Table Of Contents - Chicago Transit Authority

3.2.5 Systems
CTA Express Airport Train Service Business Plan
Each of the estimates for passing tracks, new express tracks, or new dedicated terminal facilities include
line items for all the systems equipment necessary to make a complete, safe, operational installation.
These line items include traction power substations, third rail traction power distribution equipment,
signal along the new tracks, interlockings (enhanced with remote control provisions) at the ends of the
new tracks, or where the new tracks merge/diverge from existing CTA trackage and communications
along the new tracks, as well as the required communications equipment in any new station facilities.
3.2.5.1 Train Control
Cab signal train control equipment, as used on the existing CTA lines is envisioned to be provided over
the full length of any passing or express tracks as well as on dedicated express service terminal trackage.
Interlockings are provided wherever these new tracks merge/diverge from existing CTA trackage, as well
as at intermediate locations over the longer-length new track installations. For example, on the Kennedy
Expressway express tracks, interlockings are proposed at Nagle and Harlem to expand the existing local
track interlockings. On the I-90 dedicated express line, there would be multiple intermediate
interlockings. The goal of these installations is to enhance the flexibility of the installed physical plant.
One major difference from existing CTA interlockings is that all of the interlockings proposed for the
passing or express or terminal tracks are to be equipped with remote controls, allowing CTA control
center staff to operate the interlockings. It is assumed that these provisions will also be implemented on
other CTA lines in the future.
3.2.5.2 Power
A total of five new traction power substations would be required for the Kennedy Expressway-UP express
alignment, given its longer overall length. It is possible that some of these substations could also be
used to feed the existing Blue Line, when the distance to the existing line is not great. The proposed
dedicated O’Hare terminal facility also includes one new substation, given the anticipated length of the
overall facility. In the case of the Kennedy Expressway Median passing track segment, an allocation was
made to cover the reconstruction/modification of the existing Harlem substation, since the widening of
the expressway to create the four-track right-of-way will impact this installation.
All new express passing tracks, express tracks, and terminal trackage would be equipped with the typical
third rail supported off insulated chairs, along with potheads, cables, and all other required
appurtenances to provide a safe installation. Remote control of any new power sections would be
provided, consistent with current CTA practices.
3.2.5.3 Communication
All new express tracks, passing tracks and terminal trackage would be equipped with fiber optic cable to
serve CTA control and communication needs. Any extended subway sections (approach trackage to the
I-90 alignment or the dedicated O’Hare terminal, for example) would be equipped with lossy-line antenna
to accommodate underground radio communications. New stations include an allocation for the instation
communications facilities including telephone, public address, variable message signs, etc.
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