9M111-2 “Fagot” (Nato; AT-4B “Spigot”) anti tank missile

**pzgr40** · 27th February 2021, 05:01 PM

Cutaway model of a Russian 9M111-2 “Fagot” (Nato; AT-4B “Spigot”) anti tank missile.
The 9M111 is a wire guided roll stabilized medium size anti tank missile designed by the Tula Machinery Design Bureau as a replacement for the AT-3 “Sagger”.
The 9M111-2 (described in this posting) is an improved version of the 9M111 with an improved maximum range and improved armour penetration.
The design of the missile started in 1962 and in 1970 the 9M111 was officially taken into service.
The missile was meant as a man portable anti tank system, but it is also very suitable to be used from a range of vehicles.
When compared to western ATGM’s it can be best compared with the French /German “Euromissile Milan” and the American M47 Dragon when it comes to weight, range and armour penetration.
Steering of the missile is of the SACLOS type (Semi Automatic Command to Line of Sight),
Meaning that the gunner only has to keep the crosshairs of the sight on the target by rotating two wheels –if the target moves- on the 9S451 steering electronics box to guide the missile left / right or up / down.
As this missile is a second gereration anti tank missile, it does not use a joystick anymore to steer the missile to it’s target, making steering through the sight much easier and enhancing the chance of hitting a target first time with an average trained crew to appoximately 90%.

An At-4 anti tank team normally exists of three soldiers; the gunner who carries the 9P135 launcher tripod with the 9S451 steering electronics box as a backpack and the 9Sh119 sight. The loader carries two missile containers and a third soldier also carries two extra containers.
The tripod is set up, a missile is placed on the tripod, the sight is placed and the missile is aimed at the target. The missile is now ready to be fired.
These teams normally operate from a BTR armoured vehicle that has another eight spare missile containers stored.
The weapon has a 360 degrees traverse and a +/- 20 degrees elevation, and can hit targets moving up to 60 km/hr.

Description and functioning of the 9M111-2 missile:
A launching unit exists of two main parts:

The missile, existing of:

- The steering wings (A1) with the steering magnets (A2).
- The electric impact fuze, existing of the outer cup (B1) and the inner cup (B2)
- The shaped charge (C1) with it’s red copper cone (C2) and the wave shaper (C3)
- The 9E234M base fuze (E).
- The sustainer motor (F1) with fuelstick 9Ch145-010 (F2) and the venturi’s (F3).
- The 9Ch237 electric ignition cartridge (G1) for the main engine and the black powder ignition booster charge 9Ch245 (G2)
- The gyroscope, existing of the gyroscope wheel (H1), the gimbal cage (H2) en the sector steering sliding contacts (H3).
- The pop out wings (J1) with it’s fixation band (J2)
- The steering electronics block (K1) with the inertia activation switch (K2)
- The battery’s (L)
- The infra red lamp, existing of the light bulb (M1) and the reflector (M2)
- The spring loaded protective cover halves for the lamp (N1), and the celluloid ring halve (N2)
- The wire spool (O) with 2500 mtrs of wire.

The transport container existing of:

- The container (P).
- The gas generator (Q).
- Electric igniter cartridge 9Ch284 (R) for igniting the gas generator.
- Expulsion charge (tubular powder) 9Ch146 (S).
- The front cover (T1) with the short circuit plug (T2), the lock (T3), the explosive bolt (T4), the connection plug for the guidance wire (T5) and the safety switch (T6).
- The –four- mounting lugs for mounting the container on the tripod (U).
- The back cover(V) held in place by a ring nut (W)
- The electric connection plug to the steering box (X1), the battery housing (X2), the forward (X3) and the afterward (X4) battery.

When placing the container (P) on the tripod the four mounting lugs (U) fall into the slots on top of the tripod. The electric connection plug (X1) is plugged into the 9S451 steering box.
If the sight is aimed at the enemy target, the trigger is pulled. This causes the forward thermicaly ignited battery (X3) in the battery housing (X2) to start delivering current.
The battery ignites the rocket gyroscopic driven wheel (H1) which burns for maximal 0,3 seconds to bring the wheel to it’s maximim rotation speed. The gyroscopic wheel is placed in a three axis gimbal (H2) that is fixated at the moment the wheel is swung in action –the missile still in the container-. It is important to first start the gyroscope in the gimbal as this sets the zero point against which all course corrections are executed. After the gyroscope wheel (H1) is brought to it full speed, the fixating clamp on the gimbal is retracted and the gimbal is free, with the zero point set.
On the inside of the front cover (T1) the short circuit plug (T2) is placed into the contra plug in the nose of the missile. This shortcircuits the fuze of the hollow charge (E), the sustainer motor (G1) and the gas generator (Q), so the missile cannot be fired or armed with the front cover (T1) still closed. A second safety switch (T6) enshures the electric igniter cartridge 9Ch284 (R) for the gas generator (Q) can only ignite if the cover has flipped over 180 degrees into the lock (T3). This alo activates the two battery’s (L) in the lower missile body, so the electric systems of the missile can be served.
The guidance wire is connected to the front (T1)cover by means of a plug (T5). The wire runs down the missile –protected by a cover- ending in the wire spool (O).
The front cover (T1) is opened by means of an explosive bolt (T4). The explosive bolt exists of a black powder driven cylinder with a pin on top that perforates a 1 mm thick steel locking plate, releasing the front cover (T1).
By opening the cover, all electric safety’s are removed and the afterward battery (X4) in the battery housing (X2) of the container (P) ignites the electric igniter cartridge 9Ch284 (R) that ignites the expulsion charge 9Ch146 (S) of the gas generator (Q). The gas generator pushes out the gasses through six holes in top and bottom of the vessel outward. The gas enerator is connected to the outer rim of the wire spool housing by means of three leaf springs, so a pressure build up has to take place before the leaf springs bend open and the missile is released. The back cover is also placed under perssure up till the moment where it is blown out.
The missile is now being ejected with 80 mtrs/sec from the container in much the same way as a recoiless gun.
The wings (J1) exist of stainles steel formed and spotwelded wings that are pressed flat and wrapped around the body of the missile when in the container. The wings are kept in position by a clamping band (J2) that flies off when the missile leaves the container (P). The wings (J1) are connected to the body of the missile in a 4 degrees –longitudal- angle to make the missile roll.
On the moment the missile leaves the container, the steering electronics block (K1) is started by the inertia switch (K2) in the electronics block, connecting it with the battery’s (L). This also powers the steering magnets (A2) in the nose.
Because the missile is roll stabilized the commands “left, right, up and down” must be read the same all the time , unaware of the radial (rolling) position of the missile. Therefore the sector steering sliding contacts (H3) are placed on top of the longitudal shaft of the gimbal. Four slidingcontacts run over a 90 degree (1/4 circumference) contact surface on the shaft, the other 270 degrees (3/4 circumference) isolated. Each 90 degrees sliding contact sector rotates 90 degrees compared to the one below, so forming a stepped full circle. Each slidingcontact will now steer the missile in it’s designated radial position.
In the tail of the missile an infra red lamp (M1, M2) is build in. The bulb (M2) of this lamp is protected by two springloaded half discs (N1) that are kept in position by two celluloid ring halves (N2). If the gas generator is fired the celluloid ring halves (N2) are burned, however the two disc halves (N1) are kept pushed inward by the pressure, so protecting the lamp. After the missille has left the container, the disc halves are forced open by the spring, with the lamp shining back an infra red signal to the gunner’s sight that can be tracked and corrected to the target by the gunner. The infra red light bulb (M2) is –together with the gyroscope wheel (H1)- one of the two first parts to be activated. By heating up the light bulb it becomes a little soft and flexible, enabeling it to better survive the rough handling upon ejection by the gas generator (Q).
Some ten meters after the missile has left the container the 9Ch237 electric ignition cartridge (G1) for the main engine ignites the black powder ignition booster charge 9Ch245 (G2) for the sustainer motor (F1). This ignites the fuelstick 9Ch145-010 (F2) –packed in a green rubber heat resistant pouch- which accelerates the missile to a speed of 186 mtrs/sec.
The sustainer motor has two -opposite placed- venturi’s (F3).
The shaped charge (C1) exists of a red copper cone, placed in a OKFOL (95% HMX with 5% wax) charge. In the lower part of the explosive charge a so called wave shaper (C3, white) is placed enshuring the detonation wave will hit the cone (C2) in a more even way, resulting in improved armour penetration.

The 9E234M base fuze (E ) is of the PIBD (Point Ignited Base Detonated) type. It exists of an aluminium fuze housing (1) with the booster housing (2) screwed on top. The booster housing is placed in the base of the hollow charge (C1).
The bakelite inner works contain the fuzing mechanism. This exists of two main parts; The bakelite lower plate (3) in which the groove (4) for the pyrotechnic self destruct fuze is machined as well as a slot for the ignition pellet (5). The contact point (6) for the inertia switch (7) is also placed in the lower plate (3). The forward housing is a bakelite cup (8) in which two switches (9, capacitator loading) & (10, self destruct) are placed, as well as the inertia switch (7) and the rotating arming slider (11) which houses the electric firing cap (red).
Both switches (9&10) exist of a wound spring (12) which is kept in a tensioned position by a spring tensioned pin (13) that blocks the switches (9&10) from closing. These pins are kept in the tensioned –upward- position by the composition (4) of the pyrotechnic self destruct fuze. The spring loaded pin (14) that keeps the rotating arming slider (11) in the safe postion is kept in this –upward- position by a black powder pellet (15).When the missile is thrown out of the tube by the gas generator, the inertia switch (7) sets back, closing the contact (6). This sets off the ignition pellet (5). The flame of this pellet ignites the black powder pellet (15) as well as the pyrotechnic fuze (4) (green arrows). As the black powder pellet burns away, the spring loaded pin sinks, releasing the rotating arming slider (11) to move the electric firing cap (red) under the detonator of the booster charge (2). The first contact (9) is also closed as it’s pin (13) sinks, and the capacitator for triggering the firing cap is being loaded by the battery’s. As this takes about a second, the missile is not armed for the first 70 meters.
The nose fuze exists of two thin metal cups, placed electrically isolated over one another. When on impact the nose is crushed and the outer cup (B1) touches the inner cup (B2), the electric circuit over the capacitator and the firing cap is closed, exploding the firing cap (red).
If the missile misses the target, the pyrotechnic fuze (4) will burn up (blue arrows) untill it reaches the last springloaded pin (13) which sinks, activating the self destruct switch (10) after 2500 meters of flight.
The steering corrections are transferred from the launcher to the missile by a 2500 mtrs. long wire.

List of data for the 9M111-2 :

Diameter : 120mm.
Length of missile without gas generator : 870mm.
Length of missile with gas generator : 1030mm.
Length of missile container : 1100 mm.
Wingspan : 369mm.
Weight 9M111-2 missile : 13 kg.
Weight 9M111-2 missile in container: 22 kg.
Vo : 80 mtrs /sec (expulsion by gas generator).
Vmax : 186 mtrs/sec (sustainer motor).
Minimum range : 70 mtrs.
Maximum range : 2500 mtrs.
Penetration of the 9N122 shaped charge warhead (1,8 kg) : 460mm RHA (steell).
Explosive filler : OKTOL (95% HMX with 5% wax)
Flight time to maximum range : 11 seconds.

The firing of a 9M111-2 missile, filmed through the sight. One can clearly hear the whistle of the gyroscope wheel being started, and hear the “click” of the front cover being flipped open just prior to launch.
http://www.youtube.com/watch?v=xpx5F...eature=related

View from the side where one can also observe the front cover flipping open:
http://www.youtube.com/watch?v=HBEW8VTYUKc

The 9M111 is being used by the following countries:
Afghanistan, Algeria, Angola, Bosnia and Herzegovina, Belarus, Bulgaria, Croatia, Czech republic, Cuba, Ethiopia, Finland, Greece, Hungary, India, Iran, Iraq, Kazakhstan, Kuwait, Lybia, Latvia, Lithuania, Mozambique, Poland, Russia, Serbia, Slovakia, Slovenia, Syria, Ukraine.

The 9M111 is also used by infamous terrorist groups like the Hezbollah en the Tabiban.

Regards, DJH