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	1,030 (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, with an average protection value similar to the glacis. With DFM, the TR-65/68 are protected from hand-held anti-tank weapons like RPGs, single charge second-generation ATGMs like the Fagot and early TOW/MILAN missiles, 105 mm and 120/125 mm HEAT shells, and 105 mm APFSDS. It is even able to resist early 120 mm APFSDS like the DM13 and DM23, but against the more modern DM33 (1987) or JM33 fired out of a 120 mm L/44 barrel, with 470 mm of penetration at 2,000 meters, the tank is protected from a distance greater than 1,500 meters.

However, the most significant drawback to the DFM package is 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. The weight alone negatively impacts speed and mobility, and with the armor mass all at the front and unbalanced, it wears down the turret drive and suspension more rapidly.

Add-on armor

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.

All TR-65/TR-68s also received a belly armor package to protect against anti-tank mines. It consisted of 20 mm steel plates spaced 80 mm from the hull bottom, located where the driver's station would be, as well as a reinforcing strut inside the tank. Though simple, it significantly increased the survivability of the tank and its crew, at the cost of reduced clearance.

Smoke

All Riysian tanks since the TR-56 have had the Sahaaba thermal smoke generator (سحابة, Cloud), which is controlled by the driver. Fuel is injected into the exhaust, which generates thick, persistent white smoke that obscures in the visible, NIR, and SWIR bands, and is the same temperature as the tank, potentially offering some concealment against thermal imagers. 10 liters of fuel are used per minute during smoke generation, and the generator can be used for up to ten minutes continuously with a five minute break in between uses. Six smoke grenade launchers are also available to lay a defensive smokescreen, with three on each side of the turret firing forwards.

Tanks upgraded as part of the New Model program replaced those six launchers with the extensive RDD-1 Sadeem smoke launcher system, with a total of 16 launchers (8 RDD-1/A, 8 RDD-1/B), which was integrated as part of the larger Nadi-1 defensive aids system. The RDD-1/A, used for laying smoke approximately 300-350 meters in front of the tank, is controlled by the loader, while the RDD-1/B, used for generating a defensive smokescreen close to the tank, is operated by the commander.

Active protection systems

Starting in 1985, TR-65/68MJs received the Nadi-1 defensive aids system, with the NIL-D Nadi (ندى, Dew) laser warning receiver mated to the RDD-1 Sadeem (سديم, Nebula) smoke launcher system. The addition of a laser warning system with automatic smoke grenade launchers, a rare feature in its time, significantly increased the combat effectiveness of the tank series.

Later on in the 1990s, TR-68MJAs that were still in service received the Saraab-1 active protection system, as well as some of the TR-65/68s in storage. Many of the mothballed TR-65/68s have likely further received the improved Saraab-2 system as a cheap upgrade, allowing it to remain relevant against ATGM threats.

CBRN defense

Like the TR-56 before it, the TR-65 was equipped with the advanced Mina nuclear collective protection system, with a gamma radiation detection unit and a supercharger in the ventilation system. Within 0.3 seconds of the detection of gamma radiation, all openings and portholes would be explosively sealed using an electrical trigger, and the supercharger would activate generating overpressure inside the now sealed-off crew compartment. The ventilation's NBC filter would scrub any air entering in; the crew could safely operate in a WMD environment without having to don any extra gear. In the event of a failure in the detection unit, or if biological or chemical weapons were present instead, both the seals and the supercharger can be activated manually by the driver.

Concurrently with the launch of the TR-56A, the TR-68 added an anti-radiation/spall lining to the crew compartment. Made of lead-impregnated polymer textile sheets, the new liner reduced the amount of penetrating (gamma & neutron) radiation experienced by the crew by 9 times and background radiation by 14 times, and reduces the amount of spall generated by a penetrating hit as well as narrowing the spray cone of a shaped charge. The lining could not be retrofitted to the TR-65 as the crew compartment was too cramped to handle its thickness.

With the New Model upgrade, the Mina system was replaced by the more advanced Arafah NBC collective protection system, also used by the T-72AVR tanks. Arafah features a cyclone air sampler to detect biological and chemical weapons, and a control panel for the driver, with a dosimeter and colored lights for different threats (nuclear burst, background radiation, biochemical contaminants). The response time was reduced to under 0.1 seconds. Also, both the TR-65MJ and the TR-68MJ received external anti-radiation cladding protecting against neutron bombs, made of a boronated polymer textile, further increasing crew protection.

Firefighting and incendiary protection

All TR-65/68s are equipped with an automated halogen fire extinguishing system, which is also installed on the TR-56. Eight thermal sensors and fourteen extinguisher nozzles are spread throughout the tank, in both the engine space and the fighting compartment. The system can operate automatically, or semi-automatically, where the crew is warned and the commander or driver can choose if and when to activate the extinguishers. Due to the toxicity of the halogen gas mixture, the crew must evacuate the tank if the system is activated. In addition to the system, a standard CO2 fire extinguisher is typically located in the driver's compartment, serving as a backup or for extinguishing small fires.

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 (1965) - Basic model of the TR-65. Approximately 1,030 completed at 'Adra Tank Factory exclusively, producedfrom 1965 to 1969.
    • TR-65AQ (1968) - Command derivative for battalion and brigade commanders, with additional radios and navigation equipment. Only 38 rounds are carried to make room for the command equipment.
  • TR-65B (1974) - First major upgrade to the TR-65 series, as part of a larger program involving the TR-68. A new laser rangefinder/main sight and night sight is installed, along with a stabilizer upgrade, new rubber-lined tracks with increased durability, and an anti-napalm protection system. The mass of the tank is increased by approximately 500 kg to 38.1 tonnes.
  • TR-65MJ - "New Model" upgrade of TR-65s. Differs from the TR-68MJ by using a different engine and adding rubber sideskirts, along with the incendiary protective equipment found on the TR-68s.
    • TR-65MJQ (1980) - Command variant, same as TR-65AQ but with more modern equipment and the New Model upgrade.
    • TR-65MJ-1 (1998) - Further modification of the TR-65MJ with spare FCS taken from the TR-83. Limited number converted.
• 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.