Highline Approach Viaduct (West)

View an article about the construction of the Highline Bridge and Viaduct (Engineering News Record; Volume 80, Issue 9)
View an article about the construction of the Highline Bridge and Viaduct (Engineering News Record; Volume 80, Issue 9)
View an article about the construction of the Highline Bridge and Viaduct (Railway Age; Volume 64, Issue 10)
View an article about the construction of the Highline Bridge and Viaduct (Railway Review; Volume 67, Issue 8)

Located on the west side of the Highline Bridge, this lengthy viaduct makes up the west approach and Missouri Pacific connection viaduct of the Highline Bridge and Viaduct complex. After the new Kansas City Union Station was constructed, a large complex of viaducts and connecting tracks were planned to connect to the station. Prior to the construction of this viaduct, passenger trains on the Missouri Pacific were required to use a busy single track bridge to cross the Kansas River. By 1917, construction had begun on the network of viaducts which would connect the Kansas River bridge to various railroad yards. This particular viaduct would be constructed to allow easy access from the Union Pacific Railroad mainline to the Union Station.

The Missouri Pacific connection viaduct begins at the west end of the Highline Bridge, before curving north, crossing Shawnee Avenue (span #13), Adams Street (spans #24 and #25), Kansas Avenue (span #40), the former Chicago, Rock Island & Pacific Railroad yard lead (span #45), Berger Avenue (span #49) and the Union Pacific Armstrong Yard (spans #68 through #81). The viaduct consists of 81 total spans, set onto a combination of steel bents, steel towers and concrete piers, with a concrete northern abutment. The towers and bents are set onto shallow concrete footings, typical of viaducts of this design. While the majority of the viaduct is constructed of deck plate girder spans, three truss spans cross the Union Pacific Armstrong Yard near the north end of this viaduct. Span #69, the southern truss, consists of a 147-foot, 6-panel riveted Pratt through truss span, with an M-frame portal bracing. Span #79, the middle truss, consists of a 117-foot, 5-panel riveted Pratt through truss span, also with M-frame portal bracing. Span #80, the northern truss, consists of a 137-foot, 5-panel riveted Pratt through truss span, with an A-frame portal bracing and a shallow floor. These trusses all feature heavy built up members. The remaining spans consist of deck plate girder spans, of the following sizes: twenty 30-foot spans, two 35-foot spans, four 40-foot spans, five 45-foot spans, thirteen 50-foot spans, four 55-foot spans, ten 60-foot spans, four 65-foot spans, two 70-foot spans, five 75-foot spans and nine 85-foot spans, which are located between the southern and middle trusses. Bents for the viaduct are generally comprised of two columns, connected by a large steel plate bracing which runs transversely to the viaduct. Towers are constructed using two bents, connected by longitudinal tower bracing. A connection to the Union Pacific tracks exits the viaduct at Berger Avenue (span #48). The deck of the bridge originally consisted of a cast-in-place concrete deck.

The bridge has several unique features. The viaduct features a number of curves as it weaves through the streets of Kansas City. These curves create unique spans, towers and bents, which were constructed to accommodate the curved viaduct. The north abutment utilizes a combination pier and abutment, with large concrete arches cantilevered from the back wall. This abutment design was reportedly chosen due to the ample space at this location. The 137-foot truss utilizes a shallow floor, which was designed to accommodate the low clearance of the Union Pacific yard underneath. Several of the piers on the north end of the bridge are constructed of solid concrete, while pier #38 is constructed of two concrete columns, joined by a concrete arch. Spans #27 and #30 near Adams Street are set onto unusual steel towers, consisting of no lateral tower bracing, and A-shaped longitudinal bracings. Additional towers This variation was made to allow for clearance for roadway and railroad traffic underneath.

Since the initial construction, a number of alterations have been made to the bridge. Spans #2 and #3, as well as the steel tower they rest on were replaced in 1993, after a derailment collapsed the two spans. Several bents, towers and spans have been reinforced with high strength bolts and new steel, likely constructed in approximately 2005, when rehabilitation work on the Highline Bridge was underway. At this time, the concrete deck from Berger Avenue to the Highline Bridge was replaced by a precast concrete panel deck. Spans #49 and #50 received a new steel beam fascia at approximately the same time. While the bridge was constructed to serve two tracks, only one track is utilized north of Berger Avenue. Overall, the bridge appears to be in good condition, with no significant deterioration noted. The author has ranked the bridge as being regionally significant, due to the unique design and numerous unique variations.