Raytheon's rolling airframe missile, Ram
is a lightweight supersonic weapon
designed to destroy anti-ship missiles
and other airborne threats to a ship at
close range typically less than 10 miles. Much like a bullet fired from a rifled
barrel ram blocked two rolls around its
longitudinal axis as it flies. The missile uses the rolling motion
generated by its tail fins to change
direction on a dime.
It's guided by a radio frequency RF infrared seeker to intercept threats. Lasers have gotten all the hype recently
thanks to their potential to create
effective cheap defensive systems for
ships. But rams have been doing the job since
the early 1990s and are currently
deployed on 165 different vessels across
eight different navies.
They form part of a three-layered ring
of close in defense for certain U.S Navy
ships. the outer defensive ring is handled by
the sea sparrow, a ship defense missile
with a range of approximately 27
nautical miles. Inside 10 miles rams take over. The last
line of defense as the venerable phalanx
20 millimeters radar guided gatling gun
or CIWS close in weapons system which
takes on threats inside two miles.
"As advanced targets are coming in closer
and maneuvering much faster, we need the
performance in the ram block 2 to be
able to be able to engage them," says Alan Davis raytheon's director of short-range
defense systems.
The new ram block 2 has a more powerful
rocket motor and improved control
surfaces which make it faster and more
maneuverable than its predecessor. Davis says the added power not only
makes the ram block too faster, but also
allows the missile to maintain its speed
during energy sapping high G turns
needed to intercept targets.
The block 2 has two and a half times the
range of the block 1 ram which has a
reported effective intercept range of
about 5.6 miles. The latest ram also has an improved
seeker package with greater sensitivity, allowing it to detect anti-ship missiles
that employ low probability of intercept
receivers. The second piece of the improved defense
package is pairing the ram block 2 with
cram. Cram is a hybrid system consisting of an
11 round rolling airframe missile
launcher mounted on a phalanx chassis
and radar unit.
The combined gatling gun ram launcher
unit uses the phalanx high resolution
radar for initial tracking and fire
control. The march test on the porter marked the
first time that the block 2 Ram and Cram
have been integrated on a U.S Navy
destroyer. The ranges of the Ram block 2 missile
and 20 millimeters rounds of the phalanx
gatling gun overlap. While the Phalanx is a crucial last line
of defense the Ram block 2 cram combo
gives ships, particularly us navy
destroyers which haven't previously had
ram capability a better chance of
defeating threats before they get so
close that a gun becomes the only choice.
It gives you breathing room says ed
lester cram program manager and former
commander of the guided missile cruiser
uss leyte gulf. When you're on the bridge of a ship or
in the combat information center and bad
things are happening all you want is
more time, that's what the missile gives you over
the gun lester adds that the live fire
testing on the USS Porter was successful
and the effort went from concept to
reality in just 12 months.