RED HILL — About 450 feet underground, a little-known rail car and its engine start up, and true to its name, the Howling Owl subway begins its screeching ride down old narrow-gauge cane tracks to Pearl Harbor.

The underground train, along with the 20 massive fuel tanks in Red Hill that it services, were built in the early 1940s for wartime needs.

In 1995, the American Society of Civil Engineers placed the facility alongside Hoover Dam, the Eiffel Tower, Panama Canal and Statue of Liberty as a historic landmark.

Originally, it was top secret but is now declassified. However, many people are still unaware of one of Hawai'i's greatest engineering feats, even as they drive above the rail line on the H-1 Freeway, oblivious to the passage of workers and equipment below.

At its peak, the project employed 3,900 workers to build 20 cylindrical fuel tanks that are each the size of the 20-story Ala Moana Building. Two-thirds of the workers were local.

The Red Hill Underground Fuel Storage Facility is a little-known story of past accomplishment and continued use.

Started in 1940 when war clouds loomed, the Red Hill project — known simply as "The Underground" back then — was intended as a fuel storage site that was safe from attack.

Each tank has a 300,000-barrel capacity, and all 20 can hold 252 million gallons of fuel. Hawai'i's gasoline consumption in 2004 was 460 million gallons.

Today, with few major alterations, all but a couple of the steel-lined tanks contain diesel and JP-5 or JP-8 jet fuel, and still directly feed Hotel Pier by gravity at Pearl Harbor.

"We fuel the whole Pacific," said Al Hoyle, fuel distribution systems manager for Red Hill, which is operated by the Navy's Fleet and Industrial Supply Center.

That fuel flows through a massive 32-inch-diameter diesel pipeline and 18- and 16-inch jet fuel pipes along the side of the approximately three-mile rail line to Pearl Harbor. Trucks deliver fuel to other bases.

Some people may be familiar with the fuel tanks, but less well known is the rail transit system O'ahu already has underground.

The narrow-gauge rail was pulled from cane fields during Red Hill's construction, said James Murray, a spokesman for the Fleet and Industrial Supply Center.

In 1998, workers removed some older sections of track that were no longer needed, and found a then-105-year-old date on it — 1893 and "Moss Bay," leading to speculation it might have come from Moss Bay Iron and Steel Works in Washington state.

GHOST STORIES

The 15-foot-tall lighted tunnels accommodate electric trains Honu and Lapaki that ferry equipment on flatbed cars and workers in steel-mesh enclosed cars with wooden bench seats.

Until he recently started working at Red Hill, train driver and fuel line inspector Jerry Gilo didn't know the rail line crossed about 100 feet below Foster Village where he lives.

Only a few workers from the Fleet and Industrial Supply Center are needed to monitor the Red Hill facility around the clock, and its cavernlike tunnels and seemingly bottomless fuel storage tanks have given rise to plenty of ghost stories over the years.

"When I first started working here, it was kinda scary ... especially at nighttime; you are by yourself," admitted Gilo. "Then I got used to it."

Gilo rides the train or travels the pipeline tunnels by bike, making sure there are no leaks. But Gilo recalled the story of a now-retired worker named Chester who one night heard his name being called.

"He looked around, and nobody," Gilo said.

The maze of pipe-laden and sometimes dimly-lit nooks and crannies, and sheer drop in empty Tank 19, though, make it easy to conjure other-worldly images.

At about the 200-foot mark on Tank 19, a walkway extends from an access port and connects to a metal scaffolding that disappears into the darkness below.

Workers in the early 1940s toiled on narrow catwalks chipping away at the rock wall. Debris tumbled down and was carried away at the bottom on conveyor belts.

SEVERAL KILLED

Initially, the steel-lined tanks were designed to be placed horizontally, but a hydraulics engineer proposed building them vertically. Red Hill provided adequate protection, with a minimum of 110 feet of earth overhead.

Miners were brought in from Colorado and the Dakotas to work alongside local workers. About 1,200 workers were housed in barracks on Red Hill.

The first of the 20 tanks was completed on Sept. 26, 1942. The last came on line on Sept. 30 the following year. The tunnel-building success also came with a human toll, and on average, a man died every two months, according to the Fleet and Industrial Supply's Murray.

Among those deaths, two drowned, one was electrocuted, one died in a cave-in, two were asphyxiated, a handful died in falls, and a motorman ran a train over an embankment and was pinned inside.

Although once a national secret, the fuel storage facility was declassified sometime after World War II, Murray said.

But the military nature of the facility kept it from widespread public knowledge.

"When I was working here, it was kind of secret," recalled Herb Kikuchi, who started at Red Hill in 1974 and is temporarily out of retirement working at the facility again.

Tesoro pumps fuel from Barbers Point to Red Hill, and Navy tankers also provide part of the supply.

Murray said safety since Red Hill's completion "has been amazingly good." The last fatality was in the 1960s "and as far as leaks, these tanks are built so well they haven't had any major problems at all."

RAIN HEADACHES

Every quarter, the water table beneath the tanks is checked.

Work on and use of the rail system may increase with the need to replace about a mile of water-damaged train tracks at the Pearl Harbor end of the tunnel, where the rail line is within a foot of the water table.

"So whenever we get a big rain we flood out down there," Fleet and Industrial Supply's Hoyle said.

The demolition debris coming out and construction materials going in may have to be transported by train to an access point near the animal quarantine station that is protected by thick steel doors — a difficult transit, but not the first at Red Hill.

A bunch of 1940s graffiti remains just inside the concrete entrance wall, including a missive that states: "Goodbye old Oahu, I'm leaving you at last, take your rocks and mountains, and stick them ... "

A ditty penned by a guard on Christmas Day 1943 reads: "You should gripe about (missing words), standing this post so forlorn. I gave the mosquitoes their breakfast on Christmas morn."

Reach William Cole at wcole@honoluluadvertiser.com.