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Show HN: Luna Rail – Treating night trains as a spatial optimization problem

(luna-rail.com)
156 points ant6n | 1 comments | 18 Jun 25 08:50 UTC | HN request time: 0s | source

Hi HN, I'm Anton, founder of Luna Rail.

I've always thought night trains are a fantastic, sustainable alternative to short-haul flights, but they're often held back by a lack of privacy, comfort, and poor economics due to low passenger capacity.

I became overly fascinated with this puzzle. I view it as a kind of night train Tetris (my wife less charitably calls it "sardinology"). I spent way too much time learning about and sketching various layouts, trying to figure out how to fit the maximum number of private cabins into a standard railcar, while making them attractive for both day and night travel.

This eventually led to a physical workshop (in Berlin) and a hands-on rapid prototyping process. We've built a series of full-scale mockups, starting with wood and cardboard and progressing to high-fidelity versions with 3D-printed and CNC-milled parts, with various functional elements.

Hundreds of people have come in to test our various iterations, because you can't test ergonomics or comfort by looking at renderings (although we did create a bunch of nice ones).

The link goes to our home page showing our approach and some of the thinking behind them. It’s been a lot of fun working on this puzzle, and we're excited to share what we've come up with. We hope you think it's cool too and would love to hear your thoughts.

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Freak_NL ◴[22 Jun 25 08:03 UTC] No.44344932[source]▶
Sleeper trains are held back by flying getting subsidised heavily by not having kerosene taxed, and national governments giving airports effectively unlimited room to grow; happily externalising the environmental cost. Why take a train if you can fly for a fraction of the cost?

Trains in general are held back by governments not investing in rail infrastructure, because the pork barrel of another motorway link is so hard to resist (and we're not properly maintaining these either).

Sleeper trains are held back, because cross-boundary collaboration between the various semi-national rail companies is tough (for Europe).

Sleeper trains are held back, because there is a lack of modern rolling stock. Not completely new concepts; just up-to-date sleeper wagons (the ÖBB has the leading edge here now with their new wagons).

There is room for improvement in the wagon designs, but it is almost irrelevant in the face of the other challenges.

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bluGill ◴[22 Jun 25 11:56 UTC] No.44346142[source]▶
You missed a couple other points against night trains.

first trains work best if they stop many times - how will you wake people up at 3am for their stop? For that matter who would agree to that? Without that churn many destinations are not in range.

second, track needs maintenance. If the track is running at night as well when will you repair it? I makes sense to just close nost track every night for repairs. For busy two rail sections you can close on track and run very reduced service on the other - but this reduction means you don't want people sleeping as you can fill your trains just on people working night shifts.

all of the above are challenges. They can be worked around in various ways however they to be considered to see if it is worth it-

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matt-p ◴[22 Jun 25 12:06 UTC] No.44346196[source]▶
No they don't. You use the same hub to hub model as airlines. E.g London to Edinburgh, not London to Edinburgh stopping in 4 places.

One of the nice things about traveling at night is you have less time pressure and congestion so when doing track repairs it's usually fine to divert the train.

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1. Freak_NL ◴[22 Jun 25 13:20 UTC] No.44346743[source]▶
Yup. These two points are not an issue at all, and are in fact strengths for sleeper trains. Being able to redirect a sleeper train without any (or minimal) impact on its timetable is a big plus.

Usually they depart from the last boarding station around midnight, and the first disembarking station won't be hit until six in the morning. Some outliers exist, but the number of people getting on or off there is negligible. For most travellers you are in the train before 22:00, and won't leave before 6:00.

This ÖBB line is typical: https://www.nightjet.com/de/reiseziele/oesterreich/wien

Yes, you can get off in Nürnberg at 4:08. But almost no one does that. The train just happens to have a halt there¹, but 95% of the passengers get on in the Netherlands and the Ruhr Area, and won't get off until Austria (and vice versa).

1: I suspect mostly for rail topological reasons.