supply ship by helicopter. This vertical replenishment
capacity is about 30 lifts per hour per helicopter, with
a maximum load of 6,000 pounds. But that is reduced
to 15 lifts per hour per helicopter at night, which operationally is the optimal time to conduct UNREPs to
take advantage of a period when the carrier’s flight
operations might be reduced or secured.
A Heavy UNREP station will be able to transfer
6,000-pound loads at around 50 lifts per hour.
No changes to the T-AOEs’ refueling stations are
planned. But the JP- 5 system on CVN 78 will be
upgraded to receive fuel at the resupply ships’ maximum delivery rate.
Installation of the Heavy UNREP system will not
affect the T-AOEs’ ability to service the current carriers
or other combatants.
Currently, there are no plans to upgrade any other class
of ships with the Heavy UNREP system, NAVSEA said.
One of the challenges of the UNREP process is the
need to maintain a constant distance between the two
ships to minimize the strain on the transfer equipment
and the risk to material and personnel. That can be difficult during higher sea states and stronger wind conditions, which can force the ships off the required course.
NAVSEA said the Heavy UNREP system will have
nothing new to aid in station keeping during the
resupply process, but will benefit from decades of
proven performance by the current STREAM system in different
“The Heavy UNREP system, like
STREAM, is designed to passively
accommodate ship motions and
course deviations, as opposed to
actively responding to some feedback,” Barnard said. “Passive compensation has proven extremely
reliable and effective.”
The new system also will
improve the safety as well as the
speed of transfer by dramatically
improving the operator’s control of
the load during all stages of the
evolution, he said.
“Currently, we lose a lot of time in
transfer as the operators on both
ends very carefully ‘land’ the load,
both on the high-line and to the
deck on each ship,” Kaskin said.
“The new system will automate
some portions of the transfer and
provide greatly improved variable
speed control over other portions.
This allows us to make much greater
use of the additional speed in the new system.”
But ONR is funding experiments by Torrey Pines
LOGIC Inc., San Diego, of a system that would improve
communications between the supply and receiving ships
and the ability to maintain the required separation.
The developmental system, designated AN/PAQ- 6
— or 6-PAQ — would replace the phone connection
and distance-reference line system now used during
UNREP with a 10-channel wireless voice and data
communications system linking bridge to bridge and
station to station. It also provides highly accurate,
instantaneous information on distance and rates of
movement between the two ships, using eye-safe
infrared LED emissions.
Leo Bolfson, a Torrey Pines LOGIC representative,
said the system was tested with small craft at speeds
over 40 knots. ONR has funded continued development for three years that will include full Navy tests,
NAVSEA, specifically the UNREP Systems Division
at the Naval Surface Warfare Center’s Port Hueneme
Division, Calif., is leading the development, prototyping and testing of the new delivery system. After the
command has verified that the system meets requirements, including reliability and safety, the Navy will
release a detailed specification for competitive bidding,
NAVSEA said. ■
High seas splash on the hangar deck of the Nimitz-class aircraft carrier USS
Abraham Lincoln during an underway replenishment with the Military Sealift Command fast combat support ship USNS Rainier July 25 in the North Arabian Sea.