What Does It Take to Sink a Ship?

The Coast Guard spends much more time thinking about how to keep ships from sinking, than it does about how to sink them. But because the Coast Guard is tasked with maritime security and because of the potential for terrorists using a ship as a means of attack, the question has become relevant. It becomes important when you consider, is the Coast Guard adequately armed for its missions. I’ve mentioned several times that I don’t believe the 57 mm gun is adequate to stop a medium to large ship being used as a weapon. I’ll try to explain why I have reached that conclusion and offer some examples.

https://i2.wp.com/upload.wikimedia.org/wikipedia/commons/e/ea/BB61_USS_Iowa_BB61_broadside_USN.jpg

Stopping–keeping it from reaching the target–rather than sinking a ship is probably more the relevant criteria, but generally ships don’t sink rapidly, particularly if you are trying to do it with a gun, so almost inevitably it is necessary to do enough damage to ultimately sink the ship if you are going to stop it in a timely fashion. Many of the ships that I will talk about continued to fight on for over an hour after the first hits were registered. Think of sinking a close surrogate for stopping a ship before it reaches its objective.

There are of course many examples of ships either surviving grievous attacks or alternately ships sink after a single hit. What it takes to sink a ship is highly variable and at best probabilistic. Its highly dependent upon ship design and preparation, but the most important variable seems to be size.

World War II experience

Over a long period, I’ve made an informal study of this subject. The primary source I used was the US Navy Report of War Damage series available here. The same index also includes reports of individual ship damage and reports of damage to British warships. I would also recommend the “Destroyer Report: Gunfire, Bomb and Kamikaze Damage, 17Oct41-15Aug45” which includes annotated damage control plates. The amount of damage these little ships took and in some cases survived is truly amazing.

The US Navy Report of War Damage series briefly outlines all incidents of damage to US Navy Battleships, Carriers, Cruisers, Destroyers, and Destroyer Escorts as they were known at the time the document was published and includes diagrams of the location of hits.

The forth and final volume includes a summary table of what caused the sinking of 92 ships ships lost during WWII (page 4). The ships sunk at Pearl Harbor but subsequently raised were considered “damaged” rather than “lost.” These 92 sinkings included 2 Battleships (BB), 4 Fleet carriers (CV), 1 Light Carrier (CVL), 6 Escort Carriers (CVE), 7 Heavy Cruisers (CA), 3 Light or Light Anti-Aircraft Crusiers (CL or CLAA), 60 Destroyers (DD), and 9 Destroyer Escorts (DE).

Causes for sinkings were listed as follows (three were listed as disappeared, but I have corrected the figures based on information that was not available at the time of the printing):

  • 38 by torpedoes alone (41.3%)
  • 16 by suicide planes (17.4%)
  • 12 Bombs alone (13%)
  • 11 by gunfire alone (12%)
  • 6 by torpedoes and gunfire (6.5%)
  • 5 by mines (5.4%)
  • 4 by torpedoes and bombs (4.3%)
  • 1 by bombs finished off by gunfire (1.1%)

As can be seen, torpedoes were involved in 48 of the 92 sinking (52%).

As the ships get larger it becomes harder to sink them by gunfire alone. If we consider only the 23 larger major warships (Battleships, Carriers, Cruisers) lost, torpedoes were involved in sinking 17 (74%) including 100% of the battleships and fleet carriers. It is not reflected in the table but torpedoes were also involved in the sinking of all six battleships at Pearl Harbor.

  • 10 by torpedo alone (43.5%)
  • 4 by torpedo and gunfire (17.4%)
  • 3 by bombs and torpedoes (13%)
  • 3 by suicide plane (13%)
  • 2 by gunfire alone (8.7%)
  • 1 by bombs alone (4.3%)

The two large ships sunk by gunfire alone both engaged heavy cruisers and/or battleships. USS Astoria (CA34) was sunk at the Battle of Savo Is., 8/9/42. She was hit at least 65 times by 8″ and 5″ projectiles. Five 5″ hits below water line. In spite of uncontrolled fires she did not sink until a magazine exploded nine hours after the action. The opposing force was 5 CA, 2 CL, 1 DD. USS Gambier Bay (CVE73), was sunk at the battle of Samar, 10/25/44. She was hit over 26 times. Two projectiles penetrated shell plating below waterline and detonated in forward engineroom and after engineroom, respectively. Hits included battleship caliber rounds, possibly including hits by Yamato’s 18.1″ guns. The opposing force was 4 BB, 6 CA, 2 CL, 11 DD. Notice in both cases, shells penetrated below the waterline. (As a point of reference typical shell weights are: 57 mm projectiles weigh about six pounds, a 76 mm 12-14#, a destroyer’s 5″ 55#, a light cruiser’s 6″ (152 mm) 110#, a heavy cruisers 8″ (205 mm) 260#, an smaller battleship’s 14″ 1485#, the Yamato’s 18.1″ 3219#)

Only one ship appears to have definitely been destroyed by gunfire from weapons 5″ or less, the Longshaw (DD559) hit six times while aground off Okinawa, resulting in a magazine explosion that blew off the bow. No ship larger than 3,000 tons full load was sunk by gunfire from weapons 5″ or smaller.

Consider that all these ships, including the aircraft carriers and battleships, were smaller than merchant ships that are now common. The largest was the carrier Lexington (CV2), 43,055 tons (fl), 888 ft (oa), 105’5″ beam, 33’4″ draft (270.66 x 32.12 x 10.15 m) (She was destroyed as a result of the accumulation of gasoline vapors after two torpedo and two bomb hits. The direct result of the hits were relatively minor, it was the gasoline vapor explosion that destroyed the ship). Lexington was a big ship, but no longer remarkable.

Warships might be thought more immune to damage. They usually have the advantage of better compartmentalization, a larger crew for firefighting, and sometimes armor. But they also had disadvantages. They frequently have, or had, large high pressure boilers that could explode. They carried lots of highly explosive projectiles, propellant charges, depth charges, torpedoes, aviation gasoline, etc that when exposed to damage could lead to secondary explosions. Modern merchant ships can be very hard to sink or even stop. A modern double hull tanker could be a particularly difficult.

SINK-EX RIMPAC 2000

To give some more recent data, using modern weapons, I’ll refer to RIMPAC 2000. One portion of the exercise included a missile firing exercise during which four decommissioned ships were sunk at the Pacific Missile Range Facility off the island of Kauai. The “Sink-Ex” operation involved firing of more than 100 missiles at the four target ships.

The four ships were

ex-USS Worden (CG-18), a 7,800 ton full load (fl) guided missile cruiser commissioned in 1963. The former USS Worden sustained a continuous attack from two ships and from F-14 Tomcat and F-18 Hornet fighters, finally sinking 34 hours after the exercises started.

ex-USS Buchanan (DDG-14), a 4,526 ton (fl) guided missile destroyer commissioned in 1962. Three Hellfire hits, three harpoon hits and a 2,400 pound laser-guided bomb hit were not enough to sink the ship, which required an additional 200 pounds of scuttling charges before sinking.

ex-USS Ramsey (FFG-2), a 3,426 ton guided missile frigate commissioned in 1967. Missile and aircraft firing exercises involving nine ships and three different types of aircraft were required to sink ex-USS Ramsey and ex-USS Gen. Hugh J. Gaffey. Ex-Ramsey sank only after taking several surface and airborne harpoons.

ex-USS Gen. Hugh J. Gaffey (AP-121), a 20,120 ton full load transport commissioned in 1944 that had once been the Coast Guard manned transport USS Admiral W. L. Capps (AP-121). Built to WWII merchant standards, Ex-Gaffey sunk nine hours after taking a total of 13 bombs.

While I can’t claim it is dead accurate I developed a rule of thumb when developing a rudimentary naval war game. It might serve as a useful metric until something better comes along. Actual results are probabilistically distributed but on average to have high confidence of sinking another ship you need to put one pound of bombs or shells on target for every ton of ship. To disable them, usually only takes about a tenth of that.

Torpedoes, considering only the warhead, are more effective. Weight of warhead exploding at the side of the ship, is about four times as effective as the same weight of ordnance (including bomb and shell casing as well as explosive) delivered above the waterline. Torpedoes exploded under the keel are about ten times as effective as the same weight delivered above the waterline.

Using this metric to sink a 2000 ton WWII destroyer took about 36 hits from a destroyer’s 5″ guns, about 18 hits from a light cruiser’s 6″ guns, 8 hits from a heavy cruisers 8″ guns, or only one hit from a battle ship’s 16″.  A torpedo with a 500# warhead would usually sink a 2000 ton ship (unless it hit at the extreme ends of the ship). That appears pretty close to actual experience.

The only ships the Coast Guard currently has with any hope of stopping a medium to large ship are those armed with 76 and 57 mm guns. That in itself is not a good plan, because when the capability is needed, they are unlikely to be available. (I hope no one really expects to stop a determined attack by fast roping onto the deck.)

For the cutter faced with trying to stop a determined attack, I can only suggest that the CIWS may also be useful and recommend targeting the rudder and the engineroom near the waterline. Maybe hit the bow too in hopes of setting off any explosive that might be there.

In terms of making the 76 and 57 mm more effective. The Coast Guard might consider insuring the ships have available a very high velocity penetrating round, possibly using a discarding sabot as a means to get into a large diesel engine and destroy it. I know such a round is made for the 76mm, although it probably isn’t in the USN system.  (I don’t know about the 57 mm.)

https://i1.wp.com/upload.wikimedia.org/wikipedia/en/6/60/Mark-46-prop.jpgThe real answer is to arm the more numerous and more readily available smaller cutters with a weapon that can reliably stop a ship of substantial size.

I think a modified Mk 46 could be an effective ship stopper, but if you absolutely, positively have to stop a ship immediately, nothing beats a heavy weight torpedo:

“On Monday, June 14, 1999, the Australian Collins class submarine HMAS Farncomb fired a Mark-48 war-shot torpedo at the 28-year-old former Destroyer Escort (actually a frigate) Torrens. The firing was part of the Collins class trials requirements and was designed to validate the submarine’s combat system. The submerged Farncomb fired the Mark-48 torpedo at the stationary hulk of the 2700-ton Destroyer Escort from over the horizon. The plume of water and fragments shot some 150 meters skyward as the blast of the torpedo cut the ship in two. The stern section sank rapidly after the torpedohit; the bow section remained afloat, but sank sometime later.

“The torpedo warhead contains explosive power equivalent to approximately 1200 pounds of TNT. This explosive power is maximized when the warhead detonates below the keel of the target ship, as opposed to striking it directly. When the detonation occurs below the keel, the resulting pressure wave of the explosion “lifts” the ship and can break its keel in the process. As the ship “settles” it is then seemingly hit by a second detonation as the explosion itself rips through the area of the blast. This combined effect often breaks smaller targets in half and can severely disable larger vessels.

“The Mark-48 torpedo used in this test is a variation of the MK-48 ADCAP (Advanced Capability) torpedo developed for the United States Navy.

“Photos and Mk-48 Torpedo information provided by Maritime Headquarters and DSTO Australia. Photos by PO Scott Connolly and AB Stuart Farrow. This PowerPoint presentation prepared by the Northern Connecticut Submarine Library and Museum.

“Source: US NAVY, site states that all content is in the public domain.”

(Added July 2012, US Navy photo)

Royal Australian Navy's Submarine Celebrates Successful Sinking at RIMPAC

(Added July 2012, US Navy photo )

The Royal Australian Navy’s (RAN) Collins Class submarine HMAS Farncomb has successfully sunk a target ship, the 12,106-tonne former USNS (United States Navy Ship) Kilauea in Hawaii.

Farncomb fired one Mark 48 Torpedo and achieved a hit just below the bridge of the ship as part of a sinking exercise, or “SINKEX,” at Exercise Rim of the Pacific (RIMPAC) 2012.

The former USNS Kilauea broke into two parts and sank about 40 minutes later.

93 thoughts on “What Does It Take to Sink a Ship?

  1. I’ve been reading your articles on this subject, and I think you are on to something. Using torpedoes, even on a WPB, is something that would be both effective and possible. I can see us actually being able to do this, with assistance from the Navy for equipment and training.

    Whatever the solution, I hope it gets attention BEFORE an attack, and not after as a reaction.

  2. Nothing like a MK-48 to send some rouge ship to Davy Jones’s locker. The USCG should have a modified version of the Mk-48 that just stops a rouge ship in it’s tracks. Preferably something that knocks the rudder and screws off. While keeping the boat intact

    • Part of the attraction of the Mk46 is that it is considered obsolete by the Navy so there may be some available for modification. Even the Mk 46 adequate for destroying the rudder and screws. I don’t think it would take much more than a software modification to make them usable–putting the minimum and maximum depth settings near the surface and maybe changing the search pattern.

      Even the light weight Mk 46 would sink some smaller ships. The Mk 48 is much heavy and way more expensive. It would also take up much more room.

      Using heavy wight torpedoes from surface ships is very rare now, I think mostly because of assumption that fighting will be beyond visual range, but compared to a 57 mm, the maximum range is a bit less, but the effective range of the Mk 46 is probably greater.

      • “putting the minimum and maximum depth settings near the surface and maybe changing the search pattern. ”

        I don’t know about the MK 46, but when I was an ASROCateer, the initial search depth (ISD) was fifty feet. I would cut off the initial search area (ISA) because the once the area is searched the torpedoes programming moves it to another area and it starts its circle all over again until the battery runs out and then it sinks. I would definitely put the weight dump on it as are in practice fish. That way the Navy won’t have to start looking for torpedoes again.

        Hey, what’s with the photo of using the carriage and block and tackle. It only weighs five hundred pounds. Three healthy guys can pick it up, but that might be the problem. I also see in the photo the screw guard is not being used. It was not to protect the people but the fish’s screws.

      • As I remember minimum depth was selectable among two choices. It would probably need a running depth selection option. We would not want it hitting the bottom in shallow water.

        Re the weight drop, if a “war shot” fish comes floating to the surface, unless you also defuse it, it becomes a floating mine.

  3. When it comes to weapons in the Coast Guard, and its predecessor Revenue Cutter Service, the outlook has always been reactionary. The key reason is cost. Although Alexander Hamilton stated he wanted armed cutters, he stalled the idea when the captains asked for cannon. None of the cutters were armed with other than small arms and sometimes not those. Generally all Coast Guard histories tout there were “swivels” but even these did not materialize for a very long time. The gun “system” often referred to as a swivel was the 18th century wall gun that was, in essence, a very large smooth-bore musket. They became such a bother that most were returned to the West Point Arsenal about a year after they were issued.

    Coast Guard history is replete with ordnance technology that was for show. The famous cutter Hudson was totally unarmed at the beginning of the Spanish-American War, most of the cutters at the beginning of WWI had their older 6-pounder (57-mm, sound familiar) or obsolete 3″ deck guns but some of the newer cutters could fire a torpedo from a tube in the bow, that is, if they had one. I’ve seen no documentation they did. At the beginning of WWII the hand rammed 5″/25 and 5″/51 was the largest but at least these headed in the right direction.

    The root cause was cost because all of the vessels then had capability to carry more up-to-date weaponry. Chuck as been a long proponent of the torpedo for surface use and it is a great idea. However, I see the Coast Guard may do some real hand-wringing about when to or rather the circumstances to fire one as well as just who would maintain them. Gunner’s Mates and Sonar Technicians did it in past configurations but since the former is so far out of the loop of major weapons systems and the latter no longer exist, the job may fall to those ETs who perform as surrogate FTs. This does not count of the lack of anything resembling Weapons Officers which as become an OJT detail. The CGA stopped teaching ordnance in 1972 and the Coast Guard’s last Ordnance Engineer, RADM Norman Venzke retired decades ago.
    None of these are insurmountable problems but it would take some institutional will to push attitudes in that direction.

    The when to use a torpedo to stop a large vessel would be the greatest hurdle. What would be use of force policy to stop a vessel in, or just outside, a major U. S. port. How would the decision be made that would potentially sink a vessel in a main, or only, channel. It would seem that a terrorist (assuming this is about terrorism) would sink a large vessel at the entrance to the channel to Galveston. It could take at least a month to refloat and move it–that is if the vessel is not rigged to explode on its own as a very large IED.

    To prevent this would mean someone making a decision to attack near the sea buoy. It would be an attack and since the international shipping community is just now warming to the idea of putting armed people on vessels to discourage pirates, they may not take kindly to a torpedo run on one or many others.

    I realize that the Coast Guard has full legal authority to use gun fire to stop vessels. However, such gunfire is often frowned upon. One by the book Civil War RCS captain fired on a merchant vessel inside New York Bay. Another 1809 captain fired on a merchant brig at Savannah enforcing the Embargo killing one of the merchant crew and in 1941 a six-bitter fired upon and stopped a French tanker off Biloxi, Mississippi that attempted seizure (CWO Earl “Porky” Jones in command). However, these were outbound and not inbound vessels.

    I like the idea of using torpedoes for all the reasons Chuck gives. However, there should be some updated legislation that would give the Coast Guard the right to do this. If not, international pressure would have the torpedoes removed faster than a restricted man going on buoy deck liberty.

    • Bill, thanks for the historical perspective, interesting as always. I think you are spot on about the Coast Guard not having the will to actually do this, unfortunately. Just getting the ability to TRAIN with less lethal flashbang rounds has been like pulling teeth with chopsticks, I can’t imagine the panic at HQ if we were trying to run torpedoes.

      I have to disagree with your final thought though. Possibly domestic pressure, ie the public not liking their CG ships to have “scary” weapons like torpedoes could be a factor, but I think that internationally our vessels are pretty routinely recognised for what they are: Warships. I think the addition of conventional system like a torpedo would not be a big deal to the rest of the world. Many nations’ Coast Guards or small navies are better armed than ours as it is.

    • Bill, I’m surprised you didn’t mention the “I’m Alone” case.

      I did get the impression, for some people the gun was more signaling device than weapon, good for warning shots or firing star shells (night illumination) but not much else.

      We would need to move the authority as far down the chain of command as possible, but I don’t see it as any different from firing a 57 mm. Are we preparing for a terrorist attack, or just going through the motions?

      • Chuck,

        It was in my mental list but I forgot to list it. That case is still an international sore point but I believe it justified. Also it was and inbound and outbound case.

        Prohibition saw the most used of gunfire. However, some U. S. shore side inhabitants objected to one-pounder rounds being fired into their back yards. The Coast Guard then invented the first light weapons “piggyback” with the placement of the Lewis Machinegun (in 30.06) on top of a one-pounder. The project had two aims the first to save money and the second to quiet the public that continued to receive incoming in their back yards but in smaller size. Canadians were especially resentful of Coast Guard incoming small arms fire.

        I’ve only seen a written description of the arrangement. I’ve been looking for a photo. It was tested in New London. An ‘artist’s conception’ has been on my to-do list for some time.

  4. A small question. But if you knock the rudder and propeller away haven’t you just created a hazard to navigation that will have to be managed? Guns are persuaders; there is a psychological dimension to a law enforcement vessel using high end force.

    (Sorry to intrude, sir. I am looking for stuff on NSC.)

    • The circumstances we are talking about, that would require this weapon, are not ordinary law enforcement. It is stopping a terrorist from reaching his objective. That does still leave you with a problem of how to wrap up the case. They don’t surrender. Do you go on board and risk their blowing the ship up with your boarding party on board? Do you simply sink it, hopefully off shore?

      Having stopped the ship from reaching it’s objective at least gives you some time to work the problem and call in more help.

  5. Three points of discussion relating to the original post:

    1) Ships are not built to the same standard as those mentioned in your discussion. We no longer put ships to the line with 6 inch hulls but instead the standard is 1 inch or less. Look at the hulls across the fleets, you can see the ghosts of their structural members through the hull. Also, the purpose of modern naval warfare is not a hard kill but instead a mission kill. As a result air burst and variable timed rounds/missiles are the standard to remove sensors and communication ability. Five well timed rounds just under the pilot house of a DDG will make it a very large patrol boat (and those AEGIS arrays are big targets). Why waste hours trying to sink a vessel that is no longer in the fight?
    2) The CG no longer invests in the ASW mission, for the same reasons it doesn’t have harpoons….its not a Navy ship. Rather than having weapons envy just recognize that CG does not make ships of the line. Any battle group commander will just have to recognize that the CGC is not the best asset to put in that threat environment unless it really needs a torpedo sponge.
    3) The 57MM is more than just its caliber. I would gladly put a WMSL with a MK48 GWS (57MM plus the control systems) against a DDG in a guns only battle. Its not only about the size of your rounds but the rate of fire (220 rounds per minute), the accuracy (can’t disclose that but its scary good), rapid-fire rounds before reload (20 before it automatically reloads itself), control systems (pretty slick with SPQ and OSS working in tandem), and on the fly selectable rounds (6 modes). That glorious 5″ is slow, inaccurate, and manpower intensive for and extra 3NM range and pretty much the same effective range. Also, the 57MM has a much higher muzzle velocity and therefore more kinetic energy than the 5″ at impact.
    4) To stop a rouge M/V: 20 rounds fuzed to Gated proximity mode with impact priority distributed across the ship to provide them an incentive/opportunity to stop and 20 rounds fuzed to impact mode directly into the pilot house to remove their ability to maneuver the ship. If the vessel continues then 40 rounds fuzed to armor piercing into the engine rooms followed by 40 rounds fuzed to armor piercing into the steering gear and props. Reload and then I would then recommend 40 rounds of variable timed rounds about the decks just before the MSST or MSRT made final approach to fast-rope and retake the ship. At least this is what my senior ET’s and I came up with on the fantail two years ago when we gamed it out. 8,000 tungsten projectiles per round is highly effective at destroying electronics and terrorists.

    • I’m pleased to hear someone has been thinking about this.

      But a few points, Ships during WWII were not necessarily stronger than modern ships. The CVEs in particular were little more than merchant ships with a flight deck overlaid. Destroyers and destroyer escorts were lightly built. They very quickly acquired the “starved dog” look. Even the ships that were armored were only armored over limited areas. Only the newest battleships and the Essex class carriers had what was considered effective protection against torpedoes at the time, and even that would be ineffective against modern torpedoes.

      The scenario I was discussing wasn’t about making cutters battlegroup units or about making them effective in fighting other warships. It also had nothing to do with ASW–that’s a different discussion. It was about countering a terrorist attack. Terrorists don’t care about “sensors and communication ability,” They are not likely to respond to an “incentive” or “opportunity” to stop, and they may not even be steering from the bridge. In fact the steering may be auto pilot from after steering.

      If you check your physics, E=MVsquared, there is no way a 57mm approaches the kinetic energy of a modern 5″ projectile that weighs twelve times as much. I believe even the armor piercing round will explode shortly after going through the hull, which may not be effective against the machinery.

      Taking on an Arleigh Burke Class DDG with an NSC in a gun fight would be a bad bet, unless you got to open fire on an unprepared ship at short range. They are fast enough to choose the range and would be hitting you from over the horizon.

      More important than the effectiveness of the 57 mm is that we are unlikely to have a ship with a 57 mm (or 76mm) in position when the need arises. They don’t hang around our ports when they are underway, there are more potential targets than there are large cutters, and they are not kept in a high state of readiness in port. Even if they are in the general vicinity, you can’t assume you will be able to shoot from an ideal angle or at close range.

      Incidentally 8000 pellets in a 6 pound projectile means they weigh no more than .012 oz (0.336 gram) each. That doesn’t translate into much kinetic energy no matter how fast it is going, so it is really only effective against electronics and people in the open, targets that are largely irrelevant in the scenario I was discussing.

    • Thanks desk rider but no. The one I wrote about was an invention of the 1930s. However, it was not a new idea. Both open three and five inch guns had an subcaliber device (a Springfield ‘o3) that attached to the gun mount. The rifle was bore sighted to the large gun and provided a means to fire the larger gun without expending funds for the larger ammunition.

      Also, in 1905 2nd Lt. John Mel, USRCS, developed an adapter for the Hotchkiss 57mm that held the Lyle gun. All the cutters carried a Lyle line throwing gun but its use from deck was iffy at best. To the best of my knowledge Mel’s invention was never used. This may because shortly after he developed TB and was sent to Army hospital at Fort Bayard, NM, or the RCS did not see then need.

      BTW, I personally saw about 3,000 rounds from the 81mm. There may have been more but we did not keep records of what was fired. When we got low we simply asked for more. We carried about 900 rounds on board at any one time. The CO and XO got to sleep on the WP. It tended to melt in the ready service lockers.

      Also, it was CWO (Gun) Elmer Hicks who developed the .50 caliber adapter and got the Navy to give the contract to the CG yard to build everyone used in Vietnam. The primary purpose was to give the WPBs a 360-degree machine gun coverage. It seemed to work very well and, I know, it is still being used in Australia.

  6. Outside of ice breakers, the Coast Guard has never had twelve-inch thick hull plate on its cutters. The Navy only built that thickness and more into the BBs and CAs and used it for a torpedo belt. I know, I had to get a WPB alongside the USS St. Paul without dinging our hull.

    I do not know which 5″ gun you write of but, yes, it was slow. About fifteen rounds of 55-pound projectiles that could also fire VT, set fuzes, WP, and AP. It did take a large crew but could operate with fewer numbers if it had too. Besides, having that many more people trained more sailors and in most cases it was Repair 3.

    Did I mention the 55-pound projectile? As for range, the 5″/38 could shoot a projectile nine miles without the Rocket Assist (RAP). That range is 4.5 miles further than the effective range of the 57mm that fires a six-pound projectile. The 5″/38 fire control system wasn’t speedy either but it does have a record for firing more rounds in actual firing situations.

    You seem to forget the ships will be moving and if a ship armed with a 5″/38 can stay outside the maximum effective range of the 57-mm, it could pound away all day long. This strategy was formulated well over 300 years ago. The 5″/62 guided round can reach 63 nautical miles with a pretty decent fire control system.

    That weight of metal of the 5″/38 vs. 57mm only applies as long as the ammunition holds out and shooting faster does not guarantee productive hits. Once that round leaves the bore it can be anyone’s guess where it will go especially on a moving target. Besides, the NSC is a much larger target and their construction not as well done.

    It is true the little gun has a higher muzzle velocity (3P round – 3,396 fps) compared to the 5″/38 with 2,700 fps. However, at maximum rate of fire of the 57mm will soon burn out and the numbers will get closer together.

    Did I mention the weight of metal? In one minute, the 5″/38 will fire 825 total pounds with an explosive charge of about 195 pounds of explosives. On the other hand, the 57mm will fire 1364 (at the max projectile weight of 6.2 pounds) pounds of metal. Using the same round, HCER, there would be only 198 pounds of explosive material. And who cares about the fragmentation round. The target still has to receive them. Anti-aircraft rounds were made to produce fragmentation long ago and I suspect, from my limited knowledge, that the fragmentation round is for aircraft not surface craft. If a merchant vessel was intended for some nefarious purpose then the terrorists would have done their homework and armored or in some way shielded vital areas. If they could stay out of effective range or put some innocent target either before or after them that would change the command decision of what and when to shoot. The Coast Guard has no recent experience in taking out innocents by gunfire and no amount of technology will improve that situation.

    Unfortunately, those swear up and down about how new stuff is better have never been in a real shooting situation. That is when the former expectations will fall away. Don’t forget, the only shots that count are those that hit.

    As for ASW, there was no mention of it in proposal. The idea is the use of torpedoes for surface targets.
    Did I mention the MK46 torpedo has 500-pound warhead and can move at over 40 knots. Not as fast as 57mm but then again the 57mm will not hunt down the target and it would be possible for a terrorist to install subsurface torpedo tubes in the hull. That would certainly change the dynamics. The Coast Guard would never hear them coming.

    We could call the torpedoes Beagles. They keep hunting until they catch their quarry or pass out from exhaustion. One of my favorite quotes from 19th century literature is, “With all the tenaciousness of a hungry beagle.”

    • Bill Wells, If I remember right I “think” the first fragmentation shells were developed by the British for use against Napoleons armies, from there they found out how useful these shells were against intrenched troops (National Anthem anyone?) and then someone noticed how fragile planes are. Anyway that’s all I can remember.

      • Explosive shells, go back to at least the 18th century. The “Bombs bursting in air” were exploding mortar shells fired from special small vessels called bomb brigs.

        You may also be thinking of “grape” and “canister” rounds which were non-exploding, but were basically large shotguns.

        For more look here: http://en.wikipedia.org/wiki/Shrapnel_shell

  7. Bill Wells, Looking at the small end of the target spectrum. Do you know how many hits the Pt. Welcome took? As I recall it was hit several times by 70 mm rockets and 20 mm cannon fire. Do you know how long it was out of action?

  8. I probably should have added a couple more ships that took a lot of punishment and managed to continue under their own power, USS Liberty attacked by the Israelis and the 82 ft WPB Point Welcome attacked repeatedly by the Air Force.

  9. Someone above mentioned hand-wringing over authorization to fire a torpedo. Well, my impression is that Chuck and Bill are already back-peddling about torpedoes in relation to their ASW use by the CG. Why?

    The CG is a branch of the military (albeit not in DOD) tasked with maritime homeland defense (for one mission area). Is everyone blinded by terrorism-missionitis? The biggest immediate threat, and a substantial long-term threat are rogue states (Iran, N. Korea) with nuclear capabilities. Think < 3000 deaths at WTC was bad? Try a dirty bomb set off in San Francisco harbor by a N. Korean submarine…

    And what did the CG do during "the big one"? Manned transports, coxswained small boats and landing craft, and, oh yeah, ASW escort! Does anyone think a WMSL is a credible part of a CVN task force? (No, I didn't think so…). What will the Navy use them for if another major conflict breaks out? As they sit, they don't have the sensors or armament to be anything but point-defense ships. Best use would probably be to stand between an LPD or LHD and the beach to try to destroy or soak up any beach-launched ASMs sent at the amphib group. Not exactly an endearing mission for the CG parents back home, though I'm sure the Marines' parents would be thankful…

    I think the national leaders need to re-think what the military role of the CG is. I think during a major conflict the CG should guard the home ports, home shore-line, and provide useful large ships (to the CG right now, the WMSL) to the Navy. Due to modern warfare conditions, the FRC and OPC will need their larger size for greater stand-off the coast to do that protection of ports and shore mission, but they'll also need sensors and weapons that are useful. The new Mk 56 ltwt torpedo is highly capable and triple 12" torp. tubes could easily be added to all three sizes of new white-hulled cutters.

    • I wasn’t back peddling on using Torpedoes for ASW; it’s just a different issue that I was not addressing at the time. The torpedoes currently in the US inventory are not designed to use against surface ships, but I think the capability could be provided relatively easily using ASW torpedoes that are being phased out and they could be employed by relatively small vessels with relatively little negative impact.

      When we suddenly need to stop a relatively large ship bent on an attack, the large ships are are not likely to be around and their gun is inadequate anyway. We could try ramming, but….

      On the subject of restarting a CG ASW capability, I’m in favor. But I don’t see any movement in that direction:
      http://cgblog.org/2011/01/31/bring-back-the-coast-guard-asw-mission/

      Even though the emergence of drug smuggling subs has given us another reason to pursue the capability:
      http://cgblog.org/2011/03/26/towed-array-sonar-a-tool-for-drug-interdiction/

      Still the over the side torpedo shot should not be our primary ASW weapon, that should be launching an ASW helo. The submarines’ weapons (both torpedoes and cruise missiles) substantially outrange the light weight torpedoes.

  10. “Best use would probably be to stand between an LPD or LHD and the beach to try to destroy or soak up any beach-launched ASMs sent at the amphib group. Not exactly an endearing mission for the CG parents back home, though I’m sure the Marines’ parents would be thankful…”

    The parents of those in the Army and Marine Corps were thankful when we on an 82′ patrolled between the beach and the hospital ship to act, if needed, as an RPG sponge . After all, part of the role of the Coast Guard is lifesaving. Who said it had to be our own?

    If a tri-tube is put aboard what SONAR gear would be used? The Coast Guard would also have to reinvent the STs.

    I missed Chucks earlier question. The Point Welcome had some 2000 rounds of 20mm fired it. Most missed. The next attacks came from two F4s. One armed with 250 lb. “lady finger” bombs and the other with CBU canisters. Neither F4 had a gun pod.

    All the bombs missed because of Chief Patterson maneuvering the boat. Only a few of the CBU bomblets hit the after fantail and started a minor fire. There was no major damage and after about a week of repairs she was back in service.

    • In spite of all that firepower expended, the little 82 remained substantially intact.

      If an attack on a US port was detected, could we get even that much support to help stop it? I have serious doubts.

  11. I feel it’s a poor excuse of a mission to be an enemy projectile sponge whether it was RPGs back in Vietnam, or beach-launched cruise missiles in the future. The WHEC/WMSL-type Cutter is the only viable platform the CG has which is of size and weight to be useful in a broad range of military missions to the Navy. However, the CG doesn’t build them to Navy survivability standards, does not plan for advanced weapons fit, and does not train/have in inventory qualified personnel to operate those weapons and their sensors… Perhaps if the CG would agree to do these issues, the Navy would help fund the large Cutter’s construction and training for their crews? Having these capabilities would certainly not be to the detriment of the CG using these Cutter’s for their traditional peace-time roles. I’ve mentioned several times that, historically-speaking, when the next war breaks out, we fight with what we’ve equipped ourselves during the preceding peace; often in terms of naval assets for up to a year. With the probable fast pace and heavy-damage weapons of a full-scale naval war in modern times, the CG large Cutters will be found useless or quickly sunk for little-to-no benefit. A situation which is avoidable.

  12. I agree that a LAMPS helo would be better than on-board sensors and weapons, but there are a few problems:

    Are there any SH-2Fs left? That’s the only useable LAMPs for the WMEC. (Will the WMSM have an H-60 capable flight deck? [not likely…]) How long and how much money to make an RPV LAMPS helo that would fit on the CG’s smaller flight decks? (Too long, and too much.)

    The vast majority of the problem is that there needs to be an organizational shift in the way CG command and DHS look at the problem. They don’t take into account history, as far as I can see. What foresight they do have (in the area of the Natl. Def. Mission) is clouded by the singular focus of counter-terrorism. No one seems to be recognizing a bigger picture. Non-government entities (al qaeda) are not the only viable threat, now that the cold war is over. PRK, Iran, China, & Russia still have some degree of hostility or competitiveness against us and are equipped enough to be serious threats, especially in the ASW area. (There are other threads on cgblog right now talking about Chinese agression in a couple areas of sea in the Western Pacific…)

  13. “I feel it’s a poor excuse of a mission to be an enemy projectile sponge whether it was RPGs back in Vietnam, or beach-launched cruise missiles in the future. ”

    Then please explain the purpose of the screening tactics in a fleet operation. I know, it is to warn but it is also to take the hits to protect the more valuable assets. I also remember the drawing (by Coast Guard combat artist Petty Officer Vestal) of a destroyer at Normandy firing on German gun emplacements. They were also to draw fire from the more important landing operations.

    I do not believe it is the sole mission to be a sponge for any weapon type, however, it is part of the purpose of the smaller vessels.

  14. Pingback: What Might Coast Guard Cutters do in Wartime? Part 2, Coast Guard Roles - CGBlog.org

  15. Pingback: What Does It Take to Sink a Ship, Illustrated - CGBlog.org

  16. Here is a bit more detail about what it took to sink USS New Orleans (LPH-11) an approximately 18,000 ton full load ship during a sink-ex in 2010. (The article http://www.japantimes.co.jp/text/nn20120528b1.html is trying to make much out of nothing, but it does show the amount of effort required to sink this unmanned medium sized ship.)

    “According to the U.S. Navy and Australian forces, the exercise lasted for about nine hours on July 10, 2010.

    “U.S., Australian and Canadian warships started by firing antiship missiles at the USS New Orleans, which were followed by missile attacks by U.S. and Australian aircraft and laser-guided bombing by B-52 bombers.

    “Finally, the six vessels from Japan, the United States and Australia formed up in single file. After an Aegis-equipped ship from the U.S. started firing, the MSDF destroyer Akebono fired a 76mm gun and the MSDF destroyer Atago fired a 127mm gun.

    “The USS New Orleans sank at 6:11 p.m. local time, about 40 minutes after the shooting began.

  17. Pingback: OPC, Design for Wartime, Build for Peacetime - CGBlog.org

  18. Bob Stoner gave me the link to a video of the sinking of the de-commissioned USNS Concord by a Royal Canadian Navy submarine, HMCS Victoria. (Thanks Bob)
    http://www.defensemedianetwork.com/videos/live-fire-sink-exercise/
    Other units may have fired at the Concord before the Victoria was allowed to administer the Coup de Grace. The degree of any previous damage is not clear, but we can see that the ship is riding high and light and essentially on an even keel. The torpedo hits the bow (time stamp 1:55). Not the best place to do the most damage, but even so, seven minutes later she is down by the bow with the main deck awash forward. After ten minutes she is stern high with the prop and rudder well out of the water. Eighteen minutes after the hit, she is completely below the surface.

  19. Got the following form a study I have added to the reference section, you can link to it there:
    Schulte, John C., “An Analysis of the Historical Effectiveness of Antiship Cruise Missiles in Littoral Warfare,” (pdf) September 1994,

    Iran-Iraq War (1980-1987)
    “In September of 1980, the Iran-Iraq War began. The major naval involvement was the so called Tanker War. It was conducted by both Iran and Iraq. The Tanker War was designed to stop the export of oil through the Arabian Gulf. Attacks concentrated on transiting unprotected oil tankers and freighters. Although there are no exact numbers of missiles fired and hits, reports through 1984 show 52 of 53 Exocet anti-ship missiles hit their targets, and 50 of the 52 hits detonated properly]. …Results of missile hits differ with the size of the vessel hit. Among smaller freighters/tankers of 13,000 to 30,000 tons displacement, a split of 20% sinking, 60% major damage, and 20% minor damage was produced. Of large tankers 70,000 to 300,000 tons displacement, 60% of the ships were heavily damaged, and 40% saw minor damage…”

    Unfortunately, the study did not indicate the number of target vessels that fell into either the “large” or “smaller” freighters and and tankers categories, but it can be inferred from the number of sinkings (7), that at least 35 were in the smaller range. The uncertainty stems from the possibility of multiple hits on a single target, but that does appear rare.

    It is reasonable to assume at least 15 large tankers were hit, and none were sunk. We might also assume at least 40% (those with minor damage), and probably many more, were not immobilized.

  20. Pingback: What Does It Take to Sink a Ship, Illustrated | Chuck Hill's CG Blog

    • In the US Navy, only submarines have torpedoes designed to shoot at surface ships. They are not likely to be in the right place when we discover we need them. Its hard to communicate with them, and they don’t move that fast, so yes, getting a coordinated kill is complex.

      • I am well aware of how fast SSNs are, only saying they don’t move fast enough to get from their patrol areas on the far side of the Oceans, back to the US when a cutter needs help sinking a ship. Frankly, I don’t think we could get the bureaucracy to grant permission for a sub to take out a merchant ship in peacetime in less than two hours. That same limitation applies to other forms of DOD assistance as well. Then there are communications delays and for aircraft– preparing the aircraft, loading it with the proper ordnance, briefing the pilot, transit and then will the pilot be able to recognize the target from the surrounding traffic?

  21. The Hamilton class used to each have 8 Harpoons. That provided much better stopping power than a 57 mm gun. Ideally, I’d like to have anti-ship missiles that could pin point a key vulnerability on a ship with the built-in warhead and include a payload bay (in the missile) to drop off a torpedo or sub-munitions. That way you could quickly hit the bridge, rudder, engine room, vulnerable electronics, etc of a big ship from a long way off, and if that didn’t slow it down (or prevent it from attacking) the torpedo coming less than a minute later certainly would. Or use two separate missiles and upgrade ASROC to drop an anti-ship torpedo if you need to engage from a distance.

    • Actually only USCGC MELLON ever had the harpoons fitted, and that was for sea trials, and I’m pretty sure that only 4 tubes were carried for those trials. The Harpoons were never actually fitted and carried in service by any of the other 378’s.

      • I have seen photos of 378s fitted with eight tubes. I have also seen photos with only four tubes and what looks like an extra large tube that I presume was just to provide an equal weight. I have also read that at least one sailed with the full eight, but it was not really important in the long run. They were equipped for eight, but they were removed. and in the last two decades we have not had a need for them–fortunately.

      • Really my point was that while missiles may good at damaging warships they are not particularly good at stopping large merchant ships, which is what the Coast Guard should be worried about.

      • Was on the Mellon Sep 89 to May 92, after the test shot, we carried 5. The CG only got so many from the Navy, not enough for each cutter to have 8 each.

  22. Pingback: Return of the Navy’s Tiny Tactical Torpedo: The Cutie II

    • Hi Chuck,

      I was a GM on a 378 (pre-FRAM) where we used the 5″/38 to sink a vessel. It took quite a few rounds to six the craft (about 180-200ft.) even though the FT’s were spot on the waterline. This is why I do not believe the choice of 57mm to be conducive to the CG performing the defense or high level homeland security missions. I have seen the You Tube videos of the 57mm rounds – not really that impressed. I wonder what a 5″/45 VT frag round would look like in comparison. A 5″ gun has dominance over a greater range and the availability of rounds with differing payloads to match the application is greater – especially if the CG does not have missile capability.

  23. Two new developments in torpedo technology.

    New battery tech (lithium-ion) allows relatively simple high performance propulsion (speeds over 50 knots and endurance of over an hour): http://www.navyrecognition.com/index.php?option=com_content&task=view&id=1556

    And a new torpedo that is capable of ranges of up to 140 kM. It can employ GPS, and can be launched not only from submarines and surface vessels but also from trucks at the shoreline or from containers. http://www.navyrecognition.com/index.php/news/naval-exhibitions/defexpo-2014-naval-show-daily-news/1560-video-atlas-elektroniks-seahake-mod4-heavy-torpedo-at-defexpo-2014.html

    The idea of these unconventional launch platforms for heavy weight torpedoes suggest several possibilities, one interesting, others troubling.

    The Coast Guard might use shore based torpedoes to engage a terrorist controlled vessel being used for something nefarious rather than hoping there is a well armed government vessel in the area capable of doing this. (Not that anyone is going to give the Coast Guard funding for such a program.)

    Ships off an unfriendly coast might be subjected to torpedo attack from any beach where a torpedo could be lowered into the water. Such attacks are actually more likely to sink ships than cruise missile attacks.

    Torpedo armed merchant ships can now attack shipping over the horizon using long range torpedoes targeted by UAVs or satellite. The source of these attacks would be much harder to determine than attacks using cruise missiles.

    These torpedoes could also be used to attack ships or other targets in ports or along the coast, using GPS navigation.

  24. Pingback: Warship Tour–Frigate Normandie | Chuck Hill's CG Blog

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  31. Iran shows off its hyper-high speed (200-250 knot, four or five times the speed of a conventional) rocket powered torpedo.
    http://atimes.com/2015/10/iran-unveils-new-super-hi-tech-torpedo-hout-at-show/
    These are probably unguided torpedoes (other than by gyro bearing), but unguided torpedoes obviously can still be effective (The Argentine cruiser General Belgrano was sunk by two WWII vintage torpedoes fired by a nuclear powered submarine). In fact, higher speed makes the torpedoes potentially more accurate because there is less uncertainty about where the target will be at the time of intercept, and the target will have less time to take evasive action.

  32. Iran reports the testing of a new heavy weight torpedo. The warhead size is actually slightly undersized for a heavy weight torpedo, but quite adequate for most purposes. Because of hydrodynamics, smaller warheads are almost as effective as much larger ones. http://www.foxnews.com/world/2015/10/13/report-iran-test-fires-advanced-torpedo-system-capable-striking-heavy-vessels/?utm_source=feedburner&utm_medium=feed&utm_campaign=Feed%3A+foxnews%2Fworld+%28Internal+-+World+Latest+-+Text%29

  33. Pingback: Ruminating on Homeports While Playing the Red Cell | Chuck Hill's CG Blog

  34. Along with a lot of other direction from DOD, Secretary Carter asked for a new light weight torpedo. This would of course likely be a better ASW torpedo, but perhaps its development would provide an opportunity to also provide a light weight anti-surface torpedo using components from either the new torpedo or from the components of the now obsolete Mk46 and Mk54 torpedoes. http://www.bloomberg.com/politics/articles/2015-12-17/carter-orders-navy-to-build-fewer-ships-spend-more-on-jets

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

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