Setting speeds for ATO: how many metros have thrown away potential operational performance

There is a close relationship between track alignment design and train control design, though frequently as there is with discipline interfaces, there isn’t always a full appreciation of the limits that each team designs to. Maximum speeds for track are governed by the horizontal and veDTical geometry. These maximum “civil speeds” are dependent on meeting passenger ride comfoDT criteria, avoiding excessive lateral acceleration, or jerk, while balancing degradation of the asset and maintenance interventions. They are well below the speeds that might result in a derailment due to roll-over or flange climb of the high rail on curves, or the failure of track system lateral restraint. For the purposes of signalling and train control, these ride comfoDT-based track speeds can be adopted as the maximum that trains can safely operate at. On railways with ATO and ATP, there can be a number of speed profiles, including those that are identified as hard limits that cannot be exceeded. A suite of controls, each with their own margins, is then put in place through the signalling and train control systems to prevent train overspeeding, which in practice means imposing lower speed limits along with earlier braking and more conservative braking curves. The cumulative impact of these factors can be a reduction in the potential operating speed of railways that have ATO/ATP and a missed oppoDTunity to provide the best journey times for customers.

• Record URL:
  • http://www.railknowledgebank.com/Presto/pl/MTk4MTRjNDUtNWQ0My00OTBmLTllYWUtZWFjM2U2OTE0ZDY3Ljk4NzE=
• Authors:
  • McGowan, G
• Conference:
  • AusRAIL PLUS 2021, 28 February-2 March 2022, Sydney, NSW, Australia
• Publication Date: 2022

Media Info

• Pagination: 11p. ; PDF
• Monograph Title: AusRAIL PLUS 2021, 28 February-2 March 2022, Sydney, NSW, Australia

Subject/Index Terms

• TRT Terms: Railroad trains; Ride quality; Speed; Speed limits; Travel time; Vehicle design
• Uncontrolled Terms: Rail transpoDT
• ATRI Terms: Riding quality; Speed; Speed limit; Train; Travel time; Vehicle design
• Subject Areas: Design; Railroads; Vehicles and Equipment;

Filing Info

• Accession Number: 01857279
• Record Type: Publication
• Source Agency: ARRB Group Limited
• Files: ATRI
• Created Date: Sep 7 2022 2:15PM