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

(luna-rail.com)
156 points ant6n | 4 comments | 18 Jun 25 08:50 UTC | HN request time: 0.614s | 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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solardev ◴[22 Jun 25 03:57 UTC] No.44343432[source]▶
I love the concept and the renders, but I wonder... is the spatial optimization really what's holding train travel back? If you decrease passenger density in order to increase privacy and comfort, do you then have a corresponding increase in ticket prices?

In places with good train travel, it seems like they already have several cabin classes, from sardine seats (still luxurious compared to air travel) to private cabins (at several multipliers of price). Pod style rooms would presumably be cheaper than that, but still a lot more expensive than a seat?

Then in places without high speed passenger rail, like the US, this wouldn't really be able to address the major problems with train travel (slowness, lower priority than freight, low reliability, etc.).

Under what scenarios would using pods instead of cabins be more economically viable? And could these be retrofitted into existing sleeper cars, or would they have to build entirely new trains?

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rocqua ◴[22 Jun 25 07:34 UTC] No.44344756[source]▶
My experience on the Caledonian sleeper, in a 'room' was quite cramped in all senses (I am over 6 feet tall), and quite expensive aswell. If that had been optimized better, I would have enjoyed it more.
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Freak_NL ◴[22 Jun 25 07:52 UTC] No.44344865[source]▶
These renders do not make me feel as if I am even considered as a desirable passenger at 200 cm.

The new ÖBB wagons seem much more practical (and currently exist). A normal sleeper train wagon with stacked beds in compartments is fine for me. This origami concept looks claustrophobic, and the sleeping positions seem to allow for no room for the normal movements you make in your sleep, let alone getting out to take a piss or something.

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1. ant6n ◴[22 Jun 25 08:48 UTC] No.44345202[source]▶
Well, you cannot assume ergonomics from renderings. That’s why we run extensive testing. We tested on a large range of people. In the pods there’s a fall off in perceived comfort around the 95th percentile. Even then, the feedback is overall quite good.

In the larger pods, there’s actually an uptick in evaluation for taller people. Testers were often surprised how well it works.

All beds have at lest 2m, although there are different degrees of becoming smaller at the foot end — just like in aviation business class (with ticket prices 1.5 orders of magnitudes higher).

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2. pimlottc ◴[22 Jun 25 22:00 UTC] No.44350662[source]▶
As another tall person, that’s good to hear, but the pictures still make me skeptical. It would help if there were some actual dimensions listed.
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3. fnomnom ◴[23 Jun 25 14:49 UTC] No.44356387[source]▶
>All beds have at lest 2m

As another tall person here, the length of the matress/bed is not as critical as what comes when the bed ends. 2m matresses with a wall/bedend that is massive is way more umfortable for a tall person then a 1,9m matress with 20cm of air behind it.

>just like in aviation business class

Yeah but im not flying lay-down business class when i want to go Hamburg-Vienna because the trip is only 90mins. I fly lay-down business when going trans-atlantic or to asia.

4. ant6n ◴[23 Jun 25 15:56 UTC] No.44357068[source]▶
Some of the rail operators show diagrams with dimensions, although I'm having trouble finding it for Amtrak and Via Rail, it's like they don't want to show that anymore. Here's an example of what they used to show on their own website, but from a third party reseller: https://canadarail.ca/via-rail/the-canadian-train/sleeper-ca...

I think once our railcars actually operate, it would be a good idea to show something like this - especially since it allows showcasing that the seat is basically bigger than a first class seat (almost 60cm wide vs 45cm). But the dimensions keep changing around, so we don't want to make false promises for the exact dimensions.

But the goal is that all beds at least have 2m length, even if narrow at the end.