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Posession Management
Subschema: Infrastructure
Stift.png (version(s) not yet specified)
For general information on use cases see UC:Use cases

Use case / Anwendungsfall

Posession Management
Management of restrictions and possessions in the railway network.

Description / Beschreibung

Whenever non-nominal conditions occur on a right-of-way, it may be necessary to impose restrictions on the local rail network capacity. These conditions may arise from maintenance or construction activities on the right-of-way itself, or due to exceptional events in the vicinity of the tracks. Ideally these restrictions are planned and coordinated ahead of time. But even restrictions due to unforeseen events need to be managed for the time of their effectiveness.

The impact of a restriction heavily depends on the disturbance that causes it. It may range from a speed reduction, to the deactivation of track side systems, or to the complete closure of a track section. A single restriction may have different impacts on different parts of the network. And each of these impacts may apply on different time intervals. It is part of the restriction planning process to negotiate the protective safety requirements and the operational availability demands. This may require several exchanges and updates of restriction and impact data between maintenance planning and capacity planning systems.

This restriction data is also of special interest to train operators: If a restriction affects one of their routes, they may have to adjust schedules to account for reduced speeds or increased runtimes. Deactivation of overhead wires or other track side system restrictions may require re-planning rollingstock to keep running on the impacted routes. If this is not possible, they may have to re-route their trains to avoid the restriction area altogether. In a later stage, the information about restrictions along the route are also relevant to train drivers, as they may have to follow specific rules of operations in the impacted areas.

In case of construction and maintenance work with on-site personal, it may be necessary to plan and implement a possession. This means that a Person in Charge of Possession (PICOP) takes over the responsibility for a part of the network from the network operator. They activate the possession by implementing and verifying the planned safety measures before work starts. When the work has ended, they deactivate the possession by releasing the safety measures. It is important, that the network operator and the PICOP have up-to-date information about the location and time interval of these restrictions, what protective measures are planned, and how they impact train operations.

Especially in the context of construction and maintenance work, there may be work-related trains that are not affected by the restriction in the same way. For example, they may be allowed to enter a track section, that is otherwise closed to regular traffic. For proper planning and safe dispatching of these trains, it is important that these trains are clearly specified.

Data Flows and Interfaces / Datenflüsse und Schnittstellen

Restrictions may be ordered by the construction and maintenance planning systems. They interface with the capacity planning system.

The capacity planning system needs to inform

  • the train planning systems about new or updated capacity restrictions and availabilities.
  • the train management system and train operators about effective restriction impacts and security measures.

Interference with other railML® schemas / Interferenz mit anderen railML®-Schemen

Organizational units are specified by references into the common schema.

Work trains are specified by reference into the timetable schema.

Characterizing Data / Charakterisierung der Daten

The data belongs mostly to the infrastructure. It should be possible to describe restrictions and their impacts in terms of functional infrastructure objects, without the need of a microscopic network topology.

The planning aspect requires the description of temporal validities.

Some administrative data is necessary to track and manage restrictions throughout their life cycle.

How often do the data change (update)?

Possession and restriction planning is part of the timetable construction starting at the LTP phase:

  • LTP: yearly reports
  • STP: regular updates
  • VSTP: daily reports

How big are the data fragments to be exchanged (complexity)?

The scope of possession and restriction exchanges typically aligns to the timetable exchange:

  • all available data for the entire network throughout a full timetable period.
  • updated data since the last exchange, possibly restricted to a time period.
  • all available data for the upcoming days.

Which views are represented by the data (focus)?

The data has two related aspects:

  • Restrictions: Locations and periods of capacity reductions.
  • Impacts: Impacts of restrictions on train operations.

Which specific data do you expect to receive/send (elements)?

Infrastructure location descriptions of varying granularity:

It should be possible to formulate restriction locations based on the functional infrastructure with little or no topology data.

Content of a restriction:

Basic operational train data

If the possession and restriction data is bundled with timetable data, there may be more timetable elements.