Failure of a small cam pin can cause
significant damage to the Phalanx ammunition handling system. MTTC is working
with the Navy and the original equipment manufacturer to re-design a more robust pin.
February 12, 2001; Louisville, Kentucky: There are currently 320 Phalanx Close-In Weapons
Systems in the U.S. Navy fleet. It is a complex system for countering low
flying anti-ship cruise missiles and small surface craft. Phalanx uses a 20mm
Gatling gun firing 3000 to 4500 rounds per minute. The M61A1 gun system that is used was
adapted from the existing gun used in fighter aircraft. As a result, it was not designed
to withstand the exposed environment seen on surface ship installations. The very high
rate of fire requires a very complex ammunition handling system (AHS) with many moving
parts, all of which have to be precisely timed. For these reasons, the AHS has been one of
the high failure items in Phalanx. To make matter worse, when a single part fails in
operation, it often leads to cascading failures in other parts of the AHS. The cost of
replacement parts can easily exceed tens of thousands of dollars.
One of the primary root causes of AHS destruction is
the failure of the Actuator Cam Pin. Until recently, the only way to reduce the Cam Pin
failure rate was to exercise the AHS and religiously perform preventive maintenance. Even
with careful maintenance, the fleet continues to experience at least 10 major AHS failures
a year. The very small Cam Pin (3" long, 1/2" diameter) requires a redesign to
enable more robust operation. It must be alternate and interchangeable with the existing
pin to enable a low cost fleet introduction.
MTTC is working with the Phalanx In-service
Engineering Agent at the Naval Surface Warfare Center, Port Hueneme Division, Louisville
to have the original equipment manufacturer, GDAS/Burlington VT, to redesign the cam pin
and produce several prototype parts that can be used in system testing.
All MTTC / Navy Fleet Maintenance Projects