In 1931 a construction
contract was let to Six Companies, Inc., a consortium of six major
western firms. Together with the government, they built almost 30
miles of railroad connecting Boulder City with all the facilities
needed to build Hoover Dam (eg., cement mixing plants, quarry pit,
gravel sorting plant).
The Hoover Dam
construction railroad system had three segments. The first, from
Las Vegas to the Boulder City site, was built and operated by the
Union Pacific Railroad.
The second segment
was built by the U.S. Government. It ran from Boulder City down
Hemenway Wash to Himix, the concrete mixing plant on the rim of
the Black Canyon overlooking the dam. It provided concrete for the
final 242 feet of the dam and the buildings on its crest. The airline
distance from Boulder City to Himix was 6.7 miles. A drop in 1100
feet in elevation however, necessitated ten miles of winding tracks
to keep the grades from being too steep.
Six Companies,
Inc. built and operated the third segment of the system. The tracks
branched off the U.S. Government Construction Railroad at Lawler,
about a mile up Hemenway Wash from the Visitor Center. It crossed
Hemenway Wash and followed the base of the River Mountains and then
looped eastward to the gravel plant on the flat overlooking the
Colorado River. One branch went upstream 7.3 miles from the gravel
plant to the gravel beds on the Arizona side.
Isolation demanded
the tons of concrete needed for the dam to be manufactured locally.
An electric dragline with a five cubic yard capacity loaded gravel
into railroad cars. Concrete was made by mixing sand and crushed
rock, called aggregate, with portland cement and water. Over four
million cubic yards of aggregate were taken from the Arizona side
of the river.
The other branch
followed the river downstream into Black Canyon, to Lomix, a concrete
mixing plant situated at the base of Black Canyon. Lomix provided
the concrete for the diversion-tunnel linings, the powerhouse foundation,
and two-thirds of the dam. To prevent the concrete from drying during
transportation the mixing plant was put as close to the river as
possible.
Locomotives
hauled tons of gravel to a screening plant on the other side of
the river 24-hours a day. A round trip took slightly over two hours.
The foundations of the plant are now about 150 feet below the water
level of Lake Mead.
The Six Companies,
Inc. Railroad was, of course, abandoned after the completion of
Hoover Dam in 1935. The U.S. Government Construction Railroad section
was sporadically used until 1961, when the last generator was hauled
over its rails and installed at the power plant.
The tracks were
dismantled in 1962 and sold as scrap to Lucia Brothers. The tunnels
and trail were nominated in 1984 to the National Register of Historic
Places.
Today you can
walk or bicycle along the elevated railroad bed used to haul supplies
and materials for the construction of Hoover Dam. Enjoy the spectacular
views of Lake Mead and the surrounding desert landscape.
