This guy is a historian of the first water, but who has been under the radar. I've looked at some of my primary Japanese sources and whaddayaknow, there he is. He's kinda like us - lurking in the background.

I've said hello and indicated my interest. We'll see what develops. Ciao. JWE

BTW, MO chimed in with his bets. I was stunned. I forgot that stuff. You certainly won't, and MO certainly didn't. I should tell you that there are 22 open slots in the IJ Art set. Filling them won't work with Stock (or Babes Stock) scenarios, but they are there and we'd like to make our implementation like yours.

[Dili]

Excellent find.

While this didn't see the light of the day my idea for converted auxiliaries in a WITP Europe was split more or less this:

Motorfisher type
Trawler type
Tug type
Sailing type
Yacht type
Slow small xAK type.
Fast small xAK type.
Slow small xAP type.
Fast small xAP type.


Then would be split by tonnage. 0-100 , 100-500, 500-1000.

Edit: the idea was also to have most of this ships status as stopped building(or in need of upgrade), forcing a cost benefit decision to use them as warships.

[Symon]

Oh yes, my goodness. Gonna have to add a couple classes to Babes. Now I know a bit more about the vessels, can grind away and develop some differentiated specs depending on nominal HP.

Lots of the small, cargo ‘babies’ were coal, or mixed, fired expansion/piston types. Chunka, chunka, chunka, chunka, chunka, kinda boats. But lots had old style hot-bulb diesels. More HP, better efficiency, smaller machine space. Just what one would expect of a fishing boat.

Diesel delivers more prompt throttle response (over an expansion engine), because of higher specific torque. Given a nominal HP within the algorithm, a diesel ‘should’ be able to propel a vessel at a velocity close to its Froud hull speed. For 100’ – 120’ trawlers, that would be around 12-13 knots tops, 10-11 knots econ cruise (game values). Gonna have to tweak some of the Kudai and Ha’chi and To’su classes.

So there might be some new uses for these vessels as inter-island escorts and such. Yeah?

Keeps getting better and better, don’t it?

[ed] Sorry I used GT in the OP. GT and NT are non-starters in AE. Tonnage is in 'metric'. GT is only useful for generally categorizing vessels. In AE, the best way to categorize a boat is by LOA and nominal Displacement (the equivalent of Navy Light, in metric tons).

[btd64]

Nice find Symon. It is bookmarked....GP

[Symon]

Analyzing the data, I’m finding some very interesting things. The biggie, for me, is the choice of vessel configuration for conversion into the various types. The Toku’ Sokaitei, for example, were typical 90-110’ trawler hulls, but the vast majority were split evenly between diesel and steam plants having specific HP in the 150-200 range for diesel, and 400-600 range for steam.

This is perfect for the fuel/endurance algorithm in the game (we did something right, it seems).

But what’s odd is the choice of vessel characteristics for conversion to Toku’ Kusentai (aux sub chasers). Your same basic fishing boat, but with a roughly 100 HP slo-speed diesel. The standard conversions of 1944 onward, kept the same specs off the Hino Maru No 13. Small, slooow, maybe a dipping microphone, if they are lucky. No DC launchers; they were rolled off the aft, outboard racks.

Japan went to war without the proper sinews in place. One may play games with maximum uber capital ships, but that is not what war is about. The teensy sinews …

BTW, got an invite to be sail trim on a Peterson 48 for the Isla Race out of Southern YC. God, it’s good to be on a boat and smell the sea.

[Symon]

Yep, going to have to redo/add some stuff. Stepped through Senshi Sosho and Niehorster’s listings of auxiliary craft assigned to the various Base Forces – gunboat, minesweeper, subchaser, divisions – and chased down the individual boats in Toda’s site. The type designations aren’t quite the same as what’s in AE. Leo uses PC to refer to an auxiliary subchaser (an xSC) and his named ships (and Sen’Sho’s), sure enough, show up in Toda’s Kusentai data set.

Interestingly, the vast majority of these ‘named’ (xSC/PC) ships are of a nominal trawler design; 134’ loa, 127’ lwl, with 900-100 HP, T1, steam turbine engines. So, doing the math, these little puppies had the power to get to a hull speed of 15 knots and, very likely, cruise out at 12. Not all that bad, all things considered. Armament was strictly nominal; AAMGs and such. Some had a 8cm/23 T-06, some didn’t.

They didn’t have DC ‘rails’, just ‘roll-off’ positions (left and right on the aft quarter). Acquisition was visual and experiential. Some had a dipping hydrophone but the early ones (till ’43) were limited to 100’ because of cable/wire resistance. But they are still good for keeping subs down, and maybe getting a whack, or two, in.

[m10bob]

ORIGINAL: Symon

Yep, going to have to redo/add some stuff. Stepped through Senshi Sosho and Niehorster’s listings of auxiliary craft assigned to the various Base Forces – gunboat, minesweeper, subchaser, divisions – and chased down the individual boats in Toda’s site. The type designations aren’t quite the same as what’s in AE. Leo uses PC to refer to an auxiliary subchaser (an xSC) and his named ships (and Sen’Sho’s), sure enough, show up in Toda’s Kusentai data set.

Interestingly, the vast majority of these ‘named’ (xSC/PC) ships are of a nominal trawler design; 134’ loa, 127’ lwl, with 900-100 HP, T1, steam turbine engines. So, doing the math, these little puppies had the power to get to a hull speed of 15 knots and, very likely, cruise out at 12. Not all that bad, all things considered. Armament was strictly nominal; AAMGs and such. Some had a 8cm/23 T-06, some didn’t.

They didn’t have DC ‘rails’, just ‘roll-off’ positions (left and right on the aft quarter). Acquisition was visual and experiential. Some had a dipping hydrophone but the early ones (till ’43) were limited to 100’ because of cable/wire resistance. But they are still good for keeping subs down, and maybe getting a whack, or two, in.

Great find indeed!..
As far as these ASW trawlers is concerned, the "roll off" DC racks at first glance seem overly primitive, but we must remember the USN was doing the exact same thing in 1941-42 on the east coast.
Some of those were even mounted on sailboats, so with little wind, they had a chance of blowing their own hulls off..[X(]

[Dili]

I can give data on Japanese trawlers that Italy used in late WW1 and WW2 as PG/PC.

Mario Bianco launched 1911 ex.Fukuhaku Maru N 2" 385MT 33m 1scr 544HP 12kt(other sources 11 and 13kt) Guns 2x76/40(76mm) 2000nm at 10kt, 100t coal, photo : http://www.naviearmatori.net/ita/foto-1 ... zbT0x.html

There are several others, about a dozen ex.Japanese trawlers, but this is the only one i have fuel quantity.

Some of those were even mounted on sailboats, so with little wind, they had a chance of blowing their own hulls off..

Most sail boats should have an auxiliary engine, in Italy a country poorer than US i know of no requested auxiliary as a pure sail boat.

[m10bob]

ORIGINAL: Dili

I can give data on Japanese trawlers that Italy used in late WW1 and WW2 as PG/PC.

Mario Bianco launched 1911 ex.Fukuhaku Maru N 2" 385MT 33m 1scr 544HP 12kt(other sources 11 and 13kt) Guns 2x76/40(76mm) 2000nm at 10kt, 100t coal, photo : http://www.naviearmatori.net/ita/foto-1 ... zbT0x.html

There are several others, about a dozen ex.Japanese trawlers, but this is the only one i have fuel quantity.

Some of those were even mounted on sailboats, so with little wind, they had a chance of blowing their own hulls off..

Most sail boats should have an auxiliary engine, in Italy a country poorer than US i know of no requested auxiliary as a pure sail boat.

Yeah...I got my info from a book called "Torpedo Junction", all about the American east coast anti sub patrolling leading up to WW2 and the author made a point that these were unpowered sailboats.....

[Dili]

Ok. But it is strange.

[Symon]

Oh, yes. If you look at the early war IJ DDs, they didn’t have rails, per se. They had a Type 95 Y launcher and maybe 3 DCs on the port and starboard quarter that were “arm, pull the string, and kick them off”. Rails got incorporated onto IJN ships in the '42 time frame, but the remainders used the tried and true “roll ‘em off the quarter and see what ya get.” method. That’s exactly what was done with the CHa class of xSCs. and several other Babes classes. Woof!

[Symon]

ORIGINAL: m10bob
Yeah...I got my info from a book called "Torpedo Junction", all about the American east coast anti sub patrolling leading up to WW2 and the author made a point that these were unpowered sailboats.....

Sink rate vs forward progress. There's an algorithm in there, somewhere, that keeps a patrol boat from blowing it's stern off. I mean, most people understand simple velocity phisics. A sailor who can't do those simple calculations, deserves to get his ass blown off (as it were).[:D][:D]

[ed] early war, most (if not all) IJ DDs didn't have rails. They had a Y-launcher and 3, or so, DCs on each fantail quarter. Those were "set the arm switch, pull the string, and nudge them overboard" sorta weaps. Scary as heck because they were just outboard of the props. And Japan set shallow. Woof !!

[Symon]

ORIGINAL: Symon
Yep, going to have to redo/add some stuff.

Japan had some decent converted PC/xSC types. The IJN was interested in two main types; “whale chasers” and “tuna chasers”. These were, by and large, 135’, 350t Dspl, with 800-100 HP, coal fired, turbines (some were mixed fired), capable of 12-13 knot max speeds and 10-11 knots sustained cruise. There was a second type of “tuna chaser” boat of 120’, 250t Dspl, with 500 HP, coal/mixed fired, turbines, capable of ~12 knot max speed and ~10 knot sustained cruise.

From 1940 till 2/42, Japan converted 29 identified 135’/900 HP boats to PC/xSC configuration. They only found 6 more from ’43-’45. They converted 12 identified 120’/500 HP boats (10 more in ’43 and ’44). Presumably, there were a few more out there, but the Japanese population needed to eat (Yamamoto did love his Toro sashimi), so there’s nothing with that capability that can “convert”.

The rest of the fishing fleet is more prosaic. Hulls and propulsion set up for a hull speed sweet spot around 8-9 knots, max. An indication of Japan’s early sense of ASW importance is indicated by their conversion of 40-odd hot boats and the simultaneous conversion of ~85 slow-fishers (and 24 more, in ’43) to Tokusetsu Kusentei. The conversion of the “Slow-Fishers” in ’42 and ’43, again suggests a lack of available vessels with sufficient capability.

Japan used its experience with small vessels, and actually made some purpose-built auxiliaries: Ma class, Wa class, Pa class CHa class. All of which used a standard commercial hull form, with a 300-400 HP diesel. Hull was ok, it just needed more power to get efficient

[m10bob]

We are glad you still have the interest to add stuff..We love chrome!!

[Symon]

Chrome is Good ! Let there be Chrome ! Except the chrome turns out to be worthwhile, like chrome plating gun barrels. When ya dig through Sen’Sho and Niehorster, ya can find all them ‘Marus’ belonging to sub-chaser, patrol, and mine-sweeper divisions of Guard Districts and Base Forces. Look them up in Toda, and it’s clear that there’s a capability break point. The content of the Tokusetsu Tokumutei was actually well thought out.

We have several new classes of vessels; two of them are Tokusetsu Kusentei (PC/SC); Toku Ku’tei-A and –B. These are the patrol vessels that are called out in the ‘sub-chased’ divisions and which match up with Toda (golly, gee willikers). They are, relatively, fast and capable. I use the Gerr/Wyman formulas and, according to their physical specs, the –A (~135’, 900 HP) can do 12.3 knots and the –B (120’, 500 HP) can do 10.8 knots; not bad, considering. These can actually be very nice escorts in an archipelago scenario and they are pretty darn good at ASW too.

Another new class is the Tokusetsu Sokaitei (AMc); Toku So’tei. These are the patrol vessels that are called out in the ‘mine-sweeper’ divisions and which match up with Toda. They are also, relatively, fast and capable (120’, 500 HP, 10.8 knots) and can do many of the same missions as the equivalent PC type. There is inter-conversion opportunity.

The Wa-1 and Ma-1 (AMc, CMc) were purpose built from plans by Kampon off a standard ‘tuna’ boat, with specific propulsion systems (108’, 375 HP, 10.6 knots). They had no analog in the commercial sector that had not already been enlisted elsewhere. They were different, so thought it good to give them their own bitmap and specs.

These vessels had no remaining commercial equivalent, so nothing “converts” to them. Pretty much what you see, is what was built, what was enlisted, and is what you get. The prosaic trawler/fishing fleet is pretty much useless, except as sea trucks or pickets; and that’s exactly how they were used.

[US87891]

John, you know I like the new classes but some people will complain about the specs as being too good. Are you planning to post anything about the formulas? I think you should.

Matt

[Symon]

Here’s a panel of the new Babes ship art. Images 085, 127, 129, 259, 260, and 270 are simply updated graphics and are 1-to-1 replacements for the existing bitmaps. Images 164, 165, 170, 171, and 172 are new additions. They have currently unused numbers (164 and 165 images currently exist, but they are placeholders and not referenced by a class). They are required for the Babes small-map scens (BBSM) but can just be dropped into your standard Babes/Stock ship art folders without raising any issues, and they will be available whenever you need them.

FYI, there is a Tokusetsu Kusentei - C which has different specs but shares a bitmap with the Ma-1. Similarly, there is a Tokusetsu Sokaitei – D which has different specs but shares a bitmap with the Wa-1.

The Kusentei and Sokaitei A and B can interconvert (A to A, B to B), the Ku’tei C and the So’tei D can interconvert. Nothing else can convert to any of these. These are specially selected auxiliary, poop-hot, SCs and AMc; fast, and with nice capabilities. Once you see the cargo vessel specs, you will understand why none of them can convert ‘upward’. Some of the cargo types can convert to Kanshitei (PBs), but all you get is a 25mm gun, 6 DCs on a single rail, and half the cargo capacity. Japanese Kanshitei were ‘picket line’ vessels and are configured as such in new Babes.

[Symon]

ORIGINAL: US87891
John, you know I like the new classes but some people will complain about the specs as being too good. Are you planning to post anything about the formulas? I think you should.

Matt

As you know, the formulas are all standard stuff from the texts. I’m using the basic Gerr/Wyman for speed at Lwl and SHP. Using Choat and Baker (1930s editions) for specific fuel consumption by engine type for the period, and my CRC Handbook (handbook, what a joke, the thing is huge and weighs 22 lbs) for the different fuel’s heat content, density and burn rates.

It’s not hard, but it is extensive, as your daughter Meg knows very well (thank her again for me). Not something that would sit well on these boards.

If anyone thinks they have the patience to slog through the dirty details, send me a PM, and I’ll send enough stuff to make your brain go numb [:D]
[ed] But here's some stuff to wet ya'lls whistles - valid for smaller vessels, although can be extended.

Applicable Constants:
7.2lbs/gal for marine diesel
279gal/ton for marine diesel

Heat content of fuels:
Coal (Admiralty Welsh) 74.8 MJ/lb
Fuel Oil (Bunker C) 94.6 MJ/lb
Diesel (Hy Kerosine) 98.6 MJ/lb

Brake-Specific Fuel Consumption, by engine type:
SFC Steam – 1.23 oil, 1.54 coal, lbs/hr/SHP - Triple Expansion
SFC Steam – 0.97 oil, 1.21 coal, lbs/hr/SHP - Hi Speed Turbine
SFC Diesel – 0.46 lbs/hr/HP = 0.064 gals/hr/HP

For all values, divide by speed = tons/nm
For all HP, multiply TE values by 0.79 to get Turbine
1000 HP(TE-S) = 0.768 tons/hr (coal)
1000 HP(TE-S) = 0.615 tons/hr (oil)
500 HP(TE-S) = 0.385 tons/hr (coal)
500 HP(TE-S) = 0.308 tons/hr (oil)
300 HP(TE-S) = 0.231 tons/hr (coal)
300 HP(TE-S) = 0.185 tons/hr (oil)
300 HP(D) = 19.2 gal/hr = 0.0688 tons/hr
150 HP(D) = 9.6 gal/hr = 0.0344 tons/hr
100 HP(D) = 6.4 gal/hr = 0.0229 tons/hr

[Skyros]

ORIGINAL: Symon


If anyone thinks they have the patience to slog through the dirty details, send me a PM, and I’ll send enough stuff to make your brain go numb [:D]

I thought that was what Jack Daniels was for.[8D]