Siuslaw River Bridge: Construction & Design

Siuslaw River Bridge: Construction & Design (HM1RO3)

Location: Florence, OR 97439 Lane County
Country: United States of America

N 43° 57.969', W 124° 6.521'

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Constructing Over the Siuslaw

The Siuslaw River Bridge incorporates Art Deco, Moderne, Gothic, and Egyptian influence that were important to McCullough. Due to its ability to open at the center, the Siuslaw River Bridge best represents McCullough's artistic and technical ingenuity.

Construction on the Siuslaw River Bridge began on August 5, 1934, and cost a total of $527,068.67 to complete. Over 200,000 man-hours of labor were utilized during the 20 months of construction. On average, 140 men were employed 30 hours per week during construction. Single men could only work on this bridge project for six months, while married men could work on the project for up to two years. When the Siuslaw River Bridge opened on March 31, 1936, the local newspaper reported that construction had utilized "thousands of pounds of steel, millions of cement, and oodles of lumber."

When the Siuslaw River Bridge was being built, it was known for its precision workmanship. The south section was built first and then the north section. In the original specifications, 1 3/8 inches were allowed between the leaves of the bascule in the closed position. When it was first closed, that distance was only off by 1/72 of an inch!

Conde B. McCullough
The Man Behind the Bridge

Conde B. McCullough designed the Siuslaw River Bridge, along with four others, as part of the Coast Bridge Project. His bridges were designed to be efficient, economical, and elegant. Today, McCullough's bridges are icons of the Oregon coast.

McCullough was a bridge engineer and served as the State Bridge Engineer for the Oregon State Highway Department from 1919 to 1935. He served under President Franklin D. Roosevelt beginning in 1935 to consult on bridges in Central America as part of the Inter-American Highway System. When he returned to Oregon, McCullough became the state assistant highway engineer and served in that position until his death in 1946.

McCullough preferred to work with reinforced concrete and he pioneered numerous innovations in working with it. He is famous for his tied arch, also called the bowstring arch, which practically holds itself and does not require massive supports on either end.

Through his pioneering of unusual design and construction techniques, as well as his books and technical journals sharing what he learned, McCullough contributed to the greater knowledge of bridge engineering in principle and in practice.
HM NumberHM1RO3
Marker ConditionNo reports yet
Date Added Thursday, April 14th, 2016 at 9:02am PDT -07:00
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Locationbig map
UTM (WGS84 Datum)10T E 411061 N 4868710
Decimal Degrees43.96615000, -124.10868333
Degrees and Decimal MinutesN 43° 57.969', W 124° 6.521'
Degrees, Minutes and Seconds43° 57' 58.14" N, 124° 6' 31.26" W
Driving DirectionsGoogle Maps
Area Code(s)541
Which side of the road?Marker is on the right when traveling East
Closest Postal AddressAt or near 85633-85693 Pacific Coast Scenic Byway, Florence OR 97439, US
Alternative Maps Google Maps, MapQuest, Bing Maps, Yahoo Maps, MSR Maps, OpenCycleMap, MyTopo Maps, OpenStreetMap

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