Home » Budget Industry » Updated: Navy Researching Firing Mach 3 Guided Round from Standard Deck Guns

Updated: Navy Researching Firing Mach 3 Guided Round from Standard Deck Guns

USS Ross (DDG-71) test fires the MK45 5-inch lightweight gun on April 30, 2015. US Navy Photo

USS Ross (DDG-71) test fires the MK45 5-inch lightweight gun on April 30, 2015. US Navy Photo

CORRECTION: This post has been updated to include a new statement from Naval Sea Systems Command that changes one previously given to USNI News revising the planned speed of hyper velocity projectile fired from a Mk 45 naval gun from Mach 5 to Mach 3.

The U.S. Navy’s deck guns could take on new relevance if ongoing tests to fire a guided round at three times the speed of sound from their muzzles are successful, USNI News has learned.

Using rounds initially designed for the service’s emerging electromagnetic railgun, Naval Sea Systems Command are now in early testing phases of using the planned hyper velocity projectile (HVPs) with the service’s existing gunpowder-based deck guns found on almost every U.S. Navy surface ship, NAVSEA told USNI News.

An artist's conception of BAE Systems' Hyper Velocity Projectile. BAE Systems Image

An artist’s conception of BAE Systems’ Hyper Velocity Projectile. BAE Systems Image

The HVPs from a traditional deck gun will be slower than one launched from a railgun — a little over Mach 3 versus Mach 5 — but still more than double the speed of an unguided regular shell from the service’s Mk 45 five-inch gun found on its guided missile cruisers and destroyers, according to information from NAVSEA.

While deck guns are standard through out the fleet, they lack the range precision of the guided missiles found on cruisers and destroyers and have had shrinking utility in high-end warfare.

A high speed guided round from a deck gun could give U.S. ships more options to deal with air and ballistic missile threats while the Navy continues to refine the railgun design.

According to a service wish list for railgun applications revealed last year, the Navy wants a “multi-mission railgun weapon system to support detect, track and engagement of ballistic missiles and air and watercraft threats” by 2025.

A guided HVP round from a standard Mk 45 deck gun could bring a significant margin of the railguns promised capabilities to the fleet sooner, USNI News understands.

Unlike standard high-explosive rounds, the speed of the HVPs doesn’t need explosives and relies on the force brought from its speed to destroy targets.

The addition of the HVP to the arsenal could mean instead of sending a Standard Missile to interdict an air threat, a ship could instead fire a much more inexpensive salvo of guided shells from the deck gun to handle an enemy aircraft.

According to NAVSEA, the service is also investigating using HVP in larger guns than the MK 45.

“The round is being designed to be compatible with multiple guns in the U.S. inventory,” read the NAVSEA statement to USNI News.
NAVSEA didn’t specify, but USNI News understands the Navy is looking for alternatives to the $400,000-per-round guided rocket assisted Long Range Land Attack Projectile (LRLAP) fired from the 155mm Advanced Gun System (AGS) of the Zumwalt-class guided missile destroyers (DDG-1000).

A range of hyper velocity projectiles from different weapon systems. BAE Systems Image

A range of hyper velocity projectiles from different weapon systems. BAE Systems Image

Testing for the inclusion of the HVP in standard is ongoing and a timeframe as-of-yet for completion hasn’t been established. Likewise, there is no program of record for the effort yet, NAVSEA said.

Both BAE Systems and General Atomics have worked with the service on railgun and projectile technology, though NAVSEA did not specify any companies working on the effort.

“This is a government-led effort, and we are working to involve a number of different defense contractors at this stage,” NAVSEA said.

A BAE Systems designed railgun will undergo a first round of at-sea testing next year.

  • totalitat

    How do the hvp projectiles affect barrel wear?

    • Colin

      My first thought, the rocket propellent that Curtis suggest is the likely way to go, but i suspect guidance becomes an issue then.

    • Secundius

      @ totalitat.

      How would it? If the “HVP” is designed to “MIMIC” a standard Naval Artillery Shell, until it leaves the Guns Barrel. It would be NO different than firing a Standard Naval Artillery Shell…

    • Paladin

      My guess is that to leverage the MK45 inventory, the transition from ballistic to hypersonic will occur outside the barrel and have little impact on barrel life.

      • totalitat

        See above comment.

  • @NotRizzo

    How do they attain the Mach 5 muzzle velocity from a standard MK45 barrel? No mention of the status of the HVP in testing for use with the EMRG (shock/acceleration is one thing, but the electromagentic field must play haywire with any guidance gear on the round).

    • Steve Skubinna

      That, and the shock from the rapid acceleration is a problem. A rocket assisted round could have a gentler acceleration (relatively speaking, of course). There’s already precedent for electronic systems in Naval gun rounds, the VT fused antiaircraft projectiles for the 5″/38 of WWII had a miniature radar in the nose for proximity detection.

      I expect that given proper resources we could produce extremely long ranged terminally guided projectiles that can be fired from the existing guns. In fact, the 62 caliber barrel of the latest Mk45 was intended to permit such rounds.

      • gunnerv1

        Dear Navigator, You’re the first person to mention the “up graded” Mk 45 from 54 Caliber to 62 Caliber. There is also a Video (YouTube) of a Newer (and Faster Cycling (Firing)) 5″/62 Caliber Mount (Test Bed) hard mounted Ashore in test Phase. There’s not much “gained” in Initial Velocity from Standard Propellant/Projectile @2750 Feet Per Second (FPS) to 3300 FPS (Speed of Sound Approximately 1100 FPS). The Significant Gain is the “Terminal Guidance” feature. (Wish I was at Dalgren and/or Crane).

  • Elvis

    Sweet, look forward to see them make it work. Only question is how long will it take and if it turns out to be economical. If it works, we can even bring the mothballed battleships back into service. Imagine firing shells the size of Volkswagens that are guided and go at Mach 5.

    • Secundius

      @ Elvis.

      Isn’t that wasteful spending Sir. To reactivate a Battleship, is going to cost (at minimum) ~$1.5-Billion USD., just to deactivate it after the conflict. $1.5-Billion USD. will buy at least a couple thousand ATACMS with ranges of ~300km. and Still do the same kind of destruction. As single 16-inch Projectile with a range of ~24km…

  • Curtis Conway

    My guess is the rocket handles the acceleration after it leaves the barrel. Propellant will kick it out in the right direction, and the rocket motor accelerates to the target, and the shock of the whole operation is much less than coming out of a rail-gun. The key is potential energy first, then milk the kinetic energy.

    Actually it’s a logical and effective step TO rail-gun giving us some breathing room, until rail-gun is ready for prime-time. Most of the Mk 45 mounts have the extended guided projectile support capability (remember we paid for that and then didn’t use it). Now is a good time to take advantage of that investment. Even if the mounts all have to be upgraded, it’s more cost effective in the short term than back-fitting something that doesn’t exist yet, and will be expensive when it does exist.

    Thought to different guidance packages should be given. Ideally we would have Laser guided, programmable IR, and EM spectrum (HARM, only Projectile instead of Missile) we could target. This will be our ‘Harpe’, and tines it will have. Several technologies support this capability already. Just have to package it and test. Several rocket fuel mixes and stacks can provide the desired propulsion. One does not have to do Mach 5 coming out the barrel. The barrel has to last and do other things too.

    • Steve Skubinna

      There have been rocket assisted projectiles in the inventory before. They have not been used, IIRC, since Vietnam. There’s no reason a 5″ or larger round could not benefit from both rocket assist and terminal guidance. It would not only supplement missiles but cost much less.

      Plus, a ship can carry far more gun rounds than missiles.

      • Curtis Conway

        Thank you. Some of us have been trying to make this case since the 1980s. Wouldn’t you know it would take a fiscal crisis to get DoD (and DoN) to even consider it. So much for being responsible with the tax payers dollars.

      • Paladin

        As one of the last units to fire them in RVN, my battery “owned” the entire in-country inventory of M548 105mm HERA (High Explosive Rocket Assisted) in 1972. We fired them out of FSB Grunt II, just south of Bien Hoa. The rocket was a very short impulse that looked to activate very close to max ord, about 15-20 sec after firing. The M548 has about a 50% range advantage over the M1 cartridge. Since a ballistic round starts to slow down as it exits the muzzle, I’m quite sure the M 548 never got close to Mach 3. To achieve a Mach 3 velocity, a much higher specific impulse, than current rocket assisted ammunition, is needed. It’ll be interesting to see how the designers use the rocket assist to shape the HVP trajectory.

  • bobbymike34

    I would load a few dozen of these onto the new USAF proposed air launched boost glide prompt strike hypervelocity weapon. Use a solid propellant booster to get to M5 speeds and deploy these like very small MIRVs to hit multiple targets. Imagine a B-2 with a dozen or so missiles carrying hundreds of individual HVP warheads.

  • Steve Skubinna

    Hard to tell from the illustrations but they do look like discarding sabot rounds.

    • Paladin

      You’re right, difficult to tell. Since it looks like this round is fin stabilized, I think some sort of de-spin device will be needed to ride in the rifling.

      • Secundius

        @ Paladin.

        I suspect the HVP looks like a Standard 5-inch Projectile, but the Stabilizing Fins are covered by Sweetjudy cover panels that come-off after it leaves the Naval Artillery Gun Tube…

  • Secundius

    The Current ERGM, Extended-Range Guided-Munitions round is 12-calibers (~60-inches in length) and has a range of ~63nmi…

  • J_kies

    Yaah – fist bump – damn straight – Go NAVSEA !
    Apply guided munitions to naval artillery with / without rocket assist as needed and gain immediate military effect enhancements with the ship’s current gun / C2 systems.

    Thank god someone is talking about USEFUL R&D that doesn’t depend on defeating physics or having only fair weather operations.


    Need to do some more updating. The standard 5in/54 round has a velocity of about 2700fps or Mach2.4 at the muzzle, give or take. This may be doubled by a Mach 5 projectile, but a Mach 3 projectile is only something like 25% faster. Now, if it is twice the speed of a conventional shell at some point downrange from the ship because of better aerodynamics, that should be clearly indicated.

    • Secundius

      @ USNVO.

      There two types of systems. First is the “Base Bleed”, which creates a vacuum behind the projectile reducing its drag. And can increase the Range of the Projectile up to 30%, unfortunately it does not increase its speed. The second is called RAP, Rocket Assisted Projectile. Which is a Solid-Rocket Fueled Projectile Motor attached to the end of the projectile. Increasing its Speed and Range depending on Burn Time. Systems like this also deploy small Pitched Blades which Power a Generator while in flight to power its Onboard Guidance System. Allowing it to steer its way to the target, there usually three guidance systems for Redundancy. GPS, Laser/Optical and Inertial Guidance…

      • Paladin

        I think you’ll find that the gas generator in BB ammo fills the vacuum rather than creates one. Additionally, RAP ammunition in 105mm (M548,M913) and 155mm (M549, M549A1, and M795E1) are all ballistic (unguided) projectiles.

        • Secundius

          @ Paladin.

          What about 105’s or 155’s, I made NO reference too either…

          • Paladin

            ” Systems like this also deploy small Pitched Blades which Power a
            Generator while in flight to power its Onboard Guidance System.
            Allowing it to steer its way to the target,” Pointing out that all assisted projos are not guided.

          • Secundius

            @ Paladin

            I was trying to answer a question in general terms, Not trying to point to a specific system. And at the “time” I couldn’t remember the “type” of power generation system employed. I mean I knew the System, just not it’s Name…

    • Marjus Plaku

      Really important point, as discarding HE for kinetic only would be foolish in my opinion if there is only 25% more velocity at impact. Some argument can be made about time to target, but again, if the overall speed differential over the entire course of flight is not too significant, that argument also doesn’t hold a lot of water.

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  • Secundius

    @ James B.

    Most “Smart” based Naval Artillery Systems, the Projectile is “Nose Heavy”. This allows the Head of the Projectile to make first contact with the Target, the Penetration or Business End of the Projectile…

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