Saengpuen (), was responsible for the keeping and training of firearms. Royal court strictly controlled the firearm trade in Siam. Firearms could only be purchased by the royal court and unpurchased firearms should be taken back. The Siamese had been able to cast their own cannons since the Ayutthaya period. Native Siamese large muzzleloader cannons were called Charong (), which were made of bronze and usually 4-5 inches in calibre. Charong cannons were put on city walls or on warships. Bariam cannons ( from Malay meriam) were European-produced cast-iron cannons with relatively larger calibre and shorter barrel. Barium cannons inflicted high damages on the battlefields and were sought after to purchase from Westerners by the court. Small breechloader cannons were also used. In the reign of King Rama III, the Siamese learned to produce small cast-iron cannons from the Chinese. In 1834, Christian Vietnamese from Cochinchina immigrated to settle in Bangkok and formed the Vietnamese firearm regiment that specialized in cannons and muskets. In the early Rattanakosin period, Siam accumulated cannons and firearms. In 1807, there were total 2,500 functioning cannons in Siam, with 1,200 of them stationed in Bangkok, 1,100 distributed to provinces and the last 200 installed on 16 royal warships. The total number of firearms in Siam in 1827 were over 57,000. Navy Before 1852, Siam did not have a standing navy. Most of the Continental Southeast Asian warfare was land-based or riverine. When a naval warfare was initiated, the authority would gather native Siamese riverine barges and, if possible, Western galleons or Chinese junks. The Siamese relied on either Chinese or Malay junks for seafaring activities. Commercial and war vessels were used interchangeably. The navy was manned by the Krom Asa Cham or the Cham-Malay regiment who possessed naval knowledge. The naval commander would be either Phraya Ratchawangsan, the leader of Krom Asa Cham, or Phrakhlang, the Minister of Trade. Growing powers of the British and the Vietnamese in the 1820s urged Siam to engage in naval preparations against possible incursions from sea. Siamese temporary fleets composed of sampans, which were for riverine and coastal campaigns and either constructed or levied. Siamese warships were essentially Chinese junks armed with Charong cannons. In the 1820s, Chao Phraya Nakhon Noi maintained his dock at Trang and became an important Siamese shipbuilder. In 1828, Nakhon Noi constructed augmented Chinese junks rigged with Western masts. These Chinese-Western fusion war junks