Artery: A Brief History of the Baltimore Belt Railroad and Its Howard Street Tunnel", Lee, J. Lawrence, ASCE Civil Engineering Conference and Exposition 2004 B&O Power: Steam, Diesel and Electric Power of the Baltimore and Ohio Railroad 1829 – 1964, Sagle, Lawrence W., Alvin F. Staufer, 1964 External links Baltimore and Ohio Railroad lines CSX Transportation lines Electric railways in Maryland Historic American Engineering Record in Baltimore Rail infrastructure in Maryland Transportation in Baltimore National Register of Historic Places in Baltimore Railway buildings and structures on the National Register of Historic Places in Maryland Railway tunnels on the National Register of Historic Places