An interesting piece of historic fact is that the only large vessel the Royal Thai Navy lost in combat over the last 100 years was sunk by the Royal Thai Air Force on June 30. 1951.
The background was the intense rivalry between the army and the navy since the military coup of November 8, 1947. Over the next four years, three unsuccessful rebellions were used by the army to gradually increase its power and sideline the Seri Thai movement as well as the navy.
After the failed Palace Rebellion of February 26, 1949, several senior navy officers were forced to retire leading the way for younger and more radical officers. The navy had enjoyed royal prestige since its inception as its first commanders were princes of high rank, but the importance and social prestige of the naval officers were now under threat.
On June 29, 1951, Prime Minister Phibun attended ceremonies for the transfer of a US-donated dredge named Manhattan. Naval officers carrying sub-machine guns and rifles walked up the gangway of the Manhattan unobstructed and simply told the PM to go with them. PM Phibun offered no resistance and went with the armed sailors as he was told. He was led off the ship and on to another boat that took them to the Sri Ayutthaya, a navy cruiser docked across the Chao Phraya on the Thonburi side.
The coup makers, calling themselves the Save the Nation Group, informed the public that a coup had taken place through broadcasts from the navy radio. They said it was necessary to overthrow the government, which they accused of being corrupt, undemocratic and incapable of administering the country. The coup makers labeled the government leaders ''big gangsters'' and asked for public support.
The young coup leaders had assumed that with the PM as their hostage, the military junta (known as the Coup Group) of 1947 would give in. They failed to realize that despite Phibun’s popularity in the army, saving him had low priority to the junta compared with its desire to secure the army’s monopoly on power.
The Coup Group rejected the demands outright and fought back with the full support of the Royal Thai Army, the Royal Thai Air Force (formed as recent as 1947 and effectively under the control of the army) and the Royal Thai Police.
All attempts at negotiation failed and the two sides kept up a battle of words over the radio waves all through the night. Fighting broke out in Bangkok before daybreak of June 30 between the armed forces rallied around the government and those supporting the Save the Nation Group.
Rebel marines were able to take over the Wat Leap power plant and nearby telephone exchange, but a combined police and army force took back these strategic sites within a few hours. The air force conducted heavy bombing raids on targets including the coup makers' command centre, the naval dockyard on the Thonburi side and several naval bases. The Sri Ayutthaya flagship was also bombed and sunk. Phibun was saved by naval officers and swam ashore.
Fighting continued, but the Coup Group started to gain the upper hand in the early afternoon and fighting ended in the evening of June 30, 1951.
Both sides suffered heavy casualties. Official figures list 68 dead and about 1,100 injured. Civilians accounted for 44 of the dead and 400 of the injured. Besides the Sri Ayutthaya, the Kamronsin was sunk and many buildings were destroyed in the heavy fighting. The naval dockyard was burned to the ground.
More than 1,000 naval officers and sailors were charged and placed on remand. Most were later released for lack of evidence. About 100 were imprisoned. Many high-ranking naval officers were dismissed from their posts, and the navy lost a great deal of prestige and influence. The navy headquarters was moved from Thonburi to Samutprakarn while the fleet was moved Sattahip in Chonburi to keep them far from the seats of power in Bangkok. The army took over several navy buildings and bases as the navy was downsized to the bare minimum. The naval air contingent was transferred to the air force and the marines were drastically reduced in size.
