The is a

main battle tank A main battle tank (MBT), also known as a battle tank or universal tank, is a tank that fills the role of armor-protected direct fire and maneuver in many modern armies. Cold War-era development of more powerful engines, better suspension s ...

developed and used by the

Japan Ground Self-Defense Force The Japan Ground Self-Defense Force ( ja, 陸上自衛隊, Rikujō Jieitai), , also referred to as the Japanese Army, is the land warfare branch of the Japan Self-Defense Forces. Created on July 1, 1954, it is the largest of the three service ...

(JGSDF), built by

Mitsubishi Heavy Industries is a Japanese multinational engineering, electrical equipment and electronics corporation headquartered in Tokyo, Japan. MHI is one of the core companies of the Mitsubishi Group and its automobile division is the predecessor of Mitsubishi Moto ...

. Development started in 1955 and the vehicle was first deployed in April 1961. The type number follows the year of deployment. A total of 560 Type 61s were manufactured between 1961 and 1975, when production ceased. It was succeeded by the Type 74.

History

The

Empire of Japan The also known as the Japanese Empire or Imperial Japan, was a historical nation-state and great power that existed from the Meiji Restoration in 1868 until the enactment of the post-World War II 1947 constitution and subsequent for ...

had produced a wide range of

armoured fighting vehicle An armoured fighting vehicle (AFV) is an armed combat vehicle protected by armour, generally combining operational mobility with offensive and defensive capabilities. AFVs can be wheeled or tracked. Examples of AFVs are tanks, armoured ca ...

s. After the Surrender of Japan, however, all AFV development and construction had ceased, and Japan had lost the technology needed to build and manufacture tanks and armored vehicles. However, due to the

Korean War {{Infobox military conflict , conflict = Korean War , partof = the Cold War and the Korean conflict , image = Korean War Montage 2.png , image_size = 300px , caption = Clockwise from top: ...

, the

Supreme Commander of the Allied Powers was the title held by General Douglas MacArthur during the United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It con ...

ordered Japan to re-militarize, forming an armed police force (initially the National Police Reserve, later called the National Security Force, and finally renamed the Japan Ground Self Defense Force) and provided

M4A3E8 Sherman The M4 Sherman tank was produced in several variants, a result of mass production spread across several manufacturers and several years. It was also the basis for a number of related vehicles and Shermans have been modified by several nations, ra ...

medium tank A medium tank is a classification of tanks, particularly prevalent during World War II which represented a compromise between the mobility oriented light tanks and the armour and armament oriented heavy tanks. A medium tank's classification ...

s and

M24 Chaffee The M24 Chaffee (officially Light Tank, M24) was an American light tank used during the later part of World War II; it was also used in post–World War II conflicts including the Korean War, and by the French in the War in Algeria and the Firs ...

light tank A light tank is a tank variant initially designed for rapid movements in and out of combat, to outmaneuver heavier tanks. It is smaller in size with thinner armor and a less powerful main gun, tailored for better tactical mobility and ease o ...

s. These tanks had seen heavy use during

World War II World War II or the Second World War, often abbreviated as WWII or WW2, was a world war that lasted from 1939 to 1945. It involved the World War II by country, vast majority of the world's countries—including all of the great power ...

, and after their handover to Japan they required total mechanical overhauls in only a few years. Since a large amount of parts were being consumed on the Korean peninsula, it was necessary to produce the spares used in Japan domestically, and

procedural knowledge Procedural knowledge (also known as knowing-how, and sometimes referred to as practical knowledge, imperative knowledge, or performative knowledge) is the knowledge exercised in the performance of some task. Unlike descriptive knowledge (also kno ...

of American style tank design and maintenance began to accumulate. One bonus shared by the Sherman and Chaffee in Japanese use was that the average Japanese crewmember was of shorter stature than American soldiers, and the tanks were considered spacious by Japanese standards. Based on this experience, the Director General of the Defense Agency ordered the to develop a new domestic tank in 1955. During the Korean War, the performance of the

T-34 The T-34 is a Soviet medium tank introduced in 1940. When introduced its 76.2 mm (3 in) tank gun was less powerful than its contemporaries while its 60-degree sloped armour provided good protection against anti-tank weapons. The Chri ...

and

M26 Pershing The M26 Pershing was a heavy tank/medium tank of the United States Army. It was used in the last months of World War II during the Invasion of Germany and extensively during the Korean War. The tank was named after General of the Armies John J. ...

had made it clear that new Japanese tanks would require 90mm main guns. Among the tank officers of the JGSDF there were two design plans for the new tanks. One was a 25-ton tank, to match the difficult terrain of Japan, with its paddy fields and weak ground. The other was a 35-ton tank, more than big enough to carry a 90mm gun. Both plans had advantages and disadvantages, but after intense discussion, the 35-ton design was adopted. From 1956 to 1960, a series of four prototypes, numbered STA1 to STA4, were produced, and testing began in 1957. STA3/4 were satisfactory for JGSDF and introduced into service in April 1961.

Design

The Type 61 is conventionally laid out, with a central turret and the engine located at the rear of the hull. The tank has a crew of four: a commander, driver, gunner and loader. The hull is welded steel, with a cast steel turret. The maximum armour thickness is quoted as 64 millimeters. The driver sits at the front right of the hull, with a hatch immediately above him, and three vision periscopes covering the forward arc. To the driver's left is the transmission, which can be accessed for servicing by removing a large panel on the front of the hull. The commander and gunner sit in the turret on the right side, with the commander provided with a large domed

cupola In architecture, a cupola () is a relatively small, most often dome-like, tall structure on top of a building. Often used to provide a lookout or to admit light and air, it usually crowns a larger roof or dome. The word derives, via Italian, fr ...

with a hatch on the rear of it. The gunner does not have a hatch and is seated forward of the commander. A tool storage box was normally mounted externally on the rear of the bustle, and three

smoke grenade Smoke grenades used at demonstrations in Paris, 2008 upBritish L83A1 Smoke Grenade manufactured in May 2008. This grenade has already been used. A smoke grenade is a canister-type grenade used as a signaling device, target or landing zone mark ...

launchers were mounted on each side of the turret. Two large radio antenna were also attached to the rear of the bustle.

Engine and drive

The tank was powered by a 570

horsepower Horsepower (hp) is a unit of measurement of power, or the rate at which work is done, usually in reference to the output of engines or motors. There are many different standards and types of horsepower. Two common definitions used today are th ...

Mitsubishi HM21 WT V12

turbocharged In an internal combustion engine, a turbocharger (often called a turbo) is a forced induction device that is powered by the flow of exhaust gases. It uses this energy to compress the intake gas, forcing more air into the engine in order to pro ...

diesel mounted at the rear of the hull and exhausting through pipes on either side of the rear of the hull. The engine is coupled to a Mitsubishi manual transmission system which uses a controlled differential steering system. The track is driven from the front, and has six rubber road wheels on each side along with three return rollers. The suspension is a

torsion bar A torsion bar suspension, also known as a torsion spring suspension, is any vehicle suspension that uses a torsion bar as its main weight-bearing spring. One end of a long metal bar is attached firmly to the vehicle chassis; the opposite end term ...

system with the first, second and sixth road wheel fitted with hydraulic shock absorbers. At the beginning, Japanese engineers intended to adopt the cross drive system studied by observing the repair work of the

M47 Patton The M47 Patton was an American main battle tank, a development of the M46 Patton mounting an updated turret, and was in turn further developed as the M48 Patton. It was the second American tank to be named after General George S. Patton, comma ...

of the American military which was done in Japan, but did not realize it.

Armaments

M36 tank destroyer The M36 tank destroyer, formally 90 mm Gun Motor Carriage, M36, was an American tank destroyer used during World War II. The M36 combined the hull of the M10 tank destroyer, which used the M4 Sherman's reliable chassis and drivetrain combine ...

was rented around 1955 and was used as a reference material for the mounting method of 90mm gun. During this period, tanks armed with 100 mm high-caliber cannons began to appear outside Japan, so using a similarly large calibre gun in the new domestically produced tanks was considered. But after examining the M36, 90mm ammunition was felt to be the upper limit of what an average Japanese tanker could handle effectively. Additionally, due to the mountainous landscape of Japan, it was unlikely that long range engagements would occur frequently and it was thought that a 90 millimeter gun would be sufficient. Based on this decision, a Type 61 90 millimeter calibre rifled gun was adopted as its main gun. The gun is fitted with a t-shaped

muzzle brake A muzzle brake or recoil compensator is a device connected to, or a feature integral to the construction of, the muzzle or barrel of a firearm or cannon that is intended to redirect a portion of propellant gases to counter recoil and unwant ...

, which diverts firing gases sideways, and reduces the amount of dust kicked up by firing. Its breech uses a horizontally sliding breechblock for loading the fixed cartridge cases. The loader is provided with a small hatch, which has a small flap in it for ejecting spent shell cases by hand. Storage is provided for eighteen rounds in the bustle at the rear of the turret, with additional rounds being distributed in various positions inside the tank. The commander's cupola has four vision blocks, which are angled upward, and a one-meter base

stereoscopic rangefinder A stereoscopic rangefinder or stereoscopic telemeter is an optical device that measures distance from the observer to a target, using the observer's capability of binocular vision. It looks similar to a coincidence rangefinder, which uses differen ...

with x7 magnification. The gunner has a x6 magnification periscope, as well as a ×6 magnification sight. A

M1919A4 The M1919 Browning is a .30 caliber medium machine gun that was widely used during the 20th century, especially during World War II, the Korean War, and the Vietnam War. The M1919 saw service as a light infantry, coaxial, mounted, aircraft, and ...

7.62 mm machine gun is mounted next to the gun as a

coaxial machine gun A weapon mount is an assembly or mechanism used to hold a weapon (typically a gun) onto a platform in order for it to function at maximum capacity. Weapon mounts can be broken down into two categories: static mounts and non-static mounts. Stat ...

, and a M2 12.7 mm machine gun is normally mounted on the commander's cupola for anti-aircraft use.

Deployment history

The initial production rate was low, with only ten tanks produced in 1961 and 1962, increasing to twenty in 1964 and thirty in 1965 and 1966. A total of 250 had been produced by 1970, with production continuing at an increased pace until 1975, when it was terminated. A total of 560 were produced. The tanks were phased out of service in the 1990s, with 400 in service in 1990, and 190 in service in 1995. All were decommissioned by 2000, 39 years after their original deployment. During this period, the Type 61 received minor upgrades in the form of infra red searchlights and/or smoke dischargers. From 1980, Type 61's began to be supplemented by the more modern Type 74 MBT.

Operators

* – 560 in service between 1961 and 2000

Variants

* Type 67 AVLB (Armored Vehicle Launch Bridge) (67式戦車橋) * Type 70 ARV (Armored Recovery Vehicle) (70式戦車回収車)

Notes

References

Books

* * *

External links

The history of Type61
JGSDF MANIACS {{Cold War tanks, style=wide Main battle tanks of the Cold War Main battle tanks of Japan Cold War military equipment of Japan Japan Ground Self-Defense Force Mitsubishi Heavy Industries armored vehicles History of the tank Military vehicles introduced in the 1960s