100 mm 3UBK10-1 and 3UBK10M-1 rounds with

series gun barrel. It is guided towards its target by the 1K13 fire-control sight. Each T-55 MBT can carry six 100 mm 9M117 gun-launched missile rounds. In 1996, the 100 mm 9M117M missile, part of the 3UBK10M-1 round, was announced. The main change from the standard 9M117 missile, is the introduction of a tandem warhead capable of defeating active armour. During 1999 the 9M117M1 Arkan round was introduced with a potential range increase to 5,000-5,500 m, once a few minor modifications have been made to the existing fire-control system and guidance units. The 9K116-1 Bastion system was developed by the KBP design bureau (Design Bureau for Instrument Building) at Tula, also known as Tulamashzavod. An adaptation of the Bastion system for 105 mm tank guns has been proposed capable of producing a hit probability of 0.8 over ranges of 100 to 5,000 m. Known as Spear, this 105 mm version is marketed in conjunction with Diehl and Krauss Maffei of Germany (see separate entry). Description The complete 100 mm 3UBK10-1 gun-launched missile round resembles a piece of conventional ammunition. It is a fixed round with the missile projectile secured to the cartridge sleeve by a crimping ring just behind the copper drive band on the projectile body. However, the body of the missile extends almost to the base of the cartridge sleeve and the missile contains its own rocket motor. The 100 mm 3UBK10-1 gun-launched missile round is handled and loaded in the same manner as a conventional round. Once it is chambered, the laser section of the fire-control system, including the 1K13 tracker unit with a built-in missile guidance laser channel, is used to select and track a target and the missile is fired electrically. A 12/1 tubular ejection charge, containing a high nitrogen content in the cartridge sleeve, propels the missile along the barrel so that, once clear of the muzzle and after 1.5 seconds, a sustainer rocket motor cuts in to provide propulsion for approximately 6 seconds. During the early part of its trajectory and once a base unit has been jettisoned, stabilising fins at the tail unfold while small control fins are deployed pyrotechnically from the nose portion. Internal gyros are used to control the trajectory. The 9M117 missile can only be launched once the infra-red laser section of the fire-control system is switched on. The gunner places his aiming point on the target and maintains it there before and after the gun is fired. Laser receivers on the missile tail receive encoded trajectory correction signals. These are processed to alter the position of the nose-located control fins and thus guide the missile towards its target. The 9M117 missile has a 9H136M shaped charge warhead, formed from OKFOL-3.5 (HMX/Wax 95/5), located in the portion of the missile body behind the nose and control fin area and ignited by a 9E256 point detonation/graze actuated fuze. No confirmed details are available regarding the penetration capability of the 9H136M warhead but it is understood to be 650 mm of passive armour; a more conservative reference quotes 550 mm (which seems the more likely, especially as one Russian sales brochure quotes only 275 mm). The maximum engagement range of the 9K116 Bastion system is 4,000 m and minimum range 100 m. Time of flight to 4,000 m is 12 to 13 seconds. If the 9M117 missile misses its target it will self-destruct after an interval of 26 to 41 seconds. The 9M117M missile used with the 3UBK10M-1 round differs in having a tandem warhead formed by a precursor charge and a main shaped charge. The missile length is increased to 1.106 m although the missile weight remains at 18.4 kg. Armour penetration performance is quoted as 550 mm of rolled homogeneous armour and it is capable of defeating reactive armour. All other operating and other details are identical to those of the standard 9M117 missile. The exact production status of the 9M117M missile is uncertain although sales brochures promote it as part of a T-55 MBT update package along with upgraded armour. The 9M117M1 Arkan missile, introduced during 1999, has a potential maximum effective range of 5,000 to 5,500 m, once minor modifications have been made to the fire-control system and guidance units. Without the modifications the maximum effective range remains at 4,000 m. Armour penetration performance is given as 700 to 750 mm, although a complete penetration of Explosive Reactive Armour (ERA) is not assured. At least two hits are required to penetrate ERA. The 9M117M1 Arkan missile can be used with all other 100 mm gun/launcher systems, including the 2A70 used on the BMP-3 IFV. Authorised fuzes Integral PD 9E256 Equivalent rounds BULGARIA Marketing agency Kintex Type: 100 mm 3UBK10-1 round with 9M117 guided projectile Description: Specifications as text BULGARIA Manufacturer Vazovski Machinostroitelni Zavodi Type: 100 mm 3UBK10-1 round with 9M117 guided projectile Description: Specifications as text