After a day at the annual Surface Navy Association’s national symposium, it is easy to conclude that the future of Navy surface warfare is bright. Exhibits include an array of exciting weapons, sensor systems, and new ship designs. While this bodes well for the surface fleet, service leaders must not lose sight of the need to improve the warfighting capability of current surface platforms, specifically against the asymmetric threat of combined unmanned aerial vehicles (UAVs) and small-boat swarm attacks. To help the surface navy keep pace against these and other threats, a number of technically viable and technologically mature capabilities already exist in naval gunnery. These improvements could be incorporated soon and employed against threats ranging from close-in to just beyond the horizon.
Simplistic Training and Inefficient Weapons
Counter–small boat exercises are tightly scripted events conducted in favorable environmental conditions against cooperative, remotely operated targets. After a series of practice runs for crew familiarization and training, the event usually concludes with the destruction of the target. This training is useful to a point, but it does not give crews a realistic sense of what it will take to adequately counter a swarm attack with many small-boat targets, not to mention one that also includes UAVs, missiles, and aircraft.
Currently fielded gunfire systems are capable of hitting designated targets at recommended engagement ranges under ideal conditions. However, conditions are rarely ideal, targets move and require multiple hits to disable, bullets do not fly straight, and sometimes the radar track the ship is engaging is of poor quality. These challenges can be partially mitigated in training by performing pre-action calibration fires and live-fire exercises to improve system hit
rate. Ultimately, however, a successful gunnery engagement relies on the
conditions of the moment, the ability
to effectively target the track, and a
well-trained team.
In the case of crew-served weapons (CSWs) such as the M2HB and M240 machine guns, much depends on the operator’s skill, proficiency, and combat resilience. For all gunnery engagements, the result often is a number of rounds expended that do not hit their marks and—the longer the engagement continues—rapidly depleting ready service loads.
Even the best CSW gunner often needs to expend a third or more of their ammunition belt to disable a single small-boat threat. Against the same target, the Mk 38 Mod 2 Machine Gun System with the 25-mm chain gun would need a similar number of rounds, although it could engage at a slightly longer range. The same is true for the Mk 46 and Mk 50 30-mm gun weapon systems. For medium- and major-caliber weapons (Mk 110 57-mm and Mk 45 5-inch guns), even effective salvos of four or five rounds at a time result in a significant number of rounds wasted. A critical limiting factor is the small magazine capacity for each weapon system. This forces crews to be prudent in employing their weapons, ensuring they get the best “bang for their buck.” As a result, with all its guns, a ship can effectively engage fewer than a dozen or so small-boat targets at once.
Ammunition capacity normally makes naval gunfire preferable to missile systems in a multimission warfare environment that involves both asymmetric and high-end threats (small boats, UAVs, antisurface missiles, and aircraft). A generic ship loadout requires that most missiles be reserved for high-end threats, which means they cannot be considered as the first weapon of choice against a small-boat swarm attack. Similarly, automated point-defense systems such as the close-in weapon system (CIWS) should be used as a last layer of defense, preserved to engage those targets that leak through the ships’ multiple defensive layers. These constraints on missile and CIWS employment support the case for more effective and capable gunfire systems.
Performance analysis of live naval gunfire tests is useful, but the testing environment is necessarily limited in scope because of the complexity of the potential targets. What is known regarding gunnery munition effectiveness is that it often takes more than one hit to disable or destroy a small craft. Either the projectile is not destructive enough or it does not hit critical systems, components, or operators. For 5-inch and 57-mm projectiles that have significant blast effects and can be effective without a direct hit, projectile fragments have a limited effective range and only work against lightly armored targets. Therefore, regardless of the weapon caliber and to ensure effectiveness against its target (small craft, UAV, missile, or aircraft), the naval gunfire operators must be able to hit the target and not just get close.
Significant Improvements Already Exist
For an individual ship to deter a saturation-type attack, such as a small-boat swarm in the littoral where coastal
antisurface missiles and other threats also loom, it must be able simultaneously to defeat multiple threats. An adversary that can throw enough targets at a U.S. ship could overwhelm it. The following recommendations can enhance warfighting effectiveness until next-generation weapon systems come online:
- Conduct a “shoot off” to field a better guided 5-inch projectile. Candidates include the multiservice standard guided projectile (BAE Systems), Excalibur N5 (Raytheon), hypervelocity projectile (Office of Naval Research and BAE Systems), and a 5-inch variant of the Mk 332 Mod 0 high-explosive, 4-Bolt-guided projectile developed for the Mk 110 57-mm gun weapon system. Each offers a significant improvement in range and hit rate, thereby contributing to an overall increase in system effectiveness.
- Accelerate development and fielding of high-density reactive materials (HDRM) and advanced energetics. HDRM improves projectile lethality through more catastrophic secondary effects, resulting in single-shot “kills” against small craft, aircraft, and missiles. HDRM also can be applied across a range of armaments, from bullets to bombs. Coupled with advanced propellants, upgraded munitions promise improvements in projectile velocity and lethality and have the potential to reduce gun bore erosion.
- Install more remotely operated, stabilized gun systems on every ship. These systems improve the ship’s ability to fight by removing personnel from the vicinity of vertical launch systems and major caliber weapons, enabling more weapons to be operating simultaneously. Furthermore, their improved accuracy increases hit rate and reduces the amount of ammunition expended per target. Stabilized mounts already have been developed for the Marine Corps’ M2HB and M240 machine guns, but they have yet to be fielded in the Navy.
- Carry out analytical research on gunfire effectiveness against the full range of relevant targets. Current analysis within the joint gun effectiveness model is insufficient, as it does not allow for accurate salvo size recommendations for 25-mm, 30-mm, 57-mm, and 5-inch gun weapon systems against the myriad of threats. This analysis is needed to help guide decision makers.
If the surface navy truly wants to be a distributed and lethal fleet, it must improve the naval gunfire systems of existing ships with weapons and technologies that are readily available. The risk of not doing so will become apparent only after the first shots are fired and will be a surprise to the fleet. The time for a naval gunfire resurgence is today.