The fleet
has used a variety of solutions to minimize corrosion to topside connectors. The most
common solution is to wrap the connector with tape and coat with polysulfide or to employ
cold shrink tubing. These solutions are permanent and they must be replaced if it is
necessary to access the connector. For items that must be repeatedly disconnected and
reconnected for maintenance, there was no solution. RayChem, Inc. has developed a roll-on,
roll-off connector cover that permits easy connect and disconnect. The new technology uses
a toroid filled with gel. The gel permits the cover to easily slide over and completely
seal the connector from the environment. This cover can be slid back from the connector
for inspection and then restored by sliding it back. MTTC resources were used to conduct a
series of environmental and military suitability tests. These tests concluded that the
connector cover met military standards. The cover, called RayOLON, has been given limited
approval for fleet use and a large number have been procured for extensive at-sea testing.
The Navy estimates an annual cost avoidance of $250,000/year when fully implemented.
Marine
fouling causes fouling of the fleet's sea water systems (firemain, cooling, flushing,
etc.). The use of chlorination to prevent this fouling is a proven concept in both
military and commercial applications. This project was conducted to develop a portable
chlorinator unit, to determine the optimal location of the injector port, to test the unit
on a fleet unit and to evaluate the chlorinator's ability to prevent fouling. MTTC
resources were used to build and install a suitcase-sized device on a U.S. Navy ship --
USS CARR (DDG-52). The prototype was initially installed in October 1999. It has been run
on the discharge of the #2 firepump since that time. Several engineering changes were
instituted as a result of these tests (corrosion prevention, etc.). The Navy has been
satisfied with the results of the tests to date. As a result, in FY-01, the Navy intends
to build and install two or three more chlorinators on USS CARR to increase the
operational flexibility and the biofouling coverage. MTTC has transferred custody of the
test unit to the Navy for the additional testing. The Navy has estimated that this
technology will result in savings of $500K/year when fully implemented.
The current
Calcium Silicate insulation used onboard ship is heavy and very difficult to install.
Fleet maintenance personnel and shipbuilders are looking for new materials that will meet
the requirements and yet be less costly to install. K-Flex ECO insulation was installed on
USS RUSHMORE for at-sea tests. This insulation is targeted at temperature ranges up to 250
degrees F. After almost a year of testing, the Navy has determined the K-Flex ECO meets
all shipboard requirements and achieves a 40% labor reduction over Calcium Silicate and a
25% reduction over fiberglass. The Naval Sea Systems Command will be issuing a change to
the Navy specification, in the near future, to permit the fleetwide use of this new
material. The Navy has estimated that the use of K-Flex ECO in the fleet will result in a
maintenance cost avoidance of not less than $1.25M/year, fleetwide. This number does not
include obvious savings in ship construction.
For
generations, painting and deck tile maintenance have been a (negative) mainstay of a
sailor's workday. The Navy is making a concerted effort to eliminate or significantly
reduce this type of work. Hundreds of hours a year are spent on each ship waxing and
buffing tile. The current tile is "soft" and usually has to be replaced after
heavy use or impact. A commercially available decking material called "Stratica"
has been installed on several ships on a test basis. This project supported the proofing
of installation procedures. To ensure proper performance, the decking must be applied
using proper equipment, procedures and adhesives. In this project, decks were installed on
USS JOHN YOUNG (DD-973) and USS HARPERS FERRY (LSD-49). It demonstrated that the
established procedures produced a quality installation that performed admirable at sea. As
a result, the Navy has approved Stratica for use on all Navy ships and submarines. The
Navy has estimated that this project will save at least $1.6 M/year in maintenance costs.
As part of
the Fleet Maintenance Technology Transfer Program, MTTC was asked by the U.S. Navy to find
a solution to a fastener problem. The Navy needed a nut/bolt that would not corrode, would
be easy to install and remove in tight spaces and would pass the stringent shock
requirement. Superbolt™ is a commercially available product that meets most of the
requirements, but had not been shock tested. In June 1998, MTTC received approval to
perform the shock test on Superbolt. It was violently and successfully tested in November
and, as a result, received Navy approval for fleet use in April 1999. It is estimated that
the use of Superbolt in a variety of applications will save the Navy over $1 million per
year. The project was completed in less than five months and started fleet use in less
than 10 months.
Since the
Arleigh Burke Class (DDG-51) Destroyers started going to sea in the early 1990's, the
ships have experienced severe corrosion on the 47 louvers that filter the air going to the
main propulsion and auxiliary gas turbine (jet) engines. A variety of coating products and
techniques had been tried without success. MTTC was asked by the Commander in Chief,
Atlantic Fleet, to assist in finding a solution. A process called "fluidized bed
powder coating" was revealed and a company was located in Toronto Canada that had
dip-tanks that could accommodate the largest of the louvers. The Navy provided process
sheets and test louvers. These louvers were coated and shipped to Bath Iron Works where
they were installed on a destroyer, USS COOK, for at-sea testing. After four months, when
most of new louvers were already exhibiting corrosion, the test items were as pristine as
the day they were coated. As a result of this trial, the Navy has ordered all new
destroyers louvers to be treated using this process and the fleet is sending entire
ship-sets of louvers from units already in the active fleet out for this powder coating.
The Navy estimates that almost a million dollars per year will be saved by this project.
For years,
the Navy has been plagued with maintenance problems with their watertight doors. These
heavy metal doors are designed to limit the spread of fire and flooding in a ship. There
are 52,000 doors (and 104,000 hinges) throughout the fleet. The hinges and hinge pins on
these doors have been failing at an alarming rate. The Navy estimates that it expends $10
million per year on time and materials to fix the doors. MTTC was asked to help find a
solution to this problem. In conjunction with the Navy, six potential replacement kits
were identified. A multi-door test fixture was built and all six kits were tested
alongside the current hinge model. The latter failed after only 110,000 cycles. Three of
the six replacements easily withstood 1.25 million door open/close cycles. The Navy
intends to compete these three "winners" to obtain the most cost effective
replacement. The fleet is clamoring to expedite delivery of the kits. The major
shipbuilding programs are also gearing up to utilize the replacement in all new
construction ships.
Navy ships
use heat exchangers in numerous applications to provide cooling water to electronics and
equipment. Often, the primary sides of these exchangers are cooled by sea water, via the
ship's firemain system. Over time, the primary sides of the tubes become fouled by
inorganic scale (like household irons and coffee makers) and organic biogrowth (mussels,
barnacles and sea-grass). When this happens, heat transfer is severely degraded and damage
can occur to the cooled equipment. In the past, when heat exchanger needed to be cleaned,
they had to be physically removed from the ship, taken to a shore-based facility and acid
cleaned. The removal/installation time took 10-100 times the actual cleaning interval.
During this downtime, the serviced electronics could not be operated or maintained. MTTC,
in conjunction with the Naval Surface Warfare Center, SSES/Philadelphia, obtained the
necessary environmental clearances and conducted shipboard tests that would permit heat
exchangers to be cleaned without removal from their foundations. A small maintenance
module, including a pump, filter and necessary flange joints was developed. Qualified
technicians could bring the descaler equipment to the ship, hook it up, circulate the
commercial cleaner and depart the ship in less than a day. In May 2000, after rigorous
shipboard testing and evaluation, the Navy authorized qualified Navy activities and
vendors to conduct onboard cleaning of heat exchangers. The Navy estimates that $4 million
will be saved a year in maintenance costs.
Bilges are
the lowest areas on the interior of a ship. As such, all forms of liquid wastes tend to
accumulate in these bilges - including salt water, fuel, oil and hydraulic fluids. Many of
these are extremely corrosive and can cause significant damage to the ship's structure and
hull. In order to protect the metal, sailors, for decades, have been forced to continually
clean, strip and paint the bilges. It is confining and dirty work that is a true
demotivator. During the past five years, new, environmentally friendly plural epoxy paints
have been developed to coat bilges. Some have already been successfully used on commercial
ships in Europe and the U.S. However, substrate preparation has been found to be critical
to a successful epoxy application. The Navy has developed a set of formalized processes
for the surface preparation and application of epoxy bilge paint. They asked MTTC to
support the installation of test areas of two brands of bilge paint in accordance with the
approved procedures. USS DETROIT was prepared and painted in January-April 2000 and sent
to sea to evaluate the effectiveness of the paint and procedures. After a suitable period,
the Navy will audit the condition of the test areas and make a decision on service-wide
use. If the paints live up to their promise, bilge painting intervals will be extended
from months to years. The Navy estimates that over $10 million per year in maintenance
costs will be avoided.
Call
for More Information...
For
additional information about opportunities involving technology transfer for the Navy,
contact Dick Gilbert [email protected]
