T-62R

TR-65 / TR-68 Rammah
A TR-65MJ on trials in a foreign country.
Type	Main Battle Tank
Place of origin	Riysa
Service history
In service	1965 - 1999
Used by	Riysa
Production history
Designer	'Adra Tank Factory
Designed	1960 - 1964
Produced	1965 - 1985
No. built	680 (TR-65) 3,780 (TR-68)
Specifications
Weight	37.6 tonnes (TR-65) 38.3 tonnes (TR-68)
Length	9.496 m gun forward
length	6.068 m (TR-65) 6.63 m (TR-68)
Width	3.30 m
Height	2.395 m
Crew	4 (Commander, gunner, loader, driver-mechanic)
Main armament	115 mm/51 64M smoothbore cannon
Secondary armament	Coaxial 7.92 mm RMAS-D machine gun Cupola 12.7 mm RThT anti-aircraft machine gun or RMTR machine gun
Engine	Motor Adra MA428 12-cylinder diesel/multi-fuel, 730 hp (544 kW)
Transmission	Semi-automatic transmission Five forward, two reverse gears
Suspension	Torsion bar
Ground clearance	450 mm
Operational range	550 km on internal fuel
Speed	Up to 58 km/h on road, 42 km/h off-road

The TR-65 and TR-68 Rammah (رماح, English: Lancer) are Riysian main battle tanks of the second generation, replacing the first-generation TR-56 Fateh. Created on the basis of the T-62 tank mixed with domestic engineering solutions and other foreign components, they are commonly referred to collectively as the "T-62R" series of tanks. From 1965 to 1985, around 680 TR-65s and 3,780 TR-68s were completed.

History

New Model

By the 1980s,

Technical characteristics

Protection

Base armor

The TR-65 and TR-68 have a classic all-steel protection scheme, similar in layout to the TR-56, but revised with thicker armor. With the TR-65/68 being intended to be used in an offensive, MBT-like multipurpose role, significant emphasis was placed on making the new medium tank resistant to the latest tank guns and ammunition. Despite the widespread belief that shaped charges rendered heavy armor obsolete, having a high level of protection was still considered important due to AP ammunition remaining the most common threat.

As defined in development, the primary objective was to resist APDS shots from the 105 mm guns just entering service, at combat distances of at least 1,000 meters, and allow for a field of maneuver of at least 30° off-center. Using the L28A1/DM13/M392 as a representative round, such a shot would penetrate 300 mm of armor steel perpendicularly and 120 mm of steel angled at 60° from the horizontal.

Armor characteristics

Tank section	Armor thickness	Angle
Upper glacis	135 mm	60°
Lower glacis	132 mm	50°
Side hull	80 mm (+ 20 mm HHS sideskirts on TR-68)	-
Rear hull	45 mm	2°
Hull top	Up to 30 mm	-
Hull bottom	20 mm	-
Turret front	275 mm	20°
Turret sides	165 mm (175 mm on TR-68)	-
Turret rear	65 mm	-
Turret roof	Up to 54 mm	-

Based on official data, the upper glacis plate of the TR-65 and TR-68 has a thickness of 135 mm and is angled at 60°, and the lower glacis plate is 132 mm thick and is angled at 50°. The turret is as thick as 275 mm with a slight angle of 20° at its front, and with its heavy sloping and optimized shape, a similar level of protection is maintained throughout the frontal arc. The tanks are thus resistant to early APDS at at least a distance of 1,000 m, and likely so even until close range.

For the sides, the TR-65 features 80 mm of hull armor, and 165 mm of turret armor at a slight angle. The TR-68 adds 20 mm high hardness steel (HHS) ballistic sideskirts - believed approximately equivalent to 24 mm of armor steel against KE threats - which are mounted approximately 610 mm away from the hull, and increases the turret's side armor to 175 mm. The side hull of the TR-65 is resistant at an angle of 20° at 1,000 m, giving it a field of maneuver of 40 degrees, and the TR-68 boosts this to 54° of maneuvering, both values being greater than the amount specified in the tanks' original requirement.

With this degree of protection, the TR-65/68 were a formidable opponent for their time. Even when faced by the most advanced generation of APDS represented by the mid-1970s L52 series, they are able to remain resistant and maneuver at 1,000 meters or greater, though they become vulnerable closer than that. Although it wasn't specified in the initial requirement, the thickness of the armor also gives the tank some protection against 120 mm APDS; using the L15A3 as an example, the tanks are protected from it at 2,000 meters.

Unfortunately like all tanks of its era, the TR-65/68 has no effective countermeasures against HEAT/shaped charges, though the high thickness of the frontal armor may allow it to frontally resist rifle grenades and early LAWs. However, it was discovered that the large slope of the upper glacis may cause HEAT munitions to not properly fuse on impact, preventing them from detonating.

As a consequence of these requirements, these tanks dedicate a significant amount of weight to armor - around 19.3 tonnes for the TR-65, and 19.5 tonnes for the TR-68. This makes up about 51-52% of the total weight for both production versions, which is slightly more than the TR-56, and relatively on the high end for tanks, but not extremely so.

The base armor is obsolete against modern tank ammunition, and is not protected against HEAT, but is still effective against some threats. Both the TR-65 and TR-68 are frontally resistant to small-caliber APFSDS rounds - including 40 mm-class autocannons - and APFSDS and some HEAT munitions from low-pressure guns, including the 90 mm-class cannons commonly mounted on recce vehicles and tank destroyers. From the side, both tanks retain this amount of protection in their turrets from at least 1,000 meters if not closer. The side hull of the TR-65 is resistant to 30 mm APFSDS, while the TR-68's remains resistant to 40 mm APFSDS, thanks to the ballistic skirts and air gap acting as spaced armor.

DFM/"Khazaghand" armor package

One of the key goals of the "New Model" upgrade program was to boost the protection of the TR-65/68 back to a useful level, as the base armor had become outdated in the face of new kinetic penetrators, and was highly vulnerable to HEAT. In conjunction with ongoing research into composite and layered armors for the TR-83, an applique composite armor kit known as DFM - short for "Metal-Polymer Armor" (Dira' Filz-Mblemer, درع فلز-مبلمر) - was developed for the TR-65/68, offering enhanced protection against both shaped charges and APFSDS. Deployment of the kit began in 1983, and most TR-68s had received it by the end of 1985, while TR-65s received their kits later.

DFM is an early type of NERA, consisting of a glacis block approximately 160 mm thick mounted directly on the armor, and two wedge-shaped turret blocks which are approximately 300 mm thick, angled at 15°, and mounted 70 mm in front of each turret cheek. Each block consists of a laminate of thin, steeply angled high hardness steel plates and polymer filler, contained in a thin steel box and capped with a heavy front plate also made of HHS. The steel sheets used are around 5 mm thick and are angled at 65° in the glacis block and 55° in the turret blocks, and the polymer is thought to be polyurethane.

While the exact mechanism of action is unclear, as it uses a relatively unique design compared to traditional NERA arrays, it is believed that it should act similarly. When a DFM block is struck by a shaped charge or kinetic penetrator, kinetic energy transferred to the polymer fill causes bulging of the steel plates, which disrupts the action of the penetrator and/or forces more material into its path. This is especially effective against shaped charges, and the bulging action of the plates can place enough stress on a kinetic penetrator to damage or fracture the rod. Furthermore, the thick front plate helps particulate shaped charge jets and decaps/shatters kinetic rounds, and the presence of layered HHS-RHA steel may allow it to act as an even more effective dual-hardness armor array.

The glacis block is mounted onto the armor, giving it an angle of 60°. In the path of a projectile is a 30 mm HHS front plate, followed by a 10 mm RHA box wall, the steel-polymer laminate with a thickness of 110 mm, and the other 10 mm box wall. Turret blocks have a shallower angle of 20°, and so are thicker to maintain comparable performance with the glacis. The front HHS plate is is 65 mm thick, the front wall of the box is 30 mm thick, the laminate filler is 200 mm thick, and a 70 mm air gap exists after the back wall of the box, acting as spaced armor.

The protection offered by DFM is significant. It is estimated that the glacis of the TR-65/68 with DFM is equivalent to 480 mm of RHA armor against kinetic penetrators and 540 mm against HEAT, with the turret at its thickest equivalent to 510 mm against kinetic penetrators and 570 mm against HEAT. This

However, there is a significant downside to the DFM package - its weight. The total package weighs 3.5 tonnes, with 1.9 tonnes going to the turret blocks and 1.6 tonnes to the glacis block.

In addition to the DFM blocks, the New Model upgrade also added some extra armor elements to each Rammah version. The TR-65MJ received new rubber side-skirts protecting against HEAT, and a rubber skirt covering the lower front hull, which in addition to shaped charges also protects against tilt-rod mines. Weight of this package is around 100 kg. The TR-68MJ only received the front skirt, as its ballistic side skirts were already more effective than the rubber skirts.

Variants

• TR-65 - The first version of the Rammah tank, and the first second generation battle tank of Riysa. Only produced from 1965 to 1969, but gave valuable experience in designing a true main battle tank rather than a medium.
  • TR-65A - Basic model of the TR-65. Only produced at 'Adra Tank Factory, from 1965 to 1969.
    • TR-65A1 (1965) - Base production version.
    • TR-65A2 (1974) - Refit of TR-65As with a laser rangefinder/main sight and new night sight, as part of an upgrade program along with the TR-68. To save money, the TR-65A2s only received the new optics and laser rangefinder, rather than the more comprehensive upgrade of the TR-68T.
    • TR-65AQ (1968) - Command model for battalion and regimental commanders, with additional radios and navigation equipment.
  • TR-65MJ - "New Model" upgrade of TR-65s. Differs from the TR-68MJ by using a different engine and adding rubber sideskirts.
    • TR-65MJA (1980) - Base production version.
    • TR-65MJQ (1980) - Command variant.
• TR-68 - Complete redesign of the Rammah tank, derived from the experience gained with the TR-65. Compared to the TR-65, it features a lengthened hull and engine compartment to accept a larger engine, additional fuel capacity, a redesigned suspension with six rollers, a new 8-speed transmission, internal anti-radiation/spall liner, a new turret, and ballistic side-skirts. This was the most produced version of the Rammah.