5 ms·

I do a lot of work with the rail industry in the UK (both heavy and light rail) - but the UK is much more passenger focussed. Reducing cost can take a lot of t

I do a lot of work with the rail industry in the UK (both heavy and light rail) - but the UK is much more passenger focussed. Reducing cost can take a lot of tweaking to get right, and is likely to take more than one cycle to do. But new schedules do take some bedding in until they are running smoothly. Once that happens, you can then look for the next round of optimisations - tweaks to the way the trains are assembled in the yards which then start building the incremental gains. If you have a better scheduling system, you build resilience into the schedule. You open up more time for maintenance, you keep your assets in better condition, so you have fewer breakdowns. One thing to remember is that (in general) there is a Pareto on train breakdowns - 20% of the locomotives cause 80% of the problems. It will be the worst locomotives that are taken out of service, so the reduction in service affecting failures should be quite significant. You make some money on the OPEX side by doing more scheduled maintenance, and less emergency maintenance (overtime is really expensive!). You also make savings on the CAPEX side, because your assets last longer. [edit]. Changed para order

yazr 8y ago
Can you please explain why "new schedules do take some bedding" ? Cant u sort of simulate the expected scenarios and get sort-of expected performance? I realize there is unexpected events, but these will occur anyway in old and new schedules Also - does real train software has nice graphics or do u get a boring excel ? ;(
- liotier 8y ago
  In theory there is no difference between theory and practice... As for software, the optimization of rail slot allocation is far beyond spreadhseets - for the whole French network it is a math-heavy process for which a whole team harnesses a bunch of specialist software. More about the process (in French): https://tel.archives-ouvertes.fr/tel-01423840/document https://tel.archives-ouvertes.fr/tel-01423840/document
  - k3liutZu 8y ago
    > In theory there is no difference between theory and practice... This is really good.
- _red 8y ago
  Part of the problem in modeling is to also model the tens of thousands of humans interacting with the new schedule. Changing the train schedule also changes their schedules. Hence, each time a schedule changes there is an uptick of accidents, disruptions, missed trains, overcrowding, etc until all adjust to this new timetable.
liotier 8y ago
> I do a lot of work with the rail industry in the UK (both heavy and light rail) - but the UK is much more passenger focussed. Same in France - allocating freight capacity in a passenger-focused network is tricky. A paper about that (https://tel.archives-ouvertes.fr/tel-01317522/file/TH2015PESC1145_complete.pdf https://tel.archives-ouvertes.fr/tel-01317522/file/TH2015PES...) - in French but with abstract in English: "Train timetabling on a rail network is a complex task. In Europe, this issue lies within a process for which the infrastructure manager has to consider competing uses – passenger and freight trains as well as maintenance work – and several users of a scarce resource, infrastructure capacity. The aim of this research is to better understand the way this process is organised and works on the French rail network. We have chosen to tackle this issue focusing on freight as an activity which has been opened up to competition since 2006 but has experienced structural difficulties since the 1980s. The various time aspects of the capacity allocation process are the key focus of our analysis. Our approach considers the perspectives of the infrastructure manager and of their customers, foremost among which are train operating companies. We highlight that freight occupies a unique place in this process which is based on a schedule resulting from both European regulations and the legacy of decisions taken at the national level. The issue of the quality of the train paths offered by the infrastructure manager is studied with a focus on the links between short and long term requirements with regard to the train running deadline. In spite of their diversity, we demontsrate that freight operators need flexibility and visibility. Finally, we analyse catalogue paths as a specific offer that aims to guarantee capacity for freight. The German method, through the neXt project, provides an alternative insight into this issue. Accommodating freight train paths into the timetable is essentially a necessary but delicate balance of interests : standardisation vs. customisation."
MisterTea 8y ago
Interestingly here on Long Island, NY we have the NY and Atlantic RR which is a freight operator who leases LIRR tracks. They move freight between mainland freight tracks in New York City all the way out to the "forks". They even revived some abandoned LIRR tracks in NYC and LI. It's amusing to see a small freight train come rolling through a passenger station with platform. I don't know how they squeeze them in, probably only run off-peak.
- jnty 8y ago
  This is very common in the UK which runs a mix (even if passenger trains do dominate.) Our reluctance to spend the money to separate the passenger and freight traffic - even on the busiest lines - is part of the reason reliability of the network is often under question.
  - moorhosj 8y ago
    == is part of the reason reliability of the network is often under question. == The poor reliability is then used as a reason to limit future investment in passenger lines.

yazr 8y ago

Can you please explain why "new schedules do take some bedding" ? Cant u sort of simulate the expected scenarios and get sort-of expected performance? I realize there is unexpected events, but these will occur anyway in old and new schedules Also - does real train software has nice graphics or do u get a boring excel ? ;(

liotier 8y ago
In theory there is no difference between theory and practice... As for software, the optimization of rail slot allocation is far beyond spreadhseets - for the whole French network it is a math-heavy process for which a whole team harnesses a bunch of specialist software. More about the process (in French): https://tel.archives-ouvertes.fr/tel-01423840/document https://tel.archives-ouvertes.fr/tel-01423840/document
- k3liutZu 8y ago
  > In theory there is no difference between theory and practice... This is really good.
_red 8y ago
Part of the problem in modeling is to also model the tens of thousands of humans interacting with the new schedule. Changing the train schedule also changes their schedules. Hence, each time a schedule changes there is an uptick of accidents, disruptions, missed trains, overcrowding, etc until all adjust to this new timetable.

liotier 8y ago

> I do a lot of work with the rail industry in the UK (both heavy and light rail) - but the UK is much more passenger focussed. Same in France - allocating freight capacity in a passenger-focused network is tricky. A paper about that (https://tel.archives-ouvertes.fr/tel-01317522/file/TH2015PESC1145_complete.pdf https://tel.archives-ouvertes.fr/tel-01317522/file/TH2015PES...) - in French but with abstract in English: "Train timetabling on a rail network is a complex task. In Europe, this issue lies within a process for which the infrastructure manager has to consider competing uses – passenger and freight trains as well as maintenance work – and several users of a scarce resource, infrastructure capacity. The aim of this research is to better understand the way this process is organised and works on the French rail network. We have chosen to tackle this issue focusing on freight as an activity which has been opened up to competition since 2006 but has experienced structural difficulties since the 1980s. The various time aspects of the capacity allocation process are the key focus of our analysis. Our approach considers the perspectives of the infrastructure manager and of their customers, foremost among which are train operating companies. We highlight that freight occupies a unique place in this process which is based on a schedule resulting from both European regulations and the legacy of decisions taken at the national level. The issue of the quality of the train paths offered by the infrastructure manager is studied with a focus on the links between short and long term requirements with regard to the train running deadline. In spite of their diversity, we demontsrate that freight operators need flexibility and visibility. Finally, we analyse catalogue paths as a specific offer that aims to guarantee capacity for freight. The German method, through the neXt project, provides an alternative insight into this issue. Accommodating freight train paths into the timetable is essentially a necessary but delicate balance of interests : standardisation vs. customisation."

MisterTea 8y ago

Interestingly here on Long Island, NY we have the NY and Atlantic RR which is a freight operator who leases LIRR tracks. They move freight between mainland freight tracks in New York City all the way out to the "forks". They even revived some abandoned LIRR tracks in NYC and LI. It's amusing to see a small freight train come rolling through a passenger station with platform. I don't know how they squeeze them in, probably only run off-peak.

jnty 8y ago
This is very common in the UK which runs a mix (even if passenger trains do dominate.) Our reluctance to spend the money to separate the passenger and freight traffic - even on the busiest lines - is part of the reason reliability of the network is often under question.
- moorhosj 8y ago
  == is part of the reason reliability of the network is often under question. == The poor reliability is then used as a reason to limit future investment in passenger lines.