120 mm pop-&-scoot mortars: while the idea of mounting mortars on vehicles is not new, the current trend is to develop systems that increase their efficiency by providing a higher degree of automation both in terms of loading and laying. Munitions, for their part are not trailing far behind development and increased effectiveness, with some today being guide.

As with the case of lorry-mounted howitzers (see Armada International 4/2005 page 42) there are two very distinct paths taken by developers and users of vehicle-mounted mortars: one that advocates lightness and the other armouring. In the latter path, these systems go for outright turreted designs and totally dedicated vehicles. This article deals with 120 mm class mortars and thus excludes the Soltam 60mm mortar system included on the Merkava 4. The systems are here examined in alphanumerical order.

Turreted

As usual, two very distinct designs entail pros and cons. In the turreted category the pros generally include a heavy armour protection for the crew in a concealed working environment, direct and indirect fire as well as higher firing rates. On the other hand, ammunition feeding is more complex than with a traditional mortar, as it implies breech loading (as opposed to muzzle drop-loading), and almost by definition the design implies the mobilisation of a dedicated vehicle. In today's types of engagements this may, in certain cases, have the disadvantage of aggressive looks and conspicuousness with the adverse effect of calling the enemy's immediate attention.

Amos: Jointly developed by Patria in Finland and Hagglunds in Sweden, this turret is the latest to have entered the scene and features not one, but two barrels and is intended for wheeled or tracked vehicles of 15 to 25 tonnes. The history of this weapon system can be traced back to the mid 1990s, and a first prototype was delivered to the Finnish defence forces in October 2000 mounted on a Patria Pasi XA-203 wheeled vehicle for the purpose of testing both the weapon and its manoeuvrability. In September 2001, Patria Hagglunds received an order worth 4.6 million from the Swedish materiel administration for an advanced concept study; this was followed one month later by another contract valued at 5.2 million [euro] for the integration of the weapon (known to the administration as the SSG120) on a CV90 tracked vehicle. The joint company received a firm order to the tune of over 100 million [euro] for the delivery of 24 Amos to the Finnish defence forces between 2006 and 2009. The turrets will be mounted on the new Patria AMV 8 x 8 and are intended to equip two readiness brigades. Sweden, for its part, is soon expected to place an order for approximately the same number of turrets, but mounted on CV90s.

Technically, the Amos carries a crew of four (driver, loading assistant, gunner and commander--the latter two being in the turret) and can operate autonomously, as it has its own navigation and laying systems. It is able to deliver direct as well as indirect fire, but also multiple round simultaneous impact fire to a range of ten kilometres, whereby it can launch a first complement of rounds at a high elevation angle, a second at a lower angle and up to four in this manner so that the last sets 'catch up' with the earlier ones that flew a longer trajectory and finally meet and detonate on the same spot at the same time, as witnessed by the author during a demonstration in Finland. This is afforded by the ability of the Amos to deploy within thirty seconds and fire at a rate of 16 rounds per minute (it carries a complement of 48). In terms of ammunition, the Finnish defence forces have selected Instalaza's Mat 120 cargo round in late 2004. Last but not least, the Amos turret has also been tested from a fast patrol boat (Combat Boat 90).

AMS: Originally developed by Royal Ordnance (the mortar per se) and Delco (the turret) the Armoured Mortar System is the first modern Western weapon of its type. The companies involved are now respectively known as BAE Systems and General Dynamics. The only known operator to date is the Saudi Arabian National Guard, which has taken delivery of 73 mounted on Lav IIs (basically, Piranha II 8 x 8s). The 2.6-tonne turret is, however, offered for mounting on other vehicles, notably a stretched version of the M113. It has also been seen on an El-Fahad 8 x 8 in 1999. The AMS uses GPS and has tilt and cant sensors as well as a computer to calculate ballistic solutions both for indirect and direct fire with a point target capability for direct fire of 1200 metres. The smoothbore AMS fires approximately eight rounds per minute (with a burst capability of three rounds in 15 seconds) out to a maximum firing range of 9.2 kilometres. With an eye on the American Future Combat System the two manufacturers unveiled an AMS II turret at the 2003 DSEi exhibition featuring improved armouring accepting applique kits, all-electric drives and a computerised day and night fire control system.

In an interesting development, Mecar has very recently qualified a new ignition system for 120 mm mortar systems. Developed on request of "a customer", the Belgian firm developed an electrically primed ignition cartridge for its family of 120 mm high pressure, breech-loaded mortar ammunition, although the manufacturer says that it can be adapted to the more traditional muzzle-fed rounds like the M 121 used in the American BCT Stryker Mortar. This development was prompted by the fact that there have recently been, in the latter case, three fatalities as well as other personnel seriously injured as they were trying to remove misfired mortar rounds. As Mecar explains <<with percussion-fired mortar systems, any attempt to extract a misfired round from a vehicle-mounted, muzzle-loaded mortar is extremely dangerous. In this configuration, a misfired round can only be removed by grabbing the front of the mortar round with a muzzle-loaded device>>. Besides, the risks of a percussion round setting off is uncomfortably high if it is accidentally dropped on a hard surface.

Mortar Wiesel: Based on the long wheelbase Wiesel 2 chassis, the Rheinmetall Morser Wiesel distinguishes itself here by being non-turreted, yet it offers its crew of three roof protection (at least to the standards that pertain to such a light vehicle--4.5 tonnes). It features a single barrel that swivels from horizontal travelling (and loading) position, to firing elevation: the vehicle is first roughly parked into bearing position, then the weapon pack automatically elevated to the required angle and fine-tuned in azimuth. Recoil loads are not imposed on the chassis but transmitted to planet Earth via two telescopic legs mounted under the two rear corners. The two demonstrators ordered by the German defence procurement agency have already undergone extensive tests in Meppen (1000 rounds fired) and began another series of German governmental authorities hot climatic conditions trials in Arizona's Yuma range in May 2005. Upon completion of these trials in September the two vehicles will then proceed with more workout in Austria's 'arctic' air until February 2006. Using current munitions the Mortar Wiesel lofts out high-explosive heads--of which it stows 27--to a range of six kilometres, although this could be extended to eight with a new aerodynamically optimised bomb currently under development. Upon completion of all trials and related reports in November 2006--and unless extensive redevelopment is required--a production order for no less than 74 vehicles can be expected. The Bundeswehr has an urgent need for these vehicles, as they are light enough to be delivered by CH-53. About sixteen months are needed from the word 'go' to production, meaning that the first systems could be on duty around end 2008 or early 2009.

Bolt-on

In theory, bolting a mortar onto the floor of a vehicle should not pose any problems. However, this is simpler said than done, as a major difficulty has to be overcome, that of the substantial recoil produced by 120 mm munitions, which necessitates a strong braking mechanism. As a general rule about 70 per cent of the recoil force has to be absorbed. This is the reason why whilst most modern 'boltons' use existing--and therefore proven--barrels, just about every item around them has to be designed afresh. Another accessory that does not exist in classical mortars is the autoloader. This is an amenity that is obligatory to make sense in this application, since the very purpose of the vehicle-mounted mortar is to be fast into and fast out of operation. It is therefore hardly surprising that some of these designs should look rather similar, particularly the TDA 2R2M and the Ruag Bighorn.

The major advantage of this type of solution is that, when in motion, the system really is a Q-vehicle--in other words it looks like any other troop carrier or armoured vehicle. Time into operation from pulling the hand-brake typically hovers over the 30-second mark and boils down to flinging the vehicle's roof doors open, punching the autolaying button (coordinates will have already been keyed into the fire control system and the firing solution computed), dropping the round into the loading cradle and voila. The drawbacks of this type of configuration compared with the turreted mortars seen above are limited, or no, direct fire capability and lighter armour protection (particularly from the top). However, since the very purpose of the configuration is inconspicuousness, the surprise effect and speed of operation is its best protection. While certain trucks are perfectly eligible for this type of mission, their total lack of protection makes light armoured vehicles a much-preferred solution to offer the crews protection against rifle fire. The current favourites are the Mowag Piranha, the M113 and its Turkish evolution from FNSS.

On the operational front, the main hurdle these systems have to overcome, apart from the usual budget restrictions, is the armed forces ability to adopt them. As for many other types of modern weapons emerging nowadays, and given their range and accuracy, the question is: to what type of unit(s) will they eventually belong?

2R2M: Regular readers will be familiar with this Thales TDA development since it has been followed by Armada International almost from its inception. French procurement budgetary issues and priorities have mainly slowed its evolution, but the system is now mature and basically ready for production. The 2R2M has recently completed (April 2005) a one-year operational evaluation test with the French Army following a contract passed by the DGA in early 2002 requesting TDA to integrate the system into a 6 x 6 Vab. Some 500 rounds have been fired during these tests with the weapon in its final configuration with full fire control system, navigation system and ballistic computer (itself readily incorporating a link to the French Army's Atlas battlefield management system). Part of these tests also involved a second and similarly configured 2R2M integrated into a Piranha III on company funds. As mentioned above, the 2R2M, due to its high performance (it is rifled), really makes it an artillery weapon in its own right and, according to TDA, the recent evaluation tests have helped the Armde de Terre to fully accept this. It is now a matter for the chiefs of staff to do their homework and adapt the land armed forces doctrine.

While it does not strictly belong to this subject, mention has to be made here of the Dragonfire as it may well have implications in the mid-term future. The Dragonfire is a palletised and remotely operated version of the 2R2M, and one that had been ordered for evaluation by the US Marine Corps in 1996. The weapon's performance was such that the American forces took a fresh approach to the rifled genre, which finally led, in late 2004, to the adoption of the towed 120RT (that has the same barrel as the 2R2M) for its Expeditionary Fire Support System. This competitive programme was won with General Dynamics Ordnance and Tactical Systems acting as prime contractor with, at stake, an order for of 60 units to be supplied over a period of five years. Under a licence agreement General Dynamics will produce the weapon as well as its seven types of ammunition. However, and here is the implication, the Marine Corps also operates a fleet of 50 Lav-Ms that are armed with 81 mm M252 mortars. These will inevitably need to be upgraded at some stage. A logical assumption would be for the Corps to adopt the same base system. Another future programme that could see the adoption of the 2R2M is the French Boa project.

In spite of it being rifled, the 2R2M (or the 120RT for this matter) can also fire smoothbore ammunition, including the Marine Corps' own, with a penalty on maximum range of course. The nominal maximum range of the mortar is 13 kilometres but it still achieves over 7 kilometres with smoothbore rounds. In addition, this will probably stretch out to anything between 17 and 20 kilometres with the rocket-assisted and gas-actuated fin VLR-Rap bomb. Originally a TDA development tested between 1981 and 1991, this smoothbore munition would now incorporate General Dynamics' low-cost course-correction device. The autoloader enables the 2R2M to fire at a rate of ten rounds per minute to a range of 13 kilometres with the highest degree of accuracy afforded by its rifled barrel compared with its rivals. From the outset, it was designed with a 'bottom relief valve' to help evacuation of compressed air as the round drops into the barrel

Bighorn: Developed by Ruag, this is probably the closest rival of the 2R2M even though it has a smooth bore. Like its French counterpart, it is a mature design and also exists in two demonstrator examples, one being mounted on a Piranha II and the other on a stretched FNSS armoured combat vehicle. Both are complete with navigation system, self-laying capability and fire control computer. Since belching out its first round in 1997 the Bighorn has logged over 1700 firings to date and has even demonstrated its ability to speed rounds out to a range of over nine kilometres in the searing conditions (over 50[degrees]C) offered by the Kuwaiti desert climate. Interestingly, Ruag has developed an insert that allows the Bighorn to fire 81 mm calibre shells and training rounds. Ruag sees a large potential for its new mortar in urban warfare, due to both its accuracy and range.

It is interesting to note that Ruag also spotted some rivalry between artillery and its mortar, artillery divisions often arguing that they can perfectly well achieve the same missions. Not quite so in terms of collateral damage, where much better damage control and accuracy is required, particularly if the mortar can use guided rounds or cluster cargo rounds. In the first instance the Bighorn can fire the Saab Strix or the PGMM and, in the second, the bomblet cargo round that Ruag has jointly developed with Israel Military Industries. The FNSS-mounted Bighorn can carry 40 standard rounds, while a Piranha III equivalent could stow from 60 to 80.

Cardom: Developed by Soltam, this system (Hatchet in English) must be the veteran of the breed and as such is hand loaded (but said to be able to provide a burst rate of fire of 16 rounds per minute <<with a well trained crew>>). Interestingly, it has long been transferred as part of the artillery inventory in Israel. It basically uses the company's K-6 barrel and offers a range of 7.2 kilometres with standard bombs, although an aerodynamically improved round would stretch this to over nine kilometres. As for urban warfare capability, it is worthy of notice here that IMI has used Eurosatory 2004 to unveil its new 120 mm laser-guided bomb. A tripod-mounted laser target designator drives the bomb home with an accuracy of between one and two metres at a range of ten kilometres. The Cardom has been qualified for use by the 3rd Army Stryker brigade.

Srams: The first public appearance of this development from Singapore Technologies dates back to the 2001 DSEi defence exhibition, where it was presented in the form of a mock-up. As such it rates as one of the latest members of this club. A prototype of this system was exhibited at Idex in Abu Dhabi in February 2005 mounted at the back of an AM General Hummer (see photograph herewith). This may look a bit humble a vehicle to sustain the recoiling forces of such a weapon, however, it must be noted that it sported a hydraulically operated spade to drive the recoil into the ground. Unfortunately there were no company officials available at the time to provide any operational details of this configuration because it is obvious that this limits the traversing capability of the mortar. Presumably, the same conclusions could be drawn from another variation on that theme, one that involves mounting the mortar on an even lighter vehicle--the tubular 4 x 4 space-flame Spider chassis from the same manufacturer. And yet, the adoption of the Srams on vehicles like the Bronco or the Terrex is a different proposition altogether. One of the most striking performance figures given by Singapore Technologies is the firing rate of the system: 18 rounds per minute. This intensive rate of fire has necessitated the implementation of a cooling device that injects water mist into the barrel.

From Russia

The Motovilikha Nona-S (at right) is basically a 120 mm breech-loaded rifled 2A60 mortar mounted on a BMD airborne combat chassis. Using a semi-automatic loader it provides a rate of fire of six to eight rounds per minute. A variation is the Vena 2S23 which is mounted on a BTR-80. From the same company is the Vena 2S31 as seen here at left, photographed at Nizhni Tagil's Uralexpoarms. Based on a BMP-3 chassis and fielded in 1999 it sports a longer 2A80 barrel and can fire the KBP Gran laser-guided bomb. (Armada/YL)

Mortars, Yes, but ...

Often regarded as the <<poor man's artillery>> the use of simpler mortars has proliferated in recent years amongst rogue regimes. This has prompted the investigation into counter mortar round devices by Rheinmetall Oerlikon Contraves and General Dynamics. Oerlikon, for its part, tested its Ahead munition against incoming mortar bombs at a sea range in Northern Germany in 2004 and proved that the hail of tungsten pellets dispersed by its 35 mm shells had the ability to trigger the mortar bomb's proximity fuze at a safe distance (from unofficial sources, it seems that some pellets had also managed to detonate the explosives). Similarly, but using its test-bed tactical high energy laser built for the US Army, Northrop Grumman shot down multiple mortar rounds in August 2004. During these tests the laser 'fried' both single and salvo rounds.