ARRC Collision Avoidance System

1. ARRC Collision Avoidance System 2005 ASME/IEEE Joint Rail Conference March 16-18, 2005 Presented by Chinnarao Mokkapati Robert D. Pascoe Union Switch & Signal Inc.

3. Alaska Rail Road Facts (2003 Data) • Employees • 722 Year-round • 10.8 average years of service • 43.2 average age • Operating Statistics • 446,162 Passenger ridership • 8,324,395 Freight tonnage • 102,292 Revenue car loads • Trains per day • 33 Freights • 14 Passenger - Summer • 1 Passenger - Winter • Operating Data • Miles of track • 466 main line • 59 branch line • 86 yards/sidings • 611 Total • Rolling Stock • 1,625 Freight cars • 42 Passenger cars • 60 Locomotives • Train Control • ~500 miles of DTC • ~30 miles of CTC

4. ARRC CAS Objectives • PREVENT TRAIN TO TRAIN COLLISIONS BY ENFORCEMENT OF AUTHORITY LIMITS • ENFORCE SPEED RESTRICTIONS • PROVIDE PROTECTION FOR ROADWAY WORKERS AND EQUIPMENT • IMPROVE EFFICIENCY OF OPERATIONS • INCREASE CAPACITY

5. FRA Requirements • Generation of safe mandatory directives • Enforcement of authority limits • Enforcement of speed restrictions • Protection of Maintenance-of-Way workers and equipment • Rule 236 Subpart H compliance required • Performance Std: New system must be as safe or safer than the system being replaced • Operating conditions, parameters, constraints must be defined • Structured qualitative and quantitative assessment of safety (Base Case and New Case) required • Product Safety Plan or Safety Case

6. Some Definitions CTC and DTC Operation

7. Some Definitions Track Bulletins Used in System

8. Collision Avoidance System

13. Block 5 Block 9 (( )) Existing Comms Block 6 Block 3 Block 7 Block 11 OSS Dispatcher Work Stations Servers CAD Vital Independent Check of LOA, Bulletins General Philosophy of CAD and OSS Subsystems Track

14. Vital Checks Done by OSS • Via the OBC, the position of all trains are known to the OSS • ‘Occupies’ Virtual blocks • ‘un-occupies’ Virtual blocks • Checks Bulletins associated with Blocks & LOA

15. Network Interface Adapter CAD Subsystem Ethernet Switch Ethernet RS423 Microlok II Microlok II RS423 HUB RS423 RS423 RS423 Microlok II Microlok II OSS Hub Physical Architecture

16. Block 6 Block 1 Block 3 Block 5 Block 7 Block 9 Block 11 Block 13 S#7 S#5 Software in MicroLok II Units North • Executive Software • Operating System • Application Processing • Serial Communications Control • Safety Diagnostics • User Interfaces • Event Logging • Application Data Tables • Track Sections defined as Virtual Blocks • Switch locations • Other identifiable points

17. OBC Requirements: • Profile Generation • Train Location and Speed Determination • Digital Track Data Map • Communication via Digital Radio

18. LOCATION AND SPEED DETERMINATION • DGPS • Accelerometers • Tachometers • Digital Map The result is that the OBC vitally determines its location on the rails and transmits its location to Central

19. New On Board Computer (OBC) - ATP

20. Existing Network Communication System

23. Communication Backbone

24. MONITORING DEVICES Rail Integrity Switch Position Signal Aspect in CTC

25. Short Range Data Radio Locomotive Broken rail Device Short Range Data Radio N R Locomotive Device Short Range Data Radio Aspect Locomotive Device • The Locomotive’s ATP Interrogates Three Wayside Devices • using a short range data radio: • A Rail Integrity Device • Broken Rail Detection • MicroTrax • A Switch Position Device • Normal or Reverse • A Wayside Signal Device • Aspect

26. CAS Safety Assurance • Safety resides in OSS and OBC, though CAD performs some safety-related functions • OSS is implemented on US&S MICROLOK II Platform • OBC implemented on US&S MICROCAB Platform • These platforms use a combination of Inherent Fail-Safety and Diversity & Self-Checking safety architectures • Certified by independent safety assessors • Extensive service history

27. CAS Safety Assurance • Compliance with FRA Rule 236 Subpart H • Risk analysis of CAD-only DTC/CTC Operation (Base Case) • Derive safety requirements for CAS • V&V of CAS design and operation • Risk analysis of CAS (CAS Case) • Risk assessment • Show CAS provides higher safety than CAD-only DTC/CTC operation

28. Risk Analysis • Conduct Hazard Analyses • PHA • O&SHASSHA • Determine MTTHE using FFTA

29. Derive safety requirements for CAS • Potential hazards in Base Case • FFTA of CAS elements • CAS subsystem safety requirements

30. V&V of CAS design and operation • Normal operation • Systematic faults • Random hardware faults • Common Mode faults • External influences

31. Risk analysis of CAS (CAS Case) • Conduct Hazard Analyses • PHA • O&SHASSHA • Determine MTTHE using FFTA

32. Risk Assessment • Show CAS provides higher safety than CAD-only DTC/CTC operation • Submit PSP • 20 elements required per FRA Rule 236.907

33. 4/16/2005 - 10/16/2005 4/15/2006 - 10/15/2006 2005Peak Season 2006 Peak Season 2005 2006 2007 11 / 2005 CAD SAT Complete 06 / 2006 Office Safety and OBC FAT 4Q 2004 System Definition Complete 10 / 2006 Office Safety and OBC SAT 1 / 2006 CAD Cutover complete 2 / 2007 Revenue Service Project Timeline

34. Conclusions • CAS is a practical, relatively inexpensive PTC System • Scalable for larger systems • Uses proven safety architectures • Credible, straight-forward safety proof