The Chesapeake & Ohio Railroad Bridge over the Ohio River between Limeville, Kentucky and Sciotoville, Ohio was constructed from 1914 to 1917 by the McClintick-Marshall Construction Company. The structurally massive railroad bridge was designed by two famous American Civil Engineers, Gustav Lindenthal, D.Sc., the Consulting Engineer and David Barnard Steinman, D.Sc., the designer and stress analyst.1 2 6 R.T. Robinson was the resident engineer for the consulting engineer, and A. Toohey was the superintendent in charge of erection for the contractor.6
The design of the truss was unusual, as it was planned to be a two-span continuous truss.3 Each span was designed to be 775-feet in length, and the depth over the center pier was measured to be 129-feet, 2 inches. The War Department required a minimum of 750-feet.8
The trusses weighed up to 90 tons, and as a result, the bridge carried a substantial weight, and the connections in the span were riveted.3 In addition, the members measured up to 75 feet in length, and were erected in a distorted fashion to eliminate the need for secondary members. The bending of the truss members during construction in such direction and amount as to bring all members into a precise straight condition when the completed bridge is loaded to half its live-load capacity.6
The location of the bridge was considered to be one of the worst along the Ohio River for a crossing. The river on the Ohio span, although on the outside of the bend, was shallow with a rocky bottom. The low water channel was on the Kentucky span, while at flood stage, the principal current would switch to the Ohio side.3 A clear width of 370 feet had to be kept open over the Kentucky span to allow for the passage of coal barges, which dicated that a cantilever erection for the Kentucky span and falsework erection for the Ohio span. The Kentucky cantilever involved the construction of two temporary steel bents under the landward portion of the Kentucky span.
Further complicating matters was the issue of ice. It was decided that the falsework on the Ohio span had to be anchored with rock filled cribs, placed far apat so that ice could drift and pass between.3
On each bank was a narrow-gauge incline, leading from low water to 40 feet above the top of the bank. On the Ohio shore was a track that led from a crib that supported a derrick. The Kentucky incline led to a derrick boat.7
The plan included three river piers and 24 land piers. Nearly 27,000 cubic yards of concrete and 850,000 lb. of reinforcing steel was required.6 The sand and gravel was sourced from a river bar a few mile downstream. The middle pier, the largest of the 27 built, measured 18×63 feet, rising 96 feet above low water, and was built with the assistance of a cofferdam.7 Work on the pier began in October 1914 with the erection of a double wall box coffer dam, 79×127 feet outside and 14 feet high. The 10-foot space between the walls and the coffer dam was filled with sand and small gravel, decked over with a 2 inch plank.
Truss construction began at the center pier because it was located at a fixed bearing. The construction of the two spans simultaneously, over the center pier, allowed the caneilevered Kentucky span to relieve the load of the Ohio span on its falsework and sped up the building process. The erection of the middle four panels was also simplified, as the forces required for bending the members to connection were reduced.4
The construction of the Ohio span included the building of a falsework, handled by a gantry traveler that ran on the outside of the trusses.5 The gantry traveler was erected to 60 feet in height and carried two 80 foot booms on the front end for erecting falsework, floor and lower chord.3 For erecting the trusses, it was raised to its full height of 150 feet. The traveler carried three main falls of 50 tons of capacity each, and two sets of fleeting falls suspended over the centerline of the bridge, all operated by electric engines. The spans were left on the steel falsework until the Kentucky cantilever span could be self supported. When that was reached, the Ohio span was raised 8.25 inches to its final level, which released the span from its steel falsework supports.3 6 The jacking was done via ten hydraulic jacks, two of 500 ton capacity and the remainder of 200 ton capacity, along with several 50-ton Norton jacks, 30 screw wedge jacks of 200 ton capacity.
The construction of the Kentucky span was conducted with a regular top-chord or creeper-traveler method, with the building of two temporary supporting bents under panel points 8 and 4. Those bents had previously been used under panel points 8 and 12 on the Ohio span. The maximum cantilever length was 465 feet.3 6 The creeper traveler was designed and built specifically for the bridge, and was equipped with two booms, operated and swung by electric engines, with a jacking bridge suspended from outriggers. The jacking bridge served for supporting and jacking the free ends of the lower-chord sections before they were connected to their web members.
The structure opened on July 31, 1917,1 over the original estimate of November 1916,7 and featured twin tracks with two main spans, each 775-feet in length, deck truss approach spans that measured 152.5 feet each, and plate girder viaducts that measured 822 feet for the north approach and 1,062 feet for the north approach.1 2
It remained the longest continuous truss bridge in the world until 1935 and is still the prototype for continuous trusses, and the completion of the crossing marked a major advancement in the art of bridge engineering and was a major achievement in continuous truss analysis.
- Type: Continuous-subdivided Warren through-truss
- Total Length: 3,400 feet
- Main Span Length: 775 feet
- Width: 38.75 feet
- Height above low water/high water: 106.5 feet/40 feet
- Clearance at center/ends: 77.6 feet/38.9 feet
- “Sciotoville Bridge.” Ohio Historical Marker. May 2012.
- Baughn, James. “Sciotoville Bridge.” Bridgehunter.com. N.p., n.d. Web. 13 May 2012. Article.
- Pyle, Clyde B. “Problems and General Methods of Erecting the Sciotoville Bridge.” Engineering News-Record 80.2 (Jan. 10, 1918): 62-68. Print.
- Pyle, Clyde B. “Truss Erection and Jacking Operations for Two 775-Foot Continuous Spans.” Engineering News-Record 80.5 (Jan. 31, 1918): 219-226. Print.
- Pyle, Clyde B. “Erection Experiences at the Sciotoville Bridge.” Engineering News-Record 81.26 (Dec. 16, 1918): 1182-1185. Print.
- “Sciotoville Bridge Erection Is Well Started.” Engineering News-Record 77.1 (Jan. 4, 1917): 28-29. Print.
- “Building Concrete Piers for Sciotoville Bridge.” Engineering News-Record 75.9 (Mar. 2, 1916): 418-419. Print.
- “Long-Span Continuous Truss Bridge Over the Ohio.” Engineering News-Record 74.2 (July 8, 1915): 64-66. Print.