Project Overview As part of the complete rehabilitation of the 6.6 mile CTA Blue Line
54th/Cermak Branch, Union Switch & Signal Inc. (US&S®)
provided an automatic signal system to replace the existing system from Paulina
Junction on the Green Line to 54th Avenue Yard on the
54th/Cermak Branch. Specific work included ten relay-based vital
interlockings, three emergency crossovers, 200 AF-700TM track circuits, 37
Power Frequency (PF) track circuits, 42 M-23 switch machines, 50 LED color
light signals, 50 train stops, and ten highway grade crossing warning
systems.
Two of the key US&S products used in the installation of the new
interlocking systems are the MicroLok® II Vital and Non-vital Interlocking
Controllers. These microprocessor-based controllers perform a variety of
critical functions for the 54th/Cermak Branch including vital
processor logic and automatic and manual switch and signal control. The
MicroLok II is capable of simultaneously performing a myriad of tasks due to
its vital and non-vital configurations designed to automatically monitor and
manage interlocking functions.
To provide power to the new interlocking systems, US&S furnished new
signal power distribution equipment in nine relay houses, in the
54th terminal relay room, and in the ten crossing houses. This
equipment distributes AC and DC power to the MicroLok II controllers and other
equipment in the interlocking systems, as well as measures ground current
leakage.
To improve communications along the Blue Line, US&S installed a signal
fiber-optic network. The network connects the relay house/room equipment
(Microlok II units and operational recorders), maintainer workstations, and the
centralized traffic control center through a redundant-ring backbone,
fiber-optic Ethernet. Four fiber-optic lines (two transmit and two receive)
comprise the physical Ethernet interconnection between buildings.
In order to effectively manage the 54th/Cermak Branch, US&S
installed two new maintainer workstations at the 54th maintenance
facility and at the West shops. The existing maintainer workstation at the
Roosevelt maintenance facility underwent hardware and software modifications to
ensure cohesive performance among the three workstations.
The 54th maintainer facility is the only workstation to obtain
data from the field. The data is then relayed to the Roosevelt and West shops
facilities. Latter workstations can be reconfigured to obtain field data if for
any reason the 54th maintainer workstation goes off-line. The
workstations run the Graphical Event Analyzer (GEA) software, supplied by the
operational recorder manufacturer, Micro-Aide.
The GEA software performs long-term storage of the operational recorder
data. The control center modifications were made in order for the maintainer
workstations to display 54th/Cermak Branch real-time train movement.
The system-wide displays indicate track circuit status, signal and train stop
status, traffic directions, and line routes while local displays show
interlocking control area status—again all in real-time.
US&S installed new highway crossing warning systems at 10 locations
along the Chicago Blue Line. The highway crossing warning system consists of
two parts: the warning equipment and the control equipment. The warning
equipment consists of signs, bells, flashing lights, and gates. The control
equipment, housed in the crossing houses, includes a microprocessor-based
controller and associated components and circuits that operate the warning
equipment.
US&S has particular expertise in providing site modifications and
upgrades to transit agencies throughout the world. Chicago Transit Authority is
one of many satisfied customers with safer and more effective rail transit
systems due to the innovative and reliable work of Union Switch & Signal
Inc.
