While the Far East District is at the center of many
high-profile military construction projects throughout the Korean peninsula,
some of the best lessons learned come from a fuel tank recently installed at
Osan Air Base.
Frank Meleton, resident engineer at Osan, outlined the scope
of the project, installing enormous tanks capable of holding about three
million gallons of fuel each.
Tom Larkin and Kang, Ho-Sin, both from the Construction
Division elaborated on this recently completed project.
Larkin said, “Fuels is really a specialty; if you mess up,
there’s a high risk of injury or death.”
Kang agreed, “It’s important to not only adhere to the specifications
but also to have early involvement of the supplier.”
The supplier is more or less responsible for getting the
system put together, tested and ready for implementation. The supplier is
involved in specifying every component in the system—valves, gauges—prior to
commissioning, Larkin said. You have to test the system and ensure that it’s
functional before commissioning. It’s normal practice for the contractor to
test the system before commissioning and turning it over. And testing, when
done right, can provide timely insight into potential problems.
“We had some issues
with the cleaning of the tanks, before we put fuel in them. Debris in the
system had accumulated, delaying the proper commissioning of the project by
several months, ultimately leading to other problems,” Kang said.
Larkin said hydrostatic testing comes first. It ensures the
integrity of the tank, checking to see that nothing leaked before the tank is
installed, encased in concrete. It’s a demanding, meticulous testing process
that’s absolutely necessary. Thousands of gallons of potable water was used for
this testing, to comply with environmental requirements. After testing, this
water is dumped and cannot pollute.
Cleaning should be done after the flushing and cleaning of
the pipes; the contractor cleaned the pipe by sending a device called a “pig”
down the pipes, after which the contractor flushed the pipe using pressurized
air. The standard for commissioning fuel is to flush the system using fuel, to
demonstrate the fitness of the system for its intended purpose, Mr. Kang said.
Next comes fuel testing, Larkin said. The tanks have to be
tested thoroughly to ensure that everything works correctly—gauges, filters,
piping, even the lining of the tank. As much as 300,000 gallons of fuel may be
used for flushing and cleaning. By the time the testing is over, the fuel
coming out has got to be absolutely clean, just as it must when the tank is put
to use. If the system isn’t carefully tested beforehand, it could contaminate
millions of gallons of fuel, rendering it unfit for use and possible loss of
aircraft.
Coating is another specialty--different from fuels but a
major part of the overall project. Problems with coating inside the tank might cause
the coating to peel off or blister inside the tank, leaving debris. Even though
it seems that everything was done right, these problems cropped up, Meleton
said.
“There’s certain humidity and temperature requirements for
the three-coat epoxy system, and the coatings have to have a certain amount of
time to cure between applications,” Meleton said. “Monitoring the entire tank and
not small areas may have allowed for too much time to possibly pass between
coatings. After the primer coat is applied, and there’s a certain time allotted
for the curing. If that time is exceeded, the second coat won’t adhere
properly, causing the subsequent coats to peel off or degrade when put into use.
“It can be tricky keeping close tabs on the tank, which is
roughly 25 feet high and 120 feet in diameter. You have to monitor and
sandblast and prime coat in sections. Applying the second and third coats means
the process has to be stair-stepped as you go around the tank,” Larkin said. If
documentation isn’t carefully maintained, it’s easy to lose track of the
progress made and the progress required. If the contractors doesn’t have a lot
of experience working with these types of epoxy coatings, then it becomes
particularly difficult to get the really good quality coating that lasts as it’s
designed to last.
It can also be tricky coping with the day-to-day uncertainty
of military operations. For example, because the tank project was in a
restricted area, the contractors needed escorts to get to the work site. Since
these escorts are provided by the military, so it’s much harder—if not
impossible—to get escorts when a major exercise or inspection is underway. And sometimes,
the type of exercise itself may require keeping civilians out of the way
entirely, affecting contractors all throughout the area.
Some delays can be anticipated, Meleton said, with contract clauses
that inform contractors about the nature of the situation. In this particular
case, 40 working days of delays due to exercise were anticipated for this
particular contract, but were exceeded. Notifying
the contractor in advance is par for the course, trying to minimize unexpected
delays. But there are still occasions of no-notice drills and testing that
comes as if out of nowhere, and giving notice to the contractors isn’t always
feasible.
Larkin agreed. Working around these operations can
definitely impact a contractor’s ability to complete the job on time. The Corps
of Engineers team at Osan Air Base is responsible for translating these
military situations into the terms of the contract, and for ensuring that the
terms of the contract are understood and enforced.
“We’re the link between the base and the contractor,
bringing them together to get a project completed.” Larkin said. Once a
contract is awarded, the contractor asserts that he understands the timeline
and the scope of the project.
Reading and interpreting the specifications can vary between
the contractor and the designer; you’re always going to have some differences
on it, and we have to work together to find a happy medium, to complete the
project within the timelines, cost and intent of specifications and the quality
needed, Larkin said.
This is why certified engineers are part of the quality
assurance team, Kang said. The engineers have the training and experience
needed to understand both the specifications of the design and the capability
of the materials used. The manufacturer can send a certified representative who
can validate the project.
“Just because you’re certified doesn’t mean you meet
requirement of specs when we specify ask for an employee of the manufacture to
certify a specific critical item,” Larkin said. The manufacturer’s
representative is the person who knows what the materials used are designed to
do. Failing to validate the project in this way may void the warranty of the
materials used.
Depending on the size of the project, the Corps’ project
delivery team might regularly include project managers, engineers,
construction, quality assurance branch, resource management, as well as
customer stakeholders, like the base’s Department of Public Works or Base Civil
Engineering, who represent larger agencies like Pacific Air Force (PACAF) or
the Defense Logistics Agency (DLA) as the bigger and more complex the project, the
greater the team effort required.
Another tank project is coming up at Kunsan Air Base that’s
going to make use of these lessons learned.