The U.S. Navy Goes on the Prowl for a Longer-Range Torpedo
A ‘Torpedo Advance Propulsion System’ will let submarines shoot from much farther away
by ROBERT BECKHUSEN
The attack submarine is one of the dangerous naval combatants in the world owing to its stealth and ship-killing torpedoes. But limited range has long been the torpedo’s major drawback. Unlike a missile which travels through the thin atmosphere, a torpedo must fight harder to reach its target.
As a result, navies spend billions of dollars finding ways to prevent hunter-killers from getting close to their valuable surface ships. And to give their own submarines a better shot, they find ways to add range.
Now the U.S. Navy is researching how to significantly boost the range of its torpedoes starting with the Mark 48, according to an August request for information from the Office of Naval Research. If successful, America’s subs could get a lot more lethal.
The sailing branch has not yet awarded a contract for the research. However, the Navy wants to create a prototype “extended range weapon” based on the Mark 48 within two years — relatively quick for a project of this type.
The Mark 48 is a 19-foot-long torpedo with a 650-pound high explosive, proximity-fused warhead. More specifically, the Navy wants to upgrade a newer version called the Mark 48 ADCAP Mod 7 CBASS, which has a jumble of upgrades to make the torpedo quieter, smarter — it has more sonar bandwidth — and better able to avoid enemy countermeasures.
Submarines and their weapons are some of the Navy’s most closely guarded secrets. For this reason, the precise range of the Mark 48 is classified, although according to the Navy it is “more than five miles” at a speed of “greater than 28 knots.”
“Incredibly powerful, incredibly accurate, shot well with the right tactics and it’s nearly impossible to escape,” Capt. Emil Casciano said in a recent video by the U.S. Navy’s Undersea Weapons Program Office.
To extend the Mark 48’s range will take complex engineering, but it’s a conceptually simple problem. Basically, the Navy needs to replace the engine or swap out the pumps and combustion chamber for more efficient versions — making the torpedo run … slower.
Another possibility is replacing the battery with a silver-oxide aluminum battery seen in long-range Italian Black Shark and French F21 torpedoes, as each has an estimated range of more than 30 miles. A single French company, Saft, manufactures these batteries for naval use.
It’s unknown if there are new threats pushing the Navy to seek a longer-range torpedo now. The Office of Naval Research wants the prototype soon, but the U.S. Navy’s unquestioned dominance of the undersea domain is still a fact.
The United States has 52 attack submarines. Russia has 32 but the actual deployable number is likely significantly lower due to years of poor maintenance. For sure, Russia is building state-of-the-art Severodvinsk-class attack submarines, and the second of her class, Kazan, is due this year. But the Kremlin will never build more than a handful.
China is a different story with 58 attack submarines — almost all loud diesels limited in range and speed — which will grow to between 69 and 78 by the end of the decade.
Yet even Beijing’s large submarine force is best suited toward attacking surface ships, and its few nuclear-powered attack boats are on the noisy side. Nor do Chinese surface ships make for effective sub hunters, as they typically use medium-frequency sonars which are less effective than towed arrays.
Beijing also lacks other goodies for hunting submarines, such as adequate numbers of ASW helicopters and maritime patrol planes. In fact, anti-submarine warfare is one crucially important element of naval strategy which Beijing has neglected — opting instead for avoiding enemy submarines, particularly in deep water.
China would prefer to fight a limited war near its coasts for more limited ends.
“All this means that China’s current SSNs are almost certainly incapable of performing effective [anti-submarine warfare] against their much quieter potential adversaries,” U.S. Naval War College professor William S. Murray wrote in China’s Near Seas Combat Capabilities.
But those are circumstances in which the U.S. Navy would want to press its advantage to the fullest extent possible. A longer-range torpedo would be a good start.