Add tunnel resistance factor to <tunnel>
Description
Tunnel resistance is usually being calculated using information about the tunnel structure (cross section, wall material). When the tunnel has not yet been build, these parameters are unknown. Nevertheless, it should be possible to provide information about tunnel resistance in railML using "generic" tunnel resistance factors.
Background
This ticket was raised by Norway as part of the standardisation in Norway and shall be used commonly in the future.
The element is a sub-element of
The tunnel air resistance factor plays a crucial role for speeds exceeding 160 km/h. railML2.4, currently does not address tunnel resistance factors directly. Instead, it provides physical properties of the tunnel, which - in the conceptual planning stage (@status =”conceptual”) - are not known. railML2.4nor introduces an attribute for a calculated tunnel resistance factor: @resistanceFactorA.
For more details see document “railML2.4nor Infrastructure Documentation“ (https://www.jernbanedirektoratet.no/railML), version 1.3, 03.07.2020, point 4.16.1.
Links
- Forum discussion:
- Torben Brand, 20.12.2016: [https://www.railml.org/forum/index.php?t=msg&th=486&goto=1460&#msg_1460]
- Trac tickets:
- Wiki documentation:
- IS:tunnel: [http://wiki2.railml.org/wiki/IS:tunnel]
- Externals:
- PhD thesis Dr. Hürlimann, p.55f: [http://e-collection.library.ethz.ch/eserv/eth:24236/eth-24236-02.pdf]
Proposed solution in railML 2.5
Add new attributes <tunnel>@resistanceFactorPassenger
and <tunnel>@resistanceFactorFreight
for storing the tunnel resistance factor in kg/m for passenger trains and freight trains.
This solution shall be compatible with the formula defined in Dr. Hürlimann's PhD thesis on page 55:
R(tunnel) = f_tunnel * speed*speed
whereas f_tunnel
corresponds to the resistance factors that shall be introduced.