Transcript No Slide Title

CSX
207
CBTM
Communications Based Train Management
June 14, 2004
RSAC PTC Working Group
• Established Safety Objectives for
Positive Train Control (PTC)
systems:
– Prevent Train-to-Train Collisions
– Enforce Speed Restrictions
– Provide Protection for Roadway Workers
• Does not imply vitality or moving
block
CBTM meets these objectives
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C B T M
• CBTM is an overlay,
safety enhancement
system currently
deployed in non-signaled
territory
• Existing method of
operation remains in
place
• Crew maintains primary
responsibility
– CBTM does not display
authorities or messages
unless train is enforced
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CBTM Is Not Vital
• CBTM is an overlay to the existing method of
operation
– There is no need to fallback to another method if CBTM fails
• CBTM is considered to be a safety-critical
system
– It must perform correctly to provide protection for equipment and
personnel
• CBTM performs no vital functions
– Vital functions are required to be implemented in a fail safe manner,
i.e. a failure will not result in the system entering or maintaining an
unsafe state or it will assume a known safe state
– A failure of CBTM has the effect of suspending the safety benefits
associated with its use
CBTM provides a safety net
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CBTM SYSTEM ARCHITECTURE
Computer
Aided
Dispatch
Oracle Database
Zone Logic
Controller
ZLC50
Zone Logic
Controller
ZLC51
CBTM
Office
Server
COS
FEP/CC
CNS11
CNS10
Base
Station *
* - dual mode
Base
Station *
Train
(UHF)
Base
Station *
Monitored
Switch (VHF)
Base
Station *
Train
(UHF)
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Example of how a target is generated
Dispatcher contacts Crew
CSX
207
Dispatcher
“completes”
Crew acknowledges
CADS
CBTM On-board
Component
Target
Information
DTC
CBTM Office
Components
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GENERATION OF TARGETS
CSX
207
LAURENS
IRBY
MADDENS
WATERLOO
Enforcement of the switch position at N. Irby
IRBY SIDING
207
Engine CSXT 207 has an
absolute south, in the
Laurens and Irby blocks
WORK
ZONE
25 MPH
WATERLOO SIDING
Zero speed target at the end of
the Irby block
CBTM is continuously monitoring train speed
relative to the maximum permissible speed, for
reactive enforcement purposes
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CBTM Status
• Pilot program began in 1998
• Placed in revenue service in July 2000 after the
completion of both lab and field qualification
testing
• Migrated on-board hardware and software to a
“production ready” platform in 2002
– Pilot territory is between Spartanburg (AK 590.4)
and Laurens (AK 555.2)
– Program began with six locomotives
• All GE AC 4400s (CSXT 207-212)
• Began equipping more in 2003
– When complete there will be a total of 63 equipped (CSXT 201-263)
• Currently data gathering to evaluate system
performance
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2002 CBTM Enhancements
• Locally Controlled Power Switches are operated
by the crew from the cab of a locomotive
– Design has utilized alternative methods to satisfy the
requirements for signals, which are typically
associated with power switch installations
– Installed at both ends of Kilgore siding
• Benefits:
– Eliminates the need for crews to physically throw the
switch reducing the risk of injury
– Reduces the time required during meets thereby
decreasing the average train delay
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2002 CBTM Communications
Enhancement
• Installation of 50 miles of UHF ATCS Spec 200
coverage is complete
– Pilot territory shortened to 35 miles between
Spartanburg (AK 590.4) and Laurens (AK 555.2)
– Allowed the new CBTM on-board platform to be
designed, developed and tested using the ATCS
Spec 200 protocol
• CBTM can now leverage the infrastructure already installed
for radio code lines
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2003 CBTM Enhancements
• TCS Development
– Adapt CBTM’s enforcement capabilities to
signal territory on the Blue Ridge subdivision
(138.6 miles)
• Request to extend current pilot territory published
in the Federal Register
• CBTM will not replace the signal system
– It will be implemented as an overlay
• Development includes non-vital rear end protection
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2004 CBTM Enhancements
• Develop a Product Safety Plan (PSP) and Risk
Assessment to submit to the FRA for approval to
install CBTM system-wide
• Enhance CBTM to automatically initiate the horn
sequence at grade crossings if the locomotive
engineer fails to do so
• Develop the functional specification for CBTM in Track
Warrant Control (TWC) territory
• Install six ATCS Base Stations on the Blue Ridge
subdivision to improve CBTM locomotive coverage
– May use Communications Management Unit (CMU) instead
• Convert five monitored manual switches on the
Spartanburg subdivision from VHF to UHF
communications for use by CBTM
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Left hand IFD
replaced with
CBTM display
CBTM On-board Display
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Located in the
short hood
CBTM On-board Equipment Enclosure
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ATCS network
specifically installed
for CBTM between
Spartanburg and Irby
ATCS Base Station
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Antenna & Pole
installed for
CBTM
CBTM
Equipment
Enclosure
U5 Controller
added for CBTM
CBTM Wayside Monitor
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All equipment installed to
perform the CBTM Locally
Controlled Power Switch
function
NE Kilgore
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Braking Algorithm
• Causing train handling issues
• Trains are being enforced when under control
– E.g. trains operating southbound at 2 to 3 MPH approaching the
south end of the Roebuck block on 1.5 percent descending grade
using dynamic brake are being enforced
• Change to low speed operation magnified the
issue
– Previously, trains could received a warning, drop below 8 MPH and
creep up to the end of their authority
• FRA requested a positive stop
– Forces the train to stop and then proceed
• To recover the air sometimes the crew must apply hand brakes
– CSX investigating a return to original implementation
• Does not accommodate articulated cars
– Looks at tons per operative brake, which is based on the number of
axles based on the number of cars
• Looking for additional input into the braking algorithm that can mitigate
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this issue, such as “number of axles”
Braking Algorithm Cont’d
• Operative brake
– Original pilot assume worse case, 85%
– Changed in production platform to 95%
• Offset (fudge factor) is a distance added to the calculated
braking distance to ensure the train never stops past its
intended target
– Varies by speed
– Changed from original implementation, however at 30 mph, CBTM still adds
approximately 633 feet to the predicted braking distance
– Will be changed again with TCS release
• Should be about half the current implementation
• Wabtec has been asked to investigate the impact to the overall
risk assessment for CBTM if both these parameters were
removed
• The Power Brake Regulations prevent the use of dynamic brake
by the engineer from being used in CBTM's braking distance
calculations
– Will be changed again in TCS release to incorporate a predictor
• Predicts train location in 75 seconds (CBTM’s minimum warning distance) and
then calculates braking distance from there
• Does take dynamic brake into account
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Next Steps
• Continue to gather data, identify issues,
and implement fixes
• Field testing for TCS build on the Blue
Ridge subdivision and Automatic Horn
Sequence scheduled for later this year
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Special Thanks to:
BLE Division 598
Steve Wingo
Bill Lee
Roger Peace
DD Martin
Mike Thomas
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