PT - 76 The PT - 76 is a Soviet light amphibious tank which was introduced in the early 1950s and soon became the standard reconnaissance tank of the Soviet Army and the other Warsaw Pact armed forces . It was widely exported to other friendly states , like India , Iraq , North Korea and North Vietnam . Overall , some 25 countries used the PT - 76 . The tank ' s full name is Floating Tank – 76 ( , " Plavayushchiy Tank " , or ) . " 76 " stands for the caliber of the main armament : the 76 . 2 mm D - 56T series rifled tank gun . The PT - 76 is used in the reconnaissance and fire - support roles . Its chassis served as the basis for a number of other vehicle designs , many of them amphibious , including the BTR - 50 armored personnel carrier , the ZSU - 23 - 4 self - propelled antiaircraft gun , the ASU - 85 airborne self - propelled gun and the 2K12 Kub anti - aircraft missile launch vehicle . Development . After World War II , the concept of light tanks was resurrected in the USSR . They were to be used in reconnaissance units and therefore an amphibious ability was essential . The requirements stated that the vehicle should be able to cross water obstacles with little preparation . Many prototypes of such light tanks were built in the late 1940s . The most successful was designed by the engineer N . Szaszmurin working at the Kirov plant in Leningrad in 1948 . The vehicle was successful because it had a simple design , good navigational traits and a good cross country capability . At the time , its water - jet design was innovative . Further development of the design was carried out between 1949 – 1951 under the leadership of Zh . Y . Kotin , and the tank was officially adopted on August 16 , 1952 with the designation PT - 76 . Production started in 1953 at the Volgograd Tractor Factory and the Kirov plant in Leningrad . The Model 1 was produced in limited numbers and was quickly replaced in production by the Model 2 . In 1958 an improved variant , the PT - 76B , was adopted and remained in production until 1968 . Design . The PT - 76 has a typical tank layout : the steering compartment at the front , the combat compartment in the center and the engine compartment at the back . The tank has a three - man crew , with the commander also acting as the radio operator and gunner . This reduces his effectiveness as an observer . The commander and loader stations are located inside the turret , the commander sits on the left - hand side of the main gun and the loader sits on the right . They have a large oval shaped double hatch which opens forwards on top of the turret . The driver sits in the center of the front of the hull and has a one piece hatch that opens to the right , with three vision blocks and periscopes located beneath the main gun at the top of the sloping glacis plate . Under the driver ' s seat there is an emergency hatch which can be used by all crew members . At night the center periscope is swapped for a TVN - 28 night vision device which gives the driver clear vision up to 60 meters . Armament . Its main armament consists of a 76 . 2 mm D - 56T series rifled tank gun which has an effective range of approximately 1 , 500 meters and a rate of fire of six to eight rounds per minute . This gun is 42 caliber s long . The PT - 76 carries 40 rounds for its gun . A typical ammunition load consists of 24 x OF - 350 Frag - HE , 4 x subcaliber AP - T , 4 x AP - T and 8 x BK - 350M HEAT rounds . The gun is mounted in an oval dish - type circular truncated cone turret with flat sloping sides which is mounted over the second , third , and fourth pair of road wheels . All PT - 76s have a fume extractor for the main gun at the rear of the turret . The 7 . 62 mm SGMT coaxial medium machine gun comes with 1 , 000 rounds . This weapon has a maximum effective range of 1 , 000 meters in daylight while the vehicle is stationary , 400 to 500 meters in daylight while the vehicle is on the move and 600 meters at night . Maximum range is 1 , 500 meters . It can be fired in 2 to 10 round bursts and has a practical rate of fire of 250 rounds per minute and a cyclic rate of fire of 650 rounds per minute . The main gun is considered light for a modern tank which can fire BM - 354P HVAP , undercaliber AP - T , AP - T , BR - 350 API - T and OF - 350 Frag - HE rounds ( as can the 76 . 2 mm M1942 ( ZiS - 3 ) divisional gun ) and is capable of penetrating the armour of APCs and other lightly armored vehicles . The commander / gunner has a cupola on the left side of the double hatch . The cupola has the TPKU - 2B observation device and two TNP day periscopes and can be rotated 360 degrees by hand . The commander also has a 4X optical sight mounted to the left of the main armament and a TShK - 66 sight / rangefinder . The loader has the MK - 4 observation device mounted on the turret ' s roof in front of the hatch . Ammunition Characteristics . The BM - 354P High Velocity Armor Piercing ( HVAP ) round has a maximum effective range of 650 meters by day and 600 meters at night . Its maximum aimed range is 1 , 060 meters . It can penetrate 127 mm of armour at muzzle and 50 mm at 1 , 000 meters . The armour piercing round can pierce 60 mm of armor inclined at 60 degrees from a range of 2 , 000 meters . The BK - 350M High Explosive Anti Tank or HEAT round has a maximum effective range of 650 meters by day and 600 meters at night . Its maximum range is 1 , 000 meters . It can penetrate 280 mm of armour at 1 , 000 meters . The OF - 350 Frag - HE round has a maximum effective range of 600 meters at night and a maximum range of 4 , 000 meters . The gun can be fired while the vehicle is afloat . The gun can also be depressed and elevated between - 4 and + 30 degrees so like most Soviet tanks , the PT - 76 has a limited ability to depress its main gun , and therefore cannot fire effectively from higher ground . One of the greatest disadvantages of the gun used on the PT - 76 Model 1 was that it had no stabilization system and therefore couldn ' t be effectively fired while the vehicle was on the move . The PT - 76 Model 2 has a 1 - axis stabilization system and the PT - 76B has a 2 - axis system . Countermeasures . The armor of the PT - 76 consists of homogeneous , cold rolled , welded steel . Its turret has 20 mm at 35° at the front , 16 mm at 35° at the sides , 11 mm at 33° at the rear and 8 mm at 0° on top of the turret . The hull is made up of : 10 mm at 80° at the upper front , 13 mm at 80° at the lower front , 14 mm at 0° at the sides , 7 mm at 0° in the rear and 5 mm at 0° underneath . This gives it protection against 7 . 62 mm small arms fire and small artillery shell fragments . It does not protect it against 12 . 7 mm or . 50 - caliber heavy machine gun fire or larger shell fragments . Mobility . Tactical mobility . The torsion bar suspension consists of six evenly spaced large rubber - tired road wheels with the drive sprocket at the rear and the idler at the front . The road wheels are hollow to minimize weight . These hollow road wheels increase the tank ' s buoyancy by 30 % . There are no track - return rollers . The first and last road wheels have a hydraulic shock absorber and the steel tracks have 96 links each when new , each link has a single pin . There is a small , thin , horizontal skirt over each track . Its V - 6 6 - cylinder 4 - stroke in line water - cooled diesel engine develops 240 hp ( 179 kW ) at 1 , 800 rpm which gives it a road speed of 44 km / h and a range of 370 km to 400 km . The vehicle can cross 1 . 1 m high vertical obstacles and 2 . 8 m wide trenches and climb 52° gradients . The engine has a cooling system and an initial heater ( intended for use when the air temperature is - 20°C or colder ) . The PT - 76 has a 5 speed manual shaft - type transmission system similar to the one in the T - 34 / 85 . The gearbox has four forward gears and one reverse . The vehicle has a side clutch that enables it to make turns and a bandbrake . The tank has four mounts for additional external fuel tanks at the rear of the hull . The two on the corners are for flat type external tanks and the two in the center are for a drum type . These additional tanks increase the range from 370 km - 400 km to 480 km - 510 km . The PT - 76 is a reliable , simple to operate and highly mobile reconnaissance vehicle and is ideally designed for amphibious operations , but it has many limitations as a fighting vehicle . Strategic mobility . The PT - 76 is amphibious , it has a flat , boat - shaped hull which is hermetical and ensures minimal resistance when the tank is afloat . It can swim after switching on the two electric bilge pumps , erecting the trim vane which improves the vehicle ' s stability and displacement in the water and prevents water from flooding into the bow of the tank . Switching the driver ' s periscope for a swimming periscope enables the driver to see over the trim vane . When not in use the trim vane is stowed in the front of the bow over the barrel of the main gun and serves as additional armor . Bilge pumps keep the tank afloat even if it leaks or is damaged . There is a manual bilge pump for emergency use . The tank is propelled through the water by two hydrojets , one on each side of the hull , with the inlets undermeath the hull and the outlets at the rear . There are also additional assistant water - jet inlets on both sides of the hull over the last road wheels . The rear outlets have lids that can be fully or partially closed , redirecting the water stream to the forward - directed outlets at the sides of the hull , thus enabling the vehicle to turn or go in reverse . To go turn to the left for example , the left water - jet is covered , to turn to the right , the right water - jet is covered . To make a 180° turn , one water - jet sucks in water while the other pushes it out . This system was designed by N . Konowalow . It is the same system as the one used in the BTR - 50 APC which was based on the PT - 76 . The tank can swim at up to 10 , 2 km / h and has a range of 100 km . It can cross most water obstacles and can also swim in the sea . However , its amphibious design makes it disproportionally large for a vehicle of its weight and allows less armor protection than other light tanks . Equipment . The PT - 76 is equipped with a tank communication device , a gyro compass , a 10 - RT - 26E radio and has an antenna for it which extends itself when needed . It also has two headlights in front of the hull and a searchlight on the right - hand side of the top of the turret . It lagged behind other Soviet armoured fighting vehicles because only the driver had a night vision device and also because it has no fire or NBC ( nuclear , biological , chemical ) protection systems , which significantly reduced its effectiveness . The lack of NBC protection ended with the PT - 76B which has the PAZ ( " protivo - atomnaya zashchita " ) NBC protection system . Because only the driver has night vision equipment , the crew has a vision range of by day and at night . Service history . About 12 , 000 PT - 76s were built during the vehicle ' s lifetime , of which some 2 , 000 were exported . Over 25 countries employed the vehicle , including Afghanistan , Albania , Angola , China , Congo , Cuba , Egypt , Finland , Guinea , Hungary , India , Indonesia , Iraq , Laos , Madagascar , Mozambique , North Korea , Pakistan , Poland , Vietnam , and Yugoslavia . The PT - 76 was used as the standard reconnaissance tank of the Soviet Union and Warsaw Pact armies . It was also intended for water obstacle fording operations and naval infantry landings . It served in the reconnaissance subunits of tank divisions and mechanized divisions of the Red Army and Soviet marines divisions . Although it has been replaced in front line service by the BMP - 1 and BRM - 1 , it may still be found in the reconnaissance companies and battalions of some motorized rifle and tank regiments and divisions , as well as in naval infantry units . Aside from its reconnaissance role , it is also used for crossing water obstacles in the first wave of an attack and for artillery support during the establishment of a beachhead . The main disadvantage of the BMP - 1 and the BRM - 1 when compared to the PT - 76 is the absence of a powerful main armament . However , the BRM - 1 is fitted with more modern reconnaissance equipment . Also , both vehicles have stronger front armor and superior mobility features and the BMP - 1 can carry up to 8 fully equipped soldiers inside . The PT - 76 is still on active service in a number of countries mainly in the third world . The Russian Army is reported to have used PT - 76 units in the ongoing war in Chechnya . The PT - 76 is used / stationed by / in following Russian units / bases : 61st tank repair plant ( 1 ) , 61st Kirkinesskaya marine brigade ( 26 ) from Sputnik which is part of the Murmansk military district , 175th marine brigade ( 26 ) from Tumannyy which is part of the Murmansk military district and 336th Belostokskaya marine brigade ( 26 ) from Baltyysk which is part of the Kaliningrad military district . In Ludowe Wojsko Polskie ( LWP ) , PT - 76 " s " and PT - 76B " s " were used by the reconnaissance subunits of tank divisions and mechanized divisions and Coastal Defense units including the 7th Lusatian Landing Division ( officially known as 7th Coast Defense Division ) . Poland also operated FROG - 5 " Luna " tactical missile launch vehicles . PT - 76 " s " were in service with the Indian Army and they were in reserve status before they were withdrawn from service in 2009 after which they were used for target practice by the army and as static memorials at various military facilities . Combat Service . The Vietnam War . PT - 76 " s " along with T - 54 " s " , T - 55 " s " , Type 59 " s " and Type 63 " s " formed the bulk of the NVA armored forces . The first successful action of NVA armor was against the Lang Vei Special Forces camp on 6 / 7 February 1968 . Thirteen PT - 76s , of the NVA 202nd Armored Regiment spearheaded an assault against approximately 24 Green Berets and 500 irregulars . The defenders fought back with M72 LAW s ( Light Anti - Tank Weapons / 66 mm ) , and requested support from nearby Khe Sanh , who were unable to help , as they too , were under siege . The few survivors broke out , and were airlifted to safety . The first tank to tank engagement occurred in mid 1968 when a US reconnaissance airplane observed a PT - 76 being washed by its crew in the Ben Hai River in the DMZ ( 17th Parallel ) . The Forward Air Control pilot radioed the tank ' s position to a nearby M48 Patton tank unit of the US 3rd Marine Tank Battalion . With the FAC adjusting fire , the Patton fired three 90 mm rounds ; obtaining a hit with the third round . The tank crew abandoned their vehicle . Shortly afterward , some returning F - 4 Phantom jet fighter bombers , with ordnance to expend , observed the PT - 76 and bombed the vehicle into scrap metal . As expected , the F - 4 ' s claimed the kill . Battle of Ben Het . Of the US Army ' s three armor ( tank ) battalions in Vietnam , only the 1 / 69th engaged in a tank to tank duel . On March 3 , 1969 , the Special Forces camp at Ben Het was attacked by the NVA 202nd Armored Regiment . The 202nd was tasked with the mission of destroying the camp ' s 175 mm self - propelled guns . One of the PT - 76s had detonated a land mine , which not only alerted the camp , but also lit up the other PT - 76s attacking the firebase . Flares had been sent up , thus exposing adversary tanks , but sighting in on muzzle flashes , one PT - 76 scored a direct hit on the turret of a M48 , killing two Patton crewmen and wounding two more . A second Patton , using the same technique , destroyed a PT - 76 with their second shot . At daybreak , the battlefield revealed the wreckage of two PT - 76s and one BTR - 50 armored personnel carrier . First combat use of the TOW Missile . On May 9 , 1972 , the PT - 76 unwillingly participated in changing the story of armored warfare . On April 24 , 1972 , a US special experimental UH - 1B helicopter team , consisting of two helicopters mounting the new XM26 TOW anti - tank missile ( Tube Launched , Optically Tracked , Wire guided ) , accompanied by technicians from Bell Helicopters and the Hughes Aircraft Corporation arrived in country . The team , labeled the " 1st Combat Aerial TOW Team " deployed to the Central Highlands in Vietnam and commenced gunnery training . From May 2 , the team made daily flights in search of enemy armor . On May 9 , NVA armored units attacked the Ranger camp at Ben Het ; the TOW team destroyed 3 PT - 76s and broke up the attack . On May 26 , the North Vietnamese Army made another attempt to retake the city of Kontum . TOW aircraft were brought in at first light and found NVA tanks moving almost at will through portions of the city . Conventional air strikes would prove risky to friendly forces , but the TOW proved to be ideal for picking off enemy tanks . At the end of the first day , the two TOW helicopters had destroyed 9 tanks and damaged one more . Five of the destroyed tanks had been T - 54 / 55 s and the remaining four destroyed and one damaged were PT - 76s . By the end of the month , TOW missiles launched from helicopters had 47 confirmed kills , of which 24 were tanks . Other Combat Service . North Vietnamese PT - 76s were involved in the only tank - against - tank battle of the war prior to the US withdrawal . In a night assault on a US Special Forces camp , in which the Americans had been warned , the garrison , which had been reinforced with a platoon of M48A3 main battle tanks from the 1st Battalion 69th Armored battalion . The garrison also included a CIDG unit . The engagement took place on March 3 , 1969 at Ben Het in Kontum Province near the Laotian border . The North Vietnamese fired 639 artillery and mortar rounds into the camp , before a battalion from the 66th NVA Regiment supported by ten PT - 76s and a few APCs attacked the west hill held by a CIDG company supported by the platoon of M48s . The PT - 76s drove into a minefield in which two were destroyed . Two more PT - 76s and one APC were destroyed by the M48As . Six PT - 76s were destroyed by artillery fire and airstrikes . US casualties consisted of one M48 being lightly damaged . . The PT - 76 also saw action with Indian forces in the Indo - Pakistani War of 1965 and 1971 . Despite the PT - 76 being obsolete by 1971 , the superior tactics and overwhelming numbers of the Indian Army enabled it to play a vital role in defeating the Pakistani Army . In the Eastern theater the high numbers of PT - 76s proved superior to the Pakistani World War II era M24 Chaffee light tanks . It was a different story in the western theater where they proved incapable of facing Pakistani M48 Patton and Type 59 main battle tanks especially at the crucial Battle of Chhamb . The PT - 76 also saw service in the Six Day War ( 1967 ) during which the Israeli army destroyed or captured about 200 Egyptian T - 54 , T - 55 and PT - 76 tanks . During the Yom Kippur War in 1973 PT - 76s were used during the crossing of the Great Bitter Lake by the Egyptian 135th Marines Brigade . It also saw service in the Angolan Civil War ( 1975 – 2002 ) . During the Yugoslav wars , the PT - 76 saw service with the Yugoslav Peoples Army and later the army of the Krajina Serbs in a few battles during the Ten - Day War in Slovenia ( 1991 ) and Croatian War of Independence ( 1991 – 1995 ) . The Indonesian Navy used its PT - 76Bs on the Indonesia n island of Ambon during civil unrest from 2000 onwards . The PT - 76E is fitted with a more powerful UTD - 20 6 - cylinder 4 - stroke V - shaped airless - injection water cooled multifuel 15 . 8 litre diesel engine . It develops 300 hp ( 224 kW ) at 2 , 600 rpm and is taken from the BMP - 1 as is the transmission . The power to weight ratio has been improved to per ton . This also increases the maximum road speed from 44 km / h to 60 km / h , with an average cross country speed from 32 km / h to 42 km / h . The vehicle has new tracks . Driver fatigue has been reduced . The vehicle ' s survivability on the battlefield is improved with the introduction of a new fast - acting firefighting system . The vehicle also has improvements in fire control and optical equipment . This modernization program increases the PT - 76 ' s performance by 2 . 7 times , which is still comparatively low . The vehicle was accepted by the Russian marines in 2006 and about 40 or 50 vehicles were ordered .