ASROC or Helicopters?

Helicopters are generally recognized as the best ASW platform above the surface; another submarine being the best ASW platform below the surface, of course.  Unfortunately, this leads to the widespread mindset that every ship must have helos embarked for ASW.
 
The problem with the concept of helos on every ship is that the aviation element of a ship is shockingly expensive.  A helo needs a flight deck (something on the order of 80ft x 50ft), hangar (another 80ft x 50 ft), dedicated weapon magazines, fuel storage, maintenance shops and parts storage, pilot and maintainer berthing (and food, water, etc.).  The extra 160ft x 50ft of ship size means more power is needed to move the ship which means bigger engines which requires more ship size which …  You get the idea.

Another problem is that helos are only sporadically available, being notorious for needing maintenance at inconvenient times.
 
Sure, there’s a penalty to be paid for putting helos on every ship but, really, what’s the alternative since we need ASW?  Well, one alternative is ASROC (anti-submarine rocket).  ASROC began back when submarines still had to get fairly close to their target in order to attack.  Today, submarines can attack with torpedoes or missiles from far beyond ASROC range (vertical launch ASROC has a range of around 12 nm). What’s needed is a much longer range ASROC, perhaps on the order of a hundred miles.  Given that we have thousand mile cruise missiles I can’t see any problem with developing a hundred mile ASROC. 
 
In the past, ASROC used arm launchers, box launchers, and common VLS cells.  The flexibility in launch mechanism means that some kind of suitable launcher can be placed on any ship tasked with ASW.
 

A long range ASROC would offer a viable alternative to the incredibly expensive helicopter on every ship.  Note that this does not mean we don’t need ASW helicopters.  We do!  We just don’t need them on every ASW ship.  Helicopters should be reserved for true destroyers (of which there are none in the world), ASW carriers, and, perhaps, a specialized convoy escort frigate.  They should not be on corvettes, general purpose frigates, and cruisers (meaning Burke/Zumwalt “destroyers”).  Want to build a cheaper Burke?  Eliminate the helicopter!

Mk16 ASROC and Harpoon Launcher

Before the advent of VLS, missiles were launched from some type of arm or box launcher.  One such launcher was the Mk16 ASROC/Harpoon box launcher.  Let’s take a closer look at the launcher.

 

The Mk16 was an 8-cell box launcher that could rotate and elevate to provide complete hemispherical coverage (minus superstructure cut outs, of course).  The launcher was sized for ASROC (RUR-5) and Harpoon missiles.  Early systems had no reloads while latter versions mounted on Spruance, Knox, California, and other classes had up to 16 automated reloads.(1)

Mk16 Launcher

 

We’ve previously discussed the relative merits of single arm launchers and VLS systems (see, “VLS Versus Arm Launchers”) and the Mk16 ASROC launcher benefits fall into the single arm category.  Trainable launchers offer some advantages over vertical launchers, as we’ve noted. 

   

In addition, one of the major benefits of a box launcher is that it has no significant deck penetration into the hull as opposed to VLS and arm launcher systems which consume large volumes of internal hull space.  Of course, the reloadable versions of the box launcher require internal volume for storage of the reloads.

 

Another benefit of the box launcher was the ability to mix loads of ASROC and Harpoon.  The reloadable version of the box launcher offered a maximum of 24 Harpoon missiles which far outguns any Navy ship today.  Even a reasonable mix would offer, say, 8 ASROC and 16 Harpoon.

 

It is worth noting that today’s VLS still does not support Harpoon anti-ship missiles although the Navy is looking at adapting the LRASM anti-ship missile to vertical launch.  Given anticipated budget constraints, that may or may not come to fruition and Navy interest appears to have greatly abated.

 

Before one scoffs at the outdated technology of a box launcher, it should be noted that the Navy, today, employs box launchers for Sea Sparrow missiles (Mk29 launcher) on carriers and RAM launchers, which are just a smaller version of a box launcher, on a variety of ships.  Similarly, the Army uses box launchers extensively.

 

Mk29 Launcher and RAM Launcher in Background

Just as we’ve previously noted that the arm launchers have certain advantages over VLS systems, box launchers share some of the same advantages such as being able to train directly at the threat and launching horizontally which eliminates the vertical tip-over and gets missiles on the threat faster.  With that in mind, it is worth considering a wider application of box launchers, possibly with the earlier combination of Harpoon and ASROC missiles.

 

ASROC Launch

 

 

Launcher with Reload Hatches in the Superstructure to the Left

 

Launcher Behind 5" Gun

 

 

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(1)http://www.seaforces.org/wpnsys/SURFACE/RUR-5-ASROC.htm