Alaska Central Railroad Tunnel No. 1
Encyclopedia
Alaska Central Railroad Tunnel No. 1 is a historic railroad tunnel located north of Seward, Alaska
in the Kenai Peninsula
. The tunnel was dug in 1906 and served the Alaska Central Railroad and later the Alaska Railroad
until the route in the area, known as the "Loop District" was rerouted in 1951.
and avoid the paths of two glaciers. A survey line was completed in between 10 and 15 feet (4.6 m) of snow during the 1904–05 winter. Between March and November 1905, engineer Frank Bartlett determined sites for the structures needed to complete the route. At Mile 48.2 the route traveled through the tunnel.
The tunnel was part of a section of the route that turned 235 degrees. The tunnel curved at 14 degrees per hundred feet
and approximately 100 degrees of the turn was completed within the tunnel. Upon exiting the tunnel, the route crossed a 1600 feet (487.7 m) trestle
that was between 40 and 90 feet (27.4 m) high and completed the remaining 135 degrees of the curve.
Construction began on January 16, 1906. The first 250 feet (76.2 m) was dug using a steam-powered
drill. Despite good progress made with the steam drill, the heat from the steam caused the tunnel to become too hot, and pneumatic power was used beginning April 28. Drilling was completed on September 25 on the tunnel finished on October 8. The total cost of labor and materials was US$
96,782.66.
In 1914, a survey crew for the Alaska Engineering Commission studied the area for a proposed government railroad and to assess the Alaska Central line. The Commission recommended that the Alaska Central line be purchased by the state, and it was incorporated into the state's Alaska Railroad
. The state extended the line north to Anchorage
.
The Loop District and Tunnel #1 were difficult and expensive to maintain, especially during the winter season. During the winter, a crew of men were stationed at the tunnel to operate a steam heating plant and large doors that had been installed at either end of the tunnel to keep the tracks inside from freezing. With rising costs associated with keeping the tunnel operable and the task of replacing many declining trestles, the railroad undertook a $1 million project in 1951 to relocate the route around Loop District between Miles 47.5 and 50.8 north of Seward. The retreat
of Bartlett Glacier made a new route possible. The completion of the new route and dedication on November 6, 1951 made the Loop District route obsolete.
The tunnel was added to the National Register of Historic Places
on November 28, 1977 and is in the possession of the Chugach National Forest
.
Seward, Alaska
Seward is a city in Kenai Peninsula Borough in the U.S. state of Alaska. According to 2005 Census Bureau estimates, the population of the city is 3,016....
in the Kenai Peninsula
Kenai Peninsula
The Kenai Peninsula is a large peninsula jutting from the southern coast of Alaska in the United States. The name Kenai is probably derived from Kenayskaya, the Russian name for Cook Inlet, which borders the peninsula to the west.-Geography:...
. The tunnel was dug in 1906 and served the Alaska Central Railroad and later the Alaska Railroad
Alaska Railroad
The Alaska Railroad is a Class II railroad which extends from Seward and Whittier, in the south of the state of Alaska, in the United States, to Fairbanks , and beyond to Eielson Air Force Base and Fort Wainwright in the interior of that state...
until the route in the area, known as the "Loop District" was rerouted in 1951.
History
In 1903, the Alaska Central Railroad began a rail project north from Seward. The company encountered the most significant geographic obstacles to construction between 47 and 53 miles (85.3 km) north of Seward, a section known as the "Loop District", where the line would need to cross a high-point in the Kenai MountainsKenai Mountains
The Kenai Mountains are a mountain range in the U.S. state of Alaska. They extend 192 km northeast from the southern end of the Kenai Peninsula to the Chugach Mountains....
and avoid the paths of two glaciers. A survey line was completed in between 10 and 15 feet (4.6 m) of snow during the 1904–05 winter. Between March and November 1905, engineer Frank Bartlett determined sites for the structures needed to complete the route. At Mile 48.2 the route traveled through the tunnel.
The tunnel was part of a section of the route that turned 235 degrees. The tunnel curved at 14 degrees per hundred feet
Degree of curvature
Degree of curve or degree of curvature is a measure of curvature of a circular arc used in civil engineering for its easy use in layout surveying....
and approximately 100 degrees of the turn was completed within the tunnel. Upon exiting the tunnel, the route crossed a 1600 feet (487.7 m) trestle
Trestle
A trestle is a rigid frame used as a support, especially referring to a bridge composed of a number of short spans supported by such frames. In the context of trestle bridges, each supporting frame is generally referred to as a bent...
that was between 40 and 90 feet (27.4 m) high and completed the remaining 135 degrees of the curve.
Construction began on January 16, 1906. The first 250 feet (76.2 m) was dug using a steam-powered
Steam engine
A steam engine is a heat engine that performs mechanical work using steam as its working fluid.Steam engines are external combustion engines, where the working fluid is separate from the combustion products. Non-combustion heat sources such as solar power, nuclear power or geothermal energy may be...
drill. Despite good progress made with the steam drill, the heat from the steam caused the tunnel to become too hot, and pneumatic power was used beginning April 28. Drilling was completed on September 25 on the tunnel finished on October 8. The total cost of labor and materials was US$
United States dollar
The United States dollar , also referred to as the American dollar, is the official currency of the United States of America. It is divided into 100 smaller units called cents or pennies....
96,782.66.
In 1914, a survey crew for the Alaska Engineering Commission studied the area for a proposed government railroad and to assess the Alaska Central line. The Commission recommended that the Alaska Central line be purchased by the state, and it was incorporated into the state's Alaska Railroad
Alaska Railroad
The Alaska Railroad is a Class II railroad which extends from Seward and Whittier, in the south of the state of Alaska, in the United States, to Fairbanks , and beyond to Eielson Air Force Base and Fort Wainwright in the interior of that state...
. The state extended the line north to Anchorage
Anchorage, Alaska
Anchorage is a unified home rule municipality in the southcentral part of the U.S. state of Alaska. It is the northernmost major city in the United States...
.
The Loop District and Tunnel #1 were difficult and expensive to maintain, especially during the winter season. During the winter, a crew of men were stationed at the tunnel to operate a steam heating plant and large doors that had been installed at either end of the tunnel to keep the tracks inside from freezing. With rising costs associated with keeping the tunnel operable and the task of replacing many declining trestles, the railroad undertook a $1 million project in 1951 to relocate the route around Loop District between Miles 47.5 and 50.8 north of Seward. The retreat
Retreat of glaciers since 1850
The retreat of glaciers since 1850 affects the availability of fresh water for irrigation and domestic use, mountain recreation, animals and plants that depend on glacier-melt, and in the longer term, the level of the oceans...
of Bartlett Glacier made a new route possible. The completion of the new route and dedication on November 6, 1951 made the Loop District route obsolete.
The tunnel was added to the National Register of Historic Places
National Register of Historic Places
The National Register of Historic Places is the United States government's official list of districts, sites, buildings, structures, and objects deemed worthy of preservation...
on November 28, 1977 and is in the possession of the Chugach National Forest
Chugach National Forest
-External links:*****...
.