The Ongoing Saga of D&H Main Line Signaling

Last we checked in on the former D&H Main Line between Albany and Sunbury/Scranton, NS had reversed its decision to abandon all of the signaling below Binghamton. Since that time NS has made some alterations to the signaling it had inherited from Canadian Pacific and after a couple of field trips and Google street view surveys I can offer up a summary of the goings on. 

First we need to dive into the crazy quilt of signaling on the old Delaware and Hudson main line that is under the control of NS after purchasing the route from CP in order to access New Englande markets via the Boston and Maine route. I previously discussed the complex ownership history of the D&H in an article on D&H interlocking naming conventions.

The D&H currently exhibits 6 different generations of signals in the 200 or so odd miles between the NS Buffalo Line in Sunbury and the Boston and Main division post in Mechanicville, NY. They can be broken down as follows:

Generation 1 includes the legacy D&H with GRS SA searchlights, relay based logic and iron/steel mounting hardware including masts, cantilevers and brackets. 

Generation 2 covers the early CP era in the 1990's with SA searchlights and relay based logic using modern aluminum structures.

Generation 3 is the Unilens Era where CP applied a solid state upgrade of its older SA searchlights, primarily at automatic block locations as those present less of a testing burden than interlockings. I believe this began in the late 90's and overlapped with some Gen 2 signals being installed at interlockings. By 2005 end of life Gen 1 interlockings were being actively replaced by Gen 3.

Generation 4, the Mystery Searchlight era, is the shortest, taking place from around 2009 through 2011. This represented CP souring on its Unilens solution and falling back on older SA searchlight guts in a custom housing. 

Generation 5, starting around 2011, is the great CP resigning that have up on searchlights entirely looked to replace Gen 1 signals at relay-based interlockings north of Binghampton with typical Safetran CL-20 type Darth Vaders.

Generation 6 is modern day with NS type Darth Vaders going in to replace both Gen 1 signals select relay plants, but also to replace Gen 3 signals at newer 2005 vintage interlockings. On the remaining CP territory this included the use of mystery N-type signals in place of CL-20's.

So how do things stand today? The CP re-signaling of the 2010's zapped pretty much all of the old D&H signaling north of Binghamton except CPF-499 and the Afton siding beginning at CPF-587.

In fact CPF-587 is seeing NS replace its southbound D&H Cantilever with a leftover CP mystery searchlight!

South of Binghampton D&H signals are holding on at CPF-648, CPF-650 and CPF-679.

CPF-650, still original D&H.

However Gen 3 Unilens signals have been replaced by NS Darth Vaders at CPF-630, CPF-631, CPF-659, CPF-661, CPF-714 and CPF-716.

CPF-716, Unilens signals replaced by Vader masts in 2022.

Interestingly enough, the intact Unilens masts have been gathered at the NS Scranton yard and the adjacent CPF-673 and CPF-672 were in their Unilens (or SA?) configuration as of November 2022. Nevertheless, almost all of the intermediate signals remain as Unilens, with just a handful having been converted by CP to CL-20 Vaders.

It will be interesting to see what the future holds, especially if NS extends between Scranton and Sunbury or if the need to replace the Unilens intermediates prompts an expansion of cab signaling.