Pennsylvania Railroad

by Mike Brotzman

Track Plan

Another 6.4 miles north of LINCOLN lies the Prince of towers on the NEC, UNION. UNION interlocking in Rahway, NJ, (formerly DK) is named for UNION county and presides over one of the best flying junctions ever designed. Initially constructed as part of an ambitious project to construct a supplemental two-track freight line from Morrisville to Elizabeth, UNION came to run the junction of the Main Line with the New York and Long Branch (NY&LB) railroad that ran down along to North Jersey Coast to Bay Head. To accomplish this the four-track Main Line grows to six tracks and the two track NY&LB splits into three tracks, two of which then fly under the Main Line in two separate tunnels to then rise up into the middle of the grade separated main line.

Union toer
Photograph by Mike Brotzman, 2002

UNION tower was constructed in 1912, right after the PRR's transition to all brick towers had taken place and it shares many design elements with such other towers as HUDSON and F. UNION was notable in that it was built with a US&S F13 interlocking machine, rather than the more typical Model 14. Furthermore, the interlocking was all electric rather than electro-pneumatic with the points being operated by 110V B-3 machines, later replaced with the venerable M-3 in the 1950's. The machine had space for 47 levers and all 47 levers were active.

UNION is perched on the side of the steep grade separated right of way and the tower operators need to use the little catwalk and adjacent steep steps to gain access to the tower. Furthermore, despite appearances, the tower is four stories tall, two of which are below track grade level, but are revealed in the image below.

Union tower
Photograph by Mike Brotzman, 2002

UNION interlocking is in actuality two semi-independent sub-interlockings. The southern interlocking is where the four-track main splits into six tracks - A, 1-4 and B from east to west. The initial usage was tracks 2 and 3 for freight, 1 and 4 for express passenger and A and B for stopping locals. Today tracks 2 and 3 are for express Amtrak trains, 1 and 4 are for NJT express trains and A and B are for stopping locals.

The southern interlocking also has three facing point crossovers from tracks 1 to 2, 2 to 3 and then A to 1. This is to allow northbound trains get routed out of the way of trains coming off of the NY&LB. The flying junction them comes into play with the No1 track of the NY&LB ramping up to track A on the main, the No2 track on the NY&LB ducking under tracks A through 2 to then rise up between tracks 2 and 3 in a straight walled single track gauntlet ending in a Y that connects with track 2 and 3. Track No3 on the NY&LB ducks under mainline tracks A through 4 to emerge on the same level with a grade depressed track B before rising up to another Y that allows access to tracks B and 4. At the end of the flying part of the junction, the tracks pass under a massive eight track signal gantry with five facing high home signals on it. This is the main point of the interlocking where the NY&LB tracks make their Y connections and there is a complete through running ladder crossover from track A to track 4. There are also a ladder from track 3 to B. Southbound trains encounter a signal bridge over tracks B through 3 right and a mast high signal for track 2.

Rahway station is located right at UNION's northern home signal and has been constructed with a high level, island platform between tracks B and 4 as well as a platform on track A. The Rahway island platform allows an excellent view of both hi-speed trains zipping through on the middle tracks as well as the Jersey Coast trains as they visibly dive out of view to make the diverging movement.

Union tower
Photograph by Mike Brotzman, 2002

UNION tower has survived largely intact aside from Amtrak filling in or bricking over its large original upper story windows and replacing them with cheap replacement windows visible in the image above. Furthermore, PRR brick towers used to have much of their wooden highlights painted a copper oxide colour, but this has since been replaced by a generic cream.

At one time UNION was considered to have the highest traffic density of any interlocking in the United States so it is no surprise that UNION is still an active tower today and furthermore, the only one on the NEC that regularly handles high speed operations. The NY&LB (originally a 50% jointly operated line with the Central RR of New Jersey) is not operated by NJT as its North Jersey Coast Line and trains approaching UNION need to frequently radio ahead for their lineup onto Amtrak trackage. UNION has also recently had 8 mph hi-speed turnouts installed in the south sub-interlocking namely at the lever 43 and 41 turnouts so that trains that need to get out of the way of converging NY&LB trains can do so more efficiently.

Union home signals
Photograph by Mike Brotzman, 2002

Finally, it is notable that the main interlocking's home signals retain their original PRR all amber position lights, despite Amtrak's near total conversion to colourized position lights. Also visible to the middle-left of the image is the No2 NY&LB track rising to meet the main line.

About the photographs

Comments about this article should be addressed to Mike Brotzman