OT-62 TOPAS Information

The OT-62 TOPAS is a series of amphibious tracked armoured personnel carriers developed jointly by Poland and Czechoslovakia (ČSSR). OT-62 stands for Obrněný Transportér vzor 62 – "armoured personnel carrier model 62". TOPAS stands for Transportér Obrněný Pásový – "tracked armoured personnel carrier".

In the late 1950s Czechoslovakia bought a license to produce BTR-50s from the Soviet Union. The received documentation was used to develop a new tracked armoured personnel carrier for Czechoslovak army and Ludowe Wojsko Polskie (LWP). The work started in 1958 and the first prototype was completed in 1962. After it passed the trials it was accepted and received the name TOPAS.

Because the standard TOPAS vehicle used by the LWP (Polish Peoples Army) was unarmed, the design bureau of Wojskowa Akademia Techniczna (WAT) (Military Technical Academy) designed a variant armed with a new turret placed centrally on top of the superstructure. Another TOPAS variant was designed by Wojskowy Instytut Techniki Pancernej i Samochodowej (Military Institute of Armour and Car Technology). The new variant received the designation WPT-TOPAS and was a technical support vehicle.

Like the BTR-50PK, the OT-62 TOPAS has a flat, boat-shaped hull and has a superstructure in the front of the vehicle. The hull of the OT-62 TOPAS is made of all-welded rolled steel with the crew compartment at the front, troop compartment in the center and the engine compartment at the rear. It can transport up to sixteen fully equipped infantrymen who sit on benches which run across the full width of the troop compartment. Their primary way of mounting and dismounting the APC is by climbing over the sides of the hull and going through two rectangular roof hatches. However, OT-62 TOPAS has side hatches in the sides of the superstructure, making for a good alternative to the rectangular roof hatches; thus it doesnt have the protection issue of BTR-50 APC in which the passengers didnt have any kind of alternative route in and out.

The 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 gives the driver a clear vision up to 60 meters. The driver also has a small hatch that opens upwards and, while it cant be used for the driver to leave the vehicle, it can be opened 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 drivers seat is an emergency hatch which can be used by all crew members.

The commander who sits on the left side of the front of the vehicle has three vision blocks, periscopes in a projecting bay, and a cupola with vision block on its basis facing forward. It is located on top of projecting bay, opens forward, and can be locked vertically. It also has two projecting bays like the BTR-50PU command vehicle instead of the one in BTR-50 APCs. However, the bays are different in shape. The second projecting bay also has three vision blocks and periscopes. On top of the second projecting bay is a cupola which replaces the additional rectangular roof hatch from the BTR-50PK.

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 ensure additional amphibious abilities. Usage of hollow road wheels increased APCs 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. OT-62 has the PV-6 6-cylinder, inline diesel engine developing 300 hp (224 kW) at 1,800 rpm. The engine gives it a road speed of 60 km/h with a cruising range of 450 km – 550 km. The vehicle can cross 0.9 m high vertical obstacles and 2.8 m wide trenches and climb 38° gradients.

OT-62 TOPAS is amphibious thanks to its flat, boat-shaped hull which is hermetical and ensures minimal resistance when APC is afloat, It 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 drivers 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, is 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 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 in 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., and is the same system as in the PT-76 amphibious light tank. The vehicle has a low freeboard of 15 cm to 20 cm; however, it can compensate for this by using the snorkel, the mount for which is located on the right side of the front of the engine deck.

The vehicle is equipped with an IR driving light and an IR searchlight. The searchlight was removed from the right side of the front of the superstructure, as the area there was used for the second projecting bay. It was instead fitted on the commanders cupola. It also has two mounts for shovels on either side of the front of the vehicle as well as two mounts for pickaxes on the left side of the superstructure. A stowage bucket is placed centrally in the front of the engine deck.

OT-62 TOPAS entered production and service with the Czechoslovak army in 1963 and shortly after it also entered service with Ludowe Wojsko Polskie (LWP) in the early 1960s. As an amphibious vehicle based on the PT-76 which was already in use, the TOPAS APC along with improved TOPAS-2AP was used by the Coast Defense units including the 7th Lusatian Landing Division (officially known as 7th Coast Defense Division). It was also exported to another Warsaw Pact member, Bulgaria, and several other countries around the world, including Angola, Egypt, India, Iran, Iraq, Libya, Morocco, Sudan and Syria.

Along with 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 and OT-62 TOPAS APCs during War of Attrition (1968–1970). 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.

Morocco used ex-Egyptian OT-62 during Western Sahara War. Moroccan armed forces lost 13 of them after a battle in Lebuirat on 24 August 1979.

OT-62 TOPAS also saw service with the Iraqi army during First Persian Gulf War and 2003 Invasion of Iraq.

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