One of the most common types of bridges for freight trains, our Truss Design Lift Bridge is a working replica of the many lift bridges that have been made over the last 100 years. Lift bridges became the workhorses of the freight railroads for many years as rail lines expanded over the rivers and ports of the world. The design was particularly useful in areas where there was no room for a bridge to swing, such as a busy industrial port. This bridge uses a small handle and crankshaft to lift the center span to the top of the truss structure, allowing trolls and other vehicles to safely pass between the two ends. The kit can be mostly made without glue and taken apart for storage. Snug slot construction and accurate cutting makes this possible!