|Name||No||Yard No||Builder||Laid down||Launched||Comp||Fate|
|ศรีอยุธยา [Sri Ayuthia]||Kawasaki, Kobe, Japan||1936||31.7.1937||16.6.1938||sunk 30.6.1951|
|ธนบุรี [Dhonburi]||Kawasaki, Kobe, Japan||1936||31.1.1938||5.8.1938||damaged 17.1.1941, partly repaired|
|Displacement standard, t||
|Displacement full, t||
|No of shafts||
2 MAN diesels
|Power, h. p.||
|Max speed, kts||
diesel oil 150
|Armour, mm||belt: 63, decks: 38+25, turrets: 102, barbettes: 102, CT: 102|
2 x 2 - 203/50 3-shiki 2-go, 4 x 1 - 76/40 11-shiki, 4 x 1 - 40/62 HI-91
Sri Ayuthia and Dhonburi, along with the Finnish ships of Vänämöinen class, appeared last classical coast defence battleships. They were ordered in Japan under the 1935 programme. They were created for the same tasks, as Ratanakosindra class, but differed by considerably increased dimensions and guns calibre. The so-called "wavy" hull form peculiar only to Japanese shipbuilding school became prominent feature of ships: forecastle deck had smooth lowering from stem to fore barbette with subsequent smooth raising to amidships frame. General forecastle length was about 3.5 of the hull length. Main deck thus on all was flat. Main calibre consisted, under one data, from 200mm/50 "type 3 No1" guns, similar to installed on early Japanese heavy cruisers, on another data from later 203mm/50 "type 3 No2" guns. Main guns of Thai ships were placed in turrets, similar to type "D" turrets of Japanese Myoko class heavy cruisers.
Armoured citadel covered only machinery. Belt thickness was 63mm. Scheme of horizontal protection repeated Ratanakosindra: 38mm lower deck passed on all hull length, upper deck was protected by 25mm sheets over magazines and machinery only. Artillery protection, in comparison with Ratanakosindra, was significantly improved: instead of splinterproof protection, turret and barbettes received rigorous 102mm armour. Barbettes reached lower deck. Thickness of conning tower, on the contrary, was decreased.
Dhonburi was hard damaged 17.1.1941 in battle at Ko-Chang by gunfire of French light cruiser Lamotte-Picquett and avisos Amiral Charner, Dumont D `Urville, Tahure, Marne; she ran aground at Laem-Ngob and abandoned by crew. Soon she was raised and towed off to Bangkok, however she was never completely repaired and was used later as command harbour vessel. She was broken up in 1967, thus fwd superstructure and turret of Dhonburi were installed as a memorial in territory of a naval academy of Thailand in Pak-Nam where they are kept on present time. Sri Ayuthia, contrary to judgement widely duplicated in literature, did not participated in battle at Ko-Chang and safely gone through the Second World War. She was sunk 30.6.1951 at Sattahip as a result of air bomb hit from aircraft of Thai Air Forces and fire of a field artillery of Thai army during the attempt of military coup d'etat undertaken by naval officers. Wreck was subsequently broken up.