Tone class, HEAVY CRUISERS, 重巡洋艦
IJN Heavy Cruiser CA-17 "Tone"
Displacement: 15,443 t (11,213 t Std)Machinery: 8 boilers, 4 shafts  Main Guns: 4×2×8 in (203 mm)/60 Main Belt: 3.9 in 100 mm
Max Length: 661 ft 5 in 201.6 mMax Power: 152,000 hp 111 796 kW DP Guns: 4×2× 5 in  (127 mm)/40 Decks: 2.5-1.2 in 65-30 mm
Beam: 60 ft 8 in 18.5 mMax Speed: 35 kts 64.82 km/h AA Guns: 6×2× 0.98 in (25 mm) * Barbettes: 0.98 in 343 mm
Draght: 21 ft 4 in 6.5 mRange: 12,000 nm 22 224 km Torpedoes: 4×3×24 in (610 mm) tubes Turrets: 0.98 in 25 mm
Complement: 874 officers & enlisted Bunkerage: 2690 t fuel oil Air Group: E13A1, 2× E8N2 * CTower: 5-2.75 in 130-70 mm

** Antiaircraft armament and Air Group as during the Battle of Midway (June 1942).

Two Tone class cruisers were originally envisaged as the fifth and sixth vessels in the Mogami class, however, by the time construction began, weaknesses in the Mogami class design had become clear, and Japan no longer had any intention of even pretending to abide by the limitations of the London Naval Treaty. This resulted in a new design, which turned out to be quite different from the Mogami class, although external dimensions were very similar. Unique to the ships was the placement of their main armaments forward of the bridge, which left their quarter decks free for aircraft usage. The Tone class cruisers were intended to provide long-range air scouting for cruiser squadrons and to operate together with aircraft carrier task forces. Commissioned in 1938−1939 these ships became the last heavy cruisers produced for the Imperial Japanese Navy.

Tone and Chikuma operated together for almost all of their careers as consorts for aircraft carriers. The ships were part of the covering force during the attack on Pearl Harbor, the Second Battle of Wake Island, operations in the Netherlands East Indies, the Indian Ocean raids, the battles of the Eastern Solomons, Santa Cruz, Philippine Sea, and Leyte Gulf.

Both Tone class cruisers took part in the Battle of Midway as a Cruiser Division 8 allotted to First Air Fleet (First Mobile Force).


Ship Builder Laid Down  Launched    Commisioned    Fate
 CA-17 利根  Tone Mitsubishi Shipyards, Nagasaki   1 Dec 1934     21 Nov 1937     20 Nov 1938     Sunk in action 24 Jul 1945
 CA-18 筑摩 Chikuma  Mitsubishi Shipyards, Nagasaki   1 Oct 1935   19 Mar 1938   20 May 1939   Sunk in action 25 Oct 1944