Ukrainian M777 can use Excalibur to guide artillery shells

Ukrainian M777

Can use Excalibur

Guided artillery shells

A video in Ukraine shows that the Ukrainian army uses a castrated version of the M777 howitzer An M982 "Excalibur" guided artillery shell was fired. The video showed the process from unboxing to loading, but at the beginning of the video a seated soldier appeared with a hammer similar to Thor's hammer next to him. It is an instrument with a square top and a handle on the bottom and a cable.

This video demonstrates how the Ukrainians used the M982 without key components. It turned out that they used an enhanced portable induction artillery fuze setter (EPIAFS, ENHANCED PORTABLE INDUCTIVE ARTILLERY FUZE SETTER).

The M777 ultra-light 155mm howitzer has a total weight of 4.2 tons. It uses a 39-fold barrel and a double-chamber muzzle brake with a traction ring. The transportation time is 10.58 (some say 9.5) meters long and 2.59 meters wide. , 2.34 meters high, can be towed by a 2.5-ton 4x4 light truck, the road speed can reach 88 kilometers per hour, the off-road speed is 24 kilometers per hour, the deployment time is less than 3 minutes, the withdrawal time is 2-3 minutes, and the gun length is 10.24 when firing. meters, width 3.72 meters, height 1.22m, barrel length 6.10 meters, elevation angle -3° to 71°, azimuth angle 23° left and 23° right, the artillery launches M795 ordinary ammunition with a range of 24.7 kilometers, M549A1 extended range ammunition, M864 Cluster bomb 30 kilometers.

The burst rate of fire is 4 rounds/minute, lasting for 2 minutes, and the sustained rate of fire is 2 rounds/minute. The gun crew has 7 1 people, and can be operated by a minimum of 5 people.

The M777A1 has digital fire control system DFCS, auxiliary generator (APU) and General Dynamics (GD) fire control specifications, and integrates digital intercom, global positioning system (GPS) and inertial navigation system (INS) .GDU (GunDisplayUnit) indicator is installed, using DFCS, it is possible to measure accurate position and direction and fire quickly using the data received from the firing command post.

In addition, the artillery commander can directly view the azimuth and other information received from the firing command post through the GDU connected to the DFCS via cable. The 2020 standard M777A2 upgrades the DFCS software and also adds the Enhanced Portable Induction Artillery Fuze Setter (EPIAFS) for the M982 guided missiles.

However, what the Ukrainians got was a castrated version. The muzzle velocity measurement radar, communication positioning assembly, fire control mission computer and power adjustment control module, and gun squad leader display and control terminal were removed, leaving only the Two instruments, the inertial navigation unit and the main and secondary gunner displays, hinder its use of the M982 Excalibur satellite-guided artillery shells.

The M982 Excalibur satellite-guided projectile was jointly developed by Raytheon and BAE Systems. The total weight is 48 kilograms, and the warhead weighs 22 kilograms. It uses canard servos and 6 rotating tail fins. It uses INS GPS correction and has a CEP of 5-20 meters. However, most of the measured CEP on the Iraqi battlefield is around 4.2 meters.

The early range was 23 kilometers, and the Excalibur IA-2 has a range of 40 kilometers. The main reason is to increase the bottom exhaust design and switch to a GPS chip with strong anti-interference ability.

Incremental IB reduces costs and can be produced in large quantities. The fuze can be programmed to explode in airburst, trigger or delayed explosion, but it needs to set the target coordinates before launch and complete the initial alignment of the missile-borne inertial navigation. This requires EPIAFS binding.

The Enhanced Portable Induction Artillery Fuze Setter (EPIAFS) is an improved product of the Portable Induction Artillery Fuze (PIAFS).

The EPIAFS system includes a Platform Integration Kit (PIK) installed in the howitzer fire control system, a 4.57 meter cable for connecting the EPIAFS to the PIK socket on the howitzer, and a PIK that can be operated in non-cable mode setter.

EPIAFS can receive data via cable or manually set the data, and then perform induction settings through the setter.

The so-called setter is the hammer with a handle. There is an LCD screen and three knobs on the panel. There is a pit at the bottom that can put the warhead fuze into, and buckle it onto the fuze when in use.

EPIAFS adopts the principle of electromagnetic induction. The fixer reads the time stamp message from the GPS handheld terminal or PIK, uses the data encoding method to perform channel modulation on the setting information, and loads it into the primary coil of the inductive coupling loop for installation. Demodulates and decodes fixed information, sends time stamp information, target and artillery data to the projectile. The secondary coil is coupled to the energy storage capacitor on the fuze circuit to provide energy. The fixer requests status messages from the projectile, and then receives and processes the projectile. Status feedback, finally completing the binding process.

The Ukrainians only need to obtain data through the inertial navigation unit that has not been dismantled, and then use a separate PIK and other equipment to connect to EPIAFS settings. The disadvantage is that it may have to be set up once for each firing, which is more cumbersome.

Judging from the results, although the use of EPIAFS will greatly slow down the Ukrainians’ counterattack speed, on the other hand, the M777 cannot fire at one gun position for a long time. It has to be moved after firing. Therefore, the M777 can also set the shell before firing, and the accuracy remains the same.