The headline translates as ‘I, who is speed, eradicate’; an apt slogan employed by the US Navy for its research into electromagnetic railguns. Electromagnetic technology is advancing in the naval domain, offering promise for offensive weapons and aircraft carrier operations.
A report written by Ronald O’Rourke in October 2016 entitled Navy Lasers, Railgun, and Hypervelocity Projectile: Background and Issues for Congress, for the US Congress’ Congressional Research Service (CRS), a research institute based in Washington DC, stated that: “although navy surface ships have a number of means for defending themselves against Anti-Ship Cruise Missiles and Anti-Ship Ballistic Missiles, some observers are concerned about the survivability of navy surface ships in potential combat situations against adversaries, such as (the People’s Republic of China/PRC), that are armed with advanced ASCMs and with ASBMs.” The PRC’s China Changfeng Mechanics and Electronics Technology Academy’s DF-21D ASBM has been extensively discussed in the global sea power community, and the weapon was shown in Beijing on 3rd September 2015, at a parade commemorating the end of the Second World War. Meanwhile, reports note that the Russian Navy continues to deploy the Novator Design Bureau 3M-54 family of satellite-guided/anti-radar homing anti-ship and land attack cruise missiles.
As countries such as the PRC and Russia, continue to arm their ships with powerful weapons such as these, the US Navy is among many navies with a corresponding concern for the survivability of their surface combatants. Decreasing human resources in particular, are forcing navies around the world to do more with less. For example, according to the globalsecurity.org website, active personnel strength across the US armed forces is expected to reduce to 1.28 million by the end of 2017 from 1.3 million in 2016. In this context, significant developments in the application of electromagnetic technology to defence systems are emerging as a promising solution to the challenges posed by the weapons of potential adversaries and personnel reductions. From aircraft carrier catapults to railguns, these technologies are promising to be more cost-effective and less manpower intensive than current conventional systems.
Electricity and Magnetism
Electromagnetic energy is the combination of electric and magnetic fields. According to the definitions posted on the World Health Organisation’s (WHO) website: “Electric fields are created by differences in voltage: the higher the voltage, the stronger will be the resultant field. Magnetic fields are created when electric current flows: the greater the current, the stronger the magnetic field.”
The Electromagnetic Aircraft Launch System (EMALS) is a being developed by General Dynamics to replace steam-powered catapults to launch fixed-wing aircraft off aircraft carriers. It comprises two parallel beams made up of segments containing wire housings that are positioned within a carrier’s flight deck, as well as a carriage that attaches to the aircraft’s nose wheel. Meghan Ehlke, spokesperson for General Atomics (GA), explained that: “Energising the beam segments in sequence creates a magnetic wave that (travels along the beams) and propels the shuttle and hence the attached aircraft down the beam length at a designated speed necessary for a successful launch from the carrier.” This process requires several megawatts of electrical power, the company continued.
An electromagnetic railgun functions in a similar fashion to the EMALS; by generating several megawatts of energy that is then sent along two rails (in a similar fashion to the two beams of the EMALS) to create a magnetic field. As explained by John Finkenaur, the next generation technologies lead for Raytheon’s advanced technology business area: “After the system stores a certain amount of energy, the capacitors (which store the generated electrical charge) send an electric pulse down two long rails, one negatively charged and one positively charged, generating an electromagnetic field.” Once this field is created, a projectile can be fired by being pulled out of the barrel containing the two long rails at very high speeds. Open sources note that these speeds can reach Mach Seven (circa 8600 kilometres-per-hour). The projectile weighs 25 pounds (approximately eleven kilograms) and is non-explosive. Instead, the shell is encased in an aluminium alloy casing that sheds away once the projectile leaves the barrel, and is filled with tungsten pellets. The sheer speed of the impact of the shell with its target, coupled with its tungsten pellets, causes significant destruction without the need for additional explosives.
The steam-powered catapults the EMALS is being designed to replace have been in service on aircraft carriers around the world since the 1950s. They were deemed the most efficient technology to be able to accelerate a 60000lb (27272kg) aircraft to 130 knots (241 km/h) from a 984 metre (300 feet) long deck. To do so, these catapults needed approximately 1353lb (615kg) of steam for each aircraft launch, plus hydraulics equipment, water to stop the catapult as well as pumps, motors and control systems. In other words, while it is an efficient system the traditional steam catapult is large, heavy, requires significant maintenance and the sudden shock provoked by the launch has been found to shorten the airframe lifespan for carrier-based aircraft. They are also limited in relation to the variety of aircraft they can launch, especially as these are getting heavier, therefore limiting altogether the potential for navy fleet modernisation on those aircraft carriers. As an example, the Boeing F/A-18E/F Super Hornet is use with the US Navy has a Maximum Take-Off Weight (MTOW) of 66000lb (29937kg), according to official US Navy figures, whereas the erstwhile Douglas A-4F Skyhawk, which was finally retired from US Navy service in the mid-1980s had an MTOW of 24500lb (11136lb), open sources add.
For Ms Ehlke: “aircraft today are increasingly heavier, faster, and more diverse, requiring launch systems with more efficient power capabilities and greater flexibility to control and manage the different launch speeds necessary to get each aircraft type off the deck.” In comparison to steam-powered catapults, the EMALS will be 30 percent more efficient, General Atomics states, and will require much less space and maintenance than its predecessor, facilitating its installation on various ship platforms with differing catapult configurations, according to Ms Ehlke. For example, the US Navy ‘Nimitz’ class aircraft carriers have four steam catapults, whereas the French Navy’s solitary FS Charles de Gaulle has two. Moreover, the variable acceleration of the EMALS, adapted to each type of conventional or unmanned aircraft’s weight, will contribute to increasing the aircraft airframe lifespan: “With a smaller footprint, greater efficiency and flexibility, and less manning and maintenance requirements, the EMALS offers significantly improved capabilities and cost reductions to support naval fleets.” Ms. Ehlke concluded.
Railguns also present a number of advantages, according to Alexander Chang, an associate at Avascent, a consultancy based in Washington DC: “chiefly amongst those is that they can fire the projectile at high speed, that is around Mach Seven, without using any explosives.” As the railgun is powered from a ship’s overall electricity supply, this eliminates the risks associated with carrying explosives or propellants, on surface combatants. The high velocity of the railgun, which is approximately twice that of conventional naval guns, leads to shorter engagement times and enables ships to deal with multiple threats almost simultaneously. This is because propellants do not have to be loaded with every new shell which is fired from the gun’s barrel. Ms. Ehlke pointed out: “By eliminating the need for propellant and high explosives, re-supply is simplified, reducing the logistics burden, while (the railgun’s) small size provides (for a) high capacity (deep magazine) and a low cost per engagement … It also offers a much higher range advantage compared to other weapons (such as surface-to-air missiles/SAMs) used for defence on surface combatants.” Mr Chang continues. The CRS report noted that, at the moment, the two railgun prototypes built by Raytheon and General Atomics for the US Navy: “are designed to fire projectiles at energy levels of 20 to 32 megajoules, which is enough to propel a projectile 50nm (92km) to 100nm (185km).” As a point of comparison, The OTO Melara/Leonardo 76mm naval gun has a muzzle velocity of circa Mach 2.6 (3294km/h), achieving a maximum range of circa 21.6nm (40km), according to publicly-available sources. According to Mr. Finkenaur: “The (railgun) can be used for naval surface fire support where there is a need to launch hundreds of nautical miles downrange, or it can be used for shorter-range engagements and anti-missile defences.”
The technology behind the EMALS is already at production stage. The US Navy, which has chosen this system built by General Atomics to propel aircraft from its new ‘Ford’ class aircraft carriers, has carried out the first load testing on the first-in-class, USS Gerald R.Ford, in November 2016, by which a dead weight representative load was catapulted into the sea. According to Ms. Ehlke, production and installation is also underway for the USS John F. Kennedy, scheduled to be commissioned in 2020, and the firm has also been selected as the single source production contractor for EMALS technology onboard the USS Enterprise for which construction is scheduled to begin in 2018. Ms. Ehlke indicated that: “We are also seeing interest in our electromagnetic launch and recovery systems from the international community, as they advance their naval fleets with new technologies and aircraft capabilities”. It is nevertheless worth noting that, while the EMALS is production ready, the design will not be able to be fitted to a vast majority of aircraft carriers at the mid-point or end of their lives due to the amount of power they require to function, the company has stated.
The Railgun, on the other hand, still faces one key challenge in the form of available power. According to Mr Finkenaur: “One challenge for the application of electromagnetic technology in defence is getting the weapon’s barrel right and reducing the wear and tear on the barrel from each projectile launch.” Indeed, the speed at which the projectile leaves the barrel causes such erosion of the gun that in early tests the barrel had to be rebuilt completely after each shot. Mr. Finkenaur also adds that: “The pulse power itself comes with the challenge of releasing an immense amount of energy and coordinating the pulse power modules to work together in concert for one shot”. These modules are required to release their electricity at exactly the right moment to create the magnetic force and pull the projectile out of the barrel. Finally, the energy necessary to propel a projectile at such speed also poses the challenge of having to pack the necessary components required to make the railgun function into a small enough physical footprint that can easily fit on different sizes of surface combatants. For these reasons, Mr. Finkenaur believes that small-scale railgun have the potential to become operational in the next five years, while a full-powered railgun using 32 megajoules of energy will likely be mounted on a ship in ten years time.
According to Mr. Chang: “Lately the USN has been putting less pressure on maturing railgun technology and has, instead, also been investing on the development of the HVP (Hyper Velocity Projectile) which, it discovered, can easily be fitted in existing conventional guns.” A technical document published in September 2012 by the Office of Naval Research (ONR) on the HVP describes it as: “a next generation, common, low drag, guided projectile capable of completing multiple missions from different gun systems,” which include, in addition to the railgun, the US Navy’s standard BAE Systems Mk.45 family 127mm and BAE Systems 155mm Advanced Gun System. The ‘secret sauce’ in the HVP design, according to BAE Systems, is an ultra-low drag design which eliminates the need for a rocket motor to extend the projectile’s range, compared to conventional shells.
When fired from a Mk.45 weapon, the projectile may achieve only half of the speed it would achieve when fired from a railgun, that is Mach Three (circa 3704.4km/h), however that remains twice the speed of a conventional shell fired from a Mk.45, according to the CRS report. Based on a media release on the US Navy website, dating from 5th August 2015: “The HVP, combined with the Mk.45, will support various mission areas including naval surface fire support, and has the capacity to expand to a variety of anti-air threats, anti-surface, and could expand the navy’s engagement options against current and emerging threats”.
For Mr. Chang, the decision of the Strategic Capabilities Office (SCO), the Department of Defence (DoD) research and development arm, to invest significantly into the development of the HVP is a way of circumventing the issue of retrofitting ships to accommodate the railgun. Thus, the US Navy will be able to use the HVP on its ‘Ticonderoga’ class cruisers and ‘Arleigh Burke’ class destroyers, which have two Mk.45 guns apiece. Additionally, while the railgun may not yet be ready to be operationally deployed on the ‘Zumwalt’ class destroyers, the first of which was commissioned by the US Navy in October 2016, the new destroyer will still be able to fire HVPs from its two 155mm Advanced Gun System weapons. Reports in January stated that the US Navy had commenced test-firings of the HVP using a US Army howitzer. There is no word from the US Navy as to when the HVP could enter service onboard US Navy warships.
In 2013, BAE Systems was awarded in a $34.5 million contract by the ONR for the development of the electromagnetic railgun under Phase Two of the Navy’s Innovative Naval Prototype (INP) programme. During Phase One, engineers from the US Navy’s Naval Surface Warfare Centre successfully fired Raytheon’s EM Railgun prototype achieving tactical energy levels, that is, 33 megajoules. Under Phase Two, according to BAE Systems’ news release of 1st July 2013, the company aims to move from a single shot to a multi-shot capability for its design, and to incorporate auto-loading as well as thermal management systems to cool the railgun after each shot. In 2013, BAE Systems also won a $33.6 million contract from the ONR to develop and demonstrate the HVP.
General Atomics started railgun technology under President Ronald Reagan’s Strategic Defence Initiative (SDI), initiated in 1983. The SDI aimed to “develop a space-based missile defence programme that could protect the country from a large-scale nuclear attack,” according to US Department of State archives. The SDI became obsolete with the end of the Cold War, and was quickly abandoned as being too expensive. The early version of the railgun, however, required so much energy to power the gun that it could only have been housed in a warehouse, according to Ms. Ehlke, therefore: “During the last eight years we scaled down the microelectronics and the semiconductors, and built smaller, high power density capacitors.” More details regarding laser weapons can be found in the author’s Back to the Future article in this issue.
Today, General Atomics has already developed a 30 megajoule railgun system and the ten megajoule Blitzer multi-mission medium range railgun. Meanwhile, a capacitor that will facilitate the storage of energy for the firing of railguns on land vehicles was successfully demonstrated in July 2016 in open-range conditions. Ms. Ehlke adds: “We’ve also successfully demonstrated the transportability of the Blitzer railgun, having disassembled the railgun, transported it from Dugway Proving Ground test range in Utah to the Fort Sill, Oklahoma test site, and reassembled it for a series of successful test firings during the US Army’s Manoeuvre and Fires Integration Experiment event in 2016.”
Raytheon has also been actively contributing to the development of railgun technology through the development of an innovative pulse power network. Mr. Finkenaur explained that: “The network is comprised of multiple pulse power containers, 6.1m (20ft) long, 2.6m (8.5ft) tall boxes, that hold and connect dozens of smaller units called pulse power modules. The job of these modules is to draw in energy over several seconds and release it in an instant.” If enough modules are put together they can generate the power necessary to operate a railgun.
In a speech delivered in Brussels on 28th April 2016, the US deputy secretary of defence, Bob Work, emphasised that: “Both Russia and China, they are improving daily in their ability to operate on the sea, in the air, on land their special operations forces. And they’re also becoming quite good in cyber, electronic warfare and in space”. The threats that these developments could cause to the US, and NATO (North Atlantic Treaty Organisation) countries at large prompted the US to develop the Third Offset Initiative (TOI). As announced by the then US secretary of defence Charles ‘Chuck’ Hagel in 2014, the TOI seeks to match or exceed the military capabilities being developed in the PRC and Russia through the application of technology. This concept arguably adheres to William Lind’s definition of manoeuvre warfare of gaining an “advantageous position relative to the enemy,” as articulated in his monograph, the Manoeuvre Warfare Handbook. In this context, rail guns and HVPs in particular represent key capabilities to countering or neutralising the potential threats posed by PRC and Chinese weapons such as those discussed in the introduction.