SW/ASW Lessons

Submarines have historically had a huge impact on naval and merchant shipping and operations that goes beyond just tonnage sunk.  Naval operations, in particular, have been greatly affected by the mere threat of submarines despite a relatively lesser impact, in terms of tonnage of naval vessels sunk.  Historically, the submarine threat to naval vessels has been serious but manageable.

Today, though, modern submarines with long range, devastatingly powerful, high speed torpedoes have been accorded an almost invincible reputation by many.  On the other hand, some, a minority, to be sure, argue that modern anti-submarine platforms and weapons will make short work of submarines who can’t cope with fleets of helos and fixed wing sub hunters in addition to ships packed with sonar, towed arrays, signal processing computing power, and smart anti-submarine torpedoes  all backed by myriad types of airborne and satellite surveillance plus SOSUS type sensor deployments.

What is the reality of modern submarine warfare (SW) and anti-submarine warfare (ASW)?  Where does the truth lie?  Well, the SW and ASW fields are probably the least open in terms of authoritative public statements of capability.  Thus, anyone who hasn’t served in SW/ASW probably has little basis for any credible claims regarding SW/ASW performance.  Those who have served and have some knowledge rarely discuss it publicly and then only in general terms.

Having just stated that very few people have the background and credibility to authoritatively discuss SW/ASW, ComNavOps is now going to do just that?!  Actually …   No. 

Instead, we’re going to examine the history of modern SW/ASW for actual lessons and see what we can learn.  Unfortunately, few documented instances of modern SW/ASW exist.  Still, we’ll work with what’s available.

Probably the best example is the Falklands War.  As described in Harper’s report (1), the following submarines took part in operations for their respective sides.

British SW forces consisted of,

(2) Swiftsure class nuclear submarines (Spartan, Splendid)

(3) Valiant class nuclear submarine (Conqueror, Valiant, Courageous)

(1) Oberron class diesel submarine (Onyx)

British ASW forces included 12 ships, 6 submarines, and over two dozen helos.

Argentine SW consisted of,

(1) Type 209 class diesel submarine (San Luis)

Argentine ASW did not really exist in any meaningful way.

Let’s look at specifics of SW operations.  The San Luis claimed to have conducted three torpedo attacks. 

1 May – Attacked medium sized warships using sonar identification and targeting only. The ships were the H.M.S. Brilliant and the H.M.S. Yarmouth. The attack failed and the sub was, in turn, attacked for 20 hours with depth charges and at least one torpedo.

8 May – Attacked a submarine. The attack failed although an explosion was heard.  Presumably, the torpedo exploded against the seabed.

10 May – Attack on two destroyers, the H.M.S. Arrow and H.M.S. Alacrty. One torpedo was launched.  The attack was unsuccessful, however, an explosion was heard on the correct bearing 6 minutes after firing the torpedo.  Arrow later found her towed countermeasure was damaged which was taken as evidence that the San Luis’ torpedo had been successfully decoyed.  The second ship was not attacked because it had moved out of range in the intervening time.

British submarines, in turn, sank a WWII era cruiser.

The conclusions are fairly obvious. 

(1) Submarine SW operations were remarkably ineffective. 

The San Luis attempted three attacks, largely unhindered by ASW efforts, and achieved zero success.  The British sank the Argentine cruiser but achieved nothing further despite having six subs in theatre.  To be objective, the cruiser appeared to have no meaningful ASW assets protecting it and was more of a live fire exercise than an example of modern SW.  Also, to be fair, the British rules of engagement probably limited their submarines from accomplishing more.  The ROE’s were intended to prevent friendly fire incidents but that simply points up the difficulty in target identification during SW.

(2) ASW operations were remarkably ineffective and achieved what limited success they had only in passive ways. 

It is doubtful that the British ever held contact on the San Luis despite a multitude of ASW assets actively searching and the submarine approaching to within torpedo range on three occasions.  The only ASW success the British achieved was with passive torpedo decoys and even then the success was only realized in a delayed fashion when the decoys were recovered and found to be damaged.  In short, an entire fleet of ASW assets was unable to locate a single submarine despite the sub conducting three attacks and thus being in near proximity.

(3) Submarines exerted an influence far beyond their actual impact. 

The Argentines completely ceded the surface naval contest due to the mere threat of submarines after the sinking of the cruiser.  The British expended an enormous amount of effort attempting to counter the submarine threat and their movements and operations were greatly influenced by the ongoing submarine threat.

Let’s move on to the example of the Chinese submarine that surfaced in an American carrier group.  As the story is reported, a Song class diesel-electric submarine surfaced inside the USS Kitty Hawk group within 5 miles of the carrier on Oct 26, 2006.  US escorting forces and aviation assets failed to detect it until it surfaced.  To be fair, the carrier was undoubtedly not conducting wartime levels of ASW.  Still, operating near China, the carrier group should have been maintaining a vigilant level of awareness and yet failed to detect the sub – a sub that is of an inherently quiet type but not generally thought to be world class.

These are the only relevant real world SW/ASW examples that I’m aware of.  Not much of a database to draw lessons from, admittedly.  That said, modern SW may be less effective than is generally assumed.  Friendly fire concerns will be a major concern and impediment to SW.  Conversely, modern ASW appears to be only marginally effective, at best.

Please note that this post is not an opinion piece.  It’s simply an observation of the very limited real world operational experience that has been made public.  Whether the conclusions would hold across other navies, platforms, and scenarios is highly debatable.  At the very least, though, the data needs to be considered and factored in to SW/ASW discussions.  To blindly claim that modern submarines are invincible or, conversely, that modern ASW is lethally effective is to ignore the available evidence.  The wise student of SW/ASW would do well to exercise a healthy degree of self-doubt about their position, whatever that might be.

(1) Naval War College, Submarine Operations During the Falklands War, LCdr. Steven R. Harper, USN, 17-Jun-1994