Military Sealift Command Public Affairs
March 27, 2017
100 Years of Underway Replenishments at Sea
By Bill Mesta, Military Sealift Command Public Affairs
The Civil Service Mariners (CIVMAR) who crew Military Sealift Command's fast combat support ship, USNS Arctic (T-AOE 8), got the ship underway from Naval Station Norfolk, March 22, to do what the U.S. Navy has done for 100 years, underway replenishments at sea (UNREP).
Underway replenishments are a critical naval capability which allows U.S. Navy and allied ships to be resupplied with fuel, food and stores without pulling into a port. This capability allows naval warships to stay on station longer and continue with their mission uninterrupted.
"UNREPS keep the Navy going," said Jamie Gleber, Arctic's first officer. "If a Navy ship had to pull into port every time it needed supplies, that ship would be taken out of the game."
As first officer, Gleber is responsible for the planning and execution of all the Arctic's cargo movements and deliveries.
"The UNREPs Arctic performs include vertical replenishments (VERTREP), where we deliver non-liquid cargo, such as ammunition or repair parts to a ship using helicopters," said Gleber. "We also perform along-side UNREPS, which include wire transfers for dry cargo or hose rigs to deliver liquid products such jet fuel, water or lube oil."
"Navy ships are designed to be re-supplied at sea," added Gleber. "They really aren't built to receive cargo in port, So we keep them running."
Arctic performed three underway replenishments with the Ticonderoga-class cruisers USS San Jacinto (CG 56), USS Monterey (CG 61) and the Arleigh Burke-class guided missile destroyer USS Bainbridge (DDG 96), March 23 .
Arctic also provided three training opportunities for UNREP qualifications, known as System Qualification Tests (SQTs), for MSC's fleet oiler USNS Laramie (T-AO 203). Laramie was able to simulate taking aboard and delivering fuel. The two ships also transported simulated stores between the two ships.
"SQTs are required whenever a ship goes into the shipyard, has a large amount of maintenance or repair on its resupply rigs and/or it has a large crew turnover," said Edward Logan, Arctic's second mate. "Before a ship can be certified to use its rigs again for UNREPS it must complete SQTs."
Arctic also performed an UNREP with San Antonio-class amphibious transport dock USS Arlington (LPD 24) March 23 to send the warship fuel and perform SQTs.
In less than 24 hours, Arctic delivered 677,000 gallons of fuel to the Navy warships.
An UNREP includes an intricate series of precision evolutions which must be completed like clockwork for a successful at-sea re-supply.
Artic has both port and starboard fueling and stores delivery stations. This gives the ship the ability to provide fuel and stores for two ships simultaneously.
As the ships approach Arctic, the Romeo signal flag is raised indicating the vessel's readiness to begin the UNREP. Once Arctic's customer responds with their own Romeo signal flag, they can pull along side.
"Performing an UNREP is a very challenging undertaking because you are dealing with two very large and heavy ships which weigh anywhere from 20,000 tons to upwards of hundreds of thousands of tons which are operating within 200 feet of each other, and sailing between 12 to 28 knots," said Gleber. "So an UNREP is inherently an auspicious situation."
Members of the UNREP station teams from the receiving ship then use a bolt-action rifle, which has been modified to launch a large plastic projectile with a string attached to the other ship.
The string is used to pull the telephone and distance line (T&D line), fueling hose heaving lines and stores cables from one ship to another.
The T&D line is used by each ship's bridge team to monitor the distance between the two ships throughout the UNREP. The T&D line also contains a sound powered phone line, which is used for constant communications between the two ships.
"If you have skilled personnel working on both the sending ship and the receiving vessel an UNREP looks easy," added Gleber. "We employ teams of experienced UNREP CIVMARS which include Bos'n Mates, Able Bodied Seamen, and Ordinary Seamen who actually perform the UNREPS. We also receive manning support from the engine side and supply department to round out our UNREP teams."
Once the stores and/or fuel have been delivered, Arctic performs emergency breakaway drills, which involves retrieving all of the hoses, cables and lines in a very rapid fashion and quickly disengaging from the customer ship.
"The UREPS Arctic performed during this underway went great," according to Gleber. "There were lots of learning opportunities for the crew and they did really well. Our ships don't run without the deck-plate crew and officers, and the crew of the Arctic demonstrated that we are skilled, talented and motivated."
Arctic is one of two fast combat support ships in MSC's inventory that specialize in performing UNREPS. MSC also has a fleet of oilers and dry stores/ammunition ships that are responsible for providing Navy and allied warships with UNREP services.