Monon Trail Bridge

Information and Findings From DHPA Historic Bridge Survey

Bridge History and Significance

History The Road The Louisville, New Albany, and Chicago Railroad (LNA&C) acquired the Monon Route between Chicago and Indianapolis largely through acquisition. From the route's conception to the railroad's erection of spans over Fall Creek in Indianapolis (Bridge #178.9) spin out long and somewhat complicated threads of corporate maneuver. In 1865 a group of Delphi (Carroll County) businessmen, committed to making their town a commercial entrepot between Chicago and Indianapolis, organized the Indianapolis, Delphi, and Chicago Railway (ID&C). In 1869, the ID&C hired Alexander H. Campbell, a key figure in Baltimore and Ohio Railroad development, to survey its route. Anemic financing of the ID&C led to its reorganization in 1872 into an alliance with the Chicago and South Atlantic Railroad (C&SA), a projected road from Charleston, South Carolina, to Chicago. Finally in 1874 the ID&C with aid from the C&SA began construction, even as the C&SA moved towards collapse. Within a year, 80 of the 105 miles between Chicago and Delphi were graded and bridged, and within four years the ID&C opened a narrow gauge road over the northern part of its route. Entry into the terminal cities presented a special problem. To enter Chicago over the Chicago and Eastern Illinois Railroad's lines, the ID&C leaders had to again reorganize in 1880, this time as the Chicago and Indianapolis Airline Railroad with the aid of Chicago money committed to standard gauge tracking. The next year, the Airline struck a deal with the LNA&C which took control of the road and finally brought it into Chicago. The LNA&C was itself reorganized in 1897 as the Chicago, Indianapolis, and Louisville Railroad (CI&L). While its entry into Chicago was being completed in the early 1880s, the Airline-Monon management arranged for approaching Indianapolis through Frankfort, Sheridan, Westfield, Carmel, Nora, and Broad Ripple. The Monon's initial entry into the city's center came in 1882 via a connection with the Lake Erie and Western Railroad (LE&W) at Howland's Junction and terminating at the LE&W's freight terminal from which passenger service to Chicago was inaugurated in 1883. Late in the year the LNA&C secured permission for the Airline to use Union Station. The Monon built its own line in 1888 from Howland Junction, near 34th Street and Fall Creek Boulevard, to the Indianapolis Union Railway at Alabama Street. Crossing Fall Creek To build south from Broad Ripple to join the LE&W at Howland's Junction, located somewhere near 34th Street, the Monon had to cross Fall Creek ahead of that junction in 1882. The railroad's earliest bridging of the creek remains unknown. A timber trestle would have been relatively quick and inexpensive to build. Timber beams might have been the solution of choice for another reason: The Monon did not yet have access to the main Indianapolis terminal, Union Station. Entrance to Union Station might have suggested a somewhat different route downtown, and timber beams over Fall Creek would not have involved a heavy and necessarily permanent kind of investment. The Monon's extensive collection of bridge plans document a permanent Fall Creek crossing in 1892. They include the design of two cut-stone abutments and a pier to support a through-truss span of 124-ft and 10-in. and a pony-truss one of 100-ft. and 10-in. The shorter of these two spans remains in place today. The building in 1892 of a complete substructure suggests that no permanent one existed on that site before. This, incidentally, would be consistent with the suggested scenario that timber beams and bents may have carried the track across the creek in the earliest years. In late 1904 the Monon's engineers focused on some work on the Fall Creek crossing. They drew up plans for a new southern abutment of cut-stone seated on a concrete pad. The plan matches the extant abutment. The next year Ralph Modjeski, a nationally-recognized design engineer, planned a modest rehabilitation of the south span. Aside from one Vandalia line, the great flood of late March 1913 at first cut off all rail service into and out of Indianapolis. The Indianapolis Star reported on the 26th that "traffic on steam and electric lines to points outside of Indianapolis is almost in a state of complete demoralization. Excepting the occasional movement of a train into or out of Indianapolis over the Vandalia lines to St. Louis, railroad traffic is at a standstill." The Star reporter added that "service on the Monon is completely tied up. It was reported that 25 miles of track had been washed away." The same news report, however, implied that the Fall Creek crossing remained operational. The Monon's managers had apparently arranged emergency "suburban service." The day before the railroad operated "a special train to Broad Ripple every half hour". "No charge is made for transportation on this line, and stops are made at points where passengers desire to get on or off." But news reports which included the crossing even implicitly were somewhat equivocal. An announcement of special trains for visiting the automobile show at the state fair grounds on the 30th referred specifically to the Lake Erie and Western Road. "The Monon railroad also has consented to run trains to 30th Street, and from that point cars will carry the visitors the remainder of the distance." Since, after crossing Fall Creek, the Monon's tracks went right along the western border of the fairgrounds, one might expect it to allow travelers to detrain and entrain for the auto show there rather than at 30th Street, unless the line's bridges across Fall Creek had become problematic. Regular service had not resumed on the Monon as of 1 April 1913. "The company expects to be able to use its own line out of Indianapolis either tomorrow or Thursday, the fill at Broad Ripple, which was washed away, being the principal cause of the tieup." There is no mention here of difficulties with the Fall Creek bridges, nor did any newspaper report on bridges that had been washed away by the flood refer to the Fall Creek spans. The March flood appears to have at least undermined the Fall Creek bridge pier, for the Monon's engineers had by September drafted a plan for a new one. The plans carry notations of a final 1914 estimate from "Harding & Slattery" for timber, excavation, and masonry for the new pier. Vincent Harding was a well-known stone mason from Indianapolis, and Thomas Slattery of Crawfordsville built a number of major cut-stone bridge substructures across central Indiana. The extant spans are each still supported at one of its ends on the pier that Harding and Slattery constructed. Since the building of a new pier required the removal of the two superstructures from off the central support, it encouraged the railroad's engineers to undertake collateral changes at the same time. The flood, for example, probably persuaded the engineers to get Harding and Slattery to raise the two abutments above the new-found flood stage. It also prompted the construction of a new main span over the creek. The Monon hired the engineering firm of Allen and Garcia to draft plans, a task completed by December 1913. Allen and Garcia proposed a lattice through-truss span, and the railroad contracted with the Wisconsin Bridge Company of Milwaukee to build and erect it. The steel lattice spans Fall Creek today. The Monon Fall Creek bridges served rail traffic until the line was finally abandoned in 1986. The CI&L was reorganized in 1946 as the Monon Railroad. Following the precipitous decline of rail traffic starting in the 1960s, consolidation became inevitable. In 1971, the Monon merged into the Louisville & Nashville Railroad, which itself eventually became part of the "Family Lines," that in turn merged into the Seaboard System Railroad (1982), which finally folded into its parent company, CSX Corporation (1986). In 1989, the City of Indianapolis purchased the old Monom right-of-way and its remaining structures from the CSX. Description North Span Although entitled "lattice span" on the 1892 plans, the 100-ft. and 8-in. pony-truss span is an all-riveted, full-hip Pratt subdivided into eight panels (@ 12' 7") seated on a cut-stone abutment and pier. Whether the trusses are made of wrought iron, steel, or some combination of the two materials remains undetermined. The truss depth is 10-ft. and 6-in. (out-to-out), and the trusses are set 15-ft. and 6-in. (center-to-center) apart to carry a single track. The end post and top chord members were each made from a pair of crafted channels, cover plate, and lattice bars all riveted together. The lower chord members were built much like the upper ones, except for the substitution of latticing and battens for a cover plate. The truss web is also made up of built-up members. All the same size, the verticals consist of I-beams crafted from angles and plate. The diagonals, however, do vary in size and nature. Those in panels 2, 3, 6, and 7 are, like the verticals, crafted I-beams, which become slightly lighter in the panels towards the center. The diagonals of the two most central panels each consist of a single pair of angles riveted together with lacing bars. These center panels also carry counter braces composed of a pair of angles riveted together with battens, near where the diagonals intersect. Girder floor-beams, nearly 30-in. deep, are riveted to the verticals above the lower chord. Two runs of girder stringers, nearly 20-in. deep, are attached through angles to the sides of the floor-beams. Each run of stringers was placed to carry one of the rails attached to the timber ties directly above. To accommodate the stresses caused by locomotives and railroad loads, the span carried some extra bracing. Like most spans, it has lower lateral braces, in this case an angle attached to the bottom of one floor beam and crossing the panel diagonally to the bottom of the adjacent one. The floor-beams received additional bracing from stiffening plates that ran from near the top of each vertical to the intersection with the beam below. Gussets also stiffened the connections of each chord with the end posts. In 1905, the Pratt pony-trusses were reinforced under the direction of Ralph Modjesti. He added gussets along the lower panel points where diagonals intersected with the lower chord and replaced lattice bars on the bottom side of the lower chord members themselves with cover plates immediately under the panel points. He also reinforced the stringers and their connections with the floor-beams. South Span An all-riveted, steel, double-intersection Warren or lattice through-truss span extending 123-ft (clear), subdivided into 6 panels (@ 20' 6") rests on the cut-stone pier and southern abutment. The trusses are 28-ft. deep and carry a 16-ft. wide deck for a single track. The end-post and top-chord members all consist of a pair of crafted channels, cover plate, and lacing bars riveted together. A pair of crafted channels laced above and below supply the lower chord. The truss web has hip verticals and a collision strut along with double-intersecting diagonals. The hip verticals and the collision struts (which are riveted to the end posts about a quarter of the way up from the lower chord) are made of crafted I-beams. Starting from the end-post, top-chord connection, a set of diagonals alternate from a pair of unconnected angles, through sets of crafted I beams, and back to a pair of unconnected angles. Starting from the hip vertical's lower panel point, another set of diagonals consists only of crafted I-beams, heaviest in the outer (2nd and 5th) panel(s). Girder floor-beams (2' 7" deep) are riveted to gussets and the verticals at and just above the lower chord. Placed to be under each rail, two runs of girder stringers are attached to the sides of the floor-beams with angles riveted into place. The span carries considerable bracing. The trusses above have braced-A portal struts made from channels. The interior struts at upper panel points and the upper laterals are made from two pairs of laced angles. The upper strut at midspan was doubled to accommodate heavy knee braces (each a pair of angles riveted to a plate) connected to the two most-central diagonals. The floor system is also well braced. Lateral bars cross from one lower panel point to another, and the stringers are stiffened with struts placed at mid-panel. All the panel points in the trusses carry gussets. The entrance of the Airline or Monon railroad-the self-proclaimed Hoosier route--into the state capital, as into a number of other hoosier towns and cities, was important in the development of Indiana. Crossing Fall Creek supplied a piece of the larger picture. That these spans are now slated to become part of a Greenways system increasingly integral to the lives of capital city residents portends a different but also significant future for them. The structures at the crossing are important in their own right, too. We know that at least the center pier was built by stone masons with reputations for excellent craftsmanship extending beyond the communities where they lived. The two spans of the superstructure were both designed by out-of-state engineers, and the one span was rehabilitated under the direction of one with a national reputation. Nationally-known bridge companies fabricated and erected each of these spans. Age weighs in on the side of the pony-truss span. Nineteenth-century railroad bridges are increasingly rare in Indiana. An all-riveted one is of special note. The design of the through-truss span is special. There are only two lattice through-truss structures know to survive on Indiana highways, one of which is currently under review for replacement. This is one of around three lattices left from once-active railroads. In all there are less than a half-dozen lattice through-trusses remaining in Indiana. Both superstructures retain almost all of their original members and therefore their integrity. The pony-truss span was modestly rehabilitated in 1905; the through-truss span stands largely as it was built. That the Monon Railroad Historical & Technical Society retains the original plans for the substructures and the two superstructures is also noteworthy. "City Marooned; Traffic Tied Up; Indianapolis Practically Shut Off from Outside World by Damage to Railroads," "Trains Will Run to Fair Grounds," "Traffic by Rail Much Improved," Indianapolis Star, 36 March 1913: p3,c1; 30 March 1913: p10,c1; 1 April 1913: p18, c3-4. George W. Hilton, "The Airline," Monon Route (Berkeley, California, 1978), 39-52. Plans for North Span Superstructure (copies from Monon Railroad Historical & Technical Society): . American Bridge Works, "1-100'8" Lattice Span, LNA&C RR" (Chicago, April 1892). . Ralph Modjeski, "C. I. & L. Ry: Reinforcements of Fall Creek Bridge 1-100'8" Riveted Pony Span" (Monadnock Building, Chicago, November 1905). Plans for the South Span Superstructure (copies from Monon Railroad Historical & Technical Society) : . Allen and Garcia Company, Engineers, "Chicago, Indianapolis and Louisville Ry. Co., 121' 6" Riveted Truss Span" (Chicago, 4 December 1913). . Wisconsin Bridge & Iron Co., "1 - 121' 6" Through Riveted Truss Span, Fall Creek Bridge, Chicago, Indianapolis & Louisville Ry." (North Milwaukee, Wisconsin, Contract #7125, January-February 1914). Plans for the Fall Creek Crossing Substructure (copies from Monon Railroad Historical & Technical Society) : . American Bridge Works, "Masonry Plan for Fall Creek Bridge, L.N.A.&C. Ry. Co." (Chicago, March 1892). . Engineers' Office, C.I.& L. R'y Co., "Plan of Proposed Stone Abutment for the Bridge over Fall Creek near Indianapolis, Ind." (5 August 1904). . Office of Chief Engineer, C.I.&L. Ry, "Plan of Masonry, Fall Creek Br #B1789" (September 1913).

Bridge Considered Historic By Survey: Yes