Case for the Five Inch Gun

Currently the largest Coast Guard cutters are being equipped with the Mk 110 (BAE/Bofors 57 mm Mk3) gun mount.  By all reports it is a good defensive weapon, effective against air threats and small fast surface vessels. But is this weapon also the most appropriate for the most likely scenarios?

The Choices: Given that we can only consider weapons supported by the US Navy, there are really only two choices, The Mk 45 5″ and the Mk110 57mm; three if you consider the Mk75 76 mm which seems to be going away.

Mk75 76 mm guns, are mounted on the once large, but now rapidly dwindling  FFG-7 class in addition to 378s and 270s. There are currently roughly 50 systems installed, but that can be expected to rapidly decrease with no new installations planned.  Still, this is based on perhaps the most successful post-WWII naval gun, the Oto-Melara (now Otobreda) 76mm, one that is still being installed on some of the most sophisticated new construction foreign made vessels. There has been some talk from USN sources that they may choose to install the Mk 75 on future LCS, but unless there is a change, it looks likely the 270s will be the last operational US vessels to use the Mk75.

The Mk110 57 mm, is found on the National Security Cutter (NSC) and the Littoral Combat Ship. It is also planned for the Offshore Patrol Cutter, and will be used as a secondary mount on the Zumwalt Class DDG. It is based on the Bofors 57mm Mk3, a competitor to the more successful Oto Melara 76mm. There are currently only about six units operational on US ships now, but if all four classes are completed as planned there will be 94 systems afloat.

The 5″ Mk 45, in its three mods, is the most numerous medium caliber gun in the USN inventory, and until the 155mm Advanced Gun System (AGS) becomes operational on the Zumwalt Class DDGs it is also the largest US naval gun. (Only 6 AGS on three ships are currently planned). There are currently about 106 USN mounts afloat. Numbers have declined somewhat particularly with the decommissioning of the Spruance Class. They are still being installed on new construction and planned Burke Class destroyers, but as DDGs with one mount replace cruisers with two, the number is likely to decrease further to between 80 and 90 mounts.  It is also in service with ten foreign navies. It is the most successful mount of its class in the world.

The Advanced Gun System planned for the Zumwalt Class DDGs is simply too large to consider for use on cutters.

Why do we have guns on our ships at all?

  • We use guns to signal, firing across the bow to tell a vessel to stop.
  • We use guns to intimidate law breakers into complying, making it obvious it is futile to resist.
  • To sink derelict vessels that may be hazards to navigation.
  • To protect ports, waterways, coastal areas, and marine traffic from attack in peacetime (PWCS).
  • To fulfill war time roles.

Self defense isn’t a requirement until it becomes necessary to accomplish one of these tasks.

Signalling or intimidating the typical drug smuggler doesn’t require even a 57mm. A .50 cal is usually adequate, and if not a 25 mm certainly is.

Derelict destruction is now rare, but it apparently was a common requirement at least into the ’30s. While rare, as the Anacapa found out, when it was tasked to sink an abandoned Japanese fishing vessel, it may be more difficult that might be expected. Even so, it is rare, and there are other ways to do this mission, so its not really a consideration in the choice of weapons.

The need for a larger weapon only surfaces for the last two purposes, protection of Ports, Waterways, and Coastal Security (PWCS) and wartime tasking.

Forcibly compelling compliance.

Both PWCS and war time roles are likely to require cutters to be able to board and inspect merchant vessels and the ability to forcibly stop or sink them if they do not comply with instructions, regardless of their size. This requirement is likely to surface across the entire range of possible military conflicts from helping an ally in a counter-insurgency to a wide spread multinational conflict including operations against a great power.

If there is a major conflict, we are going to have to quickly neutralize the adversaries merchant fleet, which might otherwise engage in mining, providing intelligence, dropping off agents, supporting submarines, or even have aboard cruise missiles: http://elpdefensenews.blogspot…

The Coast Guard, and the Revenue Cutter service before it, have always needed a capability to compel compliance. Has our ability kept pace with the increased size of merchant ships?

From the 1920s through the the mid ’80s, when the 378s were FRAMed, the weapon of choice for the larger cutters was a 5″, first the 5″/51 and beginning in World War II the 5″/38. The 5″/51 was developed as secondary armament for battleships and also armed light cruisers, and a small number of destroyers. It was larger than the 4″ guns typically found on destroyers before the 1930s, when the 5/38 was introduced. (Destroyers, of course, did also carry torpedoes as their main armament.) Both the four 240 ft Tampa class (completed 1921-22) and the seven 327 ft Secretary Class (completed 1936-37) were built with two 5″/51s and two 57mm six pounders. The ten 250 ft Lake Class (1928-32) Cutters were built with a 5″/51, a 3″/50, and two 57mm.

https://i0.wp.com/www.uscg.mil/history/webcutters/img/Haida_2.jpg

240 foot Tampa Class cutter, original armament, 2×5″/51, 2x6pdr

From the reports of submarine successes during WWII, based on numbers of ships and total tonnage sunk, I infer that the average merchant vessels of the period, was about 5,000 tons. 20,000 tons was considered a big ship.

I don’t know what the average size is now, but they have gotten a lot bigger. Anything less than 20,000 tons is considered small and they go up to over 20 times that.

Give that size is a primary factor in ship survivability, today’s merchant ships are likely to be much harder to stop than the ships of the 60 to 90 years ago. Are our ships correspondingly better armed?

The boarding scenario minimizes the relative importance of gun range and sophisticated fire control. If the vessel refuses, combat is likely to commence at short ranges. Modern systems are capable of much greater accuracy at a distance, but even in the ’20s, when ranges were even less than now, because boardings parties were transported by pulling boats, virtually every round would have been a hit. There are at least two ways we can compare hitting power, first we can compare the weight of rounds the systems could have put on target and we can also compare the destructive potential of the individual rounds in terms of muzzle energy.

For reference there are the characteristics I used for calculations.

System              Projectile Weight      Muzzle velocity          Rate of fire
–                             (lbs/KG)             (ft/sec and M/sec)      rounds/minute

5″/51                       50/23                     3150/960                   8.5
5″/38                       55/25                     2500/760                  20
76mm Mk 75           14/6.3                    3030/925                  80
57mm Mk110          5.3/2.4                   3400/1035              220
5″/62 Mk45 mod4  70/31.75                 2650/807.7               20

In terms of potential for putting weight of projectiles on target, there is remarkably little difference if we compare the two 5″/51s that equipped the cutters of the ’20s and ’30s with a single mount of any of the modern systems. (Projectile weight x rate of fire)

  • System                  pounds/minute
  • two 5″/51                     850
  • 5″/38                          1100
  • 76mm Mk 75              1120
  • 57mm Mk 110            1160
  • 5″/62 Mk45 mod4       1400

I’m not sure this is the best metric for the task of disabling or sinking a ship. The projectiles need to reach the vitals of the ship. As ship have gotten bigger, the vitals become more difficult to reach and more damage resistant, which would favor the more powerful weapons.

File:USCGC Duane (WPG-33) off Greenland with SOC 1940.jpg

US Coast Guard Photo: The U.S. Coast Guard cutter USCGC Duane (WPG-33) in Greenland waters, circa 1940

The potential of the individual projectiles to penetrate and cause damage is reflected in the muzzle energy.

System                Projectile Weight     Muzzle velocity       Muzzle energy
–                              (lbs and KG)         (ft/sec and M/sec)     MegaJoules

5″/51                          50/23                     3150/960                     21.2
5″/38                          55/25                     2500/760                     14.4
76mm Mk 75             14/6.3                    3030/925                       5.4
57mm Mk110            5.3/2.4                   3400/1035                     2.6
5″/62 Mk45mod4     70/31.75                 2650/807.7                   20.7

Here the oldest system is remarkable in that of all the systems considered, the 5″/51 had the highest muzzle energy. Only the 5″/62 Mk45 mod 4 is close.

File:USCGC Campbell (WPG-32) at New York Navy Yard 1940.jpg

USCGC Campbell (WPG-32) at the New York Navy Yard, in May 1940. USCG photo

Other Wartime Roles:

I have not been privy to war plans in a very long time, and as they say, plans seldom survive first contact with the enemy, but we have the experience of the past to draw on.

In the 67 years since the end of World War II, I do not believe any cutter has fired at an air target in anger. In fact, I know of no occasion when US Navy surface ships have engaged air targets with medium caliber guns. There have been some occasions when Navy vessels and even cutters have engaged surface targets with guns, but by far the most common use has been Naval Gun Fire Support (NGFS), now referred to by the more generic term Naval Surface Fire Support (NSFS). Cutters did it frequently in Vietnam, firing over 77,000 5″ rounds. The US Navy did it in the Korean War, Vietnam, Operation Praying Mantis (1988), and the First Gulf War. It was done during the Second Gulf War by British and Australian ships. The USN was apparently doing NGFS as recently 2007 in Somalia.

Naval Surface Fire Support (NSFS)

The US Navy has an acknowledged shortfall in NSFS capability. The number of ships capable of performing NSFS has dropped precipitously. For those that remain NSFS is a secondary mission to Ballistic Missile Defense (ABMD), AAW, or ASW. If there is a major conflict, they are likely going to be called upon for other missions that will leave them out of position to do NSFS.

The Zumwalt class destroyer with its 155mm advanced gun system was to have been the primary NSFS platform and there were to have been 32 of them, but the program has been cut back to only three.

If the Offshore Patrol Cutters were equipped with a Mk45 5″ they could provide a increase in US naval  NSFS capability out of all proportion to the small marginal increase in cost.

More about the Mk45 5″

File:US Navy 070111-N-4515N-509 Guided missile destroyer USS Forest Sherman (DDG 98) test fires its five-inch gun on the bow of the ship during training.jpg

Photo: US Navy photo by Joshua Adam Nuzzo. USS Forrest Sherman (DDG 98) fires its five-inch gun.

The Mk 45 was originally designed as a direct replacement for the 5″/38 single mount. Destroyers the size of the OPC carried five 5′/38 mounts in addition to torpedoes and numerous 40 and 20 mm guns. Even in its latest version, the Mod 4, its 33 ton weight is not unreasonable for a ship the size of the OPC.

As the most numerous US naval gun a large variety of projectiles are available and there remains great potential for further development. The 5″ is effective against air targets, and special projectiles have been developed for dealing with small high speed surface targets. Add on GPS guidance can make them precision strike weapons in the NGFS role.

Conclusion:

In choosing the Mk110 57mm because it was seen as a better AAW weapon, a better anti-swarm weapon, as lighter, cheaper, easier to maintain or man, for whatever reason, the Coast Guard will have a weapon that is at best only marginally more capable, perhaps even less capable, of performing the most likely missions–stopping/sinking a surface target or performing NSFS–than the weapons of 60 to 90 years ago.

While the size, toughness, and survivability of merchant ships has increased dramatically, the Coast Guard has not provided its ships with a significantly improved capability to stop or sink a ship since the introduction of the 5″/51 in 1921. I still think the Coast Guard should add a light weight anti-surface vessel torpedo to its inventory as the cheapest was to have a truly effective ship stopper that can be made widely available. But until such a weapon becomes available, the Mk45 5″ is the best alternative available.

The 5″ Mk45 is a versatile weapon. Equipping the OPCs with this weapon make the ships more capable of performing both the PWCS and probable wartime mission and significantly enhances the NSFS capability of US Naval forces in a major conflict.

File:USCGC Cook Inlet (WHEC-384).jpg

USCGC Cook Inlet (WHEC-384), USCG photo

File:USCGC Duane (WHEC-33) returning from Vietnam 1968.jpg

USCGC Duane (WHEC-33) steaming home after completing her tour of duty in Vietnam, 1968. USCG photo

File:USCGC Rush WHEC-723.jpg
Photo: USCGC RUSH (WHEC-723) underway during Exercise Brim Frost ’85. photographer: SGT. Zachs

A photo of the Half Moon firing her main battery.

5″/38 fired from a Coast Guard 311 ft WHEC

85 thoughts on “Case for the Five Inch Gun

  1. Great article Chuck. While I’d love to have a bigger mount, the need isn’t there to justify the cost. You summed it up, manning, weight (ammo and the mount), and cost are all key decision drivers. If Bofors develops a 5″ varient then it might become more feasible with solid state electronics and simplified loading mechanisms seen in the Mk110. I still think the biggest problem is interior space and available room for the weight (especially the ammo). Its amazing how much space is now consumed on cutters with the modern berthing configurations. Its a significant improvement to habitability but a poor use of space. Additionally, cutters like the WMSL have very little available weight left and 5″ ammo is heavy. Its a big trade off and therefore a hard sell. The best chance is to design cutters like the OPC/WMSM with enough slack in the designs to add a wartime upgrade. The issue you see with the WMSL is that there is no room for growth to add major systems. Maybe you could add torpedo launchers on the bow but they would like the arc of fire for the main mount.

    The MK110 is NSFS capable, someone just has to cut a check to add the software to the control system. The 3P round has purpose designed detonation profiles that supports the mission for anti-personnel and anti-vehicle. The range is not ideal but the capability is there.

    On the merchant side, I stand by my previous statement from previous iterations of this case that its very unlikely that a CGC is going to be operating anywhere near a domestic port when an event takes place. The ‘puddle pirates’ are almost all deployed OCONUS to Alaska, the Caribbean, and eastern Pacific. You are much more likely to have Navy assets conducting training as the closest option. Additionally, the DOG/DSF forces are the CG’s response option of choice for responding to hostile merchant vessels; inserting by air to take control of the ship. The next option is to engage with long range options such as an airborne attack. Even though the only alert aircraft are prepped for air-to-air combat, spinning up an air-to-surface attack would be much quicker than dispatching a surface vessel hundreds of miles. If the counter argument is that intelligence would drive an increase in PWCS readiness then it would also drive an increase in defense readiness and shorten a land based response time.

    Regarding scuttling a derelict vessel, twice in the last year we had partially submerged barges offshore in D7. On the first occasion, a 110′ fired a few hundred 25mm rounds at it with little effect and a WMEC fired a few hundred 76mm rounds with similar results. In the end COMSAL had to mobilize and cut holes at the waterline. The next time we simply called EOD, gave them a ride a few hundred mile offshore and blew holes in it.

  2. I think I remember hearing that the CG had decided against maintaining a capability for fast roping.

    Assuming a magazine capacity of 300 rounds of 5″, a very rough estimate of the weight should be about 20 tons. That is really not that much, less than 1% of the displacement and, since it is normally carried low down, that should not be problem. Since the 57mm ammunition’s weight offsets some of that, the difference the weight of the ammunition is less important than the weight difference between the mounts, but even that should not be a problem.

    The 57mm could do NSFS, but it would be much less useful than a 5″, the 57mm may be too small to use the GPS guidance on its projectiles, the 57mm is too light to take out many of the hardened targets, and the 5″ can have up to twice the range of the 57mm.

    • As I said we can really only consider guns supported by the US Navy. For most purposes they are equal.

      The OtoBreda used to be heavier, but the latest marks have gotten lighter while the latest mod of the Mk45 has gotten heavier–not much to chose between there.

      The OtoBreda has a higher rate of fire but that is usually only significant for AAW, which is unlikely.

      They both fire the same ammunition with the exception of the Oto Breda Volcano round. The USN has made several attempt to create a long range round, but have come up with anything they were satisfied with yet. Unlike the American approach of using rocket boost to increase the range of a large shell, the Italian approach was to trade shell weight for range by using a sub-caliber discarding sabot round. The destructive capability of the resulting round is about equal to a 76mm round. That makes less sense to the US than it does for the Italians in that the US is much more likely to have robust air support to take out distant targets. The Italians may not have that luxury.

      • So would the US Coast Guard ever consider ever using the 127/64 LW Vulcano naval gun system or would they stick with Otobreda 76 mm or a variant of the Otobreda 76 mm called the Otobreda 76 mm Super rapid. Would they ever try out the 5″/54 caliber Mark 45 gun.

  3. The relatively low bursting charge weight is countered by the number of rounds put on target. The 57mm/70 is shown with the following bursting charges,

    PFHE – 0.84 lbs. (0.38 kg)
    HCER – 0.90 lbs. (0.41 kg)
    HE – 0.99 lbs. (0.45 kg)
    57 3P – >8,000 fragments propelled by PBX

    Chuck, mentioned the 5’/38 and it has a 13-pound bursting charge and the 3″/50 about 7-pounds. The latter was never intended to perform NGFS, but the 5″/38 was and had a hand crank analog computer just for that purpose.

    If shore bombardment is needed for coastal craft, the 81mm mortar could be resurrected. It is light weight, in the neighborhood of 400-pounds (not including the foundation), and the projectiles weigh in about 13 pounds with a comparable bursting charge of the 3″/50. They could also reach enfilade and defilade targets at a nominal three-mile range. The rate of fire is slower, then again, rates of fire depend upon the service need. Once in an emergency situation, a BM2 and myself pumped out some 42 rounds in about three minutes using the drop fire mode. In reference, the ready service locker on deck held sixty-fine rounds. I keep 800 rounds of HE in the forward hold.

    I advocate the larger 5″ gun mounts not from any present need, but for the future. At present, most Coast Guard gunner’s mate are small gun minded. The brain trust in larger caliber attitudes has all but disappeared and with it expertise that larger calibers can only bring. I recall when the USS Iowa was doing its shakedown firing, the only person at FTG GITMO with gun experience to be Iowa’s ship rider was a Coast Guard GMC.

    The Coast Guard and RCS has had a vacillating history with ships armaments. The very first cutters were unarmed except for small arms and remained that way until 1797. A upswing in national imperatives changed, and with it, the RCS concepts toward weapons systems. The Jefferson Administration down-sized then up-sized both cutters and cannon. The War of 1812 did not accomplish much and the numbers of cannon fell off with the emergency and need. Even the cutters Louisiana and Alabama sent to the Gulf of Mexico to fight pirates had but two 3-pounders each and despite later calls for more and larger guns the general outlook was the guns were too expensive. And so continued the ups and downs of armaments. The Civll War did not bring about a larger number per cutter, the Spanish-American War did but this was because cutters, such as the famous Hudson, had none at all. Even here, the guns were returned the Navy following war because the necessity had waned and the costs of maintenance were too high. During the Civil War, there were a couple incidents of cutters firing 12-pound shot into steamers that would not heave-to inside New York Harbor — get away with that today.

    The twentieth century saw improvements because the RCS, and later Coast Guard, was trying to more closely align itself with the USN. In addition, several RCS officers has attended the Naval War College and the weapons courses at the Washington Navy Yard. There was a growing expertise in ordnance. The RCS was tickled when it replaced its old six-pounders with the 3″ gun and when these older 3″ models were replaced with the rapid fire 3″ and then with the 4″ gun. Of course, taking over the rout-stacker destroyers for Prohibition work gave access to larger guns and more ammunition. After all, the Navy was footing the bill for training and practice.

    Chuck gave a run down on the evolution of guns in the later years. However, it was WWII that cemented the Coast Guard’s past ideas about readiness and the need to prepare for war at all times. They had found that retrofitting was possible, but it was expensive and took time. Having standardized systems, allowed the easy transition to the take over the ice breakers that initially carried the twin 5″/38 as did the 255s.

    Larger gun systems may be heavy and expensive, but it is short-sighted to think the Coast Guard could simply ramp up on short notice to use those systems. What will occur is the Coast Guard will decline participation in the next fracas because they do not have the personnel trained to do the work. On this note, Bring Back The FTs.

    Have a good Thanksgiving.

    • Speaking of mortars, there are advanced mortar systems that could give much smaller vessels (as small as 14 tons) a punch almost equal to a 5″ projectile (the shell weight, not the muzzle energy).

      http://en.wikipedia.org/wiki/Patria_NEMO
      http://www.youtube.com/watch?v=CnlB5mrigyA (this starts with a land system, but has video of a boat mounted system too)

      This is a 120mm (4.7″) breech loading mortars with a range of up to about 11,000 yards. Like most mortars they are normally fired at high elevations, but these are claimed to be useable in a direct fire mode at ranges up to 1550 meters, almost a mile.

  4. Bill I long advocated for the 120mm auto on small combatants and warboats. The dual barrel AMOS would work quite well on the lighter cutters. But it is not as great a direct fire weapon as the Mk 75 76 mm especially with the newer ammo which the USN is apparently not buying? Mortars as not particularly great against a fast moving surface target?

    • Nicky, If you have been following this website closely. You know that direct ship fire rarely sinks ships. That is why Chuck has proposed the use of torpedoes. The point of talking about supporting Marines is to show multiple use for our cutters and demonstrate a way the USCG can support the Navy in conflict. Because at present with our current weapon package we do not matchup to the Navy ships in fire power. In fact putting many of our current naval ships in the littoral waters seems like a great risk.

      • Here’s a Question, When was the last time the US Coast Guard did a Naval gun fire support mission supporting ground troops in war. Also do you think that with advances in UUV, UAV, do they have a future with the US Coast Guard.

      • So Patrick, what do you think, with you experience in Sea time and combat experience. What kind of Gun system would you want the USCG to use. Why would you want to use torpedoes when you know the USCG doesn’t have the people to run torpedoes.

      • Nicky, It is funny you would say combat experience. Because in the combined Coast Guard and Navy only two ships have sunk another ship in ship to ship combat. The first is Simpson and the second is the Constitution. The first did it with a missile the second with cannons.

        I did not propose torpedoes as I said above that is what Chuck suggested because they have a greater success rate at sinking ships. The point that he brought up from a WWII study was that naval gun fire rarely sinks ships because of the lack of arc.

        The reason for supporting naval gun fire to support Marines is an attempt to justify these weapon systems and to bring value to the US in a bigger war. I don’t believe we will ever see a WWII style beach landing. So that point is moot to me. I don’t believe our ships are capable of ship to ship fighting because of missiles being the primary weapon of ship to ship combat.

        I think our mission is going to be counter drug operations unless we make changes to advance our fleet to meet the standards of a modern navy. Because the only time our navy would need help is if we faced a tough enemy. I think much of this discussion has been centered in pre-collapse of the soviet union today the world is different. The budget is shrinking and the Coast Guard needs to focus on its core missions that we perform 99% of the time. This ongoing we can do everything is not true anymore because of advances in technology.

      • @Patrick,

        “The point that he brought up from a WWII study was that naval gun fire rarely sinks ships because of the lack of arc.”

        I’m not sure what you are saying here. Guns usually don’t sink ships because they don’t usually damage the hull below the waterline. Odds are, it will take a lot of hits to do more than superficial damage unless the shells are very large.

        “… the only time our navy would need help is if we faced a tough enemy. I think much of this discussion has been centered in pre-collapse of the soviet union today the world is different.

        Yes, we have had 21 years of relative safety from a major war since the collapse of the Soviet Union, but the times they are changing again. A new potential enemy is emerging and they are acting very aggressive. The Chinese are building as many warships every year as the US. They are not of equal quality yet, but they are improving rapidly and in 30 years they are likely to have a fleet as numerically large as ours, with an advantage in the Pacific and an overwhelming advantage in the Western Pacific that can only be overcome by cooperation with our allies.

        The question is, will the Coast Guard sub-optimize and think only of its peacetime missions or will we spend only a little more and make our ships useful as warships in time of crisis. I don’t expect our ships to ever go toe to toe with enemy frigates and destroyers. Adding a 5” would not make them capable of that. I do hope they would at least be capable of policing our own waters and those of our friends and preventing the use of merchant ships and fishing vessels for purposes that are inimical to our interests. Right now, I’m not sure they are capable of that.

        No one is expecting to land five divisions anywhere as the Allies did at Normandy, but the Navy and Marine Corp and the National leadership all believe there is the prospect of making an opposed landing on a hostile beach, and they have spent much more on the prospect than the entire budget for the Coast Guard.
        http://www.usni.org/magazines/proceedings/2010-11/hitting-beach-21st-century

        The challenge is making Congress and the Administration think putting just a little of that money the Coast Guard is a good investment.

      • Chuck ,
        The statement about naval gunfire was simple that it could not fire below the water line because of the arc of fire lines. As for amphibious landings I think this is the classic example of preparing for the last war. The last true landing was Korea and with advances in technology I see this as less and less of a need.

        The truth is I think the Coast Guard needs to re-envision itself for the future. Because of the technology crept we need ships with vastly more technology to be competent on the modern battlefield against modern navies. Because at our present technology level the USCG ships in war could only operate in a fleet because we cannot defend ourselves against air or sub attacks. In a large war against a nation like China we might be a greater liability.

        I do agree with responsible expense we could improve the present technology and weapons. But is this even a good expense? I believe increasing our response natural disasters hitting the states is more important. I think oil spills, hurricanes, and like will be the problem the Coast Guard will have to meet. And in between we will be involved with the drug conflict.

        Our present fleet should be geared at these missions first because we are not meeting our primary mission at the level we could be doing. And beyond that why not have the USCG replace the navy ships working counter drug operations and let them fight in international waters. They have more experience and better ships. The last ship to ship action was and FFG Simpson and it happened by missile fire against and Iranian ship in 1988.

        And Gavin you are right I am tired. I work in conflicts and with the recent Gaza action I have been busy putting reports together.

      • @Patrick, I understand where you are coming from. When the basics are not adequately funded, why add on a nice to have? I look at it as a way to make a better case for these ships. Imagine if we could get the Commandant of the Marine Corp to testify to Congress that he would like to see these ships built.

        “I don’t believe we will ever see a WWII style beach landing….The last true landing was Korea and with advances in technology I see this as less and less of a need.”

        Hopefully we will not see anything as bloody as Normandy, but that was a huge operation involving at least nine divisions and thousands of vessels on the first day alone. Most landings were made with far lower casualty rates. The last opposed US landing was done during the Korean War, but there have been others since including the Argentine and British landings during the Falklands War in 1982 and the Russian landings in the war with Georgia in 2008.

        In wars that include a maritime power you can almost be sure you will see three types of activity: war on commerce, ships will shoot at targets ashore (and vice versa), and the dominate maritime power will land troops on a hostile shore. That is not a feature of the last war. That is a feature of wars going back at least three millennia.

        “Because at our present technology level the USCG ships in war could only operate in a fleet because we cannot defend ourselves against air or sub attacks.”

        Nothing wrong with operating in a fleet as long as you have something to contribute. Not every ships is capable of ASW or even AAW including all the Navy’s auxiliaries. However if we design the ship to be rearmed in the case of a major conflict, as suggested here, https://chuckhillscgblog.net/2012/06/27/opc-design-for-wartime-build-for-peacetime/ they could do much more than defend themselves.

        “And beyond that why not have the USCG replace the navy ships working counter drug operations and let them fight in international waters. They have more experience and better ships. ”

        If there were a fight in international waters they would not be doing this. I would love to see us have enough ships to say we don’t need any help from the Navy, but I don’t expect it will happen any time soon. We have gotten used to the the idea that drug enforcement outside the US EEZ is a justification for CG ship days, but that could could be changed with the stroke of a pen. It is certainly unlikely, but we are only one policy decision away from eliminating that tactic.

        Defense Operations is one of the CG’s 11 missions. I don’t think either the Navy or the CG put much thought into it, but is just as valid a mission as any other.

    • That’s why Defense operations is something the USCG is severely lacking. If we ever had go to an all out War and the USCG is pushed under the US Navy. Our cutter fleet as it stands now, would be serverly inadequately unprepared to do whatever the US Navy task the USCG to do. Which is why we would be caught with our pants down if we were ever asked to do ARG convoy escort, Naval Fleet Auxiliary Force escort, Defense operations in the Littoral Environment. Which is why our White hull cutters need to have both a peacetime and war time capability and be capable within 72 hour notice be equipped for war time. Which is why the NSC should be equipped up to Naval frigate standards with the capability for Naval Gun Fire support, if called upon.

      • Nicky,
        We can dream of unlimited budgets but with current fiscal crisis and the slowing down of the budget it is not going to happen. Beyond that we have to ask ourselves do we really need the Coast Guard and Navy to provide both of these abilities. Because in the present budget choices will be made for us. In addition with the present conflicts what role can the Coast Guard really play.

      • Well here’s the question, you want to get caught with our Pants down, when we don’t have cutters that can’t even escort ARG & Naval Fleet Auxiliary Force ships. We basically don’t have cutters that can’t even do basic Littoral defense as part of the USCG’s Defense operations. We basically don’t have cutters that can’t defend littoral areas from SSK subs to fast Attack craft to Frigates. Let alone defend against Drug subs and Gofast boats.

        When Crap hits the fan and the US Coast Guard is one day going to be asked by the US Navy to defend Naval Fleet Auxiliary Force ships and troop transport ships. The US Coast Guard is going to be caught with it’s pants down because we were woefully unprepared for Defense Operations and Escort operations. It’s why the US Coast Guard needs to get back to it’s cornerstone missions such as Defense operations. It’s why we need to have cutters that can on the dime switch from a peacetime mission to a Wartime mission. Have the ability to upgrade itself to combat ship within 72 hours. Which means the NSC would have to be upgraded to have the capabilities to switch from peacetime cutter to a light frigate with full combat capabilities.

      • Like I said it is not I want, it’s what is possible under the present conditions. Beyond that what major naval power do you see us fighting that will require USCG help? You can dream up imaginary enemies but I don’t see us having a major conflict that will exceed the navies needs. In addition, the last ship to ship action for the US Navy was in 1988. That is along time ago for USCG to invest in our so called corner stone mission. The last time the USCG had any major ship to ship role would be Vietnam. I see us doing brown water work just like in Iraqi. We provide patrol craft and small craft. That is our actual bread and butter.

      • Actually you all seem to have missed the boat: the Navy pays (as they have always) for all our non crew-served weapons systems and maintenance, so it is not a CG budget issue solely that is preventing our cutters from being more heavily armed or trained to support the naval warfare mission areas we have in our past history.

        The fact is that there are many in senior positions in the officer and enlisted ranks who are non-warriors/non-cuttermen that are culturally and politically hostile to the idea of the CG taking on any combatant roles beyond Phase 0 or Phase 1 ops “someone might get hurt” and see the CG Defense Ops role as an anachronistic sideshow. Most would be just be as happy to do away with the mission if the law itself did not specifically task the service with it. In the end, it is a “don’t provide, don’t ask” type situation where Navy does not provide the additional combat systems capability because our own Flag Officers are just as happy not to ask.

      • Tim, I understand the Navy pays for the weapon systems. But the ships are designed differently to handle these weapon systems. And in fact to build a ship that can handle the overseas duty vs. a state side ship is very different in overall size and length. I believe the best service the Coast Guard can render the navy is with the PSU units, patrol boats, and like assets. I think most of our DOD support should come from the reserve forces not the active force because we already have a state-side mission. I believe using our active assets for war is crazy because that mission is already under-funded. Then you have to ask ourselves why keep funding a mission that is not really being used.

  5. why are you asking questions you can research easily and have already been discussed. As much as I enjoy rhetorical questions I really don’t.

    • Why don’t you leave him alone and stop being such a bully? Unlike you, Nicky seems to want to contribute. Are you even really qualified to talk about this subject yourself?

  6. Interesting side-conversation on what role the CG could play in augmenting the Navy in war-time. For my $.02: I agree with Patrick that PSUs are very useful and desireable for wartime activation, and they already do so and fit nicely in the Navy’s Expeditionary Command. I also see forming some of the FRCs and WPBCs into littoral patrol boat flotillas, since the Navy has a gap in that capability. The NSC’s value will be as ASW escorts from CONUS to places like Hawaii or Diego Garcia. Simply embarking a Navy (Reserve) H-60 would give enough capability in the envisioned, relatively low-threat environment. Most of the FRCs, Patrol Boats, OPCs will stay close to where they are now. Homeland Defense IS a defense operation, after all… Protecting the Navy’s facilities and anchorages, protecting commercial ports, preventing enemy agent infiltration, and tracking enemy-flagged vessels all being same as what the CG does every day. Doing those missions, frees up more Navy assets to deploy. A mission area the Navy keeps down-sizing, but is incredibly important both overseas and at home (and thus fits nicely in the CG’s Port Security mission area) during a major war, is minesweeping. If the CG picked up that banner, the Navy would love it (since they don’t have the funds or interest…)!!

    Taking the above into consideration, we can forget about any need/desireability for NGFS in the guns Cutters are equipped with. The only argument I see which holds much water, Chuck, is stopping a big vessel. I’ve seen the Mk.110 shoot through considerable thickness of steel. (It surprised me very much.) we also must consider that nasty programmable fuse which possesses a “delay” setting also. I haven’t seen it tested, but I could easily imagine the Mk.110 firing a 10-rd salvo (can we call it a “burst”?), with fuse set on delay, into steering gear spaces or engine room spaces, destroying personnel, hydraulic hoses, cooling hoses, and belts. IMO, the Mk.110 seems more-effective and more flexible for CG missions than the 5″/45. Besides, my friend, you are bucking the trend, hard! The CG replaced 5″ guns with 76mm over 20 years ago, and now is going even farther to 57mm. I don’t see, especially with CG wartime missions as I envisage, reversing course and going back all the way to 5″ mounts. Sorry.

    • I’m not sure the NSCs have any ability to be adapted as ASW escorts. I hope the OPCs will. Adding Navy MH-60Rs would not be useful unless they had a towed array to cue them and space for their weapons and equipment like sono-buoys.

      If the OPCs were built with space weight for some of the LCS modules they might be able to pick up some of the MCM mission.

      I think the 76 mm was chosen over the 5″/54 for the 378 FRAM because they needed the weight moment compensation to allow them to also fit Harpoon and CIWS.

      I suspect the 57 mm was chosen because, of the few guns the navy offered, that might do the job, it was the easiest to maintain and had the least impact on the ship’s design, not because it was the best.

      We’ll have to disagree on the 5″. It should be better at stopping large ships. If the OPCs never leave the US coast then, no they probably won’t need to do NSFS, but there are a number of other potential scenarios where the capability might be useful.

      There is a lot of uncertainty about what these ships will be doing over the next 40-50 years. That is why they need to be built with the maximum amount of adaptability.

  7. Chuck said: “I suspect the 57 mm was chosen because, of the few guns the navy offered, that might do the job, it was the easiest to maintain and had the least impact on the ship’s design, not because it was the best.”

    I must admit I was underwhelmed when I learned the biggest-caliber gun on the NSC would be a 57mm. It wasn’t until I started studying the programmable ammo and watching some tests (many can be found on youtube), that I became surprised and eventually impressed with the 57mm. Without having any knowledge of the decision-making process, I feel VERY safe in saying that effectiveness and applicability to the CG’s missions was a HUGE factor in picking the 57mm. The second factor, I would guess would be ammunition cost, as I’m sure even the programmable ammo for the 57mm is cheaper than 5″ and probably 76mm, but the practice ammo will certainly be very cheap in comparison to either of those guns. If you consider the ship self-protection capability (against aircraft and missiles) along with it’s flexibility and performance against afloat targets (esepcially the small-to-medium size “targets” the CG typically engages), it is clear the Mk. 110 is more flexible and useful than a larger-caliber gun.

    I would also say any modern gun would be fairly easy to maintain, and caliber would not effect that greatly. Now, comparing the Mk. 110 to a WWII-era 5″/38, yes, I could see that argument, but since we’re comparing a modern 5″ to a modern 2″, I think the primary difference in maintenance would be everything is smaller and lighter on the Mk. 110, which would mean fewer personnel needed in a cleaning / repair evolution, but that’s infrequent enough to not make it THE deciding factor. The recoil forces of the larger gun, I agree, will cause a more complex recoil and re-battery system, but, again, not enough to make it THE deciding factor of choosing the 57mm over the 5″.

    The 57mm round I saw punch steel went through two thicknesses of 3/8″ steel spaced over 2 feet apart. Went though both sides and kept going. Like I said before, I haven’t seen the exact test scenario of going through a double hull plus another bulkhead or two, but considering it’s velocity and muzzle energy, my guess is that it would take around 2″ of steel to stop the 57mm from further penetration. Spacing the steel, as in double-hulls and compartments between bulkheads may degrade that to say, 1.5″, but how far into a large vessel, such as a tanker or big container ship would that much steel get us? (I’m guessing through a double-hull plus a compartment or two, I bet.) If astern of even a large vessel, firing into the steering gear compartment, would not require more penetration. Going into the engineering spaces is more questionable, depending on the size of the ship, but it would take a very large ship indeed to be a certain failure of the 57mm to not penetrate.

    Also, one must ask themself: If it’s so incapable, why is the Navy going to it? Or, do you think the Navy is sacrificing war-fighting performance to get cheaper/easier maintenance?

    • I for one would say that the Navy is sacrificing war-fighting capability since they not only choose the 57mm but they chose it for the giant financial black hole known as the LCS, a very expensive, low survivability, undermanned and lightly armed ship with limited capability and mission modules that so far don’t work. The fact that the Navy chose the 57mm doesn’t prove it’s viability. Instead of designing and choosing a dedicated replacement for the Perry class FFG, they tried a “jack of all trades and master of none” approach. We got stuck with the 57mm because the Navy provides our weapons. Have you ever observed a sink-ex exercise? You can blow thousands of holes in a stationary target with no damage control and still not sink it. They usually finish it off with a torpedo. The 57mm will never stop a large rogue vessel. .

    • The 57mm has a smart fuse, but over the long term, any fuse that can be fitted on a 57 mm can also be fitted on a larger shell. Still the 57 mm has fewer projectile options than either the 76mm or the 5″. The 5″ is also getting a new fuse: http://defensetech.org/2012/12/06/more-precision-for-navy-guns/

      There are a number of things coming out now about the LCS, and one of the comments was that they are having performance and reliability problems with their guns. I’m not sure how much of that is about the guns themselves as opposed to the entire gun/director system which is different, but we will probably hear more soon.

      From Wired: http://www.wired.com/dangerroom/2013/01/littoral-combat-ship/ “It might also not be able to depend on all of its weapons in a fight. The 30mm gun on board the Freedom “exhibit[s] reliability problems.” The 57mm gun on both the Freedom and its sister ship, the differently designed USS Independence, is apparently worse: “Ship operations at high speeds cause vibrations that make accurate use of the 57 mm gun very difficult,” Gilmore finds. Worse news for the Freedom: Its integrated weapons systems and air/surface search radar have “performance deficiencies” that affect the ship’s “tracking and engagement of contacts.””

      From Inside Defense, https://defensenewsstand.com/index.php?option=com_ppvuser&view=login&return=aHR0cHM6Ly9kZWZlbnNlbmV3c3N0YW5kLmNvbS9jb21wb25lbnQvb3B0aW9uLGNvbV9wcHYvSXRlbWlkLDI4OS9pZCwyNDIxMzQ1Lw==,
      “DOT&E Report: LCS Guns, MCM Laser And Sonar Have Low Reliability
      The Littoral Combat Ship showed performance and reliability issues with both its 30mm and 57mm guns…”

      As for the 57 mm’s penetration ability, I never had any doubt it would penetrate the hull, but I is most likely to explode in the engineroom (if it is above the water line where it can hit it at all), before it gets to the engine itself, I worry that a small explosion, inside a big space creating may small fragments, is just not going to have much effect on a huge diesel or even on steering gear. No mater what the video looks like, the muzzle energy tells the tale. The 5″ Mk 45 has eight time the muzzle energy and twelve times the shell weight of the 57mm.

      “Also, one must ask themself: If it’s so incapable, why is the Navy going to it? Or, do you think the Navy is sacrificing war-fighting performance to get cheaper/easier maintenance?”

      The 57mm is only a small part of the armament on the DDG1000 and it’s anti-surface capability was originally supposed to be secondary to a missile system even on the LCS. I believe the Navy chose it for its ability to engage swarming Iranian small craft and as a AAW weapon, not because of its ability to sink or even stop ships. They have other weapons for that purpose, the Coast Guard does not.

  8. Question,
    Since the US Navy is decommissiong the Frigate and the frigate missions. I am wondering how come the US Coast Guard isn’t picking up the Frigate missions such as Convoy Escort, ARG escort, Naval Fleet Auxiliary Force escort and Defense operations in the Littoral Environment. I am wondering because if the US Coast Guard picked up the Escort mission and littoral defense mission, it would not only make the US Navy happy, it would take a load off them in the littoral zone. On the Plus side we can get the US Navy to finance those missions if we picked it up for them.

    • As you should know from our previous discussions, the number of large cutters is going down not up. We don’t have any ASW capable frigates and are not likely to get them. The government just does not seem to work as you seem to think.

    • I am of the opinion that the 57mm is superior at naval gunfire support to either the 76mm or the 5 inch. According to my research the 57 mm can put more ordinance on target faster than either other system, of course at shorter range, which is around 10.5 miles. Programmable fuzed ammo also add to its lethality, keep in mind the 57mm can fire 220 rounds per minute. The days of the coast guard providing fire support are long over, and the 57mm is perfect for the coast guard and small vessels.

      • eddie, The 57mm can put out a lot of rounds but for Naval Surface Fire Support (NSFS) ability to penetrate is also important, including the ability to break into bunkers or destroy tanks. For that the 57mm is the least capable of guns considered. As noted the potential for actual weight of projectiles fired per minute (which usually really isn’t usually important for NSFS) is nearly identical for 57mm, 76mm, and 5″/38. The 5″ Mk 45 is superior.

        While the 57mm has a smart fuse, both the 76mm and the 5″ have many more options. The nominal range for 57mm and the 76mm are essentially the same (about nine nautical miles). But the 76 has extended range options and the 5″ Mk45 has a 5000 to 7000 yard range advantage even in its basic configuration, meaning it can influence an area at least 63% larger..

        Certainly if the CG is not equipped to do NSFS, it will not do NSFS, but it is not because there is no need for the capability.

    • @Nicky, “What about naval guns that are planing to use M982 Excalibur. How would that affect the USCG.”

      There have been a number of attempts to exploit the obvious logistic advantages of having common ammunition between the Army and Navy, but it seldom works out. Both Britain and Germany have attempted to develop naval versions of their Armies’ 155mm weapons, but without success. The salt water environment requires very different materials.

      The 155mm “Advanced Gun System” developed for the Zumwalt (DDG-1000) Class is completely different.

      As noted above, the dual mode guidance system that was developed for the ground based 155mm Excalibur will probably be adapted to the Navy’s 5″ gun projectiles. http://www.defenseindustrydaily.com/new-frontiers-for-raytheons-excalibur-gps-guided-shells-014580/?utm_medium=textlink&utm_term=continuereading

  9. Pingback: Offshore Patrol Cutters (OPC), the Other LCS | Chuck Hill's CG Blog

  10. I would have to agree with Chuck. I am curious, as a taxpayer, why are we spending all this money on these very large, expensive and not so capable cutters? So I guess the CG will be able to pick and choose the adversary they will have to go up against? Hmmm..I think the Navy is now “pivoting to the Pacific”. What does that tell you – that the Berthofs will be only be engaging “swarming Iranian speedboats” in the Bering Sea?

    If the CG wants to abrogate its’ wartime role and become glorified water cops then they can do it with much smaller and less expensive ships. The 418’s have no ASW capability and they are pretty much limited to a defensive posture against any serious military surface or air threat. Looking at the possible threat – it will most likely be ships armed with missles and at least 5″ guns. The larger gunned vessel can simply stand off and pummel the 418 – assuming that the CIWS and 57mm stop the incoming missle.

    If the 418’s had 5″ main batteries they could at least present a serious threat to surface and air targets. Still leaves the issue of no ASW capability. They should train with Navy ASW helicopter units regularly. The 57mm is uttlerly useless for NGFS. Sure it has some nice whiz bang ammo, but many years of experience (WW2, Korea, Vietnam) has shown that at least a 5″ round is needed for effective fire support- meaning against hardend structures and vehicles.

    I also find the notion that the CG can simply “install” a 5/45 on a 418 in case of war is rather naive. If we get into a serious war there will not be time to do so much less the shipyard space etc. and what about training the GM’s on the new system, takes time. Sorry to say in this situation the 418’s will either be sitting out the conflict or be placed in situations for which they are not prepared for.

    If the 418’s currently had a 5″ inch main battery and if they trained with the Navy for ASW missions they coul dat least present a force that could act as a line of defense in a littoral setting – which is where the CG has much expertise. These capabilities would also enhance the law enforcement mission as well. My 2 cents.

  11. JUST WANTED TO ADD THESE THOUGHT WRITTEN FOR ANOTHER POST HERE:

    The larger shell retains more of its momentum than the lighter shells (less frontal area per pound) so the initial velocity of the smaller shells bleeds off faster. In general a 5″ Mk45 is going to be more accurate per round in addition to putting more weight on target per round. In addition while the lighter weapons put out more rounds per minute while their ready service carousels are loaded, once they are depleted, their rate of fire drops considerably, while the 5″ Mk45 can keep up its max rate of fire almost indefinitely.

    A 76mm can keep up its maximum rate of fire for slightly less than a minute. The 57mm for only about 33 seconds. A 5″ Mk45 with 300 rounds of ammunition can keep up its max rate of fire for about 15 minutes.

    I’m don’t have access to actual ammunition allowances, but I suspect that allowances for 76mm and 57mm gun equipped cutters are about 1000 rounds while the allowance for a 5″ mk 45 equipped cutter would be at least 200 rounds and probably more likely 300 rounds. If you multiply projectile weight times allowance you can see that the 5″ can put more steel on target.

    1000 57mm projectiles weighs approximately 5,300 pounds.
    1000 76mm weighs approx. 14,000 pounds.
    300 5″ Mk45 projectiles weigh approximately 20,700 pounds

    The effective range of the 5″ is about twice that of the lighter weapons.

    Lots of good info on the weapons here:
    For the Mk110 57mm: http://www.navweaps.com/Weapons/WNSweden_57-70_mk123.htm
    For the Mk75 76mm: http://www.navweaps.com/Weapons/WNUS_3-62_mk75.htm
    For the earlier version of the 5″ Mk45 which I think would be a good choice, and reduce cost because the Navy should have more than enough of in storage after decommissioning the Spruance class: http://www.navweaps.com/Weapons/WNUS_5-54_mk45.htm
    And for historical comparison the 5″/38: http://www.navweaps.com/Weapons/WNUS_5-38_mk12.htm

  12. NavyRecognition has a video including interviews from the Navy League’s 2014 Sea-Air-Space Exposition that touches on a number of systems we have talked about here. I am going to post this same comment on each of the threads I think are related. The video can be found here:

    At minute 9:00 there is a discussion of the Brimstone missile.
    At minute 13:00 we see a model of Eastern’s proposal for the Offshore Patrol Cutter. Unfortunately, there is no accompanying comments.
    At 13:15 we get an about one minute of update on the Navy’s new 85 foot MKVI patrol boat
    About minute 15:03 they talk about a new hyper-velocity round being developed to be fired from the 5″ (and other) gun.
    About 18:35 they talk about HII’s proposal for a frigate developed from the National Security Cutter. Doesn’t look like any new info.

  13. Pingback: Time to Ditch the 57mm? | Chuck Hill's CG Blog

  14. Pingback: Italy to build National Security Cutters | Chuck Hill's CG Blog

  15. I am concerned by our apparent inability to timely defeat attacks against ports and harbors undertaken using commercial vessels, either as mining or weapon platforms, or simply as enormous bombs, either as part of an initial attack in a conventional war or as a political/economic terrorist attack. If I were either a PLAN officer interested in hamstringing America’s ability to counter a military move in the WESTPAC or a terrorist interested in hurting America’s economy and killing a lot of civilians, covertly employing a large commercial vessel is certainly something I would look at doing.

    Unfortunately, such an attack is something the USN is unlikely to be in a position to interdict, although the USAF or USN aviation could possibly do so if there were any chance of them actually being specifically tasked with it. But there is no sign of that, so this will remain a CG mission, and thus ought to precedence over any sort of naval fleet supplementation, NSFS, ASW or other wartime CG mission.

    For this purpose, does it really matter very much what sort or how big of gun is mounted on the larger cutters, which are too few and unlikely to in the right places at the right times? Oughtn’t the higher priority be given instead to ship-stopping or killing weapon systems that can be provided in a smaller package and in greater numbers than a relative handful of naval guns, i.e., missiles and perhaps torpedoes?

    On a related note, is it just me, or do the Navy’s LCS’s look like they could be a lot more effective as CG cutters than as naval combat ships, much less as frigate substitutes?

    • I share your concern. The weapons I believe most appropriate for dealing with these unconventional threats are small missiles (e.g. Hellfire, Brimstone, or Sea Griffin) for dealing with small, fast, highly maneuverable threats, and light weight torpedoes for stopping larger vessels. I think we could fit two small torpedoes and four small missiles on vessels as small as WPBs. Developing a small anti-surface torpedo capable of homing on propellers should be easy. It was doable with WWII technology, it should be a lot easier now with solid state electronics, improved batteries, and brushless electric motors. Tesla could probably whip one up in six months.

  16. Pingback: China CG gets Surplus PLAN Frigates | Chuck Hill's CG Blog

  17. Pingback: Thanks for a Successful 2015 | Chuck Hill's CG Blog

  18. Update on the 5″ version of the Excalibur guided round. Claims a tripling of the effective range. Demonstration showed a 20.5 nautical mile range. They are planning to add both a laser and millimeter radar, fire and forget seeker in addition to the GPS round. They claim a less than two meter miss distance.

  19. Nice article, The penetration power of the 5” is a big plus. Given how small the the Bofors is, why not have both a 5″ gun and 57 mm gun? Certainly having both for anti-air defense would be a big plus and you would have more fine grain control on how much destructive energy you put into a target. Regarding MJ at the muzzle I believe you may have dropped the 1/2 of the 1/2mv^2 equation for energy so the values are exactly 1/2 of what you have up above.

    Also I think it is worth mentioning that most of the rounds also carry an explosive payload that adds a lot of MJ of destructive energy. For example for the Mark 55 you get around 10 MJ Kinetic energy at the muzzle plus another 26 or so MJ of explosive energy that does not diminish over range. So about 36 MJ of total destructive energy at the muzzle (TDE). In terms of TDE at the muzzle per 20 second burst and max rate of fire it is the Bofors first (274 MJ) the 76mm Oto Melara RF (270 MJ) and the Mark 45 (248) MJ. Chose 20 seconds because all the guns have ready enough ready rounds to support at 20 second burst at max rate of fire.

    • Both the 5″ and the 76mm Mk 75 can maintain full rate for 60 seconds from ammunition on the mount. The 57 mm about half that.. The 5″ can be reloaded fast enough to maintain it essentially until you run out of ammunition.

  20. Pingback: Why the Coast Guard Needs LRASM in Peacetime

  21. Pingback: Why the Coast Guard Needs LRASM in Peacetime | News4Security

  22. Pingback: WHY THE COAST GUARD NEEDS LRASM IN PEACETIME–CIMSEC | Chuck Hill's CG Blog

  23. Pingback: Could the U.S. Arm Cutters With Anti-Ship Missiles? – eMaritime Exchange

  24. Pingback: Could the U.S. Arm Cutters With Anti-Ship Missiles? | Life At Sea

  25. Pingback: Could the US Arm Cutters With Anti-Ship Missiles? | News4Security

  26. Pingback: How About a Coast Guard Sink-Ex? | Chuck Hill's CG Blog

  27. Hello Chuck. Question which Coast Guard Cutters were equipped with a 75MM water cooled barrel on the Bow of the ship? Reason I ask is that I have been asked to build a Barrel Lift tool for the weapon and the only drawing available does not really show anything. and I cannot find any pictures that show what it look like. Being that you seem to be very familiar with these guns. I figured I would ask. Thank you!

    • Can’t help you a lot, I never saw a Mk75/76mm exercise. There are a lot of variables: range, target size and maneuvers. Accuracy decays geometrically as range increases. Beyond 10,000 yards you probably could not expect more than on one hit out of ten, and probably considerably fewer. Still it is a very good system, that is just the nature of the beast

      I know the 5″/38s was a lot better AAW weapon than we gave it credit for. Toward the end of my tour at fleet Training Group San Diego, we got permission to use service ammunition for our AAW exercises against a “sleeve” towed by a business jet to simulate a high speed incoming target. I had seen many of these exercises using practice ammunition and they never worked. Ships kept failing to get any air bursts on the targets. After switching to service ammution we were actually dropping the target on the second or third round with multiple air bursts.

      Turns out the practice ammunition was fitted with fuses that had passed their “use by date.” The little battery in the VT fuse that powered the radar set was dead, so we were essentially shooting blanks.

      It was very bad training because it destroyed confidence in our weapon system.

  28. “The US Navy has revealed plans for a „mini missile“ that can be fired from warship guns to take out swarms of enemy drones and boats … DARPA developing Multi Azimuth Defense Fast Intercept Round Engagement System (MAD-FIRES), a „medium-caliber guided projectile“ which will “combine guidance, precision, and accuracy of missiles with speed, rapid-fire capability, and large ammunition capacity of medium-caliber bullets”–German Navy Blog, “Marine Forum” Daily News, 16 Jan. 2017, http://marineforum.info/Daily_News/daily_news.html

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