Massive Iwakuni runway project progressing smoothly
June 22, 2006
The largest construction project for both the Pentagon and Japan — Marine Corps Air Station Iwakuni’s nine-year, $2.4 billion runway construction project — is moving along nicely with several phases completed, said Mark Nedzbala, resident engineer for the Army Corps of Engineers in Iwakuni.
The project moves Iwakuni’s runway one kilometer (about two-thirds of a mile) out to sea, so jets won’t have to bank quickly after takeoff to avoid a nearby petrochemical plant. For residents, that means less noise: When the jets bank, the sound is cast directly into the city where mountains contain it.
The new runway requires a 533-acre landfill, enlarging the base by about 30 percent. For the fill, Japan is breaking down a nearby mountain, moving earth to the reclamation site along a conveyer belt for two miles then aboard barges for four miles. About half the mountain will be used, but what’s left will become usable land, enough for about 1,500 homes Nedzbala said.
The land for the runway is being reclaimed in three phases, using 752.5 million cubic feet of fill. The first phase, to the north, included a new deep-water harbor and was completed earlier this year. Phase II to the south was finished a few weeks ago.
With the new harbor in place, the old harbor was removed and Phase III began, bridging the gap between the north and south sections. All three areas are expected to be done by March Nedzbala said.
To fill in the sections, engineers start with special sand piles to drain the area, covered by fill. Then compression piles are forced into it to stabilize the land, which is held in by new seawalls. In Phase I alone, more than 150,000 piles of both types were placed.
Besides being the Pentagon’s and Japan’s largest project — and among the biggest in the world of its type — the reclamation will make Iwakuni one of Japan’s largest bases and the only one in Asia with a deep-water harbor and heavy-lift runway, Nedzbala said.