Frag Out! Magazine
Issue link: https://fragout.uberflip.com/i/1173894
is being marketed quite intensely. It was also showcased in Poland, which made it possible for the Polish military to get acquainted with the design's strengths and weaknesses. Amos is based on an autonomous and universal turret module housing the fire control system and two smooth-bore 120 mm mortars with 3000 mm barrels and a rocking autoloader assembly housing two ammunition lifters and two ramrods. The turret also features an auto- mated ammunition storage with two moving shelves, accommodating five 120 mm rounds each. The turret, ammunition and crew included, weighs 5.8 tons. It may be integrated on any platform that would be able to handle its weight. The Alvis Hägglunds fire control system is a benchmark in its class. It allows the crew to fire the rounds in less than 30 seconds. The vehicle may leave its firing position in less than 10 seconds. 10 kilometers is the range of the mortar, but it very much depends on the used ammunition. Amos ammunition needs to have a metal base (casing) and solely ammunition of this kind may be used. Thus, standard rounds need to be modified before they can be fired. Maximum (and battlefield-unrealistic) rate of fire is defined as 16 RPM. Comparison of Rak and Amos system is interesting, as both mortars are based around the very same design concept and remain the only Western systems of this class. Both designs feature turret systems that remain completely autonomous. Meanwhile, the fire control sys- tems offer capabilities that remain similar. The Polish turret, however, provides the commander with a higher level of situational awareness ensured by the SOD-1 Atena 360-deg observation system. Rak also al- lows the commander to lay down direct fire and fire the rounds against moving targets - thus it is a bit better, thanks to an aiming system coupled with a ballistic computer and a thermal-imaging camera. Rak has also been fitted with the Polish soft-kill Obra APS. Amos lacks a solution as such. Level of ballistic protection remains similar. The firepower comparison is where the things get interesting. In theory, the twin-barrel Amos system has a rate of fire of 16 RPM and stores 50 to 60 rounds inside its hull - thus, it seems that it has an advantage over Rak. Realistically, however, it is not as simple as it may seem. Rak features an automated ammunition magazine storing 20 rounds, with the feed being independent from the turret-hull position. What's important, the independence is mostly retained regardless of the po- sition of the breech in relation to the storage space. In case of Amos the turret ammunition storage houses only 5 rounds per barrel. Con- sidering the time required to place the rounds on the autoloader and carry them from the storage space to the barrels, after the barrels are placed in the loading position, it turns out that 16 RPM is a value that remains purely theoretical and is impossible to achieve. Realistically, if the turret storage is used (and manufacturer's spec is considered), the autoloader's rocking unit takes 3 sec to load. Then it takes 3-5 sec to align it with the chambers, and another 6 sec are needed to load the mortars. It takes 12-14 sec to fire two rounds at once. This translates into 4 to 5 twin shots per minute which translates, realistically, into rate of fire of 8-10 RPM. This should be compared to the Rak's system which is able to fire 8 RPM with a single barrel. When the gunner is loading the rounds manually, it gets even more ridiculous, as the sol- dier is unable to place the round in its place in case of a single barrel if the turret is turned more than 20 degrees off the hull central axis. This makes the double-barrel mortar a single barrel system. The time required for the loader to carry out the procedure and the ergonomics are also far from perfect. This makes the actual capabilities dubious, when compared to the marketing brochures. One could obviously claim that Amos is a shoot & scoot class system, thus the 10 rounds in the turret would be enough and the rounds could be fired in less than a minute. It is true. However, this does not really change the fact that the twin-barrel, complex Amos mortar is capable of firing two rounds more than the single-barrel Rak. Adding a proper number of extra propelling charges is a separate issue. This is often done manually, by the com- mander, over the course of the loading procedure. This, needless to say, renders the declared rate of fire impossible to achieve for any de- sign. However, Rak's ammunition storage space that remains able to accommodate 20 rounds makes it possible to initially prepare several ammunition groups, 4 rounds each, with varying quantity of propelling charges, so that it will not be required to remove those charges during the loading process. How does Amos compare to that, with 5 rounds available per barrel? This is a purely rhetorical question. All the above issues were indicated by the potential buyers who got a chance to get acquainted with both Amos and Rak. VEHICLES