Cataract Covered Bridge, Cataract Indiana

Date added: January 10, 2024 Categories: Indiana Covered Bridges Smith Truss

The Cataract Covered Bridge built in 1876, it is the only surviving covered bridge in Owen County, and one of only six Smith trusses in Indiana. This late 19^th Century bridge type was patented by Robert W. Smith and built by his company. The Cataract Covered Bridge is generally regarded as being the country's best and most intact remaining example of this truss type.

As its name suggests, the community at Cataract, Indiana, has been intimately linked to the falls in Mill Creek, originally known as Eel River. Early settler Isaac Teal built a mill about 1820 near the lower falls. Theodore Jennings, for whom Jennings Township would be named, was apparently attracted to the beauty of the falls and their economic potential. In 1841, he purchased the ruins of Teal's mill, both falls, and surrounding land totaling 1000 acres. Before long Jennings constructed mills for flour, wool, barrels, and eventually lumber. In 1876, the same year the current bridge was built, the community that grew around these workshops reached a population of about 100 and was the principal settlement of Jennings Township.

In 1876, a network of roads connected Cataract with neighboring communities. While the little village was not located on the direct route between Spencer and Greencastle, merchants and others could have made the trip between the Owen and Putnam county seats by way of Santa Fe (now Cuba) to the south and either Cloverdale or Needmore (now Cunot) and Putnamville to the north. Roads also connected Cataract to Bowling Green to the west (in Clay County) and, perhaps most importantly, to the Louisville and New Albany Railroad to the east at Quincy.

A bridge was built just below the Upper Falls before 1875, and would have provided a critical link between the mills and shops at Cataract and the residents across the river in the northern and eastern sections of Jennings Township. It was swept away, along with more than a dozen other bridges in Owen County, by a flood that crested on August 2^nd, 1875. Widespread damage across the county included the loss of much topsoil, most of the corn and wheat crops, and severed telegraph and railroad connections. While there was very little loss of life and only one reported incident of looting, the Owen County Journal estimated damages at a half-million dollars.

The county commissioners began discussing replacing the lost bridges almost immediately. On August 19^th, they issued an order advertising for bids to repair nine bridges, including "one across Eel River, known as the Cataract bridge, in Jennings township." For reasons that are not clear, the commissioners did not keep to their advertised intent to accept bids for the Cataract Bridge on August 31^st, 1875. Instead, on September 9^th, they decided to seek bids for a new wooden bridge and specified that

the style, plan and finish, are to be in all respects like the covered spans of the bridge over White River, at Gosport, and known as the "Smith Wooden Truss."

Perhaps the commissioners had initially hoped to repair any remaining fabric of the Cataract bridge or to reuse the existing abutments. Surely, they were impressed that the Gosport bridge survived the flood. Whatever the case, in specifying the "Smith Wood Truss," the commissioners were in some respects going through the motions of competitive bidding as Smith trusses were typically prefabricated by the Smith Bridge Company in Toledo, Ohio. Under these circumstances, then, it is not surprising that on October 22^nd, the commissioners awarded the contract

to furnish all material, build and complete the superstructure of a "Smith's High Double Wood Truss" Bridge across the Eel River in Jennings Township

to the Smith Bridge Company of Toledo, Ohio, at the cost of $14.35 per linear foot of bottom chord. A separate contract for the abutments was awarded to William Baragan.

There seems to be no further record of the matter in the Commissioners' Record until payment for the abutments ($1678.84) and the bridge ($2009.00) on December 5^th and 6^th, 1876. William H. Troth, who had been Owen County Auditor in 1875, received $30.00 to cover unspecified "services rendered in the construction of Cataract Bridge. The new bridge at Cataract was constructed just above the upper falls near the water-powered mill complex established by Jennings. The cut stone abutments are about 23 feet wide and 6 feet thick.

Wingwalls were built perpendicular to them out of dry-laid rubble. There are 129 feet between abutments and the single-lane bridge has about 10 feet of clearance over normal creek levels. Truss lower chords are 140 feet long; including roof extensions the entire structure is 150 feet long. The two trusses are 16' 6" tall overall; the entire structure to the peak of the roof is about 21 feet tall. There are 13 feet 8 inches clear between the inner faces of the two trusses' chords; total structure width between roof eaves is just less than 20 feet.

Little is known about the post-construction history of the bridge. A 1939 photo shows the bridge with an aged metal roof, the presence of wheel guards, and signs over both portals that read "$1 FINE FOR RIDING OVER BRIDGE ANY FASTER THAN A WALK." At some point the truss members were whitewashed. The present board siding, roof shingles, and the top layer of board decking were installed in 1995. Each may have been replaced several times before in the bridge's history. Vandals cut the first window in the north wall in 1980 to remove artwork painted on it in 1977. The present windows are the result of the 1995 repairs. A new concrete bridge replaced the Cataract Bridge in 1988. Shortly thereafter, its ownership was transferred to the Indiana Department of Natural Resources becoming part of Cataract Falls State Recreation Area, a part of Leiber State Recreation Area.

Few alterations were made to the original structure. One compression diagonal in the upstream truss had been replaced with timber of different dimensions and species. A pair of vertical steel rods had been added to the downstream truss where a tension diagonal's lower end has broken off. The concrete mudwalls atop the backsides of the abutments presumably replaced stone originals. The bridge's plank guardrails had been removed. Dates for these alterations are not known, but were addressed in the 2004 rehabilitation.

The Cataract Bridge shows evidence of its manufacturing process, advanced for a covered bridge. Many covered bridges have hewn timbers of irregular size, finish, and even wood species. The Cataract Bridge timbers have smooth, planed surfaces and uniform dimensions. Furthermore, at every joint between the dozens of timbers and spacer blocks that make up the chords both pieces of wood are match-marked with numbers painted in red. This would have been done at the factory in Toledo to ensure proper reassembly once the bridge reached Cataract.

The arrangement of the diagonal members of Smith trusses like the one at Cataract is distinctive. A truss in which the diagonals form a repeating "W" or zigzag pattern is known as a Warren truss. At Cataract there are two such patterns next to each other. Where one set of diagonals "zigs" the other "Zags" to create a type of lattice pattern some have called a "Double Intersection Warren" truss. Bolts connect the diagonals in the two planes where they cross. Another distinctive feature of Smith trusses is the inclined timber brace between the base of the end post and a point near the top of the outermost tension diagonal.

All of the main structural elements in Smith trusses are wood (metal is limited to fasteners and relatively small castings). Construction of effective tension joints has historically been problematic in wood structures, and Cataract is not an exception. Tension members in Smith trusses include the lower chords and some of the diagonals.

At Cataract, as in many covered bridges, the lower chord's timbers are spliced together with wooden "fish plates." The fish plates are shaped like elongated "C"s, whose ends fit into notches cut in the timbers they connect. At Cataract many of these joints are broken; either one end of the "C" or wood on the end of a timber has sheared off. The top chord, a compression member, uses simple butt joints.

Tension diagonals in Smith trusses also use notches. The ends of the diagonals are sandwiched between chord timbers, and both diagonals and chord timbers are notched. The diagonals must extend beyond the chord they are joined to for the tension joint to work (just as notched logs in a cabin extend beyond the building's corners). On Smith trusses all of the diagonals that point outwards as they go upwards are built like this.

Diagonals that point inwards as they go upwards are always in compression near the ends of the truss, and so can be built differently. The ends of these diagonals are simply butted up against tension diagonals where they meet the chord. The chord and the two diagonals thus all meet at about the same point.

Near the center of the trusses, however, diagonals in both directions may be in tension, depending on load conditions. Tension diagonals from different directions can't meet at a single point because of their "tails" extending beyond the chord. Instead the joints are about two feet apart (the tips of the "tails" are just inches apart). This is the reason for the changed geometry near the center of Smith trusses that has mystified some observers.

Loads on the diagonals of the Cataract Bridge trusses get progressively smaller between the ends and the center of the bridge. The size of the timbers does too. All are about 7 inches thick, but their width varies. The biggest, the outermost tension diagonals, are about 12 inches wide. The width is reduced in 1" increments until the smallest, at the bridge's center, are only about 6 inches wide. This accurate sizing of members to loads reflects the knowledge of structural mechanics that had been gained since the first covered bridges were built.

The Cataract Bridge has cast iron fittings in two shapes. One, found next to the base of the endposts, provides a solid seat for the intermediate-length brace. The other is found in the upper and lower lateral bracing, which helps maintain the vertical alignment of the trusses and resists wind loads. The Smith Bridge Company used this patented casting to firmly bolt the lateral bracing to the chords." This special casting also has flanges that keep the lateral bracing diagonals firmly notched together.

Structural evaluations beginning in 2001 identified deterioration evident in a visible "lean," the loss of positive camber, rotten timbers, and missing and broken abutment stones. Continued settling warranted the bridge's removal from its abutments in January of 2003 to the western bank of Eel Creek. A 2004 rehabilitation of the bridge was funded with assistance from Lugar Bill appropriations specifically for the preservation of covered bridges, and TEA-21 funds administered by the Indiana Department of Natural Resources. Rehabilitation included the removal of the earlier installations of a timber diagonal, steel rods, and concrete mudwall. The abutments were repaired by cleaning and repointing the mortar, relaying the bridges bearing stones, and replacing a missing cornerstone. Deteriorated material was removed from truss members, and like material was attached with bolts or epoxy. Camber was restored with the repair of sheered fish plates, and the addition of thin shims to the diagonal ends. A new cedar shake roof was installed. The portals were restored based on historic drawings and the examination of other Smith bridges. The approaches were reconstructed with dry-laid wing walls that support an asphalt path at an ADA accessible slope.

Bridge Description

The Cataract Covered Bridge is a Smith Truss type wooden bridge constructed in 1876. It spans Mill Creek in the Cataract Falls State Recreation Area, located in northern Owen County. The bridge is oriented east to west, and Mill Creek flows from south to north. It is adjacent to a modern concrete bridge that is part of County Road 1000N, and which replaced the covered bridge in 1988. The State Recreation Area lies to the bridge's north and west, and its immediate context includes a parking lot, grass-covered picnic areas, and the creek. Cataract's Upper Falls are located approximately 200' to the north, and forested private property is located to the east.

The bridge abutments are 23' wide, 6' thick, and 129' apart. They are constructed of rusticated limestone blocks laid in a common bond, and the stones in the upper courses are roughly half the size of the stones in the lower courses. Random coursed dry-laid wing walls extend perpendicular from the abutments, and retain the road approaches. A stone mud wall is located where the approaches meet the abutments. The western approach is paved in asphalt.

The bridge spans 140' across Mill Creek about 10' above the creek's stone bottom. An additional 5' in length extends off both ends. It is approximately 21' tall to the roof peak, 20' wide from roof eave to roof eave, and provides a single traffic lane of approximately 13.'

The white pine trusses are spaced approximately 15' apart and consist of alternating diagonals sandwiched between top and bottom chords, and bolted where they cross. The diagonals in tension are notched into each chord, and their tails extend beyond the lower chord. The diagonals in compression butt against the tension diagonals. The six diagonals at the center of the bridge are notched and have tails because they all can be in tension under certain loading conditions.

The chords consist of three parallel rows of timbers bolted together. Bottom chord timbers are spliced together with fish plates, and the top chords use butt joints. The chords terminate in a vertical end post, and an inclined timber brace runs from its base to near the top of the first tension diagonal.

The trusses are joined with upper and lower lateral bracing. For each set of bracing, one diagonal is adjacent (above or below) to the second, and they are bolted where they intersect. A cast iron fitting reinforces the attachment of the diagonals to the chords.

The bridge deck consists of floor joists that hang from the bottom chords and support three layers of wood planks. The bottom layer is attached to the floor joists and laid in a 45-degree angle. The second parallels the joists. The third creates two runners the length of the bridge where wheels typically track.

The bridge has a low-pitched, shake-covered gable roof that extends approximately 5' past the truss ends, and has approximately 2' eaves. The bridge is enclosed in modern board-and-batten siding painted red. The downstream side has three windows that provide views of the falls. The portal openings have rounded upper corners, and horizontal wood trim that simulates a column, capital, and pediment.