Japanese Sendai-class (1923) Light Cruisers

Introduction

The Sendai-class was planned as part of the Medium Cruiser Program of 1921/1922. A total of eight ships were originally scheduled to be built in two batches of four each. The Kako was the last in the first batch of which the keel was laid prior to the Washington Treaty in 1922. Because of this treaty, the Kako was already scrapped during her construction and the second batch of the final four (Ayase, Minase, Otonase and a ship without a name) would never be built.

Unidentified ship of the Sendai-class. Source: Wilco Vermeer collection

Definitielijst

Cruiser: A fast warship with 8,000 – 15,000 ton displacement, capable to perform multiple tasks such as reconnaissance, anti-aircraft defence and convoy protection.

Class overview

Sendai (1924)	February 16th, 1922: keel laid October 30th, 1923: launched April 29th, 1924: commissioned November 3td, 1943: sunk in combat
Jintsu (1925)	August 4th, 1922: keel laid December 8th, 1923: launched July 31st, 1925: commissioned July 13th, 1943: sunk in combat
Naka (1925)	June 10th, 1922: keel laid May 24th, 1924: 2nd time keel laid March 24th, 1925: launched November 30th, 1925: commissioned February 18th, 1944: sunk in combat
Kako	February 15th, 1922: keel laid March 17th, 1922: cancelled because of the Washington Naval Treaty
Ayase	Cancelled and re-developed as Furutaka-class
Minase	Cancelled because of the Washington Naval Treaty
Otonase	Cancelled because of the Washington Naval Treaty
without name	Cancelled because of the Washington Naval Treaty

Definitielijst

Washington Naval Treaty: Treaty signed on 6 February 1922 by The United States, Great Britain, France and Italy through which the countries imposed restrictions on each other concerning number, magnitude and armoury of the most important warships to prevent a new arms race.

History

The Sendai-class was a development of the previous Nagara-class, with improved propulsion. The ships were built according to the 1922 naval construction program. The main visual distinction was the additional fourth funnel. Like the previous class, the ships were equipped with a hangar and a flight deck platform above the No. 2 guns. However, the Sendai-class only received aircraft in 1929 when the ships were equipped with a catapult.^[1]

For the benefit of the 8-8 fleet program, the Sendai-class was originally scheduled to comprise of eight ships of 5,500 tons each. However, as a direct result of the restrictions imposed by the Washington Naval Treaty concluded in 1922, four were deleted from the planning, leaving only the remaining four to be constructed. The 3rd cruiser of the remaining batch, Naka (1925), was destroyed on the shipyard slipway by an earthquake on September 1st, 1923, but on May 24th, 1924, the keel for the ship was re-laid. Ultimately, the 4th and final ship to be built, the Kako, was cancelled while already under construction.^[2]

Jintsu. Source: Public Domain (unknown)

The three remaining ships were used during the Second World War as flagships for squadrons of smaller ships and as escort ships. All three Sendai-class vessels were lost in battle during the Second World War.

The light cruiser measured 162 meter in length with a maximum displacement of 7,180 tons and protected by a 64 mm armoured belt and 51 mm armoured deck. The eight oil-fired and four coal-fired boilers generated a power of 90,000 shp, delivering a maximum speed of 35.25 knots (65.28 km/h). The standard armament at the time of design consisted of seven 140 mm primary guns and two 80 mm secondary guns. In addition, the ships had four twin 610 mm torpedo launchers. This armament was changed over the years, with anti-aircraft in particular increasing in quantity. The total standard complemented consisted of 440 men. Initially, the ships were equipped with a hangar below the bridge and a platform from which an aircraft could be launched. This was replaced later by a catapult fitted above the two gun turrets that were positioned aft.^[3]

Definitielijst

cruiser: A fast warship with 8,000 – 15,000 ton displacement, capable to perform multiple tasks such as reconnaissance, anti-aircraft defence and convoy protection.
torpedo: A weapon of war. A cigar shaped body fitted with explosives and a propulsion and control mechanism. Intended to target after launch a nearby enemy ship and disable it by underwater explosion.
Washington Naval Treaty: Treaty signed on 6 February 1922 by The United States, Great Britain, France and Italy through which the countries imposed restrictions on each other concerning number, magnitude and armoury of the most important warships to prevent a new arms race.

Technical specifications

Class:	Sendai-class
Number of ships:	8 (3 built)
Country:	Japan
Type:	Light cruiser
Displacement:	5,195 tons (standard) 7,180 tons (fully loaded)
Length:	163 meter
Beam:	14.20 meter
Draft:	4.90 meter
Propulsion:	4x Brown-Curtiss steam turbines (in the Jintsu) 4x Parsons steam turbines (in the Sendai an the Naka) 12x Kampon boilers / after 1934: 10x Kampon boilers 90,000 shp (67,000 kW) 154kW, 110V electrical 4 propeller shafts
Speed:	35.25 knots (65.28 km/h)
Range:	9,300 km at 14 knots (26 km/h)
Armament (in original design):	7x 140 mm / 50 guns 2x 80 mm / 40 guns 8x 610 mm torpedo launch tubes (4x2) 16x 610 mm torpedos 56 naval mines
Complement:	440

Notes

Stille, 2014, pag. 215

Gogin, 2021, pag. 77

Stille, 2014, pag. 216

Definitielijst

cruiser: A fast warship with 8,000 – 15,000 ton displacement, capable to perform multiple tasks such as reconnaissance, anti-aircraft defence and convoy protection.
torpedo: A weapon of war. A cigar shaped body fitted with explosives and a propulsion and control mechanism. Intended to target after launch a nearby enemy ship and disable it by underwater explosion.