Brighton Park crossing is a major railroad crossing in Chicago, Illinois, hosting three of the major Chicago freight railroads. The crossing is northwest of the intersection of Western Avenue and Archer Avenue, in the Brighton Park neighborhood of Chicago, Illinois. The railroads involved in the crossing are CSX, Canadian National and Norfolk Southern. The crossing consisted of the CN's two-track line in a roughly east/west orientation, crossing the five north/south tracks operated by NS and CSX. Collectively, these railroads operate approximately 80 trains per day through the crossing.[1] The CN line was formerly the main line of the Gulf Mobile & Ohio and its predecessor Alton Railroad and currently carries Metra Heritage Corridor commuter trains and Amtrak passenger trains to St. Louis. The GM&O's Brighton Park passenger stop was at this location. The junction may be easily viewed from the CTA Orange Line trains that pass on an elevated structure immediately southeast of the crossing.
Until July 6, 2007, the crossing was controlled by a human switchtender in a cabin near the crossing The rail activity attracts railfans using semaphore signals. Because the crossing was not interlocked, all trains were required to make a statutory stop before proceeding over the crossing. As a major crossing — and one of the few remaining sites in Chicago with this archaic method of operation — the unique semaphore signals made Brighton Park attractive to railfans. However, this type of operation has long been an impediment to efficient movement of traffic in the increasingly congested Chicago railroad network.
As part of the Chicago Region Environmental and Transportation Efficiency Program (CREATE) project, the Brighton Park crossing, the semaphore signals, and switchtender's cabin were taken out of service on the evening of Friday, July 6, 2007 and conversion to an interlocked crossing was to ensue over the following weekend. As part of the conversion project, some of the tracks at the crossing were realigned and new crossing diamonds were put in place.
In a future stage of CREATE, it is anticipated that the at-grade crossing will be replaced with a flyover to eliminate the crossing entirely.
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The modernization effort to automate the Brighton Park crossing involved Safetran Systems, (part of Invensys Rail) with the crossing’s application development, site mock-up, and preliminary factory testing taking place in Rancho Cucamonga, California in an in-house project called “Brighton Park / Pershing Main.”
There were five different aspects of the modernization effort which consisted of (1) physical crossing interlocking, (2) vital software and hardware systems, (3) non-vital communications systems, (4) event data recording, and (5) input/output, all of which could be controlled and monitored by remote dispatch operators using display and control panels.
The project’s hardware and software consisted of existing Safetran components however the various application logic and site configuration modules were developed specifically for Brighton Park, all of which was heavily tested in California via a system-wide mock-up, requiring approximately 45 developers consisting of systems engineers, hardware and software engineers, applications engineers, test technicians, technical technicians, technical publishers, and others.
For the vital aspects of the interlocking, the Geographic Signal System [2] (GEO) device was applied. Non-vital communications between GEO devices included Wayside Access Gateways [3] (WAG) and Ethernet Spread Spectrum Radios [4] (ESSR.) Some logic control as well as event data recording is supplied by the Safetran Event Analyzer Recorder [5] (SEAR2.) A number of different I/O devices are used, including Unipolar I/O [6] (UIO.) Site monitoring and physical control is provided through large metal panels with numerous lights and switches which depict the rail control and indication points.
The vital aspects of the Brighton Park crossing is kept fault isolated from the non-vital parts of the crossing. In the event there is a hardware, software, or power fault within the vital systems, the crossing goes to the least permissive, safest state – usually with STOP signals being presented to locomotives and with crossing gate arms down with lights and bells.
There are also large control panels with many lamps and switches which operators may use to alter the flow aspects of locomotives through the Brighton Park crossing and the surrounding region. The control panels are inscribed with a depiction of the rails, and there are numerous switches, some of which can be used to instigate hardware and software testing of lamps and other devices.
In the event of a non-vital hardware, software, or power fault, the crossing may or may not be taken to a less permissive state depending upon the nature of the non-vital fault and the Rail company’s policies.
If communication to an Event Recorder is lost, for example, the maximum safe civil speed restriction in effect can continue to be used by locomotives since the lack of remote access to any such non-vital device does not impact vital safety.
If one or more vital GEO devices were to lose non-vital communications with another GEO device further down the line, however, the interlocking would go to a less permissive state since information about track occupancy and other things further down the track would become obsolete and then unknown.
The Brighton Park / Pershing Main project consists of many GEO boxes, WAGs, spread spectrum radios, Event Recorders, and other devices, all of which work to assist in the automating of this section of Chicago’s extensive rail infrastructure.
GEO devices, Unipolar I/O, and SEAR2s collect information about the crossing and surrounding region, either by monitoring voltages on wires or by passing messages among themselves. Logic software massages the real-world information and decides what signal aspects to show locomotives and decides what information to indicate to crossing predictors which assist the predictors in determining whether crossing gate arms should be lowered or raised, lights flashed, and bells rung.
Though the communications infrastructure (consisting of WAGs, radios, Ethernet bridges and such) are non-vital, messages conveying vital information is passed between vital devices using the communications infrastructure, messages which are encapsulated in Advanced Train Control System [7] (ATCS) messages and carry 32-bit Cyclic Redundancy Check [8] (CRC) values which are used to verify with extreme accuracy that messages have not been corrupted.
Vital messages also carry timestamps and sequence information such that in the event of unexpected routing delays or routing loops, obsolete messages will be ignored and duplicate messages will be eliminated.
Vital systems establish communications sessions among themselves which are constantly maintained so that in the event of interference (incidental or deliberate) sessions will drop and the crossing will go to the least permissive state.
The vital systems communicate among each other via twisted-pair LAN called Echelon [9] which operate at around 1.2 megabit per second. The WAGs take the Echelon-encoded ATCS messages and may route them out their 10-megabit Ethernet interface, causing the messages to be transmitted to other WAGs via spread spectrum radios where they are converted back in to Echelon messages.
In the Safetran Systems California manufacturing facility, a full-scale mock-up of the Brighton Park / Pershing Main project was assembled (lacking only the crossing gate arms and locomotives. Moving locomotives were simulated using Safetran GEO Test Terminal devices, and physical crossing gate arms, bells, and lights were simulated using panels with lamps.)
The modernization effort at Brighton Park took place in parallel with the mock-up effort in California, allowing application development and extensive testing to take place on the mock-up prior to the application being cut-over in Chicago. Most installation issues which developed during cross-over could be replicated and solved in California, with the only real exception being radio communications coverage between devices along the rail line.
The automation hardware and software was launched and monitored for a trial period of time during which the existing physical semaphoring system was still in use until confidence in the automation effort was achieved after which the wonderful (but obsolete) signaling system was finally discontinued.
Once the initial site installation difficulties were isolated and resolved, the new crossing system settled down and has been conveying indications and controls without difficulties (as of the close of the year 2011.)
In terms of physical freight and passenger rail loading, Brighton Park carries a heavy amount of traffic, approximately 3.5 trains every hour (as of the year 2009.) The amount of traffic might be expected to increase over time as more and more cargo is transported via rail instead of via highway trucking and inter-coastal waterways as the cost of fuel increases and as the efficiency of locomotive engines increase.
While rail traffic through Brighton Park is heavy, the communications traffic among the vital systems providing the automation is also quite heavy.
Vital session ATCS messages conveyed between GEO devices constitute hundreds of messages every second. Overlaid on the vital sessioning is additional message traffic for monitoring, remote log retrieval, command and control, and other types of messages, all of which must be created, transmitted, received, and handled quickly so that messages are not permitted to become stale.
There is a Federally-mandated initiative under way to implement Positive Train Control [10] (PTC) in the United States which would allow for track status and civil speed restriction information to be conveyed directly to the locomotive’s on-board computers and its in-cab engineers. Such controls would allow for automated braking of locomotives in the event the in-cab engineers miss seeing a restrictive signal or exceeds a posted or temporary civil speed restriction.
The Brighton Park / Pershing Main modernization project did not implement PTC in the context of providing additional automated controls over the trains which pass through this section of Chicago. Implementing PTC at Brighton Park would consist of implementing the Advanced Civil Speed Enforcement System [11] [10] (ACSES) and other PTC technologies which would more closely tie Rail company dispatch and control centers to on-board systems to regulate train speeds, stoppages, and permissions to proceed.
In some ways, the modernization effort at Brighton Park comprises a large necessary step between human-controlled semaphore signaling and Positive Train Control.