Discussion relating to the PRR, up to 1968. Visit the PRR Technical & Historical Society for more information.
  by 2nd trick op
This inquiry is, admittedly, a long shot, but I'm wondering if anyone can provide a little more information on signalling and dispatchng on the upper end of the Harrisburg-Buffalo line before World War ii

To the best of my knowledge, the Pennsy never had much, if any, Automatic Block signalling on the Northern Division; manual block rules were strengthened after a fatal accident in the early Sixties, so much so as to require creation of an "emergency block station", designated GRUGAN, halfway along the 28 mile distance between Lock Haven and Renovo. A timetable from the late Twenties showed several more passenger runs than the 2-4 in the late-steam era, and the presence of the New York-Buffalo symbol freights BNY-14/15/16 would have added to the load, so some additional Block Stations would seem to be a "given".

The seventh volume of the Barnard, Roberts "Triumph" series refers to a number of previously-undiscovered towers along this route, with several ICC valuation photos, which would have been taken around 1918-1920, but regrettably, does not go into greater detail. Information on that portion of the line between Sunbury and Williamsport is a bit easier to come by, and reveals, to cite one instance, a nearly forgotten tower at the junction wth the former Susquehanna, Bloomsburg and Berwick at Watsontown.

So I'm sure that a stronger network of Block Stations existed along this route at one time.