Faster, Safer, Heavier, More Reliable
Port Hueneme Moves Forward On Heavy UNREP
By MARVIN MILLER
Marvin Miller is manager of the Underway Replenishment Department at the Naval Sea Systems Command, Port Hueneme Division of the Naval Surface Warfare Center in Port Hueneme, Calif. In 1985 he received the Navy League's Robert M. Thompson Award for Outstanding Civilian Leadership.
"... All time spent in replenishing was time lost in combat. Sometimes it was most important that the carriers being replenished should get back into their combat area as soon as they possibly could. This is when I had impressed on me the value of time. No commander can ever tell what a few minutes might mean in the future."
Adm. Arleigh Burke in a letter to the author 30 October 1981
When the fast combat support ship USS Seattle first deployed with the U.S. Sixth Fleet 32 years ago, it marked the transformation of the U.S. Pacific and Atlantic Fleets from a time-consuming, jury-rigged, World War II underway replenishment (UNREP) system to a planned "anywhere ... anytime" system. That system, virtually unchanged, remains in service today, more than three decades later.
The transformation to the "anywhere ... anytime" system was initiated by Adm. Arleigh Burke in 1957 when he was not quite halfway through his six years as chief of naval operations. His goal was to minimize the time ships had to spend away from combat because of replenishing.
During World War II, Burke knew, more time was spent by task forces sailing to an UNREP rendezvous, replenishing, and returning to the strike area than they spent conducting strikes. During the Korean War, Burke experimented with various ways to reduce time out of combat for replenishing. At one time, he was commander of a cruiser group providing fire support to South Korean forces under heavy attack. His ship was running low on ammunition, so he directed an ammunition supply ship to come closer to shore and, while still underway, start replenishing the gun batteries at one end of his flagship while the cruiser continued firing from the other end.
A Question of Affordability
The Navy still needs an "anywhere ... anytime" UNREP system, but operational requirements have changed significantly since USS Seattle first deployed. The significantly smaller 21st-century Navy must have a better system because time away from combat spent replenishing is even more critical today. For that reason, today's expeditionary forces cannot afford:
the increased time needed to rearm aircraft carrier large-surge loads. The nuclear-powered aircraft carrier USS Nimitz several years ago demonstrated the tremendous ordnance expenditures required for maximum around-the-clock sorties.
the time to wait for the calmer seas necessary to transfer heavier loads such as aircraft engines or large missiles. The current UNREP System has a 4,000-pound helicopter vertical replenishment (VertRep) transfer capability and a 5,700-pound sea state 5 tensioned wire rope highline transfer capability. A special jury-rigged highline procedure will allow the transfer of loads up to 10,000 pounds, but only in sea state 3 or less.
to risk collisions that sometimes occur when a close ship separation is required to transfer loads greater than 5,700 pounds.
Last year Sea Power featured an article entitled "Logistics Takes Higher Priority in Navy Planning." That article discussed an UNREP revolution sponsored by the Office of Naval Research (ONR) under the Future Naval Capabilities (FNC) program. At that time the Expeditionary Logistics Project in the FNC program focused on following three product lines, or enabling capabilities, for sea state 5 underway replenishment: (1) the transfer of 20-foot commercial containers; (2) the rearming of Vertical Launch System (VLS) missiles; and (3) doubling the current sea state 5 cargo-transfer rate. The notional "customer" for these product lines would be an expeditionary force consisting of carrier battle groups, amphibious ready groups, and sea-based Marine Corps MPF (Maritime Prepositioning Force) squadrons.
The Office of Naval Research requires the customers for the FNC program to commit in advance to funding the transition of the new product lines from an early ONR demonstration phase to a production-ready status before ONR itself can start funding the development process that would lead to a full-scale demonstration.
Of the three product lines, only the increase in the cargo-transfer rate has been funded to date. The start of a product line to transfer UNREP commercial containers has been deferred at least until a concept of operations for sustaining an Expeditionary Sea Base is developed by the Navy and the Marine Corps.
Resources and Requirements
The start of a product line to double the cargo transfer capability is fully underway, though; that product line has been officially designated the Heavy Underway Replenishment (Heavy UNREP) System. The resource and transition sponsors for Heavy UNREP are the Strategic Mobility & Combat Logistics Division (N42) in the office of the chief of naval operations (OPNAV) and the Program Executive Office for Expeditionary Warfare (PEO EXW). The criteria for developing the Heavy UNREP product line were negotiated between ONR, N42, and PEO EXW. The negotiations focused on, among other things, costs, schedules, the specific technologies that would be developed, and the capabilities expected to be demonstrated at sea.
Certain traditional UNREP requirements will be included in Heavy UNREP:
Minimize the amount of machinery installed on combatant ships that is required only for UNREP;
Ensure that the new system is fully interoperable both with warships and with "legacy" UNREP ships that use the current UNREP system; and
Package ordnance and stores, whenever feasible, so a unit load is within the lift capability of VertRep helicopters.
Specific requirements for the new Heavy UNREP System include:
Double the current rearming rate (ordnance throughput);
Reduce UNREP manpower; and
Increase ship safety during UNREP.
The Underway Replenishment Department of the Naval Sea System Command's Port Hueneme Division of the Naval Surface Warfare Center has been tasked by ONR to develop the Heavy UNREP Transfer System. Port Hueneme designed both the current Underway Replenishment System and, later, the product line of Navy Standard Underway Replenishment machinery that is now installed on 85 percent of the UNREP ships in the Combat Logistics Force (CLF). In addition, Port Hueneme has been the in-service engineer for the current UNREP system since its fleet introduction and has been designated the Navy's UNREP Center of Excellence, and is thus well-prepared to manage the 21st-century UNREP technology shift.
Ordnance Times Four
The reason why the Navy must shift from manual to automatic operation is to achieve the doubling and potentially quadrupling of ordnance throughput during UNREP. In addition to the major increase in transfer rates expected, there also will be a requirement to transfer ordnance loads longer distances so ships can UNREP at wider and safer ship separation.
The current Port Hueneme manual operating system has been reliable for over three decades, so the challenge for automating the new system is to minimize complexity. The Navy wants it to work when needed and to perform as planned. Minimizing complexity and still producing an efficient high-performance UNREP transfer system requires a great deal of innovative technology, but is preferable to creating a more complex system.
Ever since the "beans, bullets, and black oil" UNREP system was invented, out of necessity, late in World War II, UNREP has been an all-hands evolution. Instead of machinery, ships still routinely use many Sailors to handle the rigging and to move the cargo. Moreover, all hands have almost always been available, even in major wars, because the Navy's combatant ships usually would leave the combat area to rendezvous with the CLF ships in a secure location to conduct UNREP.
Future expeditionary forces may have to replenish in the combat area, though. In addition, crew sizes are being significantly reduced, on many ships, so there may well be no reasonable alternative to manpower other than mechanization.
Another challenge for Port Hueneme is the traditional reluctance of combatant ships to install their own UNREP machinery. This is understandable because combat ships do not use UNREP machinery to shoot bullets. Moreover, additional machinery takes up critical space, adds topside weight, and must be maintained by the ship's crew.
For all of those reasons Port Hueneme's technical approach has focused on keeping the UNREP machinery on the CLF ship and developing innovations such as the new automatic connect-up system, which requires only a couple of Sailors on the combatant ship compared to today's long lines of line handlers. The connect-up machinery on the CLF ship will be used to manipulate the light lines used to haul across the actual UNREP rig. The concept has been well-tested at Port Hueneme, and the next step is to take it to sea for more realistic operational tests in an oceanic environment.
Traditionally, UNREP operations are conducted with the CLF ship maintaining the steadiest possible course while the combatant or amphibious ship makes its approach and takes station alongside the CLF ship. One reason for this procedure is that, in the past, many CLF ships were converted merchant ships and usually much less maneuverable than naval ships. It is the responsibility of the approach ship both to maintain a ship separation within the limits of the CLF ship's transfer rigs and to maintain a station-keeping position fore and aft that provides a favorable alignment of the approach ship's receiving stations with the transfer rigs on the CLF ship.
The Point of No Return
In the past 10 years there have been more than a dozen ship collisions during UNREP operations. Regardless of the various reasons for the collisions, there was always some point in the operation when the approach ship became aware that a collision would be a possibility and that corrective action had to be initiated. When this awareness occurs, the ship-separation distance determines the time available for the approach ship to carry out the corrective action needed.
The greater the ship separation, the more time there is to prevent a collision. The Heavy UNREP System will be fully operable at a ship separation of 300 feet, vs. today's 150 to 200 feet. This does not mean that future UNREPs will be conducted at 300 feet; it simply means that there will be more maneuvering capability before the receiving ship would have to disconnect the UNREP rigs.
Experiments on many of the most innovative features of the new Heavy UNREP Transfer System are currently being conducted at the Navy's UNREP Test Site at Port Hueneme. Testing and evaluation of all components of the Heavy UNREP Demonstration Model will be conducted at the Test Site through fiscal year 2004 prior to ship installation and the at-sea demonstration, which is now scheduled for FY 2005.
A production prototype of the system is scheduled to be operationally evaluated at sea in FY 2008 prior to transition to the fleet shortly thereafter, according to present plans.
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