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| Near
the end of an unusually long refit necessitated by major repairs
to her fairwater planes, USS Kentucky (SSBN-737) has
her starboard plane reinstalled at IMF Bangor. Accomplished
while the ship was afloat, this delicate evolution required
skillful coordination among crane operators, riggers, and the
entire waterfront crew. |
| After
spending more than nine weeks in an unusually complex refit,
USS Kentucky (SSBN-737) slipped confidently into the
open waters of Hood Canal on 19 April in preparation for her
next patrol. With 100,000 production man-hours executed in the
completion of more than 1,000 individual jobs, her refit was
a first-ever demonstration of a new surge maintenance capability
in the Pacific Northwest. |
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The
Naval Intermediate Maintenance Facility (IMF) at Naval Submarine
Base, Bangor, knew early-on that the normal refit period of
four weeks would be insufficient to perform all the repairs
and refurbishments needed by Kentucky. The ship had
previously reported noise in the fairwater planes while underway
and had asked the IMF to consider what repair options might
be available when she returned from patrol.
Because
the ship was already operating outside of her fairwater plane
specifications on a temporary waiver, and since one of the
planes appeared to be out of alignment, it was determined
that both planes would have to be removed for inspection
and repair. Although TRIDENT Refit Facility (TRF) Kings Bay
had already performed temporary repairs on the stock and hubs
for Kentucky ’s fairwater planes while she
was homeported on the East Coast, both the Fleet and the IMF
decided that it was time to examine alternatives for a permanent
fix.
When the
ship docked on 12 February, IMF immediately disassembled both
fairwater planes and discovered that saltwater intrusion and
significant corrosion had caused serious deterioration in
their material and operational condition.
Fairwater
planes are horizontally disposed control surfaces –
“wings” – mounted on the sail for controlling
the ship’s angle of rise or dive while submerged and
underway. Given the importance of keeping them in peak condition
and operating quietly, IMF considered several options. The
principal concerns were safety and cost control. Although
IMF has been accomplishing depot-level repairs and refurbishment
on major components of the TRIDENT submarines for years –
replacing main propulsion shafts and overhauling SSTGs and
SSMGs, for example – they had never completely disassembled
submarine fairwater planes. This type of work would normally
be undertaken by the Naval Shipyards, but given the constant
use of their drydocks and the consequent necessity of a long
shipyard availability, the operating schedule of the submarine
would have been compromised. Moreover, the rapid deterioration
of Kentucky’s fairwater planes demanded an
early solution.
According
to CDR John Baldwin, IMF Production Management Assistant (PMA),
and head of the project, a team of engineers, planners, machinists,
and other shop leaders from the IMF, Puget Sound Naval Shipyard
and Intermediate Maintenance Facility (PSNS&IMF), Naval
Sea Systems Command (NAVSEA), and Electric Boat pulled together
to consider repair options. “This was a major team effort
by nearly everyone involved in ship maintenance to apply the
One Shipyard concept to resolve a maintenance issue for the
Navy,” said Baldwin. “Once we got in there and
saw the extent of the damage, it became clear that we were
going to have to rethink completely the way the repair was
going to take place in order to get the ship back to sea quickly.
The IMF had a window of opportunity in its maintenance schedule
for other in-port submarines and potentially could perform
permanent repairs during the Kentucky’s upcoming
scheduled refit,” he added.
The team
determined that there were essentially three options. The
first – which would leave the ship’s schedule
unchanged – was to perform another temporary repair,
reassemble the planes with their existing deficiencies, and
defer the permanent repair until the ship went into a major
shipyard overhaul. However, because there was no guarantee
that this approach would correct the problem, and the life
expectancy of the temporary fix was unknown, it was considered
the highest-risk alternative, even though it could have been
accomplished during a normal refit and at low cost.
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A mechanic stamps the weight limit
and test date on the Navy’s first vertical fairwater plane
stand, fabricated in-house at IMF Bangor. |
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The
second option was to send the planes and stock back to Newport
News Shipbuilding, which had conducted similar repairs in
the past for other submarines homeported at Kings Bay. Given
the size and weight of the components, this would have been
extremely expensive and time consuming. The fairplane stock
– essentially the horizontal axle for rotating the planes
– weighs 13,600 pounds, and each plane alone weighs
about 25,800 pounds. The latter, when standing vertically,
are 17 feet high by 15 feet wide, which precluded shipping
them by air. Even if specially-configured trucks could deliver
them to the East Coast, Newport News was extremely busy at
the time and unable to complete the job in the narrow window
available.
The third
option – the one ultimately selected – was to
do the job in-house at the IMF, with significant participation
by a large Navy-contractor team. This approach ended up breaking
new ground, not only among the maintenance providers in the
Pacific Northwest, but Navy-wide. Secretary of the Navy Gordon
England has said that the common thread of his initiatives
over the last three years has been to improve the management
and efficiency of our naval forces. Within the maintenance
community, a Transformation Plan has been in progress to subsume
all maintenance activities into a “One Shipyard”
concept in order to gain greater efficiencies and effectiveness
in serving the fleet. Kentucky was an early beneficiary,
and ultimately her design integrity was restored, and her
operational schedule maintained.
The plan
incorporated the ideas and best practices from a number of
contributors, including the IMF, PSNS&IMF, NAVSEA, and
private contractors. The highly complex job was made even
more difficult by the need for significant welding on the
fairplane stock, an HY (High Yield) 100 alloy forging for
which the Navy had no approved welding procedures. Additionally,
there were complex metallurgic issues and the requirement
for a very large lathe for final machining.
“The
IMF proposed a plan for the repairs we intended to conduct
and the technical methods and procedures we would carry out.
Then, as the Navy’s technical authority, NAVSEA 07T
had to evaluate them and provide concurrence,” said
CDR Baldwin. “In addition, we needed to work with Commander,
Submarine Squadron 17 (CSS-17), Commander, Submarine Group
9 (COMSUBGRU-9), and Commander Submarines Pacific Fleet (COMSUBPAC)
to assure them that not only could we complete the repairs
in a timely manner, but also that the end result would pass
all tests and meet operational specifications,” he concluded.
This became the first-ever repair outside a shipyard on components
that are not normally even addressed during a major two-year
overhaul. Moreover, IMF had no authoritative source documents
or procedures to accomplish the work. |
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