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The Bridges of King County Through the Lens of T. P. Blum: 1931 - 1934

Deck, Pony and Through Trusses

There are three common placements of travel surfaces in relation to bridge structures: deck, pony and through. On the deck truss, traffic travels on top of the structure; on the pony truss, traffic travels between parallel structures that are not joined together with cross braces over the top; and with the through truss, traffic travels through the structure which is cross braced above and below the traffic.

Bridge_no_3174__June_8_1932__TPBlum

Steel Hill Bridge, Steel Hill Road, .75 miles E of Allentown: [Railroad Tracks], June 8, 1932. (Series 474, Bridge Number 3174. Section 11, Township 23N, Range 4E.)

TTY Relay 711

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