Bridge No: 2620050103100

Asset ID: 793

County: Horry

Bridge Name: Waccamaw River Memorial Bridge

Facility Carried: US 501 Business (Main Street)

Feature Intersected: Waccamaw River/CSX Railroad/S-123

Year Built: 1937

Year Reconstructed:

Main Structure Type: Girder-Floorbeam

Design: Continuous

Main Material: Steel

Railing Type: Concrete balustrades

Number of Main Spans: 4

Number of Approach Spans: 18

Approach Type: Steel Stringer

Structure Length: 1270 feet

Structure Width: 34.9 feet

Setting: The bridge carries a 2-lane highway and sidewalks over the Waccamaw River, two railroad tracks, and a local street on the east side of downtown Conway.The bridge has a high vertical profile over the river for navigational clearance.According to plans, the bridge was built in 1937 to replace a bridge that was located on a different alignment of US 501.That alignment winded to the north of town crossing the river upstream of the ACL RR bridge.

The bridge's western spans over the railroad tracks and local street are in the Waccamaw River Warehouse HD (NR 1986).The historic district consists of three, ca. 1880-1900 warehouses that were part of a railroad/steamship terminal.The warehouses are located at the bridge's southwest and northwest quadrants. The bridge postdates the district's ca. 1880-1900 period of significance and was not rated in the nomination.

The rail line crossed by the bridge was established ca. 1890 by the Conway Coast & Western RR, a short line that connected the small towns in Horry County with a main line railroad by way of the Atlantic Coast Line system at Chadbourn, NC.The short line was absorbed by the ACL in 1912 and eventually became part of CSX, which in recent years spun off the branch between Conway and Myrtle Beach as an independent short line, the Waccamaw Coast Line RR.

The 22 span, 1,270'-long bridge consists of a continuous steel girder-floorbeam main span that is a 3-span continuous unit (91'-114'-91') with two lines of built-up girders that are haunched over the piers, rolled steel floorbeams and stringers, and a concrete deck.The approach spans are steel stringers that vary in length from 42' to 53'.The bridge has a high vertical profile (47' over mean high tide) and is built on a long horizontal curve.It has concrete balustrades with cast-iron light standards set atop the posts.The light standards were placed in 1992-93 and are reproductions of the original standards.The bridge is supported on 2-column concrete piers with lancet-shape arch openings.The pier columns of the approach spans are vertically scored and have flared caps.The river piers are horizontally scored.

The 1937-38 continuous steel girder-floorbeam high-level bridge was NR-listed in 1994. The bridge is an early and technologically significant example of its type/design in the state context, representing the application of continuous design principles to a long-span bridge by the state bridge department under the supervision of state bridge engineer W. J. Gooding. Continuous designs allowed for longer spans with shallower depth beams than comparable simply supported spans, and reduced the number of deck joints, a major source of deterioration and maintenance. Continuous designs required the designer to undertake more complex stress analysis. National advances in engineering theory and analysis made continuous designs more acceptable to professional engineers starting in the late 1920s and 1930s. The bridge is also an aesthetically successful example of its type/design primarily due to the well-proportioned, architectonic piers that are highly visible due to the bridge being built on a horizontal curve with a high vertical profile.

According to the NR nomination, the bridge was built in 1937 to replace a single-lane bridge and improve connections between Conway and Myrtle Beach in response to growing automobile traffic demands. The bridge opened on April 1, 1938 with a celebration