History of Royal Thai Submarines in World War Two


© 2016 Bob Hackett
Revision 2

Thailand was one of the Axis states which assisted Japan in World War II. On 8 December 1941, Japanese forces invaded southern Thailand, but resistance lasted only a few hours before ending in a ceasefire. On 21 December 1941, a mutual offensive-defensive alliance pact between Thailand and Japan was signed.

On 25 January 1942, the Thai government declared war on the United States and Britain. Thai Lt General Jarun Rattanakun Seriroengrit's Phayap (Northern) Army invaded and occupied northeastern Burma, which was former Siamese (Thai) territory that was annexed by Britain much earlier. Thailand then proceeded to annex territories in neighboring countries, expanding northwards, southwards and eastwards, and gained a border with China.

The official policy of the U.S. Government (USG) is that Thailand was not an ally of the Axis, and that the United States was not at war with Thailand. Since 1945, USG policy has been to treat Thailand not as a former enemy, but rather as a country which had been forced into certain actions by the Japanese. Thailand has been treated by the United States in the same way as such other Axis-occupied countries as Belgium, Czechoslovakia, Denmark, Greece, Norway, Poland and the Netherlands.

In 1934, Admiral Sindhu Kamalanavin, then Chief of Staff of the Royal Siamese Navy (RSN), led a warship-procurement project which was approved by parliament in 1935. The proposal included a 6.9 million-baht budget for three submarines the Navy wanted to protect Siam's almost 1,000 mile long coastline along the Gulf of Siam from foreign incursion, most notably by the colonial French colonists. The Siamese lacked domestic capability and the experience needed to build such vessels, so in October 1935, the RSN opened international bidding for the three submarines. Bidding was was won by Mitsubishi Heavy Industries of Japan, which offered a price of 820,000 baht each for four boats and terms including technical training of prospective officers and crews in Japan.

In 1936, the RSN let a contract and purchased four submarines for delivery in 1937. Siamese navy officers and sailors were sent to Japan to be trained to operate the submarines by Imperial Japanese Navy (IJN) personnel. On 31 May 1936, the first group of about 40 officers and men departed Bangkok aboard NACHISAN MARU, the Mitsui Line's first passenger liner. On 12 June 1936, they arrived at Kobe. [1]

In May 1936, two 374.5 ton submarines were laid down at Kobe based on a private Mitsubishi design. Both were launched on 24 December 1936. In May 1936, two more such submarines were laid down at Kobe. Both were launched on 14 May 1937.

From 13 June-25 October 1936, the Siamese sailors were billeted and trained at the Funabashi Elementary School in Tokyo. There the prospective Siamese crews underwent submariner training by the IJN in Japanese language training, gymnastics, Kendo martial arts and naval infantry training. On 15 September 1936, the trainees visited Yokosuka and the decommissioned IJN MIKASA, flagship of Admiral Togo Heihachiro throughout the Russo-Japanese War of 1904–1905. [1]

On 25 October 1936, they embarked by train from Tokyo, arriving the next day at Kobe where Mitsubishi had constructed a wooden submarine model for training purposes. IJN Captain (Vice Admiral, posthumously) Yatsushiro Sukeyoshi (40)(former CO of RO-61, I-63) was their Chief instructor.

On 19 April 1937, another 41 officers and men departed Bangkok, Siam on 4,433-ton liner NACHISAN MARU. They arrived at Shiminoseki, Japan in May 1937 whereupon they embarked by train for Tokyo. [1]

On 4 September 1937, all four submarines were completed and delivered to Royal Siamese Navy. MATCHANU and WIRUN then underwent testing for several weeks including torpedo firing in Kobe Bay. Thai Submarine Day is now observed on 4 September.

In 1938, the Siamese crews underwent training on LtCdr (later Cdr) Yoshitome Zennosuke's (52) somewhat larger RO-64 that was based on the British L4 design.

On 5 June 1938, the four submarines departed Kobe for Siam. On 9 June, they arrived at Kirun, Formosa (Keelung, Taiwan) where they docked for two days. They then departed for the Philippines where on 15 June they called at Manila and later at Legapi on Luzon. Enroute to Siam, the submarines were replenished by the Siamese ship SICHANG. On 25 June 1938, the submarines arrived at the RSN’s Sattahip Naval Base where the crews refreshed before arriving at the capital of Bangkok on 25 June 1938.

On 19 July 1938, the four submarines were commissioned in the RSN as H.S.M.S MATCHANU (MACHANU), H.S.M.S WIRUN (VIRUN), H.S.M.S. SINSAMUT (SINSAMUDR) and H.S.M.S. PHLAI-CHUMPHON (BLAI JUMBOL) together with Kawasaki (Kobe) built coastal defense ship HTMS SRI AYUDHYA. The submarines underwent several exercises in 1938 and 1939. [2]

(Left) Thailand and Gulf of Siam   (right) Coast Defense Ship HTMS SRI AYUDHYA (AYUTHAYA)

On 22 June 1940, the ill-equipped, demoralized and poorly led French Army collapsed and France fell to the Germans. As revenge for Germany's WW1 defeat, Hitler chose the same site at Compiègne forest at which the 1918 Armistice was signed in a railway car. Hitler ordered the coach, that had been kept in Les Invalides in Paris after the Treaty of Versailles, be taken to the exact spot where the 1918 Armistice was signed. The 1940 armistice was signed in the same coach. Afterwards, the coach was removed to Berlin.

(Left) The 1918 railway coach in which Hitler humiliates the French in 1940   (right) The coach is moved into place by the Nazis

Soon thereafter, the French formed a Vichy government that collaborated with the occupying Nazis in France and their overseas colonies including Vichy French Indochina (now Vietnam, Laos and Cambodia).

On 24 June 1939, Siam changed its name to Thailand.

Franco-Thai War:
In October 1940, a border dispute between Thailand and Vichy-French Indochina erupted into armed conflict. Thailand launched the Franco-Thai War and invaded Vichy-French Indochina and the Thais reclaimed Laos from the French. The Thai navy was mobilized to protect Thailand's eastern territorial waters and their four submarines conducted reconnaissance in the Gulf of Thailand.

French land forces were ill-equipped to deal with the larger Thai Army. Admiral Jean Decoux, Governor-General of Vichy -French Indochina and Commander-in-Chief, Naval Forces, decided Vichy's best chance at stopping Thai incursions would be a naval attack on Thailand's fleet and coastal cities, so the admiral formed a small naval squadron at Camranh Bay, Vichy-French Indochina.

On 15 January 1941, at 2115, the French squadron, led by their 6.1 inch gun flagship, light cruiser LaMOTTE-PICQUET under the command of Capitaine de Vaisseau Régis Berenger, plus sloops DUMONT D'URVILLE, AMIRAL CHARNER, TAHURE and MARNE weighed anchor for the Thai coast. French Loire 130 float planes based Ream Naval Base, in present-day Cambodia, completed a sweep of the coast from Trat to Sattahip. They located one coast defense ship and one torpedo boat at Ko Chang, and one gunboat, four torpedo boats and two submarines at Sattahip.

(Left) Loire 130 float plane   (right) Vichy-French light cruiser LaMOTTE PICQUET

17 January 1941: The Battle of Ko Chang (Elephant Island):
Thailand's submarines were unable to prevent or participate in the Battle of Ko Chang in which the small Vichy-French force won a decisive victory over the Thai fleet that consisted of new Japanese-built eight-inch gun coast defense ships under Cdr Sunthorn Chauywongwan’s HTMS SRI AYUDHYA (AYUTHIA) and Cdr Luang Phromveerapan’s (Phrom Veerapan) HTMS THONBURI (DHONBURI), plus three small destroyers supplied by Mussolini's Italy in the 1930s. The out-gunned Vichy -French flotilla savaged the Thai ships, sinking THONBURI (later raised), forcing SRI AYUDHYA aground and sinking all three destroyers.

(Left) HTMS SRI AYUDHYA   (right) HTMS THONBURI in Yokohama

Following the battle, the submarines were sent to patrol the vicinity of Ream Naval Base in present-day Cambodia, but no further naval confrontations occurred.

31 January 1941:
Saigon. The Japanese sponsored a "Conference for the Cessation of Hostilities." Preliminary documents for a cease-fire between the governments of Vichy France and the Kingdom of Thailand were signed aboard light cruiser IJN NATORI.

9 May 1941:
Tokyo. The Japanese forced the Vichy-French to accept a peace treaty that returned parts of Cambodia and Laos, taken by the French in 1867, to Thai control.

24 July 1941:
Japanese forces occuppied Vichy-French Indochina, including airfields in Saigon (Ho Chi Minh City) at Tan Son Nhut, Thudaumot and Bien-hoa and bases at Soc Trang, Nha Trang. Tourane (Da Nang) and Siemreap, Pnom Penh and Kompong-tom in Cambodia. IJN vessels also moved into the ports of Saigon, Tourane and Camranh Bay. IJA tanks clanked through Saigon's colonial streets.

8 December 1941: The Beginning of the Pacific War:
From occupied air and naval bases in French Southern Indochina, the Japanese launched aircraft and naval vessels in support of their invasions of British Malaya (now Malaysia and the Republic of Singapore) and the Commonwealth of the Philippines (now Republic of the Philippines).

The four Thai submarines were in service throughout World War II, although they did not see any action. In 1945, the country was renamed Siam again, but on 11 May 1945, the country was officially renamed Thailand.

In 1946, Thailand agreed to hand back the territories occupied during Japanese presence in the country as the price for admission to the United Nations. Consequently, all wartime claims against Thailand were dropped and the country received substantial American aid. Following this, all Thai-occupied territories were returned to their pre-war status and became again part of the states from which they had been annexed.

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.

29 June 1951: The Manhattan Rebellion:
Ratchaworadit Pier, Chao Phraya River, Bangkok. A group of junior naval officers attempt a coup against the government of Major General (later Field Marshal) Plaek Pibulsonggram, popularly known as "Phibun", prime minister of Thailand. During the transfer ceremony of US Navy dredge MANHATTAN to the Thai Navy, Phibun is taken at gunpoint aboard Thai navy flagship HTMS SRI AYUDHYA and held hostage. However, the plotters fail to secure the opening of the Memorial Bridge, so the warship cannot continue downstream. Fighting ensues and the rebels become heavily outnumbered by forces loyal to the government.

(US Navy dredge MANHATTAN)

30 June 1951:
Wichaiprasit Fort, Chao Phraya River. Early in the morning, SRI AYUDHYA joins in the fight, but its engines are soon disabled and she goes dead in the water. She is fired on by guns, mortars and planes. Heavy fires break out, and the order is given to abandon ship. Prime Minister Phibun has to swim ashore, but is uninjured.

1 July 1951:
The Sri Ayudhya finally sank. The rebellion led to the deaths of 17 military personnel, eight police officers, and 103 civilians and more than 500 wounded. After the failed revolt, the Navy loses its power and influence.

16 July 1951:
The Submarine Group is dissolved.

30 November 1951:
All four boats are decommissioned.

Author's Note:
[1] Dates vary according to source.

[2] 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.

Thanks go to Watchara Yui of Thailand.

Bob Hackett

(posted 7/1/2016)

(posted 8/1/2016)

(posted 9/1/2016)

(posted 10/1/2016)