Historical Society of 

Mount Airy, Maryland, Inc.

The Mount Airy Junction Signal

The signal located outside of the Mount Airy Museum, which was originally installed at the Mount Airy Junction, was located south and west of Mill Bottom Road (see map).  The Mount Airy Junction was the location at which the western end of the Mount Airy Branch line (the tracks passing through downtown Mount Airy) reconnected to the B&O Railroad's Main Line.

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1  Original location of the Mount Airy Jct. signal

2  Later location of the signal

3  Location of the block control tower (see photos)

4  B&O Railroad's Main Line

5  Mount Airy Branch Line

6  Old National Pike (MD 144)

7  Mill Bottom Road

8  Interstate 70

When originally installed, the signal and the track switches at the junction were controlled from the block control tower, the wooden building, shown in the photos.  The switches were controlled using levers located in the tower connected to the switch through  mechanical linkages.  At the time these photos were taken, the main line was double tracked, so that trains could move east and west at the same time.  The signal was a B&O color position light (C.P.L.).


In 1959 much of the main line was single tracked.  At that time, the signal was reconfigured and moved to the east.  The block control tower was also removed.  After the tower was removed, the signal and switches were controlled by a central dispatcher located in Baltimore using electrical signals.

This photo shows the Mount Airy Junction, block control tower and CPL signal looking west circa 1950.

In this photo of the Mount Airy Junction, taken in 1985, the block control tower has been removed and the signal has been moved to the east of its original location.  (Photo courtesy of Dale Corn.)

This photo shows the MA (Mount Airy) Block Control Tower and switches looking east from the CPL signal in 1952

This is the Mount Airy Junction Signal shortly before decommissioning in 2004.  The replacement "color light" signal is located to the right of the CPL.