By 1929, Harrisburg's growth as a freight and passenger rail hub in the eastern United States necessitated the introduction of new rail interlocking technologies to guide the convergence of high volume locomotive traffic through the city. At that time, over 100 passenger and 20 freight trains per day passed through the yards of the Pennsylvania Railroad here on fifteen tracks. The widening of the Market Street subway in 1926 and completion of the Soldiers and Sailors Memorial Bridge in 1930 resulted in the re-working of tract alignments requiring a more advanced facility that could monitor and activate track switching, train directions and speed. Thus in 1929 was erected the Harris Switch Tower, a Colonial and Tudor Revival-styled structure complete with Flemish bond brickwork and keystone window trim, giving architectural distinction to what otherwise would be strictly a utilitarian structure. From the time it opened, the Tower was technologically advanced in signal control and circuitry to allow for remote track switching at railroad junctions. Because Harrisburg was the hub from which six major rail routes emanated like spokes on a wheel, this technology was essential in maintaining the smooth movement of people and goods as well as to aid in the prevention of train collisions. now individually listed in the National Register of Historic Places, the Tower is one of only several that still stands on the main line railroad from Philadelphia to Pittsburgh, although the Tower ceased operations in the early 1990's. Purchased from Amtrak in 1992 by the Harrisburg Chapter of the National Railways Historical Society, the Switch Tower is a landmark to the golden age of the Pennsylvania Railroad's operations in the capital city.
1955 view showing the abundance of railroad tracks with Harris Switch Tower in right foreground and old Reading Railroad Station in distance.