BAE-M777
US Marines with the 11th Marine Expeditionary Unit fire an BAE M777 howitzer during a fire mission in northern Syria as part of Operation Inherent Resolve, Mar. 24, 2017. (USMC)

Artillery systems, once considered more of an area weapon than a precision tool, are making ‘heads turn’ once again though GPS accuracy, digital target processing and advances in guidance and munitions.

Artillery has traditionally held a special place in the combat arms. It is capable of shifting the balance on the battlefield when it is employed accurately and in a timely manner. The size of artillery cannon vary depending on the mission requirements and the level of mobility needed. This was particularly relevant earlier in history when guns were towed as the gun size and thus weight dictated the means required to move it. Broadly modern artillery was classified as light, medium and heavy partly replacing the earlier historic differentiation by its use, for example field guns or siege guns. This classification covers both ‘guns’, which have flatter trajectory and ‘howitzers’, which have a higher arching projectile flight.

In the last three decades there has been a consolidation in artillery calibre with the 155mm more a standard in Western armies and 152mm in the armies of Russia and Peoples Republic of China. This is not to suggest that smaller and also larger calibres are not still found but rather that the focus of development, production and system fielding have been in these gun sizes. As recently as the 1990s artillery units would consist of 105mm or 122mm batteries for direct support roles, the 155/152mm in general support, plus 175mm guns and 203mm howitzers as Corps (higher command) reinforcing assets.

The larger artillery pieces have been largely retired by Western armies (the US M110 203mm howitzer did so in 1991) and replaced by missiles and rockets like the Lockheed Martin Missiles and Fire Control US M270 MLRS (Multiple Launch Rocket System) which is used by 14 armies. This trend was reinforced by the introduction of the more deployable M142 HIMARS firing the same rockets but mounted on a truck chassis. Their rockets can hit targets at up to 82km while its MGM-140 ATACMS missile can travel 300km.

But still the large howitzer persists. Russia displayed a 203mm self propelled howitzer, the 2S7 ‘Pion’ (S7M ‘Malka’) as recently as 2017. The 203mm is typically linked to the delivery of tactical nuclear weapons. Beyond this, ‘heavy’ gun artillery is difficult to find in front line units.

Most ‘tube’ artillery units today have largely adopted 155/152mm. This move was at least partly the result of advances in cannon technology. According to a Rheinmetall spokesperson, a German cannon developer and manufacturer, “metallurgy and manufacturing improvements allowed longer gun barrels to be made. A longer barrel permits greater propellant charges to be used. Together these give the projectile a higher velocity since there is more propellant (powder) with a longer burn which means that it will fly further. The newest Bundeswehr artillery system, the PzH2000, has our Rheinmetall 155mm L52 cannon (L52 is the calibre i.e. length of the gun barrel). The barrel is eight meters long and has chromium-lining as well as a muzzle brake. Using the standard L15A2 shell the maximum range is 35km. This is significantly greater than the 22km maximum range of the BAE Systems M109A5 and A6 6 with its 155mm 39-caliber M284 cannon using the same ammunition.”

PzH2000
The PzH2000, developed by KMW and Rheinmetall, is the newest self-propelled artillery system for the German Army. Its capabilities seek to anticipate the tactical employment of artillery. It is also fielded by Italy, the Netherlands, Greece, Lithuania and Croatia. (Krauss-Maffei Wegmann)

Though the PzH2000 is replacing the M109 in German service both Rheinmetall and RUAG (a Swiss defence firm) have developed versions which substitute the L52 cannon and a Swiss-designed L47 155mm cannon respectively. The later increases the maximum range to 36km. To do so upgrades were also necessary to the chassis to accommodate the higher gun weight and firing forces. They also upgraded other aspects of the M109 including the loading and gun laying which permitted increased rates of fire.

The US Army, the developer and first M109 user, still employs the 39 calibre cannon even in its latest M109A7 for which BAE Systems received a contract in December 2017 to begin fall scale production. The A7, as Col James Shirmer Program Manager Armoured Fighting Vehicles explained, “incorporates a number of automotive, on-board power and reliability improvements that were essential prerequisites to any gun system upgrade. With these underway it is possible to consider firepower enhancement options.” These include liquid propellant-based cannons which have been in development since the 1990s, or even electro-magnetic rail guns.

Russia, where artillery has historically been highly regarded, has likewise pursued increased gun tube length to gain performance. The 152mm has been the primary focus of new development efforts. The D-20 (towed) gun of the 1950s had a 5.195m barrel length its successor the 2A65 152mm as a towed howitzer and 2S19 Msta-S self propelled howitzer had this increased to a 54 calibre. The most recent 2S35 Koalitsiya-S unveiled in 2015 has a range of 40km using the same ammunition as the Msta-S. These larger calibres also better support the use of extended range ammunition such as ‘base bleed’ and rocket assisted projectiles which in the case of 2A65 is 45km and 65km respectively. Increasing the range of artillery has always been desired; advances in gun positioning and location determination, fire controls and ballistic calculation, firing automation, and wireless communication have allowed this to be achieved.

Improved accuracy

Being able to shoot further is of limited benefit if the rounds fired do not hit the intended target. The basis of a firing calculation is accurate gun position and target locations. The less accurate the gun position information the greater the error will be as the range to the target increases. The use of GPS, on-board navigation and digital processing has not only sped up determining the firing solution but, when combined with automated laying and loading, has allowed complex target engagement techniques like MRSI (multiple rounds simultaneous impact). As used in the BAE Archer system it automatically adjusts the elevation of each round fired so all arrive on the target together.

Rate of Fire and Loading

In most engagements artillery is still employed as an area weapon. Placing multiple rounds into the target area at the same time or in rapid succession was the purpose of battery firing by six or eight guns. The increasing vulnerability of artillery to detection by various electronic means and then engagement by opposing counter-battery fires has pushed artillery tactics to prefer smaller gun teams that will shoot and then quickly displace. The problem is now achieving the same target affect with as few as one or two guns. Automating the firing process has provided the solution. This has been widely applied in the latest self-propelled artillery. A PzH2000 crew of five can fire three rounds in nine seconds and ten per minute at a sustained rate. The Russian military claims a s 15 plus average firing rate for the 2S35 due to its pneumatic auto-loader and on-board magazine. Even unarmoured truck mounted artillery like Nexter’s CAESAR has adopted an automatic loading system speed when coupled with its FAST-Hit computerised fire management system, developed by Nexter and EADS.

Nexter-CAESAR-155
Two of the key design criteria used my Nexter in the CAESAR 155 self-propelled howitzer were that it be transportable in the C-130 aircraft and that it must be able to halt, aim, load, fire and be on the move within 90 seconds to preclude opposing counter-battery fires. (Nexter)

Towed Artillery

Guns towed by prime movers once dominated in artillery. Today they comprise less than half the inventory and are usually found in support of infantry units. A key consideration in fielding towed guns is their transportability, particularly when this can be made by helicopter. The BAE M777 155mm howitzer at 4,200kg (9,300lb) is easily lifted by the CH-47 Chinook and other medium lift military helicopters. Despite its low weight it has a range of 24km with conventional M107 rounds and 40km with the M982 Excalibur GPS-guided munition. The challenge for such guns, particularly when separated from their prime movers, is in making short distances moves once on the ground. The FH-2000, developed by ST Kinetics for the Singapore Army, addresses this by having its own auxiliary power units and drive unit. A ST Kinetics representative shared that “the FH-2000 is able to manoeuvre at up to 10km/h under its own power. This not only allows repositioning but powers the assisted rammer and on-board fire controls.” The company collaborated with Turkey’s MKEK in the development of the Panter, which continues to be fielded to its army.

M198-155mm
US Marines assigned to 3rd Battalion 11th Marines 1st Marine Division during push to Baghdad during Operation Iraqi Freedom 2003, prepare to fire a battery of M198 155mm howitzers against confirmed enemy targets in Iraq. (USMC)

The 105mm howitzer (and 122mm Russian) have become ‘light’ artillery almost by default as 155s have replaced them. Still they continue in service with many armies but are primarily only found in specialised light infantry support. Thus; the US 82nd Airborne retain the 105mm towed M102 as its direct support artillery and benefits from being able to be transported externally by the Sikorsky UH-60 Blackhawk.

The Republic of Korea’s (RoK) Army, realising it had a considerable inventory of the M101 105mm towed howitzer, has been determined to convert them into a configuration more suited to the manoeuvre demands of today’s battlefield. Their Defence Acquisition Program Administration (DAPA), in cooperation with Hanhwa Techwin, developed the EV-105 which places the gun onto a tactical truck with GPS and automated fire controls. It was announced in June 2017 that full production would begin in 2018. Despite the limited 11km range this approach does offer a cost effective way to augment indirect fires.

Similar projects have been undertaken by Vietnam, Thailand, Jordan and even the US company AM General with its Hawkeye on the HMMWV (Humvee).

The Russian D-30 122mm towed howitzer remains in use by 30 countries despite being introduced in the mid-1960s. It has a modest 15.4km range but is simple and reliable. Its tri-leg platform allows all-around training and it has been well employed in direct fire as indirect. Its ammunition includes anti-armour HEAT rounds.

Self Propelled Artillery

The need to move to survive has been a key factor influencing the move to self-propelled (SP) guns. Given new technologies in gun operation automation, computerised firing calculation, on-board navigation, and networked digital communications the SPs are almost independent fire support systems.

Korea’s K-9 Thunder, manufactured by Hanwha Techwin, is further facilitating this autonomous operational ability by providing a KI-10 Ammunition Resupply Vehicle (ASV) as a companion. By the two vehicles working together it is more possible to maintain the flexibility offered by tactical mobility while also being able to sustain the high ammunition usage that military planners predict. The latest improvements to the K-10 provide greater automation of the ammunition transfer moving 12 rounds per minute using a conveyor.

The BAE Archer uses a similar pair employment, with an accompanying Volvo A30E articulated 6×6 truck configured with ammunition stowage and a handling conveyor system. This concept reinforces the capability of the artillery and one can expect it to become a highly desired if not required feature in future artillery. An indication of this is that Japan’s Type 99 155mm SP includes an ASV as does the People’s Liberation Army PLZ05 155mm SP.

BAE-Hagglunds
Sweden’s Archer 155mm wheeled self-propelled howitzer from BAE Hagglunds has a magazine and is fully automated allowing the crew to execute the entire fire mission in under a minute without leaving the armoured cab. (BAE)

Munitions

Much of the enhanced capability of artillery is due to relatively recent advances in ammunition. Ranges have been extended by base bleed projectile designs and the incorporation of flight canards in extended range munitions. Accuracy has been increased with GPS programmed warheads and laser guided homing seekers. One of the factors influencing the move toward the 155 and 152mm size was its better suitability for carrying ‘packaged’ sub-munitions. These could allow multiple targets, including armoured vehicles, or larger areas to be attacked with each projectile. Artillery, once considered effective if it paced rounds in a 100m area can now, with the proper warhead and ground coordination, hit not just a specific building but a single room in that building.

Artillery Rebirth

Much has been written in the last few years about the renewed recognition of the capabilities and importance of artillery. If there was ever a doubt about its importance it certainly was not a universal view. The Russian emphasis in the use of artillery in the Ukraine demonstrates this comprehensively. As is often the case in warfare the weapons themselves are only one aspect of combat effectiveness. The other, and perhaps more importantly, is how they are employed. In this the advances in artillery are providing new possibilities.

by Stephen W. Miller