© 2016 Bob Hackett
Tabular Record of
6 May 1936:
Kobe. Laid down at Mitsubishi Shipbuilding as Boat No. 1, a 374.5-ton
24 December 1936:
Launched and named MATCHANU. 
4 September 1937:
Completed and delivered to the Royal Siamese Navy.
Kobe Bay. MATCHANU and sister WIRUN undergo
testing including torpedo firing.
(MATCHANU and WIRUN)
5 June 1938:
MATCHANU and sisters WIRUN, SINSAMUT and PHLAI-CHUMPHON
depart Kobe for Siam.
9 June 1938:
The four submarines arrive at Kirun, Formosa (Keelung,
11 June 1938:
All depart Kirun.
15 June 1938:
The four submarines arrive at Manila, Philippines.
All arrive at Legaspi, Philippines.
All depart Legaspi for Siam. Enroute, the four submarines are
replenished by Siamese ship SICHANG.
25 June 1938:
The submarines arrive at RSN Sattahip Naval Base.
29 June 1938:
The submarines arrive at Bangkok, capital of Siam.
(MATCHANU in Bangkok Harbor alongside coast defense ship HSMS SRI AYUDHYA)
19 July 1938:
MATCHANU and her three sisters are commissioned in the
RSN together with Japanese-built coast defense ship HSMS SRI AYUDHYA.
1938 and 1939:
Gulf of Siam. The submarines undergo several training
24 June 1939:
Siam changes its name to Thailand.
22 June 1940: The Fall of France:
The ill-equipped, demoralized and
poorly led French Army collapses. As revenge for Germany, Hitler chooses the
surrender site at Compiègne and the armistice is signed in same railway carriage
in which the 1918 Armistice was signed which ended the First World War. Soon
thereafter, the defeated French form a Vichy government that collaborates with the Nazis.
A border dispute erupts into armed conflict. Thailand
launches the Franco-Thai War and invades Vichy French Indochina. The Thais
reclaim Laos. The navy is mobilized to protect Thailand's eastern territorial
waters. The submarines conduct reconnaissance in the Gulf of Thailand.
17 January 1941: The Battle of Ko Chang:
Gulf of Thailand. The
submarines are unable to prevent or participate in the battle in which the
larger Vichy French Navy wins a decisive victory. Following the battle, the
submarines are sent to patrol the vicinity of Ream Naval Base in Sihanoukville,
Vichy French Indochina (Cambodia), but no further naval confrontations occur.
28 January 1941:
Japan mediates the conflict and a general armistice
9 May 1941:
Tokyo. A peace treaty is signed between Thailand and
Thailand officially joins World War II. The submarines
are in service throughout World War II, but they do not see any action.
14 April 1945:
At 1430, USAAF Boing B-29 “Superfortress” heavy
bombers bomb Bangok’s Wat Liab and Samsen power stations. The bombing plunges
Bangkok in the dark. The city is without running water and electricity. The tram
MACHANU and WIRUN are pressed into emergency service and ordered to dock at the Bangkok Dock Company as power
generators for the BKK Tram Lines. They run their engines enough to produce electricity; but the tram still will not run.
It requires repairs for a few months before the Wat Liab Power Plant resumes electric supply for the tram.
16 June 1945:
The 2,000 KW Samsen power plant is put back on line, but needs another four years until it resumes
Post-World War II:
The four submarines lapse into dilapidated condition because supplies and parts are unavailable
as a result of the Allied occupation and disarmament of Japan. The RTN's battery factory is not capable of manufacturing
batteries for the submarines. The four submarines are moored in the Chao Phraya River near Siriraj Hospital Pier.
16 July 1951:
The Submarine Group is dissolved.
30 November 1951:
All four boats are decommissioned.
The Thai Navy sells the submarines as a scrap to the Siam Cement Co. for 500,000 Baht
Part of the superstructure of MACHANU is preserved at the Naval Museum opposite the Naval Academy in
Samut Prakan Province.
 The Royal Thai Navy's submarines were named after fictional literary characters known for their mythical diving
abilities from the Ramakien, Phra Aphai Mani, and Khun Chang Khun Phaen. Matchanu is named after his father, Hanuman a great
monkey god and his mother, Supanmatcha, a half-fish creature in the ancient Hindu epic "Ramayana."
 Also known as MACHANU.
Thanks go to Watchara Yui of Thailand, Sander Kingsepp of Estonia and the guys at Axis History Forum.
– Bob Hackett.
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