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Comment by somat | Hacker News Reader

Dangle-trains are one of those things that appeal to me for unknown reasons, they just look so cool. But I am unable to really quantify the appeal, so here is my attempt.

Advantages:

keeps your electrical plant out of the weather

allows the track to be out of the road while allowing street level access to train. This one is a bit iffy as the dangle train will usually be put above street traffic.

Disadvantages:

look at how much steel it takes to make that box beam.

Every thing is in tension, leading to complicated structure to contain it, joints can be much simpler in compression.

Any how as a dangle-train connoisseur I leave you with two additional videos.

A dangle train in japan https://www.youtube.com/watch?v=ZGLrP5eawdY

The Tim Traveler (perhaps the best all around esoteric travel channel) https://www.youtube.com/watch?v=9Kwpj1UOrhs

View on HN

The reason this was used in Wuppertal is that because the town is a steep valley with a river in the middle, so the best/only place to hang the track was over the river.

Wikipedia has the (not very long) full list of every "dangle-train" ever built: https://en.wikipedia.org/wiki/Suspension_railway

And all currently operating trains are in one of China, Germany, Japan.

Monorails are somewhat cheaper than elevated trains (if you don't have extreme disabled-evacuation laws) but more expensive than a conventional train at ground level, and junctions are a nightmare. So they only work where you have a single isolated line and would need to elevate most of the track anyway (and suspended rather than straddle-beam improves cornering performance but at a cost, so is only worth it if your route has many sharp corners as well).

For Wuppertal, where the town is pretty linear along a river valley, it works. (Even then, a straddle-beam monorail would probably be more cost-efficient if you were starting from scratch). For most places it doesn't.

Monorail needs bigger tunnels than conventional rail so if you need underground sections - which most systems need - they are more expensive.

even if you are only need a single isolated elevated line though monorail still loses just because there is no standard: when you need spare parts in 20 years it is questinable if you can get them.

Why would they need a bigger tunnel? Monorails are usually built to a smaller loading gauge than conventional rail.

I've never seen a monorail that wasn't on some massive rail, about a foot by a foot in cross section or more.

That raises the monorail floor, which makes the whole thing larger.

Modern trams can have nearly-ground-level floors.

> Monorail needs bigger tunnels than conventional rail so if you need underground sections - which most systems need - they are more expensive.

It's rare to need much in the way of tunnels on an elevated line, by its very nature. And since the beam is narrower than the carriages, it doesn't actually increase the tunnel diameter (for a round cross section) that much.

> even if you are only need a single isolated elevated line though monorail still loses just because there is no standard: when you need spare parts in 20 years it is questinable if you can get them.

These days there are systems that have been built for decades by big name manufacturers, often the same manufacturers that make trains. Hitachi or Alstom-nee-Bombardier aren't going to disappear and leave their clients high and dry, if only because it would be bad for their broader rail businesses to do so.

I'm no fan of monorails - quite the opposite - but there are cases where they work.

Those are still single vendor systems so if your vendor disappears - as has happened - you are stuck. You also don't get competition for spare parts so who knows if the price will be reasonable in the future.

Isn't it pretty similar for any regular railway? Sure the physical track might be more standard, but that's not where the expense comes in, it's the signalling system, the trains, and especially the interface between the two - and that's all going to be the same either way.

It's arguable for modern rapid transit signalling systems, because those tend to be a bit more bespoke than mainline railway systems and you might not be able to switch to a different supplier without swapping out all the interlockings, and the trackside and train-borne equipment in one go, but for the trains I don't follow your point – switching manufacturers when ordering the next generation of trains is par for the course, and having the signalling system of your choice plugged into the train of your choice is standard procedure even on rapid transit and light rail systems.

Bangkok changed the plans of its two most recent transit lines (Yellow and Pink) from standard rail to monorail for the cost savings - since they're completely elevated. I guess they solved the evacuation issue by making the space between the two rails a solid platform.

+1 for the Shonan-Monorail.

For those travelling to Tokyo, go to Kamakura, take the famous Enoden to Enoshima, then take Shonan-Monorail to Ofuna and return to Tokyo.

Oh! Last time I went to Kamakura was in 2006 and I didn't visit Enoshima nor Ofuna. I'm going to Tokyo this next month again. Are those visits worthy?

If you like The Tim Traveler you’ll probably also like “What On Earth is This?”, very much the same vein, no overlap in what they’ve covered. His latest video is on a 1960’s underwater cable car in France.

https://youtube.com/@whatonearthisthisthing?si=OCSx2leuGaDSG...

Japan has a lot more of these, though normally the tracks are below the wagons, which is presumably more efficient.

Japan has exactly two (Chiba & Shonan). But that's still a lot by world standards, since there's less than 10 total in existence.

I’ve seen a lot more monorails than just two. Are we talking only about hanging monorails (since I was about both above and below)?

The one that immediately comes to mind is the Tama monorail.

Yurikamome Is technically not a monorail, but it pretty close in terms of experience.

Tokyo Disney Resort Line is also an actual monorail.

Japan indeed has many monorails, but only the two I mentioned are suspended. The Ueno Zoo monorail was also suspended, but it was a bit of a toy and it's decommissioned now anyway.

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