Matrix Games Forums

The nearest thing I can find to a "small AK" is

Haruna Maru Class (there are 7 others fairly similar - pre war ships were rarely identical).

She does use about 500 tons of fuel (as in the CHS Small AK) - actually 476 but I favor rounding.

On that she goes only about 5000 nm - not the 10,000 of the CHS class. And she is slower - 7 or 8 knots vice the 9 knots of the SMALL AK.

And she carries a thousand tons less - 1549 grt vice 2625 in the game small AK - I round that to 1500 tons.

About 500 of Japan's "small" AKs were coastal steamers - 76 grt or 80 tons deadweight. This means we should average many of the bigger ships with these and end up with many small AKs. This will go a long way to solving the too much shipping power in WITP.

The Large AK might be represented by Syunten Maru class (about 117 similar in 1941 plus 4 more building). These ships are fast - 14 knots full - Japan has the fastest merchant marine in the world and this is not properly in the game. They are about 5500 GRT (5623 actually) - pretty close to the game Large AK at 5250. But they need 1700 tons of fuel to go 7200 nautical miles at 10 knots - this is faster than the game cruising speed of 9 knots for the large AK - but a third of the range. Japanese steam engines are not as efficient as Western models, and so their ships carried more fuel to get less far. Many still used reciprocating engines, and the boilers themselves are not as efficient. There are probably too many Large AKs, but I must continue analysis.

I am completely unable to verify the specifications you have given for the Haruna Maru (small - there was an identically named ship of just over 10,000 tons). Can you please point me to a reference?

I find it interesting your ship has the exact same grt rating - 1549 - as mine! The speed is right - 11 knots. Even so, 1549 grt should not imply a full load displacement of over 10,000 tons. My ship can be seen listed Rising Sun, Data Annexes, Page A1-3, and in Lloyds Register of Shipping for 1939. She is listed as built in 1923. It seems to have the correct engine type - reciprocating. And the fuel is also about right - except to tell you have to add the two fuels together in your data (coal plus oil). It may be your material is, as reference material often is, design data, or as built data. Operating two decades after construction, in wartime conditions (when the ratio of coal and oil may not be optimum) service data may well be quite different with respect to range. Nevertheless, it seems there is so much in common I think you probably have found this ship, even though you think you have not.

Yes, I agree that we are talking about the same ship. I was somewhat confused by differences in speed and endurance from your original post.

I was hoping that you might share your sources in such a way that I could access them - either web links or book title/author/ISBN. Especially the Lloyds data, which I do not have.

The primary sources for Japanese Merchant Shipping in CHS were:
http://www.history-on-cdrom.com/id132.htm (the source of the above data)
http://www.amazon.com/exec/obidos/tg/detail/-/155750959X/qid=1131200841/sr=8-2/ref=sr_8_xs_ap_i2_xgl14/103-8773551-2139832?v=glance&s=books&n=507846
http://www.amazon.com/exec/obidos/tg/detail/-/159114888X/qid=1131200885/sr=1-2/ref=sr_1_2/103-8773551-2139832?v=glance&s=books
http://www.amazon.com/exec/obidos/tg/detail/-/1557506779/qid=1131200921/sr=1-1/ref=sr_1_1/103-8773551-2139832?v=glance&s=books
and, of course, the original data in Scenario 15.

As to Japanese AKs:

Matrix originally generalized these into two classes – Large and Small. In CHS we added another dozen or so classes of AK and the SD type Sea Trucks as AG.

The Sea Trucks need to be AG due to the re-spawn rule. There were several hundred of these but slot limitations meant that only 25 were included in CHS. But, as AGs, they respawn when sunk so a constant stream is available.

As we identified ships in the “new” AK classes we either added them or pulled them out of the Large/Small classes. All ships that we could not identify as belonging to one of the new classes were left in the Large/Small classes. We could have added more AK classes and pulled more ships from the Large/Small class but there is not enough room to define every class and every ship. Also, each new class requires a new icon. So we picked a point and stopped – leaving everything else in the original Scenario 15 classes.

Capacities of the new AK classes were originally set as 90% of GRT. Then, in responses to concerns about excessive capacity, all cargo ships were reduced by another 25% (I think that was the figure). The total capacity of the CHS Japanese merchant fleet is now approximately equal to the historical GRT totals (from Parillo).