Bridge No: 1040070300100

Asset ID: 1303

County: Charleston

Bridge Name: Ben M. Sawyer Memorial Bridge

Facility Carried: SC 703

Feature Intersected: Intercoastal Waterway

Year Built: 1944-1945

Main Structure Type: Swing Span

Design:

Main Material: Steel

Railing Type: Tubular metal panels with concrete posts

Number of Main Spans: 2

Number of Approach Spans: 12

Approach Type: Steel Stringer

Structure Length: 1154 feet

Structure Width: 31 feet

Setting: The bridge carries a 2 lane highway over the Intracoastal Waterway between Sullivans Island and Mt. Pleasant.

The 14 span, 1,154'-long bridge has a vertical profile with a 248'-long swing span with thru truss superstructure over the navigation channel at mid-bridge.The truss is traditionally composed of built-up steel members.The swing span appears to be center bearing, but this can't be confirmed from the information available in the state inspection file.The operator’s house is in the overhead position.The steel girder-floorbeam approach spans are four, 3-span continuous units of 70'-86'-76' with tubular metal panel and concrete post railings.The bridge is supported on a reinforced concrete substructure.Other than routine maintenance, the bridge has no history of major alterations.Plans library indicates this bridge was rehabbed in 2011.

The Ben Sawyer Memorial Bridge, named posthumously for the first prominent commissioner of the state highway department, has been determined eligible as part of advancing a replacement project (2005).The bridge is 1 of 7 swing span bridges dating from 1929 to 1960 in the study population.It was built by the state highway department in 1944-45 to improve access to Sullivan's Island, a popular resort, replacing a timber stringer causeway further to the west.The bridge was also built during WWII with federal funds usually reserved for roads/bridges considered critical to national defense, probably having been identified as an important access route to coastal defenses guarding Charleston harbor.The bridge is a long but otherwise conventionally composed example of the swing-span technology that was developed in the late 19th century and remained one of the most popular movable bridge types through the 1950s.According to inspection reports, the bridge has significant loss of steel fabric from section loss.