British Royal Navy adds Missiles to 30mm Gun Mount

Martlet Light Multirole Missile launchers mounted on 30mm gun mount

Britain’s Royal Navy reports they have successfully tested the “Martlet” Light Multirole Missile from their 30mm DS30M auto cannon mount, a mount similar to the Mk38 Mod2/3 used by the Coast Guard on the Webber class and planned for the Offshore Patrol Cutter.

This is certainly not the first time we have seen missile launchers attached to a gun. The Israelis have been doing it for years using the Typhoon gun mount which is the basis for the current 25mm Mk38s as used on the Webber class. .

Spike LR Missile launched from a Typhoon weapon station on an Israel Navy Super Dvora Mk 2. A similar configuration was recently tested by the US Navy, from an unmanned surface vessel (USV-PEM). Photo: RAFAEL

The dimensions of the British missile and American APKWS and Hellfire are provided for comparison.

  • Martlet LMM: Length: 51 in. (1.3 m), Diameter: 3 in. (76 mm), Weight: 28.6 lb (13 kg), Range: 8,000 meters
  • APKWS: Length: 73.8 in (1.87 m), Diameter: 2.75 in (70 mm), Weight: 32 lb (15 kg), Range 5,000 meters
  • Hellfire: Length: 64 inches (1.6 meters), Diameter: 7 inches (180 mm) (17.8 cm), Weight: 100–108 lb (45–49 kg), Range: 8,000 meters

The Martlet has the option of proximity fusing and Laser Beam Rider guidance (in addition to semi-active and IR homing), that probably makes it more effective against air targets, particularly smaller ones like drones. It has been used successfully against a target drone. It also has a longer range than APKWS, but is probably more expensive. Its biggest disadvantage from our point of view is that it is not in the USN inventory.

I am not advocating for this particular weapon, but both Israel and the Royal Navy have seen the wisdom of combining missiles with auto cannon.

  • It minimizes manning requirements in that a single operator can control both missiles and guns.
  • It minimizes space requirements
  • It eliminates the need to pass the targeting information from one fire control to another as the target enters gun range.

Unlike separate systems it probably also means you cannot engage two targets simultaneously.

We need a gun for the signaling, the proverbial shot across the bow, but it is not the best way to neutralize a threat. In an installation like this, the missile is more accurate, has longer range, and is less likely to cause collateral damage.

My feeling is that the Coast Guard would be better off with Hellfire than APKWS. We probably will not have to engage a large number of small targets as the Navy might, but our targets might be larger and this might be the largest weapon available to us. Either APKWS or Hellfire would be an improvement over what we have. The nominal effective range of the 25mm Mk38 is 2,700 yards (2,457 m). The APKWS would double this and the Helfire would triple the effective range. Either would allow us to engage from outside the likely effective range of any improvised weapon system that might be used in a terrorist attack, which I estimate would not exceed 4,000 yards.

When the Mk38 Mod3 was announced, there were indications BAE intended to add a capability to launch APKWS from the mount. I am still hoping.

MAD-FIRES –Multi-Azimuth Defense Fast Intercept Round Engagement System

DARPA is working on what is essentially a gun launched guided missile, and reading their description or this report of testing of the rocket motor, you would not know that it is intended for the 57mm Mk110 gun currently mounted on the National Security Cutters (NSC) and planned for the Offshore Patrol Cutter (OPC). Fortunately the video above makes that clear. The portion related to MAD-FIRES is time 6:30 to 7:35. (I have seen some indications they plan to use the same technology on different size rounds, but the 57mm looks like the first beneficiary.)

“Envisioned benefits of MAD-FIRES for future systems include:

  • “Improved real-time defense against evolving air and surface combat threats, facilitated by:
    • “Extreme precision
    • “An ability to defend against greater numbers of simultaneous and diverse attacks
  • “Decreased per-engagement costs by a factor of 10 or more
  • “Potential future applicability to air and ground platforms”

MAD-FIRES Projectile. Photo by Dederot

Sea-Air-Space 2019 Virtual Tour

Like most of you I did not make it to the Navy League’s 2019 Sea-Air-Space Exposition, so I have found some YouTube reports that can at least provide some of the information passed along at the event. The descriptions below each video are from the YouTube description.

Day 1 video coverage at the Sea Air Space 2019 exposition. In this video we cover:
– Boeing MQ-25 Stingray aerial refueling drone with Rear Admiral Corey
– Future USVs and XLUUV/Orca programs with Captain Pete Small
– Austal USA new range of medium and large size USVs
Textron Systems CUSV with surface warfare payload
– ST Engineering range of USVs

Day 2 video coverage at the Sea Air Space 2019 exposition. In this video we cover:
– Raytheon SPY-6 radar
– Raytheon / Kongsberg NSM for USMC
– Northrop Grumman PGK for naval 5 Inch and 155mm guns
– Lockheed Martin Freedom-class lethality and survivability upgrade
– Lockheed Martin FFG(X)
– Navantia / BIW FFG(X)

Day 3 video coverage at the Sea Air Space 2019 exposition. Washington-based naval expert Chris Cavas is our guest speaker for this third and final day at Sea Air Space 2019. Cavas covers the follow topics:
– Bell V-247 Vigilant VTOL tilt-rotor UAV in U.S. Navy configuration
– Austal USA USV concepts
– Austal USA FFG(X) Frigate
– Fincantieri FFG(X) Frigate
– GD Bath Iron Works FFG(X) Frigate
– Lockheed Martin Type 26 CSC
– Lockheed Martin hypervelocity missile
– Mic drop

Small Vessel Hellfire Vertical Launch System

Photos: Above, Modular Missile Launcher, also seen below amidships on the Textron CUSV (Common Unmanned Surface Vehicle). Note relatively small size and innocuous appearance. 

Textron Systems’ CUSV with Surface Warfare payload at SAS 2019

Naval News reports that, at this year’s Sea-Air-Space Exposition, Textron showed one of their Common Unmanned Surface Vehicle (CUSV) craft equipped with a remote weapon station and a modular vertical launch system for the Longbow Hellfire.

I find the Hellfire VLS particularly interesting, as it might find application on Coast Guard cutters. The launcher appears to be about 2’x2’x7. The missile itself is 64″ long (1.6 meters), 7″ in diameter (17.8 cm), with a 13″ span (33 cm).

The CUSV is about 39′ (12 meters) in length. The CUSV’s load space is reportedly 20.5′ x 6.5′.

This earlier report indicates a missile shoot from a CUSV is expected in 2019. 

There would of course be concerns about how to mount these missiles on a cutter. The effects of the smoke at launch on he crew and the possible effects of the engines ingesting the smoke would have to be considered.

The planned transfer of six Webber class cutters to Bahrain, to replace the six Island class cutters assigned to PATFORSWA, might provide the incentive necessary to plan and test a Hellfire installation on this class.

“Navy Mk38 Gun Systems Gaining Co-Axial Small-Caliber Machine Gun” –Seapower

7.62 mm Chain Gun as Coax as optionally installed on 25 mm Mark 38 Mod 3. Image copyrighted by NAVSEA Dahlgren.

The Navy League’s online magazine Seapower is reporting that ” The Navy is installing a co-axial 7.62 mm machine gun on the mounts of its Mk38 chain gun systems, a Northrop Grumman official said….the addition of the co-axial Mk52 machine gun gives the gunner another “right-sized” option for countering a small target, such as pirates or terrorists on jet skis…Northrop Grumman is installing the Mk52 guns in the Mk38 under an indefinite delivery/indefinite quantity contract.”

This has been proposed for several years now, but this is the first indication it is happening. The proposed weapon, the 7.62mm Mk52, is in fact an electrically powered chain gun like the 25mm Mk242. (The article appears to be incorrect in this regard.)

The article also discusses the possibility of upgrading the Mk38 by replacing the 25mm gun with guns of 30 or 40mm.

I think the Coast Guard could make a good argument for upgrading its Mk38s to 40mm. The change would make very little difference to a DDG, also equipped with a 5″ gun and anti-ship missiles, but the Mk38 is the largest weapon available on about 75 Coast Guard cutters and these cutters could at any moment be required to face a vessel much larger than the Iranian boats the Navy has been fixated on. We already know the 30mm is a quantum leap in capability compared to the 25mm. Effectiveness is closely related to projectile weight. The 30mm projectile weighs about twice that of the 25mm. The 40mm projectile will weight three to four times as much as the 25mm. Since the rate of fire for these guns is similar, the 40mm is likely to be at least three times as effective against more difficult targets and also has a greater effective range.

Addendum:

The Coast Guard plans to install the Mk 38 on 64 Webber class and 25 Offshore Patrol cutters. The older crew served version of the Mk38 is on the remaining 378s, the 210s, and the remaining 110 foot Island class WPBs. I expect we may see the Mk38 on the Polar Security Cutters and the 87 foot Marine Protector class WPB replacement when they are built.

This would of course be less important if the vessels had something like the Long Bow Hellfire, which would be more effective than any of these guns against virtually any size targets.

 

Chinese Are Outbuilding the US in Warships

Respected Naval blogger CdrSalamander has a short post on the US Naval Institute blog warning that “The Pacific Will Pivot With or Without You.” It is really a quick look at a longer Reuters report, “China’s vast fleet Is now tipping the balance in the Pacific.” At the center of the stories is the chart above, showing how fast the Chinese have begun to build. The message is simple.

We are in a naval arms race with the most prolific shipbuilding nation in the world. 

The new reality is that China is building up their navy at a rate about twice as fast as the US, not just in numbers but in overall tonnage. That appears to mean, in about 30 years, the Chinese Navy could be twice as large as that of the US. Hopefully there will continue to be mitigating  factors, but since any conflict is likely to be in the Western Pacific, the Chinese also have an enormous geographical advantage.

It is time for the Coast Guard to step up their game as an armed force, with real arms and actual missions for a major war that the service has planned, practiced, and equipped for.

50mm Chain Gun, More Detail

Comparison of 50mm Bushmaster III with the 30mm Bushmaster II. By comparison the 25mm’s length over all is 105.2 in (2.672 m) and its barrel length is 85.6 in (2.175 m)

SNAFU has a discussion about what up-gunning Infantry Fighting Vehicles might mean to land warfare and included the graphical information above.

The dimensions provided give us some clues about the characteristics of the gun that were not available before. Length of the barrel in calibers (bore diameter) tells us something about the gun. You usually see it written as caliber/length in calibers, e.g. 5″/38 where 5″ is bore diameter and the barrel is 38 time 5″ in length. Length in calibers suggests other characteristics including muzzle velocity, time of flight, flatness of trajectory, accuracy, and penetration ability relative to other weapons of the same caliber. Greater length in calibers usually translates into higher muzzle velocity which imparts a flatter trajectory to a given range, which usually translates into greater accuracy and better penetration ability relative to other weapons of the same caliber. Larger caliber weapons might, and usually do, exceed these characteristics even using relatively shorter length calibers.

The Coast Guard uses or has used 5″/38s, 3″/50s, 76mm/62s, 57mm/70s, and 25mm/87s. In each case, greater length in calibers translated to higher muzzle velocities.

The barrel length for the 50mm indicated in the diagram above, 117.6″, translates to a length of 60 calibers, so we should expect a muzzle velocity similar to that of the 76mm/62 Mk75 (3,000 – 3,024 fps (914 – 925 mps)), perhaps slightly lower.

There are not a lot of contemporary weapons of similar characteristics. Perhaps the closest was a Soviet 45mm/78 anti-aircraft gun with a maximum ballistic range (firing at an elevation of 45 degrees) of 12,140 yards (11,100 m). Certainly the 50mm’s performance will exceed that of the Soviet 43mm/46 which had a max ballistic range of 10,060 yards (9,200 m).

On a more practical basis this probably means that, while the Army claims an effective range of 4000 meters (probably against another Infantry Fighting Vehicle), even without guided projectiles, it would start scoring hits against larger maritime targets at 7,000 yards, which was the maximum range we used to train 3″/50 crews for, using local control. In any case it would be able to engage from beyond 4000 yards which I believe would be the maximum effective range of any improvised armament available for use on even a terrorist vessel.

Looking at the two rounds mentioned above, Programable Air Burst Munition-tracer (PABM-T) and Armor Piercing Fin Stabilized Discarding Sabot-tracer (APFSDS-T).

  • The APFSDS-T is probably going to have a better chance of disabling a large marine diesel engine than any weapon we currently have in service.
  • The PABM-T should be effective against personnel in small fast highly maneuverable vessels and the programable feature means misses will detonate before going any great distance beyond the target, minimizing the possibility of collateral damage. It might also be effective against drones.

Thanks to Lee for pointing me to this information.