Tiffany Stone Bridge

Located near the small town of Tiffany, this iconic stone arch bridge carries the former Chicago & North Western Railway mainline across Turtle Creek. The first bridge at this location was likely a large timber pile trestle, constructed when the line was first built. Early on, the C&NW invested significant capital into this line, constructing stone and iron bridges wherever possible. In 1867, Chief Engineer of the C&NW Van Mienen began planning a large stone structure to carry the line across Turtle Creek near Shopiere Station, which would later be renamed Tiffany. Van Mienen had originally come to the United States in 1865 on orders of the French Government to report on the American Civil War. Van Mienen had been inspired by stone arches constructed in France, and it is believed that he began planning the new bridge to be similar to a bridge at Compiegne, France. To construct a bridge of such magnitude, large amounts of stone would be required. Quarries across Wisconsin were searched for high quality stone required for the bridge. A special quarry was opened at East Waupun, Wisconsin to quarry stone for the substructures. Limestone from Joliet, Illinois was shipped to form the voussoirs (arch lines), while limestone quarried at Duck Creek, Wisconsin was used for the spandrel walls. Stone quarried locally at Janesville, Wisconsin was used for the walls and to provide a solid backing throughout the interior. The stones were shipped rough to the site by railroad cars, where laborers carved the stone into the proper sized blocks. The stones were placed by use of ropes and pulleys, and mortar was used to fill the joints. Fill for the bridge was excavated from adjacent fields, leaving pits that survive today. Work on the bridge progressed through 1868, and the structure was completed in 1869 at a total cost of $12,826. Construction of the bridge was carried out under the direction of Henry Crane, a local bridge builder who became Superintendent of Bridges for the C&NW. John Watson, a local contractor, completed the structure.

The bridge is constructed of five 50-foot stone arch spans, which are constructed at a width of 16 feet and use a radius of 26.5 feet. The end to end length of the bridge is 387 feet, and the tracks are located 43 feet above low water. The base of the piers use a rectangular design, which is angled on the upstream side to protect the bridge from ice and debris. Three courses of vertical stones are placed above the piers, and the voussouirs rest on a slightly wider course. While the walls between the voussouirs is flat, the tops of the arch use a design with each row of stone projecting slightly further out. The abutments use an elongated U-shaped design, and do not contain any wing walls. Stone for the abutment walls has a distinctly yellow color, and is believed to have been quarried at Janesville, Wisconsin. The piers and west abutment are founded on solid limestone, while the east abutment is founded on timber piles. Originally, the upstream portion of the piers used timber boards to protect the pier, which have since been replaced by iron beams. Iron pipes placed along the top course of stone provide drainage for the deck.

Since the initial construction, the bridge has seen only two significant alterations. In 1887, a bituminous coating was added to the deck to provide greater waterproofing. It is possible that the iron pipe system was also added at this time. As the weight of trains increased, it became necessary to reinforce the arches to allow for safe and continuous operations. In 1931, linings were constructed under each arch span. An approximately 2-foot-thick reinforced concrete slab was added under each arch, which is was wedged above the pier by removing portions of the stone between the voussouirs and pier bases. It is unknown if this lining was completed by railroad company forces or by an unknown contractor. The most recent alteration to the bridge came in 1935, when the original chain railing was replaced by an iron pipe railing, giving the bridge its present appearance. Stone arches were commonly used by Midwest railroads, but structures of this size are exceptionally unusual of in this part of the United States. The C&NW constructed hundreds of examples of stone arch bridges and culverts along their lines, but it is believed that this is the largest such structure. Today, the bridge remains in regular use, and has seen no major alterations since the 1931 lining project. Overall, the bridge appears to be in good condition, with only minor deterioration noted to the stone. The concrete lining appears to be in excellent condition, with very little spalling or cracking noted. The author has ranked this bridge as being nationally significant, due to the size and age of the structure. Through the efforts of Rock County, the Wisconsin Department of Natural Resources and adjacent landowners, a park has been constructed northwest of the bridge, and the west bank offers excellent views of this historic structure.