The BTR-50 is a Soviet amphibious armoured personnel carrier based on the PT-76 amphibious light tank chassis. The BTR-50 was tracked, unlike most members of the BTR series, which were wheeled.

Like the PT-76, the BTR-50 has a flat, boat-shaped hull. Unlike the PT-76 it has a new superstructure added to the front of the vehicle. The hull of the BTR-50 is made of all-welded steel with the crew compartment at the front, troop compartment in the center and the engine compartment at the rear. It has an ability to transport up to twenty fully equipped infantrymen who sit on benches which run across the full width of the troop compartment. They mount and dismount the APC by climbing over the sides of the hull. Driver sits in the center of the front of the hull and has three vision blocks and periscopes located at the top of the sloping glacis plate. During night operations the center periscope is switched for the TVN-28 night vision device which gave the driver a clear vision up to 60 meters. The driver also has a small hatch that opens upwards and while it can't be used for the driver to leave the vehicle, it can be opened by the driver in relatively safe areas for extra vision. When in combat the hatch is closed and the driver can use a vision block for a limited vision. Under the driver's seat there is an emergency hatch which can be used by all crew members. The commander who sits on the left hand side of the front of the vehicle has three vision blocks and periscopes in a projecting bay and a copula with vision block on it's basis facing forward. It is located on top of projecting bay, opens forwards and can be locked vertically. The vehicle can operate in temperatures between -40°C and +40°C.[2]

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. Road wheels are hollow to ensure additional amphibious abilities. Usage of hollow road wheels increased APC'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 with a single pin have 96 chain links each when new. There is a small, thin, horizontal skirt over each track. The engine used in the BTR-50 is the V-6 6-cylinder 4-stroke in line water-cooled diesel engine developing 240 hp (179 kW) at 1800 rpm gives it a road speed of 44 km/h with a cruising range of 400 km. The vehicle can cross 30° side slopes, 60° gradients, 1.1 m high vertical obstacles and 2.8 m wide trenches. The engine has a cooling system and initial heater (intended for ignition when air temperature is -20°C or below). The BTR-50 amphibious APC had the 5 gear manual shaft-type transmission system similar to the one in T-34/85 medium tank. The gearbox has four forward gears and one reverse gear. The vehicle has a side clutch that enables it to make turns, mechanical transmission and a bandbrake. The vehicle has three fuel tanks, two in the right side of the front of the engine compartment and the other one at the rear. All three fuel tanks carry 400 liters of fuel when combined. The vehicle has four mounts for additional external fuel tanks in the rear of the hull. The two mounts on the corners of the hull are for a flat type external fuel tanks and the two mounts in the center of the rear of the hull are for a drum type external fuel tanks.

BTR-50 is amphibious thanks to its flat, boat-shaped hull which is hermetical and ensures minimal resistance when APC is afloat and can swim after switching on the two electric bilge pumps, erecting the trim vane which improves the stability and displacement of the vehicle in water and prevents the water from flooding the bow of the APC and switching the driver's periscope for a swimming periscope that enables the driver to see over the trim vane. There is also a manual bilge pump for emergency use. The bilge pumps keep the APC afloat even if it is hit, damaged or leaks. In water it is propelled by two hydrojets, one in each side of the hull, with the entrance under the hull and exits at the rear of the hull. There are also additional assistant water-jet entrances in both sides of the hull over the last road wheels. The rear exits have lids that can be fully or partially closed, redirecting the water stream to the forward-directed exits at the sides of the hull, thus enabling the vehicle to turn or float reverse, for example to go left the left water-jet is covered, to go the right the right water-jet is covered and to make a 180° turn the left water-jet sucks in water and the right water-jet pushes it out. This system was designed by N. Konowalow. It is the same system as the one used in PT-76 amphibious light tank. The vehicle has a low freeboard of 15 m to 20 m and lacks a snorkel therefore it has swimming capability limited to only the calmest waters.

It's armour composed of homogeneous, cold rolled, welded steel is very thin by modern standards, 13 mm in the front, 10 mm on sides and top, 7 mm in the rear. While it's maximum armour protects it fully against small arms fire and small artillery shell fragments, it doesn't protect it against big artillery shell fragments and a .50-calibre machine gun fire which can penetrate BTR-50 maximum armor of 13 millimeters. Also while it's front armour protects it against 7.62 mm small arms fire, the 7.62 machine gun fire can sometimes penetrate it. The vehicle is equipped with an IR driving light and an IR searchlight. It lagged behind other Soviet armoured fighting vehicles because it had no fire or NBC (nuclear, biological, chemical) protection systems, which significantly reduced its effectiveness. The only APC variant to have NBC protection system was the BTR-50PK.

The BTR-50 was developed in 1952 and entered service with the Soviet Army in 1954. The BTR-50P was first shown in public on November 1957.[1] It served in motorized rifle regiments of tank divisions and mechanized brigades in the Soviet and East German armies. The typical mechnized brigade consisted of three battalions of which each had thirty APCs and one command vehicle. They were replaced in front line service by BMP-1 IFV. Command vehicle variants were employed by many Warsaw Pact armies. Finland still employs the BTR-50 chassis as the basis for a communication vehicle used within the latest digital field communication network.

Along BTR-50, the OT-62 TOPAS were used by Egypt and Syria in the Six-Day War (1967). Some vehicles were captured and commissioned by the Israel Defense Forces. Both sides used BTR-50 APCs during War of Attrition (1968 - 1970). During operation "Raviv" (8-9 September 1969) - an amphibious raid across the Suez channel three T-54 tanks and six BTR-50 APCs were used to wreak havoc behind the Egyptian lines. During the Yom Kippur War (1973) the BTR-50 and OT-62 TOPAS APCs were also employed by both sides. Some of the Israeli BTR-50 and OT-62 TOPAS were later transferred to the South Lebanon Army.