During the Cold War, the US Navy concluded that lightweight
torpedoes were largely ineffective against Soviet submarines, in terms of
achieving a kill. Even heavyweight
torpedoes were questionable and thought to require multiple hits to kill. Lightweight torpedoes were considered more of
an annoyance to Soviet subs than a lethal threat.
Lightweight torpedoes are a lethal threat only to small,
lighter built diesel subs.
Lightweight torpedoes are not a ship-sinking threat to
anything much bigger than a patrol boat and are not capable of sinking surface
ships, either merchant or naval.
That being the case, why is the Mk54 lightweight torpedo so
ubiquitous throughout the surface Navy?
Wouldn’t it make more sense for ships to mount heavyweight torpedoes?
Here’s a brief comparison of the Mk48 heavyweight and Mk54
lightweight torpedo characteristics.
Characteristics vary, of course, depending on the exact model but these
are representative. Note the lightweight
torpedo’s warhead weight and range deficiencies compared to the heavyweight
torpedo.
- Sinking merchant ships
- Sinking submarines
- Sinking surface ships
- Destroying maritime structures (oil platforms and such)
Is the small size of the lightweight torpedo to have ammunition commonality with the air dropped torpedoes carried by helicopters? As I understand it, the lightweight torpedo can be fired out of triple torpedo tubes and carried by ASW helos. The Kaman Seasprite was relatively small, as helicopters go - I can only imagine the difficulties it would have had in trying to carry a Mark 48.
ReplyDeleteDestroying maritime structures like oil platforms can create an environmental disaster. These oil platforms have no defenses. I see no sense destroying them. If the Navy wants to destroy oil platforms then the Navy first should build AAW and ASW warships and special vessels for clearing the sea from the oil products.
ReplyDeleteYou can't be serious? War is an exercise in environmental disaster! Do you have any idea how many gallons of oil were spilled in WWII? If environmental impact is your major concern then you're in the wrong war! This is simply not a concern.
DeleteYou might also want to review Operation Praying Mantis where we attacked various platforms.
It is very unfortunate that when any war ends, many say that they will never allow war again. In peacetime, nothing is done to prevent the outbreak of war or to make its conduct ineffective in any environment. When a war begins, the military suffers very heavy losses, civilians are mobilized into the army and industry to provide for the military. In wartime, military-industrial complexes are built and work there until the end of the war. They are built by civilians who became builders in the war. But as soon as the war ends, gradual demobilization occurs. Instead, army sappers and naval mine-clearing ships are rapidly decreasing in number, and demining of mined areas of land and sea has been going on for tens, if not hundreds of years. Worse still, the ruins are not restored as quickly. Ecological disasters are almost never eliminated at all. Two options. The first is to design ships in such a way as to prevent natural disasters and oil spills. The second is to have specialized ships that would clean the sea surface from oil. They should be legalized no worse than medical ships, so that no one could shell them and had no right to do so.
Delete"design ships in such a way as to prevent natural disasters and oil spills."
DeleteThis is patently absurd. Again, if environmental concerns are a major factor then you have to seriously question why you're in the war.
This has actually been tried and, generally, failed miserably. We've tried building Eco-friendly munitions and weapons and, invariably, they have worse performance than their original, unfriendly counterparts. Over the last few decades, we've banned highly effective corrosion control coatings for warships and are paying the price in rotting ships.
One of the major targets in any war, by any side, will be oil tankers (just as in WWII). Do you see some way to sink them without releasing oil? Absurd!
Commander of Naval Opinions I have one question. Look at the situation. It has been reported that Iran has mined the Strait of Hormuz lately. We know tha the US Navy retired its all Avenger class mine hunters. Also we know that the LCS are not able to search and destroy the mines. The question is how to search and destroy the naval mines? I see you know very well how to design AAW, ASW, anti surface warfare ships, aircraft carriers, carrier aircraft and so on. Sure you know what kind of warships I needed to deal with naval mines. How to project them, deploy and do the mission - search and destroy naval mines. You say that you did an ideal fleet structure for the Navy, but there are no mine hunter warships. There is no way to ignore this vital thing. Write an article and post it on your blog. It is very actually.
ReplyDeleteThere is evidence that Iran has mined the strait, only unconfirmed rumors that may have been planted by Iran as part of a propaganda effort. There have been no reports of any ship encountering any mine.
DeleteThat aside, I've discussed the concept of mine clearance at length throughout the blog. Search the archives and you'll find a great deal of information.
I left out minesweepers and the like from the fleet structure page simply for space considerations. I also left out oilers, cargo ships, replenishment ships, etc.
What tags or keywords are relevant to this theme? Please advise. I want to study this topic thoroughly.
Delete“All of this leads me to ask, why isn’t the Mk48 standard on surface ships?”
ReplyDeleteThe need is clear, but to state the obvious: because the USN, particularly the surface navy, clearly does not value the capability that having a fast, deep diving torpedo with the explosive capability to sink or heavily damage whatever it hits provides.
The Navy also does not value modern EW systems, heavy anti-ship missile, fast logistics ships, and a host of other weapons and systems needed to prosecute war. Some of this is due to budget reality (these wars of choice in Vietnam, Iraq, Afghanistan, Iran etc. have impact!), and some of it is due to ignorance bordering on criminal negligence. We bear the fruit of a lack of focus on mission/threat/method/end-state lasting for decades.
If I was a committee chairman in Congress, I would haul every living SECNAV and CNO into session going back to Vietnam, and ask why they requested funding for all these ships, which are supposedly designed around the weapons they carry, and within the operational constraints governing their employment?
GAB
When heavyweight torpedoes were a destroyer's primary armament, can you find any class of ship that carried more than 16? Its a 6 to one difference in size. Cut 2 x 3 mk 32s to get one round of mk 48? No way. Reality is our lightweight torpedoes have about double the warhead of the Russian ASW rockets they are still using. They are also shaped charge warheads. Water still doesn't compress so there is still that explosive adder under water too. Design a cruise missile with a MAD sensor and one torpedo to drop. Better yet, a VTOL fixed wing UAV that can do ASW from a destroyer size helo deck.
DeleteFor helo's that's why we have lightweight torpedoes and the soviets built hundreds of diesel electric subs.
ReplyDeleteAs for surface ships I guess it's because they are fire and forget? while the heavy torps are wire guided so no rapid manuvering after firing.
Plus the 3 shot launcher and 3 lightweight torps weigh just a little more than a single heavyweight torp so having multiple heavyweight torps in a launcher is a lot more weight which US ships already struggle with according to what you have wrote about it.
Lightweight torpedoes are a very niche weapon. Their target set is small, lightly built diesel subs and that's about it. As noted in the post, a heavyweight torpedo has many more uses and would, therefore, be much more useful.
DeleteAs far as weight, the added weight of a heavy torpedo over a light torpedo is insignificant if designed in from the start. The 3500 lbs of a Mk48 torpedo is nothing compared to the 10,000 tons displacement of, say, a Burke class destroyer.
A Mk48 is a fire and forget the same as a Mk54 when used at the same range. The Mk48 wire guidance is a useful option that expands the torpedo's effectiveness, not a limitation!
It would seem that the Mk 54 lightweight torpedo would be applicable for implementation with ASW helicopters or ASROC.
DeleteThe Mk 48 would be awfully heavy in those applications.
But how much of the weight of a Mk 48's 3,700 lbs is part of the 31+ mile range of the weapon?
Theoretically, the ASW helicopter, or the ASROC launcher, should be placing the torpedo fairly close to an identified enemy submarine.
Why not design a lighter torpedo that doesn't sacrifice warhead capability, but instead saves weight by reducing the maximum range of the torpedo once it is in the water and activated?
The SH-60s should be able to carry even a Mk 48, so a lower weight torpedo should be well within its lift capabilities.
And the ASROC needs to be revised to increase its range anyway, so why not build a new system that accommodates a heavier rocket that can carry a torpedo heavier than a Mk 54 but lighter than a Mk 48?
Lutefisk
That's some great thinking!
DeleteMH-60R isn't carrying a mk 48. The hard point used to connect the lightweight torpedo's is a 2000lb hard point, not that even that weight is relevant. https://www.aviatorsdatabase.com/wp-content/uploads/2013/07/MH-60R-Seahawk.pdf
Delete2 x Royal Navy mk viii torpedoes sank the General Belgrano in in 1982. This was an old style cruiser ex USS phoenix 1939 so armour etc I belive they have about 800 lbs warhead, so I would have thought 3 or 4 hits by a mk 54 should do some serious damage.
ReplyDeleteThe Belgrano was a forty year old, poorly maintained ship with a poorly trained crew sailing with all watertight doors open, according to reports. It was lucky to put to sea and not spontaneously sink!
DeleteThe Mk 54 lightweight torpedo has a warhead weight of around 95 lbs. Compare that to a heavy torpedo with 750 lbs warhead (Mk VIII) or whatever. I don't know exactly what torpedoes the RN sub had available.
IMHO, the only reason Navies have lightweight torpedoes is because helicopters can carry only lightweight torpedoes, and they are supposed to be the tool that can box a submarine and kill it. Lightweight torpedoes on a ship don't make any sense, but nor do heavyweight torpedoes. In any case, ASW works only in exercises, a submarine launching missiles from more than 50NM cannot be pursued.
ReplyDeleteYou don't study naval warfare, do you? As noted in the post, heavyweight torpedoes would be very useful for sinking merchant shipping, as one example.
Delete"a submarine launching missiles from more than 50NM cannot be pursued."
I almost don't know where to begin. Submarines have no magical targeting capability from 50 miles away. In fact, their long range sensors are fairly limited: zero field of view and only vague acoustic indicators at that kind of range. No target, no launch.
Surface ships will have helos ranging out from the ship, searching for submarines and between the ship's sensors and the helo's they have a very real chance of detecting a submarine. If we would develop a VL-ASROC-ER, we'd have a useful combination of sensors and weapons.
This is not to say that ASW is easy. It's not! But to think a submarine has some kind of magical capability is ignorant.
You need to study naval warfare tactics and capabilities.
At about 3,700 pounds each, how many Mk 48 torpedoes do you think a Romeo helicopter could carry?
Deletezero as designed. an S model could sling load a few.
DeleteNot just US, China also has both heavy and light torpedoes. AJC015 paraded last year is a long range rocket assisted light torpedo. Analysts estimate its range between 100 to 200km. It works with unmanned submarines - unmanned submarines to find opponents' submarines, send information back, AJC015 is then fired from a ship's VLS. Heavy torpedoes are too heavy for this kind operation. Multiple AJC015 can be fired to sink a large nuclear powered submarines.
ReplyDeleteIn the same parade, China displayed two new unmanned submarines. There is no information on their power system. Some guess it is electrical or hydrogen fuel cell. Either is very quite, quieter than any manned submarines. Hydrogen fuel cells give this kind submarine much longer under water range than battery. China has mature technologies on both.
https://www.asianmilitaryreview.com/2025/09/china-unveils-a-host-of-new-naval-capabilities-in-beijing-parade-foc/#:~:text=There%20was%20also%20an%20underwater,YJ%2D20
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