The High Bridge carries Norfolk Southern Railroad across the Kentucky River near Wilmore, Kentucky. The bridge was once the highest bridge in North America and the highest railroad crossing in the world.
History
Original High Bridge
In March 1850, Kentucky approved the establishment of the Lexington & Danville Railroad (L&D) to construct a 35-mile railway connecting the major cities of Lexington and Danville. 10 One of the formidable obstacles was the deep Kentucky River gorge, with some areas plunging nearly 300 feet. Surveys showed that the most feasible and economical location for crossing the river was between Dicks Creek and Shawnee Run. In response, the L&D in 1854 engaged notable engineer John A. Roebling to devise a suspension bridge that would span the Kentucky River. 1 4 8
The engineers concluded that a bridge supported by piers spaced 200 feet apart using wooden trusses would not be structurally sound. Furthermore, the concept of a modern cantilever bridge that could be constructed without scaffolding on that scale was untested at that time and considered excessively expensive. 10
Roebling had just finished constructing a double-track wire suspension bridge over the Niagara River near Niagara Falls in New York, which featured a main span of 800 feet. 10 He closely inspected the suggested site for a bridge over the Kentucky River and found it to be an excellent spot for a suspension bridge; the gorge had nearly vertical walls on both sides, and the river itself took up only a small portion of the potential main span.
The main concern with suspension bridges was their susceptibility to dangerous oscillations caused by the stress on the cables. 10 However, Roebling assured that this issue could be mitigated by installing vertical ties anchored into the ground at short intervals. This, combined with horizontal ties attached to the gorge’s walls and into the valley, would help stabilize any movement caused by the wind.
The railroad company approved Roebling’s design for a suspension bridge, with an estimated cost of $225,000. 10 This was significantly less expensive than a truss bridge, which would have necessitated very tall scaffolding due to the extreme height needed. At this time, work had also started on preparing the railway’s path from Danville, which included the construction of masonry structures and the excavation of a 400-foot-long tunnel on the northern side of the Kentucky River. At the intended location of the bridge, workers had erected four towers, each standing 87 feet high, with their bases securely anchored to the bedrock. Furthermore, a considerable amount of the cable and truss materials needed for the bridge had already been transported to the site by steamboat along the Kentucky River. About $100,000 had been expended in Roebling’s bridge project. 4
In addition, the Lexington & Danville Railroad’s charter was altered to allow the line to extend to a point on the border with Tennessee. 10 Negotiations were successfully completed to sell a sufficient number of the railroad’s first mortgage bonds on Wall Street, raising the necessary funds to complete the line to Danville and to push it further south.
Before the bond transaction could be fully completed with the delivery of the securities, a financial crisis caused the collapse of the money market, effectively halting the sale of the bonds. 10 This financial setback proved insurmountable for the railroad, which never managed to recover. Despite this, the railroad managed to lay tracks from Lexington to Nicholasville before the outbreak of the Civil War. Consequently, this section of the railroad came to be operated by the Covington & Lexington Railroad.
After the Civil War ended, Cincinnati merchants were looking for a direct route to southern markets, hoping to bypass the longer and more cumbersome river route to Louisville and the Louisville & Nashville Railroad. 4 The city of Cincinnati had been planning its own railway line to Knoxville, Tennessee since 1835. 5 The city finally initiated this vision by acquiring the bankrupt Lexington & Danville Railroad and awarding the first construction contract for its Cincinnati Southern Railway in December 1873. 6
On October 16, 1876, work on the railroad bridge crossing the Kentucky River recommenced. 4 The Cincinnati Southern Railroad discarded the initial suspension bridge plans due to the heavier weight of new locomotives and cars. 10 The original bridge design was intended for maximum locomotive weights of 35 to 40 tons, but the requirements had escalated to accommodate locomotives weighing between 55 to 60 tons, necessitating a stronger bridge design.
The railroad selected S. Shaler Smith 5 from the Baltimore Bridge Company, Maryland, to build a Whipple deck truss bridge instead. 1 2 3 4 This new single-track bridge was completed at a cost of $404,856 1 2 3 on February 20, 1877. 4 Following testing in late April, 9 an inaugural train journey across the bridge took place. 4 8
The newly completed High Bridge, measuring 1,125 feet in length and 275 feet in height, was recognized as the first cantilever bridge in the United States. 7 It also held the record as the tallest bridge in North America until 1888, when Young’s High Bridge near Tyrone surpassed it. 1 2 3 Furthermore, at the time of its completion, it was the tallest railroad bridge in the world.
President Rutherford B. Hayes officially inaugurated the High Bridge on September 17, 1879. 4 He was accompanied by his sons, Birchard and Rutherford, and the esteemed Civil War General William T. Sherman, all of whom were honored guests of the railroad company.
Reconstructed High Bridge
Due to the relentless growth in train traffic and the heavier loads of modern locomotives, a redesign was necessary for the bridge. Gustav Lindenthal took on this task, creating plans for a new double-track steel superstructure. 4 11 This new structure was built around the existing bridge between 1910 and 1911 at the cost of $1.25 million. 2 8 The American Bridge Company of New York 2 8 11 managed the construction of this project, with the Oliver Brothers and the Hunnicutt Company awarded principal sub-contracts. 11
To accommodate this expansion, the sandstone anchor towers, remnants of the original, unfinished suspension bridge, had to be removed. 2 In the erection of the new superstructure, which was 31 feet higher than the original, 13 7,000 tons of steel and 178,500 rivets were required. 12 14 The rebuilt High Bridge opened to traffic on September 11. 14
The Lexington Interurban Railway suggested repurposing the old High Bridge framework for a new crossing over the Kentucky River at Camp Nelson. 13 This was part of a plan for a proposed electric railway line that would stretch from Nicholasville southward to Lancaster, Danville, Richmond, Harrodsburg, and Stanford.
The High Bridge was declared an engineering landmark in 1986 by the American Society of Civil Engineers. 2 3 4
Gallery
Information
- State: Kentucky
- Route: Norfolk Southern Railroad
- Type: Baltimore deck truss
- Status: Active - Railroad
- Total Length: 1,323' (1911)
- Main Span Length: 525' (1911)
- Deck Width: 25' (1911)
- Total Height: 275' (1877); 320' (1911)
- Above Vertical Clearance: 282' (1911)
Sources
- “High Bridge, Kentucky.” Kentucky Atlas & Gazetter, 27 Feb. 2009.
- Powell, Tim. “High Bridge History.” WorldTimZone 2008, 27 Feb. 2009.
- “High Bridge.” Jessamine County Kentucky Tourism, 27 Feb. 2009.
- Kocher, Greg. “A bridge to the past.” Herald-Leader [Lexington], 8 Sept. 1999, p. 18.
- “The Birth of an Idea.” Cincinnati Southern Railway. N.p., n.d. Web. 14 Dec. 2014. Article.
- “Historical Timeline.” Cincinnati Southern Railway. N.p., n.d. Web. 14 Dec. 2014. Article.
- Marsh, Ramona W. “They Said It Couldn’t Be Built But High Bridge Still Standing.” Lexington Leader, 17 Aug. 1974, pp. C1-C2.
- “High Bridge.” Advocate-Messenger, 20 Jun. 1916, p. 7.
- Interior Journal, 27 Apr. 1877, p. 2.
- Pickett, William D. “Roebling Consulted on Building of High Bridge.” Lexington Herald, 21 May 1906, p. 8.
- “More About High Bridge.” Lexington Herald-Leader, 17 Aug. 1909, p. 8.
- “New High Bridge Is Opened To Traffic.” Advocate-Messenger, 19 Sept. 1911, p. 3.
- “Best Use to Make of Old High Bridge.” Lexington Herald-Leader, 20 Sept. 1911, p. 4.
- “New High Bridge Open.” Advocate-Messenger, 12 Sept. 1911, p. 1.
There is a scale model display in the Smithsonian Museum about the High Bidge