Fun Facts re JP Transports

[JWE]

Japanese merchant fleet as of:

01/1940: ~ 1,220 vessels, over 1000 GRT, for 5,256,000 tons of shipping
01/1942: ~ 1,550 vessels, over 1000 GRT, for 5,860,000 tons of shipping

Of the 1550 vessels, they break down as follows:

24% from 1000 to 1999 gross tons
19% from 2000 to 2999 gross tons
16% from 3000 to 3999 gross tons
23% from 4000 to 5999 gross tons, centered at 5000 gross tons
14% from 6000 to 8999 gross tons, centered at 7500 gross tons
04% from 9000 onward gross tons, centered at 10000 gross tons

Centering at 5000, 7500, and 10000 gross tons captures the median about the three main tonnage figures of merit for ocean going, long voyage vessels. Everything below 4000 gross tons, would be intended for near seas routes. Doing the math, you get:

372 ships @ avg. 1500t = 558,000t
295 ships @ avg. 2500t = 737,500t
248 ships @ avg. 3500t = 868,000t
355 ships @ avg. 5000t = 1,775,000t
217 ships @ avg. 7500t = 1,627,500t
062 ships @ >8000t = ~ 620,000t
1550 ships is approximately 6,186,000t

A bit more than 5,860,000, but not much. The difference is about +320,000t (+5.5%) and is well accounted for by slight skews in the percentages and/or the centers of the average values, and/or the reported statistics for Japan for 01/1942.

Please also note that the 01/1942 values, as well as the statistical summary, does not include the second, third or fourth Requisitions. The data is from Western and Japanese shipping company records, which were either not aware of, or did not report, the extent of allocation of vessels to military requirements. Those ships designated for, or actively undergoing conversion to, Naval vessels, as of the beginning of 1941 are accounted for (about 220,000 tons, most from the bottom category), but all ships eventually allocated as fleet auxiliaries, after 1/41, are included in the totals given above (c.f. Kimikawa Maru, and all others). Thus, about 1,200,000 tons (about 150-200 ships) need to be deducted from the above totals to account for all the AVs, AKs, APs, AOs, AEs, ASs, etc, as of 1/42. Notably, these deductions must be made from the bottom 3 categories

This implies the majority of ships > 6000 tons were utilized as auxiliary and/or transport vessels by the IJA/IJN, leaving a scant 600, or so, vessels in the > 3000 ton range, and a very limited few in the > 5000 ton range, as a commercial shipping basis (beginning to see the Japanese shipping crisis??).

It gets worse when modernization is considered. The age of the Japanese merchant fleet, in years, as of 01/1940, is as follows:

<6----6-10----11-15----16-20----21-25---->25
27%--11%-----7%------16%-----23%------16%

45% of the fleet is 15 years old, or less. 41% of the fleet, in 1941 is 4000 gross tons or more; Hmmm. When you take away the allocated vessels, there aren’t many fast, modern, vessels left to ‘acquire’ from commercial routing for duty as transports, etc.. Thus the ‘demand’ for 600,000 tons of shipping by the IGS in Sept-Dec 1942 becomes very important in context. Japan only built 210,000 tons in 1941 (included), and 260,000 tons in 1942 (not included). All figures include tankers!

[el cid again]

The scholarly study of this matter is The Japanese Merchant Marine and World War II by Parillo. There is a great deal absent above - including vast numbers of ships of small size - not all for local usage. Japan STILL has tiny AKs for transoceanic shipping! There were vast numbers of other craft used - taken over from other nations - and traditional vessels. And an astonishing fraction of the fleet is passenger vessels. Worse, these were not used for trooping - but for general cargo - while AKs were used for troops - believe it or not.

A game listing of most of the vessels larger than a few tons can be found in a Command at Sea supplimentary volume. This has some indication of the details for each ship.

There is also a brand new book listing all the world's merchant ships over a certain size when the war began - 6000 listings - advertised in the current USNI mailing.

[JWE]

Oh dear me. I also absented launches, harbor craft, workboats, barges, lighterage, sampans, fishing boats, excursion craft, junks, sloops, yawls, rowboats and Nik's rubber duck. Such neglect is inexcusable. Did I miss mentioning somewhere that this was vessels >1000 GRT ?

[Don Bowen]

ORIGINAL: el cid again

(snip)

There is also a brand new book listing all the world's merchant ships over a certain size when the war began - 6000 listings - advertised in the current USNI mailing.

Sid, are you speaking about Jordan's Merchant Fleets 1939?? You got me interested for a minute but USNI doesn't have anything new. Merchant Fleets 1939 has been on most of our bookshelves for years.

[el cid again]

ORIGINAL: JWE

Oh dear me. I also absented launches, harbor craft, workboats, barges, lighterage, sampans, fishing boats, excursion craft, junks, sloops, yawls, rowboats and Nik's rubber duck. Such neglect is inexcusable. Did I miss mentioning somewhere that this was vessels >1000 GRT ?

Actually, in East Asia in this period, vast numbers of shipping was below 4000 grt - probably more ships than above it. Your comments apply to boats - and while these also were significant - particularly in forward combat supply -
they are present mainly in abstract form in WITP and not a problem. I referred to the ships - not to the boats. I also referred to the captured large ships - which with rare exceptions - we do not have. The game "scuttles to prevent capture" but does not seem to capture - either at sea or in port. Somewhat in between the boats and the small ships is yet another very significant category in that period: junks. We have, however, modeled the largest of these in RHS - using them in "groups." [Not quite the largest - a junk can be 3000 - 5000 tons - where as we used 600 ton types]
Junks matter more than you might guess because they are used for blue water work.

Not always were small vessels used for local work. Both in Japan and among colonial powers, small trade routes were worked by tiny AKs - and these just happen to be nearly perfect for forward area supply in a military sense. We have put in the largest of the wartime versions of these - called Sea Truks - both C and D species - but not the many civilian models - except to the extent they were already present (mainly as Allied "coasters").

[el cid again]

ORIGINAL: Don Bowen

ORIGINAL: el cid again

(snip)

There is also a brand new book listing all the world's merchant ships over a certain size when the war began - 6000 listings - advertised in the current USNI mailing.

Sid, are you speaking about Jordan's Merchant Fleets 1939?? You got me interested for a minute but USNI doesn't have anything new. Merchant Fleets 1939 has been on most of our bookshelves for years.

Probably. I just remembered it in the last flier - and I guess I assumed they had a new book. Sometimes they reprint old things. There is even one USNI book they originally refused to publish - after it was written for them - but which now they carry in reprint! [Advance Force Pearl Harbor, whose author I know slightly, and who told me about how he had to self publish his first edition]

[JWE]

ORIGINAL: el cid again

ORIGINAL: JWE

Oh dear me. I also absented launches, harbor craft, workboats, barges, lighterage, sampans, fishing boats, excursion craft, junks, sloops, yawls, rowboats and Nik's rubber duck. Such neglect is inexcusable. Did I miss mentioning somewhere that this was vessels >1000 GRT ?

Actually, in East Asia in this period, vast numbers of shipping was below 4000 grt - probably more ships than above it. Your comments apply to boats - and while these also were significant - particularly in forward combat supply -
they are present mainly in abstract form in WITP and not a problem. I referred to the ships - not to the boats. I also referred to the captured large ships - which with rare exceptions - we do not have. The game "scuttles to prevent capture" but does not seem to capture - either at sea or in port. Somewhat in between the boats and the small ships is yet another very significant category in that period: junks. We have, however, modeled the largest of these in RHS - using them in "groups." [Not quite the largest - a junk can be 3000 - 5000 tons - where as we used 600 ton types]
Junks matter more than you might guess because they are used for blue water work.

Not always were small vessels used for local work. Both in Japan and among colonial powers, small trade routes were worked by tiny AKs - and these just happen to be nearly perfect for forward area supply in a military sense. We have put in the largest of the wartime versions of these - called Sea Truks - both C and D species - but not the many civilian models - except to the extent they were already present (mainly as Allied "coasters").

Actually Sid, I am passing on certain statistics developed by the govt on the distribution of Japanese merchant vessels greater than 1000 grt. If you wish to discuss other topics, such as your PHS scenarios, sea-going junks, sea-trucks, tiny AKs and everything other than the distribution of merchant vessels greater than 1000 grt, it would be much more polite to start your own thread as opposed to hijacking someone elses.

[Terminus]

That would require extensive training in politeness first...[:@]

[Ol_Dog]

If you are just putting out data as opposed to something specific related to a scenario, perhaps it belongs above in research where it won't get lost among the many posts and comments about scenarios.

[JWE]

ORIGINAL: Ol_Dog

If you are just putting out data as opposed to something specific related to a scenario, perhaps it belongs above in research where it won't get lost among the many posts and comments about scenarios.

Perhaps, but the information does not pertain to a research site. Many people use generalized information in order to construct their own scenarios. Data is not required to be scenario specific.

[el cid again]

JWE: I did not intend to hijack your thread - although it seems to be relatively common that it happens - and quite intentionally - and even rudely. I innocently believed you were posting information about shipping for anyone who cared about shipping - and it was my intention to outline omitted portions of that. My intentions were (and always are) constructively intended - and it never occurs to me there are actual bounds to a topic of interest (since I always like every scrap of related material).

[el cid again]

ORIGINAL: Terminus

That would require extensive training in politeness first...[:@]

A subject in which, no doubt, you could be my teacher? [This is an attempt at humor]

[spence]

At least Cid didn't go on and on about the nuclear-powered, 100kt, 520000 ton freighter/tanker (depending on the master's mood of the day) that the Japanese were just finishing fitting out on Aug 15 '45 but which is now buried under a mountain in North Korea. Give him that much.[;)]

[JWE]

Whoa !! 100 kts [X(] Actually, I thought Cid's explanation was quite gracious. Perhaps he sometimes forgets that many modders design their scenarios based on other game systems. Many of them are, quite reasonably, very happy with a higher degree of abstraction and become discouraged over the time and effort required to manage and account for very fine grained 'historical' levels of detail, particularly in the more prosaic tasks.

By way of explanation to Cid (I think he deserves one), some of these designers are unhappy with the degree of simplification of transports in the stock system and have asked for a set of rules, as it were, to add (limited) detail. Others are unhappy with the degree of complexity in the historical systems, and have asked for a set that allows simplification. It seems that general summary data is the most useful to this group. It allows for development of detail and differentiation, but avoids unnecessary (for them) minutiae. Very often, exposing every scrap of related material can overwhelm the entire original premis. One can, indeed, put too many raisins in the pudding.

I appreciate that constrains on enthusiasm are undesirable and often counter productive. For my part, I will, in the future, attempt to make it unambiguously clear whenever I am posting for a non-RHS audience. I trust that will suffice to suggest a contextual review and provoke a contextual response if such is warranted. Should keep things from turnin into boiled okra. Sound ok ??

[JWE]

OK, had my closing arguement before the studio audience; done now. Tomorrow is tomorrow, and today is what is. So:

Actually, in East Asia in this period, vast numbers of shipping was below 4000 grt - probably more ships than above it.

Not probably; rather definitely. After all deductions, "tonnage" above 4000grt may well have been a bit less than "tonnage" less than 4000grt. Necessarily, the number of ships in the smaller tonnage category will be significantly larger than the number of ships at 4000grt and above.

I referred to the ships - not to the boats.

I was being sarcastic; and I am sorry.

I also referred to the captured large ships - which with rare exceptions - we do not have. The game "scuttles to prevent capture" but does not seem to capture - either at sea or in port.

True, the game doesn't model capture. However, good stats can subsume that portion of the Chinese merchant fleet that Japan acquired for her own use. Not all, or even most, Chinese ships were put into Japanese service. Most were retained to service their pre-war routes; modeled in the (stock) game by the flow of supply along (reasonably) secure contiguous hexes. The number of significant 'capture' vessels that were put into service can be counted on fingers and toes.

Somewhat in between the boats and the small ships is yet another very significant category in that period: junks. We have, however, modeled the largest of these in RHS - using them in "groups." [Not quite the largest - a junk can be 3000 - 5000 tons - where as we used 600 ton types] Junks matter more than you might guess because they are used for blue water work.

Oh dear. To me, they don't matter much at all. Existence does not necessarily imply capability. I've never heard of a junk in the 3000 - 5000 ton range. I submit (actually, I state rather categorically) that it was technically impossible (pre 1984) to build a useful, classical junk-type design with measurement characteristics >1000grt. Even today (07/31/2007) it is not technically possible to build a useful, classical junk-type vessel with measurement characteristics in the 3000 grt range. I am able to defend these statements against anyone, with any degree, from any university, anywhere, with a naval architecture program.

Not always were small vessels used for local work. Both in Japan and among colonial powers, small trade routes were worked by tiny AKs - and these just happen to be nearly perfect for forward area supply in a military sense. We have put in the largest of the wartime versions of these - called Sea Truks - both C and D species - but not the many civilian models - except to the extent they were already present (mainly as Allied "coasters").

Actually, yes they were. Japanese shipping company records do not suggest, but rather state, unambiguously, that their fleets were denominated into groupings of continental importance. Small trade routes were indeed worked by 'tiny AKs', but these are modeled by base-to-base transfers and, as such, are irrelevant to the game system.

I don't know whose military systems these conclusions are based on, but the United States Military (and the JDF, and the Chinese, and the Russians, and the Taiwanese, and the Indians, and the Indonesians, and the Thais, and the Philippinos) did not, and do not consider "small" vessels as even adequate, much less nearly perfect, for forward area supply. This was a desperation move by the Japanese. Any suggestion that they were inherently adequate for forward displacement is misdirected.

Okey dokey, serve & volley.

JWE