As you can hopefully see from the 1992 diagram CORK has an interesting layout that grew out of the monolithic realignment project that spawned it. First of all the interlocking is over 3 miles from end to end with everything being wired directly into a Model 14 power frame. Second the new station was built with the then novel high level platforms. Of course to prevent restricting freight clearances passenger trains had to use special "station tracks" to platform at them.
By the first decade of the 21th Century the complicated plant at CORK was more than a little anachronistic. The through tracks for freight were rusty and infrequently used with most local freight using the "0" track. You can see how the interlocking machine and model board looked in these three picture. Note the cute self portrait on the upper right corner.
Unfortunately CORK was right in the cross hairs of a re-signaling project that by 2009 was nearing completion. This would split up the single interlocking into 4 independent plants and retire the venerable Model 14 machine. Fortunately the tower would be left open until the entire line could be wired for CTC. At some point I will devote a post to CORK tower and its history.
In my 2008 survey I had taken enough still photos of the east end of CORK interlocking so this time I decided to try some video. Here is what will become the new CONESTOGA interlocking. A full crossover now replaces the single facing point 9 switch and the connection to the freight tracks are streamlined for medium speed movements as the 0 Track is optimized as the freight bypass track as opposed to a local delivery track. In the video we first pass under the 10R signal complete with train order lamp. Then the in service 9 switch and then a not in service trailing point crossover that will be part of the new interlocking, before passing the 10L dwarf. Finally we pass the bagged signal masts of the new interlocking.
Here is the station area. You can see how the main tracks were re-aligned to replace the station tracks. Before the mains were moved and after the station tracks were removed you had a number of switches to nowhere.
Here is the old CORK tower with the new CORK relay hut in front. I really dislike Amtrak's new signage policy that involves barely readable text labels instead of a large interlocking name placard.
Here we can see the rebuilt 27 and 37 switches to the freight tracks. The 25 and 35 switches to the station tracks are gone.
The crossovers at CORK. For some reason Amtrak used low profile US&S M3 electric machines in this project. Those are normally used in mass transit applications.
The original signal heads are still in place on the eastbound gantry. On the left is the Track 1 signal and next to it the two signals off the Columbia Secondary goods line. Note each signal has a train order lamp and the lower head is of the original PRR design that only provides a backing plate to the Medium Speed | . The idea was that trains approaching a Restricting or Slow Approach would be traveling slow enough to not need the higher contrast of a backing plate. The advent of the Medium Approach aspect in 1956 somewhat upended this idea and since then new signals have gotten the full lower backing plate.
The connection with the former Reading RR Lititz Branch branch to Lancaster has already been spun off as its own interlocking with a panel in CORK tower. LITITZ interlocking is only in service on track 2 and the signals on track 1 (which did not protect anything) have been removed. As the Track 2 signal at Lititz is distant to CORK it gets a lower head for Approach Medium indications.
This marks the start of Rule 562 operation which means cab signals without fixed wayside signals except at interlockings and distants. The westbound signal at LITITZ is equipped with a special 'C' marker light which authorizes Rule 280a, Clear to Next Interlocking, in case a train suffers a cab signal failure.
New automatic signal 708 eastbound distant to CORK on track 1 displaying approach. All new signals are of the colourized position light variety.
New automatic 718 eastbound distant to LITITZ on track 2.
RHEEMS interlocking is a brand new CTC crossover installed to replace the old hand operated Temporary Block stations Florin and E-Town. The interlocking is R-STATE tower. Here you can see the brand new crossovers all with movable point frogs and the new overhead catenary to support them.
Eastbound signals at RHEEMS. Note the 'C' boards and improper use if round backings for the lower signal heads. These new signals also use LED lamps. There might be less issues with bulb out protection due to the cab signals and redundancy from position lights. May not have the charm of all amber PL's but they are still very impressive compared to plain old colour lights.
New automatic distant to RHEEMS. Use of distant signals in Rule 562 territory relieves trains with failed Cabs from having to approach the next interlocking prepared to stop. Also it provides the engineer better information as to potential conditions as cabs compress 21 some odd signals into 4.
Automatic 923 w/b distant to ROY.
ROY interlocking in Royalton has long been remote controlled from STATE tower. With the re-signaling project the pulse code CTC was replaced with more solid state components and the interlocking was converted to modern bi-directional signaling. In this picture you can see the new westbound home signals. The signal on the NS Royalton Branch was moved west a bit to exclude a grade crossing and switch to a MoW yard from the new interlocking to cut costs.
Hey look at that, Amtrak installed proper lower signal heads on the eastbound gantry signals at ROY. Note how the NS track did not get the fancy new concrete ties.
The 962 automatic signal on the NS Royalton Branch was not upgraded.
The new 964 automatics on the Main Line. The use of a full backing plate for the lower | head is a bit overkill and Amtrak is beginning to use the pill shaped plate on newer installs. All of the new PL signals are Safetran units as US&S no longer manufacturers position lights.
We reach the outer limits of STATE interlocking here as we cross over the 123 switch. The 120R and 122R signals are just visible in the background. This trailing crossover was used for shunting movements to an express yard. It hasn't been used much since express and mail handling here ended.
Now entering STATE proper at the 100L and 102L signals. The trailing outer crossover and express yard is visible in the distance. STATE was built in 1937 with the new electrification project and operates out of an office in the Harrisburg station complex.
Semi-automatic signal 106R is located above the 102L and acts as a holdout for shunting moves at the express yard.
101 and 99 switches start off the outer facing point ladder.
Pot signals abound here at the eastbound entrance to the outer ladder. This is all slow speed (15mph) trackage now.
The terminal begins to expand at the 75, 77 and 81 switches. Everything here still uses pneumatic points, which is a good thing as STATE interlocking frequently finds itself under water when the adjacent Susquehanna River floods.
STATE still has one double split switch, although it used to have more. STATE has been gaining more responsibility with the CTC project, gaining a new panel for ROY and a new interlocking with RHEEMS. STATE is staffed by a train director who handles other duties like crew sign in and coordination with the power dispatcher upstairs.
More expansion at the 69 and 65 switches. The track heading off to the right in the background leads to a turning wye.
The track in the foreground is a stub where locomotives or cab cars are sometimes stores. The bright yellow pipe running around is the natural gas main for the burner type point heaters.
Well here ends part one. Parts 5-8 will cover the former PRR Middle Division from Harrisburg to Altoona. We will actually return to the Amtrak portion of the PRR Main Line later in the Eastbound direction after we reach Pittsburgh. Anything that was not covered in the first 4 parts will be in the final three which are set in 2010 and include a year of additional "progress" on the resignaling project.
I'll leave you with this picture of PRR GG01 #4859 on #5 track under the Harrisburg trainshed.