Mass Transit - 37

the other component mounted.
"The wayside-mounted units
detect the presence of a train and
picks up the location of the roadway worker as the worker moves
along the tracks," Maguire said.
"The wayside devices give visual signals to the train operator
ahead of the roadway worker.
It also detects the passing train
and sends a signal to roadway
workers ahead that a train is approaching their location."
The portable system is a bit
different utilizing three components, which include a personal
alert device, a portable train detector and a portable warning
horn and light. Maguire explains
the portable system can be placed
anywhere along the track or work
zone to provide workers enough
time to move if a train is detected.
"Transit [agencies] that want
both RWP protections and the
ability to track the movement of
mobile wayside crews would select the ProAccess Wayside Worker Location and RWP System,"
Maguire said. "Transit systems
that want the operator to have a
visual and audible warning that
they are approaching a wayside

worker or crew would select the
vehicle-based Ranging Protracker
System. Transits that only want
the feature where they are warning wayside workers of approaching trains would select the Portable Protracker System."

Confidence in Realtime Train Location

In addition to secondary warning systems, train control systems also provide critical safety
information for MOW workers.
While communications-based
train control (CBTC) systems use
static RFID tags, wheel odometry
and dead-reckoning software to
identify a train's position, Metrom
Rail's CERTIS Train Localization
System (CERTIS) incorporates
ultrawide-band RF technology
(UWB) to provide real-time train
positions "down to a resolution of a
few inches," said Rick Carlson, director of business development and
corporate strategy, Metrom Rail.
CERTIS utilizes wireless communication with UWB antennas
located on the train and a network
of UWB Nodes (antennas) that
are strategically spaced 600-2,000
feet apart along the wayside.

"The trains utilize ranging data
along with onboard track maps to
calculate absolute train position
many times per second," Carlson
said. "This data is then verified for
accuracy and then delivered via
vital ethernet protocol into any
commercial CBTC system."
Carlson adds that a benefit of
the CERTIS System is all data lo-

MILLER
INGENUITY'S
ZoneGuard
system
uses several
components
to consistently
detect vehicles
entering a
workzone.
Miller Ingenuity

"Using eRWP as a secondary warning system
gives workers peace of mind while performing
maintenance on the tracks, which increases
productivity, and more importantly, allows them
to return home safety to their families."

- CHRISTINE NESTOR, Marketing Communications
Specialist, Miller Ingenuity

cation processing takes places onboard CERTIS itself. The CBTC
system uses the localization data
from CERTIS to perform all its
current processing responsibilities.
"This greatly simplifies full
safety re-certification of integrated solutions, further accelerating
modernization efforts of transit
agencies," Carlson said.
APRIL/MAY 2020 | MassTransitmag.com | Mass Transit |

37
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