Tag Archives: PRR position light signals

Main Line Position Lights on Borrowed Time

Anticipating change is key to documenting the railroad. In nearly three decades of photography along the former Pennsylvania Railroad Main Line, I’ve tuned my images to clues of this route’s past. While the PRR vanished into Penn Central in 1968, key PRR infrastructure has allowed necessary visual cues that retain elements of the old railroad. Among these are PRR’s iconic Position Light style signals that date to the steam era, and have survive the decades of change. However, a wise photographer will have noted that this style of signal hardware is out of favor. While Norfolk Southern has been gradually replacing its PRR era signals with color lights, I’ve learned that a recent NS application with the Federal Railroad Administration includes elimination of most remaining wayside signals from its former PRR Main Line between Harrisburg and Pittsburgh.


PRR signals at Lilly, PA
The morning of July 1, 2010, was clear and bright. I set up on the outside of a curve near Lilly, Pennsylvania, to get a good view of the automatic (intermediate) signals at 254.7. Here NS maintains three main tracks with the center track signaled in both directions. This arrangement stems from a Conrail-era modification in the 1980s, when it converted the line from PRR’s directional four-track system (the two south tracks were for eastward trains and two north tracks reserved for westward trains). In this view of NS freight 12G, I used a 100-400mm Canon zoom with my Canon 7D mounted on a Bogen tripod. The lens is set at 285mm; image exposed at ISO200 f/9.0 1/250th second (camera RAW adjusted in Photoshop). By using a long focal length aimed directly at the signals I’ve maximized the effect of the position light arrangement.
Lilly, Pennsylvania
Norfolk Southern 12G is crawling upgrade, which gives ample time to expose many images. This one offers a more dramatic angle on the leading General Electric DASH9-40CW while keeping the signals in view. I’ve adjusted the 100-400m lens to 180mm, and closed the aperture slightly to f/10.0. (Camera Jpg, unmodified).

The writing is on the wall for these signals. Among those to go are favorites on the ‘west slope’ (between Gallitzin and Johnstown, Pennsylvania). I worked this area intensively in summer 2010, making an effort to capture trains passing former PRR Position Lights. Be forewarned: the signals that protected trains hauled by PRR’s magnificent K4s and M1b steam locomotives and have survived these long decades will soon pass from the scene.

Former PRR main line.
In this June 30, 2010, view. I’m looking downgrade (west) from the ‘Railfan’s Overlook’ at Cassandra, Pennsylvania. I’ve set the 100-400mm at its maximum focal length to capture a set of light helpers drifting west toward the signal bridge near Portage. In the distance an eastward train is climbing. While the signals are incidental, they offer a touch of PRR heritage. A wink of sun improves the composition. The exposure was at ISO200 f/5.6 1/500th second with Canon 7D.

I researched the development of PRR’s Position Light signals for my book Railroad Signaling. Here’s an excerpt:

PRR’s first position lights were installed in 1915 along the Main Line between Overbrook and Paoli, Pennsylvania, in conjunction with its new 11,000-olt AC overhead electrification. Early position light signals featured large background shields to protect the view from effects of harsh backlighting. Aspects mimicked those of upper quadrant semaphores by using rows of four lamps. After a few years of service these position lights were deemed successful. However, before PRR adopted the signal for widespread application, the form of the position light signal head was refined: Each head used rows of three lights oriented around a common center lamp with the outer lamps forming a circle. Lamps were mounted on bars with a circular background panel affixed over the lamps and shades to prevent backlighting. Traditionally this panel was made of Armco iron, measuring 4 feet 4 inches in diameter, with 7-3/4 inch holes punched in it for the lamps. Each single head can display several basic aspects: ‘clear’, represented by three vertical lights; ‘approach’ by diagonal lights at a 45 degree angle running from the 1:30 clock position to the 7:30 clock position; ‘restricting’ by diagonal lights at a 45 degree angle running from the 10:30 clock position to the 4:30 clock position; and ‘stop’ (or ‘stop’ and proceed) by three lights running horizontally. An individual signal head is only provided with lamps for the aspects it is expected to display and unnecessary holes are covered over. The lower of two heads, tended to use a slightly different shape for the shield panel. By using two heads, a great variety of speed signal aspects mimicking those of two and three head semaphores are possible. Slow speed aspects are provided by dwarf position signals that use a slightly different light pattern.

Signals at Summer Hill, Pennsylvania
On June 30, 2010, an NS SD40E helper set (rebuilt from SD50s) drifts down at Summerhill, Pennsylvania. These signals are easily accessible from the village. By design, position light signals are meant to be viewed head on, which makes it difficult to capture their aspects in photographs in bright daylight. Canon 7D with 28-135mm lens set a 70mm, ISO200 f/5.0 1/800.