Conventional Warheads On SLBMs?

An article from Bloomberg caught my attention as I was putting together the Daily Sub News report over at Ultraquiet No More. The article talks about a plan to put conventional warheads on some Sub-Launched Ballistic Missiles in place of the nuclear warheads that we can neither confirm nor deny that they currently carry. Excerpts:

"The Pentagon wants to spend up to $500 million through 2011 to replace nuclear warheads with conventional warheads on some submarine-launched ballistic missiles, according to budget documents.
"The purpose is to allow quicker preemptive attacks on deeply buried enemy command centers or stockpiles of weapons of mass destruction. U.S. submarines carry ballistic missiles that fly at supersonic speeds, faster than those launched from land- based silos or airplanes...
"...The fiscal 2007-2011 defense budget plan calls for building as many as 96 conventional warheads for installation on 24 of the Navy's roughly 336 nuclear D5 Trident missiles, according to a 33-page Dec. 20 memo signed by Deputy Defense Secretary Gordon England. Each missile carries up to four warheads...
"...This new strategy ``places the ballistic missile submarine on the front line of U.S. offensive capabilities,'' Arkin said. ``Trident missiles will be able to place a conventional warhead on target in only 12 minutes, far quicker than any other long- range weapon.'' Any strikes would be coordinated by a new joint-service unit that the U.S. Strategic Command set up in November at Offutt Air Force Base, Nebraska."

The article also discusses the important issue of notification of other nuclear-armed countries in the event we fire one of these conventional missiles.

I remember, back when I was a JO, working out how much kinetic energy an incoming ballistic warhead would have. I can't remember the exact number, but it's pretty big. (If you assume a 500kg warhead traveling at Mach 6, it works out to about 1000 MJ -- about 500 lbs of TNT.) Add a decent size warhead made of the right material, and you've got a pretty good ground-penetrating weapon.

One problem with this proposal, of course, is the cost; these would be the most expensively-delivered bombs in history. A Trident D-5 missile costs about $29M, and they're obviously not reusable. On the other hand that's a lot less than the cost of a plane you might lose going against strongly defended targets. And being able to put ordnance on target within a half hour of identifying it could be fairly useful in certain situations...

Plus, it'd be way cool, from a guy perspective, blowing up a Jihadi from thousands of miles away... I'm all for it.

Going deep...

Bell-ringer 2234 18 Jan: Lubber's Line had discussed this concept earlier; and, for the truly interested (or insomnia-afflicted), here's a 27 page Adobe document that covers the issue in much greater depth...