The impacts of weather on railway infrastructure in Sweden

Figures & data

Figure 1. Distribution of faults between 2006–2020.

Table 1. Fault Examples.

Asset	Example Faults
Switches	Snow and ice obstruction Electrical shorts Anomalous temperatures Animal obstructions
Signals	Lineside failures Track circuit failures Control system failures
Track	Cracks Buckles Leaves on the line Vegetation obstructions
Catenary	Broken cables Electrical faults Poor connection with vehicle pantograph equipment Ice formation on cables

Table 2. Top five reasons for faults of six different track components.

Ballast		Fastener		Rails
Poor track geometry	2947	Short circuit	338	Poor track geometry	2439
Not possible to define	1136	Not possible to define	318	Not possible to define	2163
Deformation	436	Poor track geometry	193	Rail breakage	1910
No error	260	Wear	148	No error	1598
Wear	72	Deformation	134	Rail damage	924
Ties		Sleepers		Track
Short circuit	23,099	Poor track geometry	660	Not possible to define	13,981
Insulation failure	2912	Not possible to define	655	Poor track geometry	11256
Interruption	1318	Deformation	321	No error	5746
Not possible to define	1247	Fire	265	Deformation	2524
Material Failure	1179	Wear	207	Interruption	1106

Table 3. Overview of weather variables, collected between 2006 and 2020.

Weather Variable	Number of Observations	Number of Weather Stations
Daily Average Temperature (°C)	1,031,675	258
Daily Average Precipitation (mm)	1,178,347	282
Daily Average Snow Depth (cm)	528,050	222
Daily Maximum Wind Speed (m/s)	506,394	134

Figure 2. Distribution of railway stations amongst the Köppen-Geiger climate zones (adapted from Beck, Zimmermann, McVicar, et al. (2018), the Swedish Transport Administration, and the University of Texas). Top right subset map to highlight climate zone Cfb.

Figure 3. Distribution of weather stations amongst the Köppen-Geiger climate zones (adapted from Beck, Zimmermann, McVicar, et al. (2018), the Swedish Meteorological and Hydrological Institute, and the University of Texas).

Table 4. Number of railway stations in each climate zone.

Climate Zone	Full Name	Number of Stations
Cfb	Temperate Climate	2
Dfb	Humid Continental Climate	567
Dfc	Sub Arctic Climate	326
ET	Polar Tundra Climate	0

Table 5. Overview of the variables used for the analysis.

Type of variables	Variable names	Variable names	Variable names	Variable names
Time & location	Date	Station	Climate zone	Lat., long.
No. assets/station	Switches	Signals	Track	Catenaries
No. faults	Switch faults	Signal faults	Track faults	Catenary faults
Asset fault rate (f.r.)	Switch f.r.	Signal f.r.	Track f.r.	Catenary f.r.
Asset weights	Switch weight	Signal weight	Track weight	Catenary weight
Weather variable	Temperature	Precipitation	Snow depth	Wind speed
Avg fault rate (f.r.)	Avg switch f.r.	Avg signal f.r.	Avg track f.r.	Avg catenary f.r.
Stdev fault rate (f.r.)	Stdev switch f.r.	Stdev signal f.r.	Stdev track f.r.	Stdev catenary f.r.
Fault rate threshold (mean + 1 stdev rate; fr.thr.)	F.r.thr. switch	F.r.thr. signal	F.r.thr. track	F.r.thr. catenary

Table 6. Sample size bins for each weather variable.

Weather Variable	Sample size bins
Daily Average Temperature (°C)	5°C
Daily Average Precipitation (mm)	10 mm
Daily Average Snow Depth (cm)	10 cm
Daily Maximum Wind Speed (m/s)	5 m/s

Figure 4. Example of fault rate with lower bound for switches and temperature (°C).

Figure 5. Fault rates for switches, signals, tracks, and catenaries and daily average temperature (°C).

Figure 6. Fault rates for switches, signals, tracks, and catenary and daily average precipitation (mm).

Figure 7. Fault rates for switches, signals, tracks, and catenaries and daily average snow depth (cm).

Figure 8. Fault rates for switches, signals, tracks, and catenaries and daily maximum wind speed (m/s).

Table 7. Summary of relationships being carried to Section 5, where ‘X’ indicates a determined relationship.

	Switches	Signals	Tracks	Catenaries
Temperature	X		X	X
Precipitation			X	X
Snow Depth	X		X
Wind Speed			X	X

Table 8. Summary of results regarding the thresholds of significant fault rates.

	Switches	Signals	Track	Catenaries
Temperature	<0°C & >+25°C	>+15°C	<-20°C & >+10°C	<-10°C & >+5°C
Precipitation	<0 mm	>10 mm	>20 mm	>20 mm
Snow Depth	>10 cm	<0 cm & >110 cm	<0 cm & >70 cm	<0 cm & >40 cm
Wind Speed	<5 m/s & >25 m/s	>10 m/s	>10 m/s	>15 m/s

Figure 9. Fault rates for switches, tracks, and catenaries and daily average temperature (°C) between climate zones Dfb and Dfc.

Figure 10. Fault rates for tracks and catenaries and daily average precipitation (mm) between climate zones Dfb and Dfc.

Figure 11. Fault rates for switches and tracks and daily average snow depth (cm) between climate zones Dfb and Dfc.

Figure 12. Fault rates for tracks and catenaries and daily maximum wind speed (m/s) between climate zones Dfb and Dfc.

Table 9. Summary of results regarding the differences in asset vulnerability between climate zones. Where ‘–’ indicates the relationships not carried forward in this analysis and ‘X’ indicates a strong difference between climate zones.

	Switches	Signals	Tracks	Catenaries
Temperature		–	X
Precipitation	–	–	X
Snow Depth			X
Wind Speed	–	–	X

Table 10. Summary of results regarding differences in thresholds between climate zones.

	Tracks, Dfb	Tracks, Dfc
Temperature	>5°C	<-20°C & >+20°C
Precipitation	>0 mm	>40 mm
Snow Depth	>50 cm	>90 cm
Wind Speed	>5 m/s	N/A

Beck, H. E., Zimmermann, N. E., McVicar, T. R., Vergopolan, N., Berg, A., & Wood, E. F. (2018). Present and future Köppen-geiger climate classification maps at 1-km resolution. Scientific Data, 5(1), 180214. https://doi.org/10.1038/sdata.2018.214

 PubMed Web of Science ®Google Scholar

Data availability statement

Datasets are available from the corresponding author upon reasonable request.