Seeking to extend the operational life of its submarine
fleet, the U.S. Navy is introducing new maintenance practices-aimed not only
at improving ship performance but also at reducing the time boats spend at the
shipyard.
The Navy's program manager for strategic and attack submarines, Capt. James
Dullea, said the service is "getting smarter" about how it manages
improvement programs for its fleet of aging boats, mostly the Los Angeles class.
Many of these nuclear-powered subs are reaching the end of their approximately
30-year life span.
For Dullea, getting smarter means, among other things, "not replacing everything"
when a boat comes in for a scheduled maintenance checkup and overhaul to one
of the Navy's four yards. These facilities are located at Pearl Harbor, Hawaii;
Puget Sound, Wash.; Norfolk, Va. and Portsmouth, N.H.
During base closures in the late 1980s and early 1990s, the Navy lost three
yards at Charleston, S.C., Long Beach, Calif.; and Mare Island, Calif.
"We have been operating nuclear submarines since the 1950s," Dullea
said. "There is a certain amount of degradation that we have learned to
expect over a given time period."
But the Navy today is under growing pressure to keep more submarines in top
shape because regional commanders rely on them, more and more, for intelligence
collection and surveillance.
Unless something is in obvious need of repair, he said, "there is no reason
to go ripping out perfectly good parts" and keep the boat out of commission
longer than needed.
Maintenance Process
When a submarine arrives at the yard, the first order of business is called
condition-based maintenance. That includes work on items such as pumps or brakes,
which, because of acoustic and vibration levels deep under water, tend to wear
out more quickly. If, for example, a pump has become noisier while operating,
it must be replaced.
Each submarine undergoes a so-called "maintenance effectiveness review,"
explained Dullea. That is when the question is asked: "Are we doing this
too soon?" This technique, he said, made it possible for the Navy to eliminate
tens of thousands of hours of maintenance work.
The cost of maintaining and repairing submarines is hard to estimate, given
the Navy's practice of spreading these expenditures throughout many different
accounts. Dullea said that it would be misleading to put a fixed price tag on
what it runs to give each sub its maintenance checkup, overhaul, repairs and
upgrades. "It really depends on what has to be done," he said. "There's
really a mish-mash of funds from which we operate."
For refueling and overhaul of one submarine in fiscal 2001, the Navy requested
$201 million.
Dullea estimated that it takes 200,000 worker-days to accomplish the required
tasks on a single boat. Also, he said, costs are influenced by whether or not
the work is done at a Navy yard or at a private shipyard. In addition, costs
vary according to what subsystems need to be replaced, such as weapon systems,
sonar devices or towed arrays.
Officials at the Navy's four yards have been instructed to reduce the amount
of time that a sub spends out of the water.
"Our job is to get boats back out to the fleet faster," said Dullea.
"Not only do we have fewer yards than we did several years ago, we also
have taken a decrease in personnel resources."
Rear Adm. Albert H. Konetzni Jr., commander of the U.S. Pacific Fleet submarine
force, noted that "maintenance time has been cut in half."
"Deferral is becoming a way of life," he told a recent shipbuilding
conference on Capitol Hill. "We are running our ships [and sailors] into
the ground."
Yet with fewer yards and personnel, Dullea said, there has been a significant
increase in the number of boats lining up to be serviced.
During the next seven years, Dullea expects a demand for at least 35 submarine
maintenance projects. By comparison, the Navy worked on 11 overhauls during
the past seven years.
More Operations
Konetzni explained that submarines currently are much busier than they were
during the Cold War. They now operate at an 85 percent "optempo" rate,
which means boats spend 28 says in-port out of 180 sailing days. The optempo
rate was 65 percent during the Cold War.
At the current rate of operations, Konetzni projected that the Los Angeles
class ships will run out of fuel before their 33-year life spans elapse. "What
good are boats that you have to keep on a shelf and not use because they're
low on fuel?" asked Konetzni.
To cope with the increase in traffic, the yards have gone to a "class
maintenance plan," where each boat keeps track of its own repair schedule
and routine maintenance checks. Dullea said the yards start planning two years
ahead of a boat's arrival.
Modernization Upgrades
Submarines rotate in for maintenance every 42 months, or three-and-a-half years.
A boat can be expected to remain in the yard for more than two years if it needs
both refueling and maintenance. Modernization upgrades can take 16 months.
There is some room for flexibility if the three-and-a-half-year checkup runs
over. However, the 10-year maintenance schedule cannot be pushed out to 12 years,
Dullea asserted. "There are too many safety and reliability issues to take
a chance on that," he said.
"We can't have a boat coming in and requiring more man-hours than what
we had expected to perform," Dullea said. "We have to make sure that
each yard has the specific skills [people and tools] to handle the job that
is to be done."
With smaller maintenance crews and fewer yards, Dullea added, it would be difficult
to handle "unexpected maintenance surprises" with the wrong skill-set
in place and an insufficient number of people to do the job. Advance planning,
he said, has allowed the yards to become more efficient and accomplish more
work on a greater number of boats.
Twelve submarines is the maximum the yards can handle at any one time. "You
don't want to have too many boats in the yard at once in case they are needed,"
he said.
One significant assist to maintenance managers and crews at the yards has been
a so-called "current ship maintenance plan," he said. Under this plan,
those items that tend to break at sea are repaired at sea. The success of preventive
maintenance-fixing something or replacing a part before it breaks-has eased
the workload at the yards, Dullea added.
"Submarine crews have the attitude that they can fix anything that breaks,"
said Dullea. "And most of the time they can."
This increased self-sufficiency is one of the big reasons why there are only
two U.S. submarine tenders operating in the world. Tenders are ships assigned
to service submarines when something breaks down. One is stationed at Guam in
the Pacific and the other is quartered in Italy. Both tenders are on forward-deployed
status, said Dullea.
The Navy, he believes, found it is cheaper, but no less efficient, to maintain
shore bases than to keep up a fleet of tenders.
So far, he added, the shore-based tenders have done a good job.
One way to ease maintenance burdens for submarines is the use of commercial
technologies on ships, particularly electronics. In the past, when equipment
was made strictly to military specifications, ship crews were installing devices
that had been developed six or seven years earlier, and, therefore, obsolete.
The growing use of commercial products has been welcomed by the submarine fleet,
Dullea said. "There is now more consistency across the product line that
we didn't have before."
He noted that the Navy recently purchased flat-panel displays that are more
rugged and adaptable to newer suitcase or drawer, "rack-style" methods
of stowage. They also make for easier maintenance and upgrades.
In fiscal 2001, the Navy requested funding for submarine communication suite
improvements, including the installation of high-data rate antennas, improved
multi-function antennas, and radio automation efforts to enhance the throughput
of submarine radio rooms.
Los Angeles class boats, additionally, are being upgraded with new acoustic
equipment under a commercial technology insertion program. These upgrades will
offer upgraded towed array, spherical array and under-ice sonar processing.
Better Technology
"Not only do we have more reliable, longer lasting equipment," Dullea
said. "Better technology has given us the tools that allows us to do non-destructive
tests on equipment and the hull."
One of the issues most frequently addressed within the fleet, he said, is hull
safety, especially in boats that are being kept past their expected life spans.
"The hull is not typically the main problem," he offered. Dullea gave
credit to thorough and efficient maintenance.
It used to be that each shipyard wrote its own separate maintenance procedure
manuals, Dullea continued. There is now a push for commonality in shipyard manuals,
work and processes. This effort is being spearheaded by the office of Submarine
Maintenance Engineering Planning and Procurement (SUBMEPP), headquartered at
the Navy yard in Portsmouth.
"Due to this growing commonality in process, we now have more flexibility
to move our people around as we need to," said Dullea.