Observations made during the conflict in Ukraine once again demonstrated the importance of choosing between towed and self-propelled artillery. Thus, the vulnerability of artillery batteries, performing several fire missions from one position, was again shown. The opponent's ability to detect, locate, fire and destroy, or at least seriously reduce battery support capabilities has been demonstrated more than once. The advantage of towed guns is their low mass, which makes them easier to transport, especially by airplanes and suspended from cargo helicopters. In most cases, they are also easier to maintain. The main limitation is that they must be towed by a tractor, usually a tactical truck, which increases the time required to prepare for firing and take them out of position.
On the other hand, a self-propelled gun, having its own self-propelled chassis and, as a result, moving according to the commands of the crew, can receive a firing mission even while moving, and immediately stop. shoot and then start moving again, often spending only a few minutes on it. These cannons are also structurally complete systems with automated control, navigation and ammunition on board, and often automatic loading, which determines a high rate of fire. Self-propelled guns, as a rule, are heavier than their towed counterparts and, moreover, until recently were based mainly on tracked chassis. Both of these features make it difficult to transport SPGs by air and limit their use where bridges and roads are weight-limited.
Therefore, the dilemma that has re-emerged in connection with the events in Ukraine, but in general has long been well known to everyone, is the following: it is necessary to have fire support systems that would be mobile enough to quickly change positions (so as not to become a victim of counter-battery fire) even in less developed infrastructurally rural areas, and which at the same time could perform the entire range of fire missions. Some armies also require the ability to deploy military transport aircraft for deployment anywhere in the world. In addition, it is desirable that the cost of such systems be within reasonable limits, as well as operational reliability. As a consequence, the idea arose to "marry" the mobility of a tactical truck with the firepower of a howitzer. In this case, the artillery unit, as a rule, is installed on the rear cargo platform, often with stops that lower to the ground and reduce the impact of the rollback impulse.
The ability of the cargo chassis to move quickly can significantly reduce the overall weight, especially if booking is limited to the driver / crew cab or even completely absent. In this case, the platform is required to quickly take up a firing position, quickly shoot back, and then, in order to avoid return fire, quickly change position, using its advantage in mobility.
The head of the CAESAR project at Nexter, which created one of the most successful "artillery systems on a truck", said: firing several shots and removing from position. It has been demonstrated more than once that exceeding this time interval is fraught. A modern advanced enemy can detect, determine the location of the firing gun and open fire on it during this time.
SPGs' weak or no ballistic protection is a deliberate decision that reflects the fact that towed guns also lack such protection, but they cannot independently change positions at such a speed. On the one hand, the combination of a mobile chassis with an installed gun is very similar to a towed weapon, which needs a tractor of one type or another for towing, but on the other hand, it is still fundamentally, one might even say ideologically, different.
This new combo works well when supported by motorized infantry. However, it can become a disadvantage for light infantry, which will be deployed with the support of helicopters. In this case, the total mass of the "truck / gun" system, at least in the segment of medium 155-mm guns, may exceed the carrying capacity of many helicopters. Of course, this is not a verdict, since the developers have already demonstrated light tactical trucks with specially configured howitzers, usually 105 mm. These systems can be transported on the suspension of such heavy helicopters as, for example, Boeing CH-47D / F Chinook and Sikorsky CH 53E / K.
The advantages of self-propelled artillery systems on a car chassis are so obvious that the military of an increasing number of countries is showing increased interest in them. In addition, the creation of such systems does not require too high a technical level of engineering school and rich design experience. As a result, a number of countries have developed their own localized versions of the truck / gun combination. This allows you to quickly and often cost-effectively increase the mobility of army artillery at a lower financial cost.
Self-propelled artillery components
As a rule, a self-propelled unit of this type includes a finished truck chassis, a gun and a carriage, a stabilization system and a fire control system, which often includes an integrated ground navigation and positioning subsystem. In some projects, automatic or semi-automatic loading is also added in order to reduce the number of crews and increase the rate of fire for faster completion of the firing mission and removal from position.
Nexter developed the CAESAR howitzer with the aim of obtaining a highly mobile artillery system that could be deployed with a C-130 Hercules military transport aircraft anywhere in the world. After extensive testing, it was adopted by the French army in order to replace not only the towed 155-mm guns, but also the self-propelled tracked platforms. In the French army, the artillery unit is mounted on the chassis of a Renault Sherpa 5 6x6 truck, although there are variants mounted on a Mercedes-Benz UNIMOG 6x6 chassis. Although the SPG's cockpit is armored, the total weight does not exceed 18,000 kg. This is consistent with the company's stated requirement to "determine the need for self-propelled artillery that could be deployed by expeditionary forces by air."
The artillery unit is a modernized version of the 155 mm TRF1 towed gun with a 52 caliber barrel length. For firing at the rear of the machine, the large opener is hydraulically lowered and the four rear wheels are lifted off the ground for excellent platform stabilization. The unit has a built-in navigation and guidance system from either SAFRAN or Thales, connected to the actuators. A Nexter spokesman confirmed that "the inertial / GPS positioning system, digital fire control and mechanized loading allow the installation to fire six rounds and withdraw from position in less than 100 seconds."
CAESAR is the world's most widespread artillery system on a car chassis, bought by Saudi Arabia, Lebanon, Indonesia, Thailand and of course France. It has been tested in combat in Mali, Afghanistan and Iraq. Its version CAESAR 2 on an 8x8 chassis was adopted by Denmark.
Not only France holds the market for self-propelled guns on an automobile chassis, several other countries have developed or are developing mobile artillery systems. For example, the Thai army, which has already bought six CAESAR howitzers, is completing its own platform, which is an Indian-made Tatra 6x8 truck and a 155mm ATMOS gun system from Elbit Systems, obtained through technology transfer. The plans provide for the manufacture of 18 self-propelled howitzers to equip one battalion of the Thai army. The project, announced in April 2018, is scheduled to be completed within 28 months.
The Republic of Korea increased the combat capabilities of its artillery, while making the most of existing systems, saving the necessary financial resources for this. The EVO-105 self-propelled howitzer (photo above), manufactured by Hanwha Techwin, is a combination of a 105-mm cannon and artillery unit taken from the M101A1 towed howitzer already in service and a 5-ton Kia KM600 (6x6) truck.
This significantly increased the mobility of the howitzer, its ability to take and remove from position, and also increased the survivability of the crew and the platform itself. The system can receive a firing mission while moving, stop, shoot and start moving again within 60 seconds. Through the use of a traditional artillery unit, the South Korean army can fully deploy all of its existing ammunition arsenals. In addition, the soldiers are already familiar with this system and trained to work with it. The operational characteristics of the installation are further enhanced by a positioning and guidance system that is connected to a digital control system. The Ministry of Defense said that the EVO-105 howitzer began to enter the troops in 2017, and a total of 800 systems will be delivered.
The Chinese company NORINCO also keeps up with world trends, having in its portfolio self-propelled howitzers on truck chassis, which are also offered for export. The company offers both a Russian-made 122mm cannon and a NATO-compliant 155mm cannon. The SH1 howitzer is a 155 mm / 52 caliber howitzer on the chassis of the Wanshan WS5252 6x6 serial truck with a modified protected cab. For firing, a large opener is lowered at the rear of the machine. The ammunition load is 25 rounds, and the howitzer itself has already been purchased by Pakistan and Myanmar. Recently, a variant of this cannon could also be seen in service with the 72nd Artillery Brigade of the Chinese Army. The SH2 122mm howitzer, similar in appearance, uses a cannon from the Chinese towed howitzer PL96 (a copy of the Soviet D-30). Again, the desire to simplify the transfer of self-propelled systems by air influenced these developments.
The self-propelled howitzer Archer FH77BW L52 from BAE Systems Bofors was designed as an independently operating fire support system of the "shot and leave" type. The howitzer itself, accompanying the ammunition supply vehicle and the support vehicle, allow increasing the autonomy and tactical flexibility of this complex. A fully automatic 155 mm / 52 cal howitzer with a magazine for 21 shots is installed on the modified chassis of the Volvo A30D 6x6 articulated commercial truck. The calculation can stop, shoot within 30 seconds, remove from position and start moving within the next 30 seconds, while the whole process does not require leaving the protected cockpit. This is achieved through on-board guidance navigation systems and a fully digital fire control system that allows you to fire in the MRSI mode ("Flurry of fire" - firing mode, when several (in our case, up to six) shells fired from one gun at different angles, reach the goal at the same time). Currently, the Archer howitzer is in service only with the Swedish army.
As a further development of the CAESAR self-propelled howitzer, Nexter recently introduced an improved version on the 8x8 chassis. For the CAESAR 2 ACS, a 155-mm / 52 cal howitzer was taken and installed on the Tatra T815-7 8x8 truck chassis, which has an increased level of protection against mines and improvised explosive devices. The loading and firing system is fully automatic, allowing the calculation of 2-3 people to make six shots in two minutes. A larger vehicle with increased off-road cross-country ability made it possible to increase the ammunition load to 30 rounds. In 2017, Denmark chose this system to replace its M109 tracked self-propelled artillery mounts.
The relative ease with which a wheeled howitzer can be deployed attracts those countries that wish to modernize their armed forces. This was demonstrated, for example, by the Jordanian company KADDB (King Abdullah II Design and Development Bureau), which presented its RUM-II system at SOFEX 2018. In this case, a combination of a DAF 6x6 truck chassis and an M126 155 mm / 23 howitzer is implemented. A rear opener and two side stops are used to stabilize the platform. The RUM-II self-propelled unit is mainly designed to increase the mobility of the gun and is manually operated by a crew of six people, who are located in the cab on two inseparable seats.
The Indian army is also with its characteristic "activity" implements projects in the field of wheeled artillery systems. The goal of the Mounted Gun System program is to purchase ready-made 155-mm guns with a barrel length of 52 caliber. Initially, 200 systems will be purchased, followed by another 614 to be manufactured locally. Prospective candidates include CAESAR, ATMOS and the Indian Tata Power SED self-propelled gun. The RFQ was released in early 2018. As part of the project, Nexter Systems signed a consortium agreement with Indian firms Larsen SToubro (L&T) and Ashok Leyland Defense. Israeli Elbit Systems has merged with the Indian firm Bharat Forge. Tata's proposal was reportedly developed in collaboration with South African Denel and was first shown in 2012. In April last year, the Indian company Ordnance Factory Board presented a new version of the Dhanush towed howitzer, which could meet the country's needs for a mobile artillery installation. In November 2014, the Indian Defense Procurement Council approved a $ 2.5 billion grant for 814 artillery systems on a truck chassis.
The creation of self-propelled howitzers that could be delivered directly along with the airborne assault force is a non-trivial task, since there are a lot of problems associated with carrying capacity, dimensions, subsequent logistics, etc. As a result, the airborne units mainly use towed guns (the American army, for example, uses M119 105 mm and M777 155 mm howitzers), the mobility of which, as already noted, is insufficient. Mandus Group, in cooperation with AM General, offers a solution, which is a 105-mm howitzer mounted on an M1152A1w / B2 HMMWV armored vehicle. This system uses the roll-out principle and four quick-deploy hydraulic stabilizers (two at the front and two at the rear of the platform) keep the platform stable. The digital fire control system allows the Hawkeye to receive a firing mission on the move and prepare to open fire in a matter of seconds. An AM General spokesman explained that “Hawkeye's unique anti-rollback system allows fire from a light HMMWV vehicle. The system is light enough to be transported on a CH-47 helicopter suspension. The installation is immediately ready for action after a fire request. The mobility of the HMMWV chassis allows the system to remain in the same battle formations with light infantry and easily move in order to avoid counter-battery fire. The cannon is serviced by the calculation manually and can fire all types of 105-mm ammunition in service with the American army, including M1 and M760 shells, M60 / M60A2 smoke, M193 high-explosive fragmentation (HE), M314 lighting and M1130A1 HE shells with ready striking elements . The US Army conducted demonstration firing from a Hawkeye howitzer early last year.
Artillery on the chassis of wheeled vehicles provides a high level of tactical mobility, which in vehicles in the 8x8 configuration is almost equal to the mobility of tracked artillery systems. Having increased range at least. 155-mm guns, you can perform fire missions without the need to use tracked chassis, which have a higher cross-country ability.