As nations worldwide continue to pursue the modernisation of their armoured vehicle fleets, growing concerns over high intensity warfare and its downstream effects on energy supplies is increasingly shaping the conversation regarding future propulsion systems for armoured vehicles. Armoured vehicles are notorious for their energy requirements, and as successive modernisation programs continue to integrate additional subsystems and modules with legacy platforms, power supply and management issues are becoming more apparent.
Indeed, most armoured vehicles currently in service rely on high-powered diesel or gas turbine engines, which with each additional survivability upgrade decreases fuel efficiency and mobility as additional armour adds additional weight to the platform. Furthermore, the increased digitisation of the battlefield has led to armoured vehicles being integrated with a growing number of complex electronics and computers. However, the reliance on mechanical energy source, such as a fuel powered generators further decreases efficiency due to the difficulty of optimising power management and thus creates a need for alternate power sources to support platform electronics.
This has proven to be a particularly poignant issue for the US Army, which operates a diverse fleet of armored vehicles which is increasingly incapable of meeting their operational needs. This was recently illustrated during the live fire exercises conducted at Grafenwohr Training Area in Germany in June, where the integration of new C4ISR equipment on the Stryker Infantry Fighting Vehicles (IFVs) caused issues with overall power supply, leaving vehicle crews energy constrained as the onboard batteries provide insufficient power to conduct extended ‘silent watch’ operations with the engines inactive. The Army faced similar power issues with the M2 Bradley family of IFVs over the last two decades, with supplemental armor and C-IED systems having pushed the Cold War-era M2A2 variants to their limits.
In order to address this, the Army contracted BAE Systems in June 2018 to upgrade 164 Bradley’s to the A4 variants, the EPC2 variants of which include enhanced Cummings VTA-903T engines with better transmission and a smart power management for better electrical distribution throughout the platform. Nevertheless, this upgrade decision typifies the wider trends in the armoured vehicles propulsion market, as caution regarding the technological maturity of hybrid-electronic propulsion systems in the defense sector is stymying the appetite for procurement of radically innovative platforms, leaving nations with fleets of ageing vehicles poorly optimised for the energy intensive nature of network centric warfare.
This caution regarding the push to adopt electronic propulsion as the universal standard is to a certain extent well-founded, as some analysts have noted that increased reliance on electronic propulsion in the defense sector would only further increase supply chain vulnerabilities amongst Western militaries due to their reliance on rare earths and minerals sourced from China and other geopolitical competitors. As such, the argument goes that prioritising the modernisation of legacy systems is both more cost-effective and forward thinking, as doing so ensures armed forces retain viable capabilities with established supply chains capable of sustaining production and MRO should international conflict disrupt the ability to mass-produce new systems. However, the previously cited examples of recent power supply issue indicate that this argument is reaching its breaking point, as the increasingly digitised nature of modern armoured vehicles renders traditional mechanical propulsion systems incapable of satisfying the operational requirements of future motorised and mechanised forces.
Indeed, despite the aforementioned risks to supply chain security, electric propulsion systems offer numerous tactical and logistical benefits which will prove increasingly crucial to ensuring the effectiveness and survival of future armoured vehicles. As optronics and situational awareness systems continue to evolve, signature management has become a key factor in platform survivability due to the highly visible thermal signatures given off by fuel-powered vehicles. The increased modularity of electronic propulsion systems coupled with their reduced thermal signature permit for radically innovative vehicle designs, as the engine and generator can be situated almost anywhere in the chassis, making them easier to conceal and protect. Furthermore, electric propulsion will facilitate the integration of computers and intelligent technologies, which will have the two-pronged effect of enabling additional precision control of platform movement and speed to reduce energy consumption, whilst further enhancing energy efficiency of onboard electronics due to the optimised power transmission when compared to mechanical energy sources.
Amongst the myriad of advantages and benefits offered by electric propulsion systems, one of the most revolutionary is the capacity to generate and distribute power organically. Indeed, by leveraging the benefits commercial of hybrid-electronic drive trains each electric vehicle can in essence become a mobile power source for other systems, as excess energy generated by vehicular motion can be stored in internal batteries to then be re-purposed for the benefit of other units, platforms or systems. This capacity for organic generation of energy supplies would allow ground forces to conduct radically different operations in the future, as the reduced logistical burdens and increased mobility will provide ground forces with electric propulsion vehicles with a quantifiable strategic advantage over those lacking such technology. Increased operational range and mobility, reduced energy consumption and thermal signatures, greater powertrain efficiency and enhanced design flexibility are all potential benefits offered by electric propulsion which even improved mechanical propulsion systems will fail to deliver to the same extent. Though these factors are gaining increased recognition over time, the prevailing policy of caution in military procurement circles has resulted in a segmented adoption of electric or hybrid-electric propulsion systems in less critical platforms and vehicles first.
Defense primes such as Oshkosh Defense, BAE Systems and General Dynamics are all currently focusing research and development of electronic propulsion tactical vehicles or logistical support platforms, as this renders is easier to demonstrate and field test this emerging technology while minimising operator risk during the process, as next generation propulsion has yet to demonstrate its reliability in extremely adverse conditions such as active combat operations. On this front, observers note that we are likely still around a decade away from fielding fully electronic vehicles in combat scenarios, though as concerns continue to grow over the outbreak of high intensity warfare, the imperative for radical modernisation of land domain equipment is only getting stronger. In conclusion, the potential benefits offered by electric propulsion objectively outweigh the additional risks which come with the transition to a semi or fully electrified propulsion solutions for ground vehicles and platforms, and as such a technological revolution in the field armored vehicle propulsion is no longer simply a novel possibility, but rather an undeniable certainty for the future of land domain platforms.