Good Thunder Railroad Bridge

Located near the small town of Good Thunder, this unique truss bridge carries an abandoned Milwaukee Road line across the Maple River. The first bridge at this location was likely a timber bridge, either a pile trestle or timber truss bridge. In 1905, the bridge would be replaced by a 158-foot Pratt through truss span, originally fabricated in 1882 by Edge Moor Bridge Works for the first Rock River bridge at Byron, Illinois. That span was originally the east span of a five span bridge, and other examples from this structure continue to survive at Bridge #K-1270, Bridge #M-522 and Bridge #Q-212. By 1929, the 1905 bridge had become too light for traffic, and another truss span from the second Rock River bridge at Byron, Illinois would be moved here. It is believed the previous truss span was scrapped at that time.

Currently, the bridge consists of a 140-foot, 8-panel, pin-connected Pratt through truss span, approached by timber pile trestle spans and set onto timber pile piers. The truss span uses a heavy 45-degree skew, and consists of built-up members, a traditionally composed floor, and one vertical endpost on either end. In addition, the span uses a lattice portal with a solid bracket for each heel bracing, indicating this span was one of the center spans at the Byron bridge. The vertical endpost uses a built-up member, consisting of two parallel channels connected by plates. At the time of relocation, the truss span was shortened from 160 feet to the current 140 feet. The truss was designed Albert Richardson and Onward Bates, who worked in the Bridge and Building Department of the Milwaukee Road. This railroad did many bridge designs in-house. It is currently unknown what contractor fabricated the steel. It is believed that the shortening was likely carried out by railroad forces.

Truss bridges were commonly used to cross large waterways. Bridges such as this one were built at a heavy skew, to allow for the waterway to be crossed at an acceptable angle. Many railroads reused steel and iron spans where appropriate, to help reduce costs and save on new material for bridge projects. The Milwaukee Road practiced this extensively, and very rarely let any bridge span go to waste. The railroad operated a sprawling bridge shop at Tomah, Wisconsin; where this span was likely modified. The two end spans from the Byron bridge are believed to have been reused at Rock Valley, Iowa. The other two spans were also likely reused at undisclosed locations, although it is unknown if they are still standing. Overall, the bridge appears to be in fair to good condition. The bridge is now privately owned, and the landowner is proud to own the bridge. The author has ranked this bridge as being regionally significant, due to the unique design and relocation history.