M60 Patton

Impetus

During the Hungarian Revolution of 1956, a Soviet T-54A medium tank was driven onto the grounds of the British embassy in Budapest by the Hungarians. After a brief examination of this tank's armor and 100 mm gun, British officials decided that their 20 pounder was apparently incapable of defeating it. There were also rumors of an even larger 115 mm gun in the works. Hence there was a need to adopt a 105 mm gun, which emerged as the famed Royal Ordnance L7. This information made its way to the United States, where the Army had been experimenting with a series of upgrades to their M48 Patton tanks. These experiments were concerned with improving the armor and the introduction of a variety of autoloader systems, such as that used in the 105 mm gun tank T54, and upgraded rangefinders.

The T95 program, launched after the Questionmark III conference in June 1954, was the intended replacement to the M48. It featured a host of innovative and experimental components such as its 90 mm smoothbore T208 cannon rigidly affixed to its turret, and its new powertrain and suspension. The burden of developing them however slowed the overall program to a crawl. General Taylor approved of a new tank development program in August 1957. This incorporated many ARCOVE recommendations and foresaw the eventual replacement of the light, medium, and heavy tanks with two types: the airborne reconnaissance/assault vehicle, and the main battle tank (MBT). The MBT was to combine the firepower and protection sufficient for the assault role with the mobility to perform as a medium tank. A tank of the T95 series, armed with a smoothbore cannon and powered by a compression ignition engine, was envisaged by the Army Staff as the bearer of the role of future MBT.

The course of this tank program was the source of widespread debate. The Bureau of Budget (BOB) believed that the Army was not progressing with sufficient speed in its tank modernization program and recommended the immediate replacement of the M48A2. Correctly predicting that the BOB would not approve the procurement of the M48A2 after the fiscal year of 1959, the Deputy Chief of Staff, Logistics (DCSLOG) proposed a tank based on the M48A2 featuring improved firepower and the AVDS-1790 engine. The alternative was to introduce a tank from the T95 series, but it remained highly experimental with its compression ignition engine not as developed as the AVDS-1790. An influential group of senior officers, by May 1958, concluded that the T95 had only marginal advantages over the M48A2. They proposed that the most important improvements, better firepower and fuel economy, could be achieved by mounting a compression ignition engine and a more powerful gun on the M48A2.

Choice of components

The main gun was chosen after a comparative firing test on the Aberdeen Proving Grounds. Participating in the test were six guns: the 90 mm M41 (armament of the M48A2 although tested with the new T300E53 HEAT round), the 90 mm T208E9 (a smoothbore weapon firing T320E62 APFSDS), the 105 mm X15E8 (a British gun developed from the 20 pdr), the 105 mm T254 (an American gun firing the same APDS ammunition as that of the British), the 120 mm T123E6 (a lightened variant of the M58), and the 120 mm M58 (armament of the M103). The 120 mm T123E6 was preferred by the Ordnance Department because its ammunition, the same as that for the M58 gun, was already at an advanced state of development. The T123E6 however had a slow rate of fire as, unlike the M58 on the M103, there would be only be one loader servicing it. This led to the weapon having a max rate of fire of 4 rpm vs. the T254's 7 rpm. The factors evaluated were accuracy, lethality of a hit, rate of fire and penetration performance. Based on these tests, the 105 mm T254E2 was selected and standardized as the M68. Until American-made tubes could be obtained with comparable accuracy, British tubes were to be used.

Composite armor made with fused silica glass was intended on the turret and the hull. This composite armor provides protection against HEAT, HEP, and HE rounds. However, repaired castings suffered a loss of kinetic energy protection. This led to the front of the hull taking the shape of a flat wedge, instead of the M48's elliptical front, as it simplified the installation of this armor. Limitations in manufacturing capacity and the added cost however lead to this special armor being dropped and all M60 series tanks were protected with conventional steel armor.

Initial versions

In 1957, plans were laid in the US for a universal or all purpose tank. Fulfilling this requirement with an interim tank resulted in the M60 series, which largely resembles the M48 it was based on, but has significant differences. The M60 mounted a 105 mm M68 main gun with the bore evacuator mounted towards the middle of the tube, compared with the M48's 90 mm M41, which mounted the bore evacuator towards the end of the tube right after its T-shaped muzzle brake. It also had a hull with a straight front slope whereas the M48's hull was rounded, had three support rollers per side to the M48's five, and had road wheels constructed from aluminum rather than steel, although the M48 wheels were often used as spare parts.

The improved design incorporated a Continental V-12 750 hp (560 kW) air-cooled, AVDS-1790-2 diesel engine, extending operational range to over 300 miles (480 km) while reducing both refueling and servicing. Power was transmitted through a CD-850-6 cross drive transmission, a combined transmission, differential, steering, and braking unit.

The hull of the M60, like its predecessor the M48, could be cast as a single piece or by welding smaller castings. The turret was similar to the M48A2's and was made as a single piece casting although it was modified to accept the new larger diameter cupola and the M116 mount for the 105 mm gun. The hull was divided into three compartments, with the driver in front, fighting compartment in the middle and engine at the rear. The driver looked through three M27 day periscopes, one of which could be replaced by an M24 infrared night vision periscope.

The M60 was the last U.S. main battle tank to utilize homogeneous steel armor for protection. It was also the last to feature an escape hatch under the hull. (The escape hatch was provided for the driver, whose top-side hatch could easily be blocked by the main gun. Access between the driver's compartment and the turret fighting compartment was also restricted, requiring that the turret be traversed to the rear).

Originally designated the XM60, the new vehicle was put into production in 1959, standardized as the 105 mm Gun Full Tracked Combat Tank M60 on 16 March 1959, and entered service in 1960. There was a proposal in April 1959 to change the nomenclature to 105 mm gun main battle tank M60; this was however rejected due to a conflict with the Federal Cataloging Agency Policy. Over 15,000 M60s (all variants) were built.

M60A1 series

Approved in March 21, 1960 was the initial program that lead to the M60A1. This new variant was first produced in October 1962 and stayed in production until 1980, featured a larger, better-shaped turret and improvements to the armor protection and shock absorbers.

While the M60 continued to use the turret based on the M48A2's, T95E7 style turrets were not abandoned. Work continued on an elongated turret based on its design. The turret, even without the siliceous cored armor, provided improved ballistic protection. Additional space for the turret crew was also made available by mounting the cannon 5" forward. In addition to the added protection offered by this turret on production M60A1s, the upper glacis armor was increased from 3.67 inches to 4.29 inches at 65 degrees while the sides over the crew compartment went from 1.9 inches to 2.9 inches at their apex. This brought the frontal armor up to the same 10" line of sight armor standard of the M103 heavy tank. Shock absorbers were installed in the first two and last road wheel arms. The uncomfortable wire mesh seats were replaced by padded seats. The brake and accelerator pedal were rearranged for more efficient and comfortable operation while the steering wheel was replaced by a T bar steering control. The engine and power train were upgraded by the addition of the Continental AVDS-1790-2A and the CD-850-6A. The new engine lowered fuel consumption and smoke emissions. Combination day-IR periscopes were introduced, the M32 for the gunner and the M36 for the commander although the commander's periscope could be substituted with the M34 for binocular vision without IR.

As development of a new main battle tank stalled with problems and cost escalating quickly, the M60A1 was forced to serve longer than originally intended with production lasting over 20 years. In that time span numerous product improvement programs were put forward. The first of which was TLAC, for Top Loading Air Cleaner. This reduced dirt and dust ingestion, which increased engine life. Its top loading configuration also made it easier to service. Next came the AOS meaning Add-On Stabilization that was introduced in late 1972. As its name implies, this was an add on stabilizer kit made to fit with minimum modifications to the existing hydraulic gun control system. It was made up of several components: the rate sensor package, a control selector box, the electronics package, a shut-off valve, the traverse servo-valve assembly, the elevation servo-valve assembly, the handle shaping assembly, an hydraulic filter, and an antibacklash cylinder. At short to medium ranges, hit probabilities better than 50% from a moving M60A1 were obtained in Aberdeen test results while without a stabilizer it was essentially zero. M60A1(AOS) was the designation received by M60s equipped with the TLAC, AOS and the new T142 steel track, which had replaceable rubber pads and improved service life.

In 1975, the M60A1(RISE) meaning Reliability Improved Selected Equipment was introduced. Its AVDS-1790-2C diesel engine engine featured several changes in order to improve service life and reliability: new top-loading air cleaners; stronger cylinders; improved starter, fuel injection lines, and nozzles; and better turbosuperchargers. A new 650 ampere oil cooled alternator, a solid state regulator and new wiring harness with more accessible disconnect were also incorporated into its electrical system. The M60A1(RISE)(PASSIVE), which debuted in 1977, featured passive night vision sights for gunner and commander, a new night vision device for the driver and a deep water fording kit.

M60A2 "Starship"

The M60A2 was intended as a stop-gap solution until the projected replacement by the MBT-70. The M60A2, nicknamed the "Starship" due to its "Space Age" technology, featured an entirely new low-profile turret with a commander's machine-gun cupola on top, giving the commander a good view and field of fire while under armor but spoiling the low profile. It featured a 152 mm (6.0 in) main gun similar to that of the M551 Sheridan light tank, which fired conventional rounds as well as the MGM-51 Shillelagh anti-tank missile system. The fitting of a CBSS (closed breech scavenger system), which used pressurized air to clear the breech after each shot, solved the problem of unburnt propellant from the main gun rounds fouling the barrel and pre-detonating subsequent rounds. The M60A2 proved a disappointment, though technical advancements would pave the way for future tanks; the MBT-70, which relied on much of this technology as it was used in the M60A2, never advanced beyond prototype stage. The Shillelagh/M60A2 system was phased out from active units by 1981, and the turrets scrapped. Most of the M60A2 tanks were rebuilt as M60A3, or the hulls converted to armored vehicle-launched bridge (AVLB) vehicles.

M60A3 series

In 1978, work began on the M60A3 variant. It featured a number of technological enhancements, including smoke dischargers, a new flash-lamp pumped ruby-laser based rangefinder (AN/VVG-2) that could be used by both commander and gunner, an M21 ballistic computer, and a turret stabilization system.

Late production M60A3s omitted the commander's cupola. Compared to a conventional pintle mount, the remote-controlled M85 machine gun was relatively ineffective in the anti-aircraft role for which it was designed. Removing the cupola lowered the vehicle's relatively high silhouette. The cupola's hatch also opened toward the rear of the vehicle and was dangerous to close if under small-arms fire owing to an open-locking mechanism that required the user to apply leverage to unlock it prior to closing. U.S. Army A3 version all retained the cupola until the tank was phased out of service.

The M60A3 was phased out of US service as a training aid in 2005, but it has remained a front-line MBT into the 21st century for a number of other countries.

In May 2016, Raytheon revealed they had engineered a Service Life Extension Program (SLEP) for the M60A3 as a cost-effective upgrade to procuring more modern tanks. Changes include increased engine power from 750 hp to 950 hp, new electric turret controls that are faster, more responsive, and quieter than the previous hydraulic controls, adding the larger L44 120 mm gun along with digital fire-control and targeting systems with thermal sights, and protection enhancements of side skirts, slat armor, and likely reactive armor. The M60A3 SLEP puts the vehicle's performance on par with tanks such as the T-72 and M1A1 Abrams, while keeping training and maintenance costs down as crews are already familiar with the basic M60. The vehicle has undergone testing at the U.S. Army's Aberdeen Proving Grounds. Changing out the hydraulics with electronic systems decreases weight by one ton and the digital FCS allows for firing on the move.

United States

The M60-based M60 AVLB (Armored Vehicle Launch Bridge) and the M728 Combat Engineer Vehicle were the only variants of the M60 deployed to South Vietnam. The AVLB, commonly referred to as the "bridge tank", was mounted on an M60 tank hull, and the M728 Combat Engineer Vehicle was an M60 tank mounting a short-tubed 165 mm (6.5 in) main gun that fired a HEP round.

Late in the M60's U.S. Army service a number of prototype upgrades were evaluated. These were passed over in favor of simply producing more M1 Abrams. Due to the end of the Cold War, surplus US Army M1s were absorbed into the remaining USMC units, allowing the Marine Corps to become an all-M1 tank force at reduced cost. Except for a small number in active service, most M60s were placed in reserve, with a few being sold to US allies.

The M60A3 participated in close air support trials with the F-16 in the 1980s. M60A1s are still used by the USAF for testing of ground radar equipment on new aircraft and for ground force adversarial work at Red Flag at Nellis AFB Nevada. USMC M60A1 tanks were used in Grenada and Beirut in 1983.

During Operation Desert Storm in 1991 at least one US Air Force unit was equipped with M60s. The 401st TFW (P), deployed to Doha, Qatar had two M60s for use by explosives ordnance disposal personnel. It was planned that using the MBTs would allow the EOD crews to remove unexploded ordnance from tarmac runway and taxiway surfaces with increased safety.

In early February 1991, US Marines used 200 M60A1s of the 2nd Battalion drove north from Khafji, Saudi Arabia into Kuwait. In Kuwait, they encountered an Iraqi force of T-54/55, Type 69, and T-72 tanks at Kuwait City International Airport. The Marines won this battle, destroying some 100 Iraqi tanks with only one M60A1 lost.

The last 18 M60A3s were maintained at the Combat Maneuver Training Center (CMTC) near Hohenfels, Germany. They were used in the OPFOR Surrogate role by Delta company 1st Battalion, 4th Infantry Regiment until 2005.

Israel

The Israel Defense Forces (IDF) purchased its first M60A1 tanks from the US in 1971. M60s and M60A1s saw action with Israel during the 1973 Yom Kippur War in both the Sinai and the Golan Heights (although mainly in the Sinai). The United States sent additional M60s to Israel just before and during hostilities. Israel had about 150 M60A1 tanks in service at the start of the war. Many Israeli M60s were destroyed by Egyptian troops with AT-3 Sagger anti-tank missiles in the first few days after Egyptian forces crossed of the Suez Canal. The tank is highly regarded in Israeli service and been praised for its firepower and maneuverability.

Following the war, the IDF received many more M48s, M60s and M60A1s from the U.S. Israel further upgraded their inventory of M60s through the 1970s and into the 1980s. The Israeli modifications included new tracks and explosive reactive armor (ERA). This variant was known as the Magach. Further work in Israel has been done on the upgraded Magach models, adding new armor, new fire control system, a thermal sleeve and smoke dischargers. The latest versions, the Magach 7 (with variants A through C), have been used by some IDF units.

In the 1982 Lebanon War (Israeli Operation Peace in Galilee), M60 Pattons (locally named Magach 6) encountered Syrian T-54/55 and T-72s as well as PLO T-34s. Some were destroyed by Syrian infantry hunter-killer teams with ATGMs and supplemented by RPG-7s. Several other M60s were damaged by HOT missiles fired from Syrian Gazelle helicopters. One Magach 6 was destroyed by a T-72 and another was abandoned by its crew after taking damage.

In July 2013, Israel began a program called Teuza (boldness) for the purpose of turning some military bases into sales lots for obsolete IDF equipment. Older models that are not suited for Israel's forces will be sold off, or sold for scrap if there are no buyers. M60A1/A3 and Magach tanks are among those being offered. Main buyers are expected from Latin American, Asian, and African countries.

With the disbanding of the last M60-equipped divisions in 2014, the tank is no longer in service with the Israel Defense Forces.

Kuwait

The M60A1 RISE Passive of the U.S. Marines saw action during Operation Desert Storm in the 1991 Persian Gulf War, opposing Iraqi armor which included the T-54, T-55, T-62, Type 69, and T-72. The M60A1s were fitted with add-on explosive reactive armor (ERA) packages and supported the drive into Kuwait City, where they were involved in a two-day tank battle at the Kuwait airport with ten tanks lost. They saw service with the United States Marine Corps and the Saudi Arabian Army.

Other users

Extensive numbers of M60 tanks served within the Iranian military during the Iran–Iraq War, with varying combat success during the eight years of attrition and campaigning.

The U.S. military continues to have significant stockpiles of M60s waiting to be scrapped, sold-off, converted, or used as targets in weapons testing, or used for radar objects for jet attack planes. Some vehicles that use the chassis are still in use, however. Most of the M60s still used are much upgraded models. Pattons formed the basis for many 'new' tank designs, some using the chassis but with all-new turrets, others using various upgrade packages. Jordan, for example, is modifying two battalions of M60A3 with the IFCS system.

In 2005, M60 variants were in service with Bahrain, Bosnia, Brazil, Egypt, Greece, Israel, Jordan, Portugal, Spain, Tunisia, Turkey, Thailand, ROC (Taiwan), Iran, and some other nations to varying degrees. Royal Thai Army M60A3s were engaged in combat to recapture Border Post 9631 from Myanmar Army forces in 2001, and reportedly exchanged fire with Type 69 tanks.

Greece offered to donate 13 M60A3 tanks to Afghanistan in 2007.

Variants

Specialized

Additional equipment:

International

Operators

Former operators