Prior to Bethlehem's incorporation as a city in 1917, the north side and the south side were independent municipalities. During the latter part of the 1910s, three bridges crossed between Bethlehem and South Bethlehem: the Minsi Trail bridge, the New Street bridge, and the Main Street covered bridge. The Main Street bridge was narrow and was regularly damaged by floods and ice. It crossed several tracks of the Lehigh Valley Railroad and the Reading Railroad on the south side as it led to Wyandotte Street. The Pacific Hotel stood between the southern portal to the covered bridge; the adjacent image shows the active freight and passenger railroad tracks travelers crossed to reach the bridge. To the right was Union Station, the passenger station of the Lehigh Valley and Reading Railroads with service to Buffalo, Harrisburg, New York, and Philadelphia.On the north side, it crossed the Lehigh Coal and Navigation Canal and the tracks of the Central Railroad of New Jersey before continuing up Seminary Hill to the Main Street business district.
Construction 1921-1924
Community leaders found the covered bridge to be a barrier to commerce between "the Bethlehems". As a result of the consolidation of the two municipalities into a single city, sufficient resources became available to design and construct a new bridge connecting Fountain Hill and Seminary Hill. By 1921, a commission was in place to design and oversee the construction of the new Lehigh River span. Commission members were the city's first mayor, Archibald Johnston, J.S. Krause, G.H. Blakeley, O.L. Henninger, A.A. Woodring, A. Geo. Shoffner, Dallett H. Wilson and C.W. Hudson. Construction on the Hill to Hill Bridge began on August 1, 1921, after many previous plans. As constructed, the bridge had nine approaches, eleven abutments, forty-eight piers, and fifty-eight spans. It was considered an engineering marvel of its time. By September 1924, the bridge was complete and provided safe, grade-separated connections between the two halves of the city.
Modernization
The structure of the Hill to Hill Bridge was modified significantly during the years after World War II. The first significant change to traffic on the bridge came during the construction of the expressway portion of Route 378 north of the bridge, known locally as the "Spur Route". Initially, the Second Avenue ramp on the north side was closed in 1967. In 1968, the expressway portion was opened. Three other ramps were removed as part of safety, structural, and redevelopment efforts. On the north side, The South Main Street ramp leading to Lehigh Street and the industrial area along the Monocacy Creek was removed in 1965. The River Street ramp leading to Sand Island was removed in 1988. On the south side, the Second Street ramp was removed in 1989.
The Hill to Hill Bridge today
The bridge saw extensive repairs in 1990, and was painted in spring of 2009. The painting process had caused two of the four traffic lanes to be closed, and had resulted in major traffic congestion. The painting project was finished in time for the opening of the Sands Casino Resort Bethlehem.
Bridge structure
The bridge is noted for its many ramps and branches. It was designed by Clarence W. Hudson and its structure makes use of "a combination of steel through truss and concrete closed spandrel deck arch spans" A unique characteristic of the bridge was the design of the two truss spans, needed to provide clearance over the railroads. Because the Second Street ramp intersected the bridge at the point of the southern truss span, the normal diagonal trusses could not be included. Engineer C.W. Hudson designed an alternative truss configuration, now known as the Hudson truss, which allowed an opening in the truss web between its vertical members. This bridge's spans are the only known examples of this truss configuration.
1924 (original) ramps and overcrossings from south to north
