Yale Bridge
Encyclopedia
The Yale Bridge or Lewis River Bridge spans the Lewis River
near Yale, Washington
. It was built in 1932 by Cowlitz and Clark
counties. The suspension bridge
has a clear span of 300 feet (91.4 m), with a total length of 532 feet (162.2 m), replacing a previous steel truss bridge at the site. Construction of the Ariel Dam
had created Lake Merwin
with a water depth of 90 feet (27.4 m) at the site, requiring a new bridge that did not need to have support piers in the water. The road deck, stiffened by a steel Warren truss
, is 50 feet (15.2 m) above the high water line of the reservoir.
The bridge was designed by Harold H. Gilbert of the Washington State Highway Department, and was constructed by the Gilpin Construction Company of Portland, Oregon. The only short-span steel suspension bridge in Washington, the bridge incorporates unique features. Only the central span is slung from the cables, with separate unloaded cables acting as backstays running from the 88.75 feet (27.1 m) tall towers to concrete anchorages in the canyon's rocky sides. The approach spans were originally supported from below by a timber structure. The cables are discontinuous at the towers, unlike most suspension bridges in which the cables run over a saddle on the towers. With less wear, the cables could be smaller. The bridge deck is made of timbers with an asphalt overlay. The counties transferred the bridge to the Washington State Department of Highways in the late 1930s and it was rebuilt in 1957-58 with steel approach spans. It is noted for prominent brackets supporting osprey
nests.
The bridge was placed on the National Register of Historic Places
on July 16, 1982.
Lewis River (Washington)
The Lewis River is a tributary of the Columbia River, about long, in southwestern Washington in the United States. It drains part of the Cascade Range north of the Columbia River. The drainage basin of the Lewis River covers about . The river's mean annual discharge is about . Unlike nearby Lewis...
near Yale, Washington
Yale, Washington
Yale is an unincorporated community in Cowlitz County, Washington, United States. Named for Yale University, the only school teaching forestry in the 19th century, Yale is located in the Speelyai Creek Valley at the junction of State Route 503 and Lewis River Road...
. It was built in 1932 by Cowlitz and Clark
Clark County, Washington
Clark County is a county located in the southwestern part of the U.S. state of Washington, across the Columbia River from Portland, Oregon.Clark County was the first county of Washington, named after William Clark of the Lewis and Clark Expedition...
counties. The suspension bridge
Suspension bridge
A suspension bridge is a type of bridge in which the deck is hung below suspension cables on vertical suspenders. Outside Tibet and Bhutan, where the first examples of this type of bridge were built in the 15th century, this type of bridge dates from the early 19th century...
has a clear span of 300 feet (91.4 m), with a total length of 532 feet (162.2 m), replacing a previous steel truss bridge at the site. Construction of the Ariel Dam
Merwin Dam
Merwin Dam is a concrete arch gravity-type hydroelectric dam on the Lewis River, in the U.S. state of Washington. It is located on the border between Cowlitz County and Clark County. Its reservoir is called Lake Merwin....
had created Lake Merwin
Lake Merwin
Lake Merwin is a reservoir on the Lewis River in the U.S. state of Washington. It lies on the border between Clark County and Cowlitz County. It was created in 1931 with the construction of Merwin Dam....
with a water depth of 90 feet (27.4 m) at the site, requiring a new bridge that did not need to have support piers in the water. The road deck, stiffened by a steel Warren truss
Warren Truss
Warren Errol Truss , Australian politician, is the current leader of the National Party of Australia in the Parliament of Australia. He has held the House of Representatives seat of Wide Bay since the 1990 election...
, is 50 feet (15.2 m) above the high water line of the reservoir.
The bridge was designed by Harold H. Gilbert of the Washington State Highway Department, and was constructed by the Gilpin Construction Company of Portland, Oregon. The only short-span steel suspension bridge in Washington, the bridge incorporates unique features. Only the central span is slung from the cables, with separate unloaded cables acting as backstays running from the 88.75 feet (27.1 m) tall towers to concrete anchorages in the canyon's rocky sides. The approach spans were originally supported from below by a timber structure. The cables are discontinuous at the towers, unlike most suspension bridges in which the cables run over a saddle on the towers. With less wear, the cables could be smaller. The bridge deck is made of timbers with an asphalt overlay. The counties transferred the bridge to the Washington State Department of Highways in the late 1930s and it was rebuilt in 1957-58 with steel approach spans. It is noted for prominent brackets supporting osprey
Osprey
The Osprey , sometimes known as the sea hawk or fish eagle, is a diurnal, fish-eating bird of prey. It is a large raptor, reaching more than in length and across the wings...
nests.
The bridge was placed on 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 July 16, 1982.
External links
- Yale Bridge at the Historic American Engineering Record, 12 B&W photos, 11 data pages, 1 photo caption page
- Yale Bridge at Clark County, Washington