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Posted 4/12/2016

Release no. 16-022


By Eric Hamilton

USACE Far East District Public Affairs

 

OSAN AIR  BASE, South Korea - 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.