Pennsylvania Railroad

by Mike Brotzman

Track Plan

NASSAU (CD) interlocking is 7.9 miles from the former location of MILLHAM in Princeton Jct. NJ and like MILLHAM, NASSAU no longer exists. Princeton Junction is where the single track line to Princeton proper branches off of the NEC. The line, known by locals as the PJ&B (Princeton Junction and Back) has been the chief territory, since the line was electrified in the thirties at least, of the "Dinkey". The Dinkey is a single car MU train, that meets mainline trains at the Junction and then runs to Princeton station, 2 miles away. Currently an NJT Arrow III MU car, back in the PRR era Princeton students were known on several occasions to steal the Dinkey for joy rides, then played by an MP-54. Like whenever a line branched off one of its main line, the PRR also constructed a full mainline crossover and power substation.

Nassau tower
Photograph by Mike Brotzman, 2002

As you can see in this cold December photo, NASSAU was built in the "Corridor Style", popular with the PRR for new New York Division towers during World War 2 and discussed on other pages. NASSAU was named for Nassau Hall, one of the central buildings on the Princeton University campus. NASSAU also tread a fine line regarding duplicate interlocking names on the same railroad. The PRR wholly owned subsidiary, the Long Island Rail Road also had a NASSAU interlocking, in Mineola NY, named for NASSAU county. While this causes confusion with local rail buffs, it has never been a problem in the actual railroad community.

Built in 1944, NASSAU came equipped with 35-lever US&S Model 14 electro-pneumatic machine with 21 working levers and controlled brand new 45mph crossover turnouts. NASSAU was part of the same World War 2 initiative to replace mechanical towers on the New York division, here replacing the previous one built in 1900. The interlocking contained a full five-track crossover with the Princeton Branch entering from the south before turning into the No 5 track. There was also a No 6 track for storing the Dinkey in off hours.

View towards Nassau tower
Photograph by Mike Brotzman, 2002

Here is what remains of NASSAU interlocking today - you can see the tracks have all been straight-railed. The only connection to the Princeton Branch is a non-interlocked trailing point crossover onto Track 4. The Dinkey is now stored in a student proof, well-lit enclosure. The only real remnant of the interlocking is the southward 5-track signal bridge, a signature of the interlocking. The former home signals have been converted into automatic signals for northbound trains on Tracks 1to 3. The signals for southbound trains are where the northward home signals used to be. As you can see, two of the signals have had their lower heads stripped off, but the signal over Track 1 has inexplicably kept its lower head to give a RESTRICTING aspect. When trains on Track 1 clear what used to be the interlocking limits the signal changes from pure STOP to RESTRICTING allowing following trains to proceed into the occupied block without even needing to come to a halt. In this image it is particularly clear how while the tracks have been straightened, the overhead wires have not.

We can also see the mammoth PRR electric substation and the lo-level auxiliary platform that allows passengers to board trains on the center express track during special operating conditions.

Nassau tower
Photograph by Mike Brotzman, 2002

Amtrak has embarked upon an aggressive illumination campaign for its interlocking complexes for both safety and security. This makes interlocking towers particularly amenable to night photography. In this head on image of NASSAU we can see that the lower floor still contains a spaghetti of wires and relays (active or not) and that the upper floor still seems occupied and filled with knows what, probably junk.

Nassau tower
Photograph by Mike Brotzman, 2002

In this other night image of NASSAU tower, taken from right behind the 5 track, we can see once again the sheer size of the PRR substations used on their electrified lines. With the general decline of rail travel in the 1960's and 1970's, through trains to Princeton proper (for college sporting events, reunions, graduations etc) were eliminated and NASSAU became only useful as a full crossover on the NEC. Sometime in the mid-1980's, Amtrak decided to completely eliminate NASSAU as an interlocking plant. This left about a 15 mile stretch without a crossover and although this can lead to headaches with express Amtrak trains getting caught behind NJT commuters for extended periods of time, the decision does make some sense. First of all, interlocking plant costs aside, each turnout costs as much as $25,000 a year to maintain and NASSAU had 12 of them. Second, NASSAU was right in the middle of perhaps the fastest stretch of track on the NEC with speeds as high as 135 mph. Traditional turnouts take a lot of abuse at these speeds and might even require speed restrictions. Since this was hi-speed track, trains would face sporadic and minimal delays while receiving reduced operating costs and increased speeds. The choice was clear.

Winter view of train passing Nassau tower
Photograph from the collection of Bob Vogel

Lastly we have an image courtesy the collection of Bob Vogel. This mostly provides the clearest view of what remains of NASSAU interlocking as well as the lateral view that the Corridor style towers provided. Centerpiece of this photo is the New Jersey Transit APL-44M hauling brand new Comet V stainless steel coaches in the aftermath of an early December snowstorm.

About the photographs

Comments about this article should be addressed to Mike Brotzman