St. Joseph's swing bridge carries both maritime and railroad commerce across the St. Joseph River by pivoting open for vessels and closing for trains, and it is typically left open until a train approaches. Three swing bridges have stood at this location: the first opened in 1870 when the Chicago & Michigan Lake Shore Railroad expanded, the second was built by the Chicago & West Michigan Railroad in 1887, and the present bridge was commissioned by the Pere Marquette Railroad and completed in 1904. The 1887 bridge was replaced after sixteen years because it proved too light for newer locomotives. During boating season, a bridge attendant is on duty 24 hours a day to allow passage for boats and freighters, but in winter the bridge is unmanned and locked to accommodate trains. Owned and maintained by CSX Transportation, the well-balanced present bridge is 231 feet long, weighs 300 tons, can be turned by a single 10-horsepower electric motor, and takes approximately 42 seconds to open.