In 1938, the Navy Shore Development Board began searching for a more secure and adequate method for storing the near 4 million barrels of fuel kept to supply the Pacific Fleet.
The intention was to move the fuel from the exposed Doheny oil tanks in the back of the Navy Yard to a series of underground horizontal tanks.
The tanks were arranged in two parallel rows, with adjacent tanks spaced by 100-feet at least. The parallel arrangement allowed access by tunnels built between them with branches to each tank. Tops and bottoms of the tanks were dome-shaped for strength.
Ninety percent of the work was done underground, below at least 110-feet of earth. Outside night work was done under blackout conditions brought on by the war. A 20-watt bulb mounted inside a tin can and suspended three feet from the ground was a typical light source.
Charlie Boerner of Maui, the civil engineer inspector of the Navy’s supervisory group, described it best. “All we’re doing is getting inside a hole that doesn’t exist and digging until it does. O.K., so the miners keep widening the hole out from the shaft, making it v-shaped so the rock will roll down.”
The sequence of operation in driving the tunnels was drill, load (dynamite), blast, muck out, timber, and repeat. Progress was hampered by the presence of cinder pockets and irregular rock stratifications.
Tunnels through softer rock required pre-fabricated arch-shaped steel ribs with heavy timbers between the ribs to make the tunnel safe for work to proceed. Tunnels through harder rock were simply coated with Gunite to consolidate any loose rock. (HAER No. HI-123)
Muck was carried by conveyor to a quarry. Eventually, all of the five million tons excavated from Red Hill was used in surfacing highways, making concrete and as landfill to connect Kuahua Island to the Pearl Harbor shoreline.
After the tanks were hollowed, the walls were lined with ¼” steel plating, much like stained-glass pieces create a Tiffany lamp shade, Gammon described. (John Bennett)
Each tank has a 300,000-barrel capacity, and all 20 can hold 252 million gallons of fuel. 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. (William Cole)
The first tank was completed and immediately utilized on Sept. 26, 1942; the last, on Sept. 30, 1943. The reservation was transferred to the Navy’s control upon completion of the project, and was part of the strategic fuel oil for the Pacific Fleet. Access to the complex is via a system of tunnels totaling 7.13 miles. (John Bennett)
“Snaking throughout the honeycomb are a series of tunnels. A short cross tunnel connects each pair of tanks at their bottoms, making ten cross tunnels altogether. Similarly, another ten cross tunnels connect the tanks at their springline, the base of the upper dome.”
“The lengthy harbor tunnel extends for an additional two and one-third miles before finally rising to the surface at a secluded and bombproof underground pumphouse on Pearl Harbor Naval Base.” (HAER No. Hl-123) There is a link which runs to the Commander in Chief of the Pacific’s Headquarters building located at Makalapa. (John Bennett)
To aid in the transport of materials, 13,000 linear feet of train tracks were removed from Oahu’s cane fields and laid in the lower tunnel. (WestOfSunset)
As the miners inched their way through their subterranean passageway, gangs of track-laying crews followed at their heels. As fast as the tunnel moved forward, rail lines were laid, and the excavated rock and earth was rolled away in miniature rail cars. (HAER No. HI-123)
The only continuously-operated railroad on Oahu runs the 3½ miles from Red Hill to a pump house at Pearl Harbor. It’s 450 feet underground, transporting men and equipment. At the pump house, only four men at a time are needed to monitor the elaborate system that took thousands to build. (Boykin, Hawaii Pacific Architecture)
The two-car train, pulled by a miniature electric-powered narrow-gauge ‘locomotive’, was named ‘Howling Owl’ that propelled the train through the underground, hauled workers and equipment to various stops along the route – it could reach 15 miles per hour at full ‘steam’. (WestOfSunset)
The train passes under Makalapa Crater, Makalapa Elementary School, Salt Lake Boulevard, and Foster Village, at which point it is nearly 100-feet below the surface.
As it snakes through the tunnel, riders could easily believe that they are in the New York subway except that no one has spray painted ‘Chico loves Gloria’ on the walls.
Leaving Foster Village, the Owl travels beneath Aliamanu Military Reservation, the freeway, and Coast Guard housing. At the last location, residents have claimed that their homes vibrate when the train passes below. (Mass Transit Exists!)
The origin of the name ‘Howling Owl’ is long lost. One theory suggests that the train’s mournful hoot is similar to the hoot of an owl.
Another theory claims that the name stems from the Underground Railroad used by escaping slaves in the southern United States. Slaves planning to flee were told to await the signal – a howling owl. (WestOfSunset) The 15-foot-tall lighted tunnels later accommodated electric engines Honu and Lapaki.
