Vehicle turrets are growing increasingly sophisticated in a number of areas, from advances in ammunition to different uses of automation. There has been a range of changes in recent years, depending on calibre size and vehicle role. However, a number of themes can be highlighted.
As with all aspects of warfare, the particular demands made of turrets very much depend on the nature of the foe. A clear trend over the past decade has been a heightened appetite for Programmable Airburst Munitions (PABM) in medium calibre weapons. This was initially driven by a number of factors, notes OykunEren, weapon systems and core engineering manager at FNSS, a Turkish joint venture involving BAE Systems and Nurol Holding, including the need for more effective ammunition against widely dispersed troops in the open, infantry behind cover, and troops in trenches and bunkers. For more information on the workings of airburst munitions, please see the accompanying How It Works box.
|How It Works: Airburst
As their name suggests, airburst munitions detonate above the surface. Principally employed against troops in the open, or soft targets, airburst munitions are particularly advantageous when employing fragmentation. Detonated above its target, an airburst munition will disperse its effect evenly over a wide area, whereas a munition detonating on the surface will always have some of its power absorbed by the ground. However, the latter munition is more effective against fortified targets.
PABM have a number of advantages, Mr. Eren explained. For example, they require fewer rounds than traditional high explosive ammunition when used against the targets outlined above. This provides an increase in ‘stowed kills’, Mr. Eren observed. This is an indication of how many targets an Infantry Fighting Vehicle (IFV) can effectively engage with the number of rounds stowed inside the platform. Nevertheless, new targets are emerging, notably the proliferation of unmanned aerial vehicles (UAVs) on the battlefield. Dealing with UAVs is primarily the responsibility of air defence systems, Mr. Eren adds, while IFVs face challenges in detecting such aircraft in the first place, given that the ranges and altitudes with some UAVs fly it may necessitate a radar for detection. “For low and slow-flying UAVs, turrets with advanced fire control systems and airburst munitions have a better chance of engaging (UAVs) than with older turrets using conventional ammunition,” he stated. Such fire control systems can be effective in detecting the UAV and plotting a fire solution, with airburst munitions dispersing fragments in proximity to the UAV which may be sufficient to cause the aircraft’s destruction.
The rise of airburst ammunition was highlighted by a number of companies as a major development in the medium-calibre space. Definitions differ, but medium calibre weapons typically fall into the 12.7mm to 40mm category. Rune Werner, vice president of Kongsberg’s Protech Systems division, pointed to the “spread of fragments that can be used for several operations.” Leonardo (formerly Finmeccanica) also sees strong advantages in airburst munitions in medium calibres, which it views as allowing more flexibility to IFVs during their missions, in terms of being able to engage a range of targets. The Italian company expects that within a few years, airburst munitions will be the new standard for medium calibre turrets. This has been driven by changes on the battlefield such as the rise of asymmetrical warfare (seemingly mismatched armed forces engaged in conflict), in which it is necessary to defeat an enemy at long distances; often the enemy is lightly protected or hiding behind a wall, or other makeshift fortification.
David Coughtrie, business director at CTA International, a joint venture involving the BAE Systems and Nexter, states that “airburst natures are key”, pointing to their uses in attacking “UAVs, helicopters, slow-moving air threats … If you can spot them, which is the first difficulty, you’ve got to have something to take them out.”
The rise of UAVs is a major driver of demand for airburst ammunition today, notes Dan Lindell, platform manager for the BAE Systems’ CV-90 tracked IFV for the company’s Hägglunds division. This was not the case when the company first introduced airburst munitions onto the CV-90 back in 2004, he said, when it was “mostly (used against) soft targets”. The usefulness of airburst munitions was very calibre driven, Mr. Lindell states. A 35mm round could carry double the number of tungsten pellets as a 30mm round, he said, making it “double as attractive for one round in terms of the amount of shrapnel it spreads.”
Calibre size is of course a crucial factor when it comes to lethality. The standard choice for new gun procurements in the medium calibre arena has moved from 25mm up to30mm or even 40mm, according to Leonardo, with some armies looking interested in the possibility of increasing from 30mm to 40mm with a minor modification. The increase in calibre sizes is driven by a number of factors, including the ability to engage targets at longer distances with such weapons. In addition, using calibres in the 30mm to 40mm range with airburst munitions allows for fighting in both symmetrical (evenly-matched belligerents) and asymmetrical scenarios using the same gun, the Italian company told Armada.
The 30mm is without question the most popular calibre in the West, Mr. Lindell added. However, he expects to see a rise in the uptake of this calibre in the future, particularly as other countries are working with much larger calibres. “It’s a lot easier to upgrade your lethality (compared to) up-armouring (vehicles). It’s also more expensive to up-armour than to upgrade your lethality,” he said.
Mr. Coughtrie echoed Mr. Lindell’s assessment noting that the entry level for medium-sized calibres “is now being sort of reset”. While it was once the case that 20mm would be the ‘entry-level’ calibre in the medium calibre domain, 25mm would be good, and 30mm would be best, “now we’re finding that really 30mm is insufficient and you’ve got to really go towards the 40mm and 50mm (calibres).” For this reason, he said that his company’s 40 Cased Telescope Armament System aimed to pack the power of a 50mm weapon, with the volume of a 30mm: “50mm calibre, medium calibre on these turrets, is just huge … you’ve got to have that performance, but with a volume of something smaller.” Likewise, Mr. Eren stated that he expects the ‘older’ calibres such as 20mm and 25mm to be replaced by larger and more lethal calibres in the future. “For the very near future, I can say 30mm will stay as the popular calibre, but depending on the evolution of the threats, a trend towards larger calibres may be expected.”
Much of the debate over calibres for IFVs naturally comes down to cost. Mr. Eren said, with ammunition prices rising rapidly as calibres increase from 25mm to 40mm, PABM (see above) could be particularly expensive when compared with high-explosive ammunition. “However, as the serial production of programmable ammunition (munitions which can be electronically programmes to detonate in a particular fashion) becomes more widespread, it is expected that this price gap will eventually decrease,” he added.
The demands being made of turrets are growing all the time on an increasingly complex battlefield with numerous targets. There was a need for all sorts of weapons, from machine guns to Anti-Tank Guided Missiles (ATGMs), observes Yizhar Sahar, director of marketing and business development for Rafael Advanced Defence System’s land manoeuvre systems directorate. “The main thing is the capability to have either a turret that supports multiple weapons that can be replaced by the crew, or a turret that supports more than one weapon simultaneously, and in particular a cannon and/or a machine gun with an additional launcher for ATGM,” he explained.
Leonardo also views the integration of ATGMs into medium-calibre turrets as a key development in recent years, as well as the integration of Remote Weapon Stations (RWS). Yet the increasing complexity of the battlefield has impacts across the ranges of calibres. On the large calibre side, the requirements have shifted from “kind of anti-armour-centric rounds to more multi-purpose effects”, said Lieutenant Colonel Kyle McFarland, product manager for large calibre ammunition at the US Army’s Ammunition Programme Executive Office (PEO), which covers munitions ranging from 105mm to 120mm. “Previous generations of munitions focused really just on defeating thick and complex armours on a tank-on-tank battlefield,” he told Armada. Although they still need this capability today, “they also require the ability to take out bunkers (and) concrete structures in an urban environment,” as well as engaging “dismounted personnel threats at extended ranges. So (we have) really seen a transition for the munitions and how we have to approach those things to get that broad capability set.”
This had been driven by the increased complexity of the battlefield, he said, which has changed considerably from the days of Operation DESERT STORM, the US-led expulsion of Iraq from Kuwait in 1991, and armoured formations taking on armoured formations. “In Iraq and Afghanistan, and other conflicts around the globe, you’ve seen the rise of dismounted ATGM teams, the need to fight in an urban environment with a very diverse target set,” he said. “So it’s not enough just to have anti-tank munitions on board. You need things to account for that more diverse target set.” Lt. Col. McFarland pointed to a number of areas of potential development in the large calibre domain in the coming years. For example, he said that as technology enabled the identification of targets at longer ranges, the Ammunition PEO, expected a need for ammunition to be upgraded as well.
Crewed or not?
A major theme in recent years has been the rise of RWS and unmanned turrets, with different companies outlining the various pros and cons of the systems. Mr. Lindell said that BAE Systems had not placed an unmanned turret on the CV-90 family as yet, though this was simply because there had not been customer demand. “We don’t have a problem at all to do that,” he added, if such a requirement was requested. He pointed to a number of positive characteristics vis-a-vis RWS, arguing that such turrets could be placed anywhere on the vehicle, unlike a heavily-protected inhabited turret. That said, especially in a troop-carrying vehicle like an IFV, any potential weight saved by using an unmanned turret could be counterbalanced by the need to place the crew in the chassis, which would take up storage volume that would have been free when using an inhabited turret. This meant the vehicle would have to be larger, “and all the weight saving … has now gone away. So that’s one of the problems.”
Nevertheless, RWS are capable of accommodating the same lethality as inhabited turrets, argued Mr. Eren. “All the calibres that are used in manned turrets can also be integrated into remote systems,” he said. “Remote turrets that are well designed also offer (an) equivalent number of ready rounds with the (inhabited) systems.” The gun itself can have the same level of lethality whether the system is remote or crewed, Leonardo believes. However, the broader question is more complex, and depends on the kind of turret in question. It could, for example, be easier to manage a misfire in a manned turret, or to reload the weapon, the company believes.
There has been and will continue to be a “blurring of the lines between what is considered the ‘conventional’ RWS and what is considered a conventional inhabited turret,” notes Nils-Ola Svensson, head of business development and sales, combat systems and C4I solutions at Saab. The main discriminator for lethality is the base platform (the vehicle that the turret will equip) and the turret’s Size, Weight, Power and Cost (SWAPC) considerations, rather than whether the system is crewed or not. Mr. Svensson said that while taking into account the time from detection to effect (known as the kill chain), electrical and electromechanical sensors “still lag some way behind the (human eye) … (although) these technologies greatly aid the commander.”
He added that high-quality sensors and fire control technology were essential for effectiveness, and when combined with a stabilised aiming platform like the company’s Trackfire RWS allow “targets to be detected, acquired and locked even when the host platform is on the move, with engagement taking place as soon as the host platform comes to a stop, thereby increasing the host platform’s survivability”.