Japanese-built Coastal Defence Ships/Cruisers

Many people do not realise that during the period before the outbreak of the Second World War, the Japanese built warships for other nations. Amongst these were two pairs of coastal defence ships/cruisers, one pair for the Chinese Navy and the other for the Royal Thai Navy.

The two Chinese ships (the Ning Hai-class cruisers) were small, compact light cruisers that suffered from high centres of gravity, which made the ships unstable in heavy seas. They were also powered by obsolescent triple-expansion steam engines, which meant that their top speed was less than 25 knots ... far lower than that of contemporary light cruisers.

The two ships were slightly different when completed, and their characteristics were:

• Displacement: 2,486 tons
• Dimensions:
• Length: 360ft (109.7m)
• Beam: 39ft (11.9m)
• Draught: 13ft (4.0m)
• Propulsion: 4 mixed coal/oil-fired boilers; three triple-expansion reciprocating steam engines each driving a propeller
• Speed: 21 to 23 knots
• Range: 5,000 nautical miles
• Complement: 361
• Armament:
• Both ships: 6 × 5.5" (140mm) 3rd Year Type guns (3 x 2); 4 × 21" (533mm) torpedo tubes (2 x 2); 9 × depth charges:
• Ning Hai only: 6 × 8 cm/40 3rd Year Type anti-aircraft guns (6 x 1); 8 x Vickers 2-pounder anti-aircraft guns (8 x 1); 10 × machine guns
• Ping Hai only: 3 × 3" (76mm) anti-aircraft guns (3 x 1); 4 × 2" (57mm) anti-aircraft guns (4 x 1); 4 × machine guns
• Armour: Belt: 0.98" (25mm); Deck: 0.752 to 0.98" (19mm to 25mm); Turrets: 0.98" (25mm); Conning Tower: 25 mm (0.98 in)
• Aircraft carried: 2 x floatplanes (Ning Hai only)

The two Thai ships (the Thonburi-class) were sometimes referred to as 'pocket heavy cruisers', as they carried the same 8-inch guns as the Japanese Navy's heavy cruisers. However, their speed was more in keeping with their role as coastal defence ships.

The Thonburi-class's characteristics were:

• Displacement: 2,265 tons
• Dimensions:
• Length: 251ft (76.0m)
• Beam: 47ft 4 in (14.43m)
• Draught: 13ft 8in (4.17m)
• Propulsion: 2 x MAN diesels driving 2 propellers
• Speed: 15.5 knots
• Range: 11,100 nautical miles
• Complement: 234
• Armament: 4 × 8" (203mm) guns (2 x 2); 4 × 3" (76mm) anti-aircraft guns (4 x 1); 4 × 40mm anti-aircraft guns (4 x 1); 4 x 20mm anti-aircraft guns (4 x 1)
• Armour: Belt: 2.5" (64mm); Turrets: 4" (102mm); Barbettes: 4" (102mm); Decks: 1" to 1.5" (25mm to 38mm); Control Tower: 4" (102mm)

These two classes make an interesting comparison, especially as the Japanese never built equivalent ships for their own navy. They preferred to use obsolete and partially re-armed armoured cruisers, although they did take the Chinese ships into service in 1944 as escort ships. Both had been sunk by Japanese aircraft in 1937, and had subsequently been raised and used as training vessels and barracks ships (Ning Hai became Mikura and Ping Hai became Mishima). Both ships were renamed when they were returned to service as escort ships, Ning Hai becoming Ioshima, and Ping Hai became Yasoshima. They were sunk by the US Navy on 19th September (Ioshima) and 25th September 1944 (Yasoshima).