| From: | Sommers sommers@*****.umich.edu |
|---|---|
| Subject: | Shipping (was Re: the value of education) |
| Date: | Thu, 15 Jul 1999 21:33:26 -0400 |
>On Thu, 15 Jul 1999, Sommers wrote:
>
> > In a lot of ways a stealth ship would be a lot cheaper than a fighter.
>
> The hell it is. Have you ever looked at how much it costs to
>build a ship? It's ridiculous.
Sorry, you are absolutely right. A stealth aircraft costs on the order of
30-60 million for a fighter class. On the other hand, a stealth ship
compares in job function more readily to a bomber for function and weapon
carrying ability. The B-2 costs about1 billion a copy, although a new
design might be cost less now that the original proof-of-concept is now
done. A frigate sized ship runs in the several hundred million range if I'm
not mistaken, so would compare to a bomber
> > It can carry a LOT more ordinance internally than an aircraft.
>
> Yes, but in order to make it suitably stealthy, it had to be a
>very small ship, which in turn cuts down its payload. Further, it's got
>to get it to where it can be useful. Stealth technology is all well and
>fine, but as soon as you launch missiles or torpedoes, you've likely been
>detected. Remember, we're talking about attacking other groups of ships.
>At least aircraft can high-tail it outta there. A surface ship is much
>slower, and is resultingly more vulnerable.
Part of that depends on what your definition is for "suitably stealthy."
The Sea Shadow was a prototype that was supposed to demonstrate the concept
of stealth in a ship, and as a specialized type of air-defense vessel. It
would be part of a fleet that provided air-defense, so it was going to be a
target anyway. The point was to make it as difficult as possible for those
aircraft to hit it. AFAIK it was never designed to attack surface ships at
all.
> Also, it's pretty much a given that the less time you spend in
>your enemy's sensor envelope, the less likely you are to be detected. An
>F-117 flying at 400 knots is going to be exposed to enemy air-search radar
>a hell of a lot less time than a Sea Shadow doing like 20 knots (trying to
>be sneaky)
True as far as it goes. But the F-117 is supposed to be an offensive weapon
that is used to take out air-defense systems and other hard targets. It was
going into enemy territory to take out targets, so hid it as much as it
could. The Sea Shadow was a defensive weapon system that would be used to
form an air-defense screen. It made its own territory; its job would be to
deny an enemy entry into that airspace. Hiding makes it more effective in
that job, but its stealthiness is supposed to prolong its life until it can
knock out the attacking aircraft.
> > Thermal emissions are a smaller on a ship than on an aircraft.
>
> Don't bet on it. It may not be as hot, but in terms of actual
>heat it's much higher. The energy it takes to move a ship at decent
>speeds is pretty staggering. Granted, you can vent a lot of your waste
>heat into the water, but then any overhead thermal imaging system is going
>to see your heat plume and follow it to you.
Looking at an article from the April 97 issue of Popular Science about the
Sea Wraith ship being designed for the British. It can run at 26 knots with
gas turbines, and uses a heat exchanger to feed waste heat back into the
incoming air to improve fuel efficiency and reduce thermal emissions. The
thing also has a system that sucks up cold sea water and produces mist
around it to both hied it and reduce the thermal signature further.
> > The SWATH design is faster than a sub AFAIK.
>
> Depends on who you want to believe. Like I said, for the
>application that the Sea Shadow was designed for, I still think that
>stealth aircraft launched from a carrier are a much more economical way to
>go. Hell, both technologies (stealth planes and carriers) are already
>well developed, so you cut your R&D down to a matter of figuring out a
>good way to launch and recover the planes. Much cheaper.
For power projection and pinpoint attacks, I agree with you that carriers
and stealth fighters are much better. The new F/A 17 EF variant has a lower
radar cross section, and the new joint tactical fighters that might be made
mid next decade will be even better.
For pure destructive force, the arsenal ship, or converted ballistic
missile subs seem better for pure destructive force. The stealth ship would
be the way to go for anti-submarine and anti-aircraft duties, as well as
special forces work.
Sommers
Insert witty quote here.
