Beginning in March 1942, the Japanese embarked on a program of construction of merchant vessels such as cargo ships and oilers to be built to standard designs by private yards. Sources vary on the number of these ships completed. Complicating the accounting, some were laid down as 1TLs, but completed as 2TLs. At least nineteen oilers of the 1TL design were completed during the war. Of these, the IJN operated 16 completed in 1943-1944, including AZUSA and SEIYO MARUs.
 The 19 wartime 1TLs were AMATSU, AZUSA, HAKKO, HAKKO No. 2, HASHIDATE, ISSHIN, KYOKUEI, MIRI, NAMPO, NIPPO, NIYO, OKIKAWA, OMINESAN, OTAKISAN (became CVE), RYOEI, SEIYO, SHIMANE ((became CVE), TAKANE and TOA MARUs.
|Kawasaki, Kobe |
Mitsubishi, Nagasaki and Yokohama
|Gross Tonnage:||10,000-tons (nominal).|
|Dimensions:||526.7' x 65.7’ x 29.10’|
|Propulsion:||Geared turbine, 9,500 shp, maximum speed 18.5 knots|
|Oil Cargo Capacity:||100,600 barrels @42 gals/barrel
or approx. 13,724-tons of crude oil
@7.33 barrels per metric ton