Japanese potential troop transport Yubaye Maru in December 1921

On 22 May 1922 (!) received the Dutch naval staff at The Hague, Netherlands from the Dutch embassy at Tokyo, Japan a detailed specification of Japanese merchant ships of minimum 1.500 tons tonnage usable for troop transport over sea on 13 December 1921. If the transport was over a short distance for instance Japan-Philippines or Japan-Chinese harbour was the transport capacity increased with 10% and on a distance within 24 hours even doubled. The figures were supplied by non-Japanese experts, partly based on the troop transports between Japan-China and Japan-Siberia. The transports were kept secret. At that moment was Japan already considered as a potential enemy. For each ship was mentioned how many troops included equipment could be transported over a longer distance, for instance to an island belonging to the Dutch East Indies. In February-March 1942 invaded Japan indeed the Dutch East Indies

Speed probably less then 10 miles, net tonnage 1,958 tons, gross tonnage 3,200 tons, transport capacity 1,050 men and owned by Kokusai K.K. Coal-fuelled.

Source

Archive Dutch Naval Staff 1886-1942 inventory number 137 (National Archive at The Hague, Netherlands).