There is a proposal for a single track train tunnel under the Grimsel Pass, from Innertkirchen to Oberwald in Switzerland. This post analyses some timetabling options that this offers.
For more information on the project, visit grimseltunnel.ch
- 27 minute journey Innertkirchen <=> Oberwald, which should be achievable with 60km/h Innertkirchen <=> Handegg and 80km/h Handegg<=>Oberwald.
- Single track, no passing loops, 1m narrow gage.
- Existing services based on 2021 timetables.
- Good connections are available in Innertkirchen, in fact, the service works best as an extension of the existing Meiringen <=> Innertkirchen service.
- Connections in Oberwald are always going to be inefficient, given that connecting trains heading east (Andermatt) leave at :42 / arrive :09 and to the west (Brig) at :12 / arrive :39. Connections to/from Andermatt would probably be of higher priority given alternate connections to Brig via the Loetschberg base tunnel.
- The single track tunnel allows for an hourly service in each direction, half-hourly Innertkirchen <=> Guttannen albeit with operational challenges.
Sample train schedule:
Reg – regular hourly Taktfahrplan. Peak – additional peak services. Sp* – potential special purpose trains (asset transfers, car train (although turn-around times would probably require a >1 hr layover at each end) … listed examples requires signalisation to allow trains to follow within 3 to 4 minutes from each other and likely double track from Innertkirchen to the start of the tunnel.
Half-hourly Guttannen service with connection to Meiringen <=> Innertkirchen peak would require the Innertkirchen dp :29 train to combine in Guttannen with oncoming special purpose service (if such a service runs) or combine regular Oberwald => Innertkirchen service (or run empty ahead of that service). Service leaving Guttannen at :16 would need to get there as part of the :59 Innertkirchen => Obwald service or run 4 minutes after that service.
There are options for other train operations, e.g. cargo deliveries to Handegg (power plant) from both Innertkirchen and Oberwald (grey lines in graphical timetable)
Trains in bold are trains running the proposed new line. Trains in normal font are existing (2021) train services.