analysis of capacity on double-track railway lines
DESCRIPTION
Analysis of capacity on double-track railway lines. Olov Lindfeldt February 2008. Disposition. Introduction – freight capacity question TVEM (model) Infrastructure modeling Application - Three-pattern case Conclusions. Freight capacity question. - PowerPoint PPT PresentationTRANSCRIPT
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1February 2009
Analysis of capacity on double-track railway lines
Olov LindfeldtFebruary 2008
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2February 2009
Disposition
• Introduction – freight capacity question
• TVEM (model)
• Infrastructure modeling
• Application- Three-pattern case
• Conclusions
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3February 2009
Freight capacity question
• What is the capacity for freight traffic on existing lines if high speed lines are constructed?
It depends on the timetable!
Ways to find the timetable for 2050: - Assume one- Make more general assumptions an generate a large number
of timetables
Develop an algorithm that generates timetables and evaluate freight capacity as a distribution…
Disregard disturbances (delays)
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4February 2009
Freight capacity question
• What is the capacity for freight traffic on existing lines if high speed lines are constructed?
• It depends on the timetable!
Ways to find the timetable for 2050: - Assume one- Make more general assumptions an generate a large number
of timetables
Develop an algorithm that generates timetables and evaluate freight capacity as a distribution…
Disregard disturbances (delays)
![Page 5: Analysis of capacity on double-track railway lines](https://reader035.vdocuments.site/reader035/viewer/2022062423/56814781550346895db4b364/html5/thumbnails/5.jpg)
5February 2009
Freight capacity question
• What is the capacity for freight traffic on existing lines if high speed lines are constructed?
• It depends on the timetable!
• Ways to find the timetable for 2050: - Assume one- Make more general assumptions and generate a large
number of timetables
Develop an algorithm that generates timetables and evaluate freight capacity as a distribution…
Disregard disturbances (delays)
![Page 6: Analysis of capacity on double-track railway lines](https://reader035.vdocuments.site/reader035/viewer/2022062423/56814781550346895db4b364/html5/thumbnails/6.jpg)
6February 2009
Freight capacity question
• What is the capacity for freight traffic on existing lines if high speed lines are constructed?
• It depends on the timetable!
• Ways to find the timetable for 2050: - Assume one- Make more general assumptions and generate a large
number of timetables
Develop an algorithm that generates timetables and evaluate freight capacity as a distribution…
Disregard disturbances (delays)
![Page 7: Analysis of capacity on double-track railway lines](https://reader035.vdocuments.site/reader035/viewer/2022062423/56814781550346895db4b364/html5/thumbnails/7.jpg)
7February 2009
Research view
Aim• How do the infrastructure and the timetable affect
capacity?
Method• Combinatorial analysis of infrastructure designs and
timetable structures.
TVEM: Timetable Variant Evaluation Model
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8February 2009
TVEM: Assumptions
• Passenger traffic operated with a periodic timetable Train patterns
• All patterns are scheduled according to a priority order.
• A train with higher priority is never given scheduled delay for a train with lower priority.
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9February 2009
TVEM: Structure
Infrastructure
Train patterns Scheduling algorithm
Evaluation of results
Scheduling order
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10February 2009
TVEM: Variables
• Run times between overtaking stations(infrastructure + vehicle)
• Deceleration and acceleration supplements(for overtaking situations)
• Regular stops
• Track dispositions at stations
• Frequency of service
• Scheduling order
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11February 2009
TVEM: Calculation scheme
• Periodic timetable train patterns
• Scheduling order for train patterns
• Time step: 1 minute
• Last pattern: as many freight trains as possible
Schedule as many trains as possible in pattern N
Search and store alternative paths for pattern n, given paths for pattern 1,…, n-1
Chose first path for pattern n
If n = N
Scheduling of pattern 1 (n=1)
n = n + 1
If n < N
n = n + 1
n = n - 1
Unused alternative paths for pattern n remaining?
Chose next unused path alternative for pattern n
If n = N
Yes No n = n - 1
If n > 1
If n = 1
All variants scheduled. Brake.
If n < N N
Search and store alternative paths for pattern n, given paths for pattern 1,…, n-1
n = n + 1 Chose first path for pattern n
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12February 2009
Infrastructure modelling (1/2)
• Real distribution for inter-station distance.
• Fitted Weibull distribution (M-L).
• Mean: 22,7 km Std: 109 km2.
0 10 20 30 40 50 60 700
0.01
0.02
0.03
0.04
0.05
0.06
Den
sity
0 10 20 30 40 50 60 700
1
2
3
4
5
6
Distance between adjacent overtaking stations [km]
Num
ber
of o
ccas
ions
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13February 2009
• Effect of additional overtaking stations?
• Halve the greatest distance repeatedly. relationship between parameters
Infrastructure modelling (2/2)
0 10 20 30 40 50 60 700
0.02
0.04
0.06
0.08
0.1
0.12
0.14
0.16
Inter-station distance [km]
Den
sity
0 2 4 6 8 10 12 14 16 18 20 22 240
2
4
6
8
10
12
Mean [km]
Sta
ndar
d de
viat
ion
[km
]
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14February 2009
Application: Three-pattern case
High-speed, regional and freight trains
0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 50
2
4
6
8
10
12
Number of passenger trains/h
Num
ber
of f
reig
ht t
rain
s/h
Mean number of trains (capacity):
• Two speed combinations - 160/115 km/h (dotted)
- 210/160 km/h (solid)
• Two infrastructure layouts.Inter-station distance:- mean 22 km (lower)- mean 17 km (upper)
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15February 2009
Conclusions
• Combinatorial / deterministic approach TVEM
• Infrastructure treated as a variable. Modeled stochastically (replications)
• Regular passenger timetable train pattern combinatorial timetable analysis
• Evaluation: mean capacity, variance caused by:- Infrastructure- Timetable
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16February 2009
Thank You for the attention!
Hallsberg - GöteborgAntal godståg per timme
0
0,05
0,1
0,15
0,2
0,25
0,3
0,35
0,4
0,45
0 0,5 1 1,5 2 2,5 3 3,5 4 4,5 5
Referens 2008
2020 pt hög
Number of freight trains/h