[netbioserror]

The author keeps asserting the "inherent weakness" of steel-on-steel railways; however, there are very good reasons it has been settled on as a good choice. Friction and sound losses are generally minimized, thanks to a very small contact surface and smooth, hard materials with little give; wheels can be re-machined back into spec a couple times rather than being replaced; rails can be re-used for lower-speed applications when worn; unlike pneumatic tires, steel can be machine into conical, self-centering, turn-adapting geometries with fixed axles and no need for differentials; the list continues and is quite long. Apparently, a recent change to wheel geometry reduced wear and extended lifetime by as much as 40%.

See Practical Engineering's latest video: https://www.youtube.com/watch?v=Nteyw40i9So

[ianbicking]

Makes a lot of sense for freight... lots of weight, most miles going through lower population areas.

Feels a little silly for relatively light humans being transported through high population areas.

[TylerE]

The humans may be light... the car around them built to survive a 100mph crash certainly isn't.

[ianbicking]

Imagine what airplanes would look like if we wanted to build them to survive a crash...

I'm also a little unclear how humans could survive a 100mph crash even if their container makes it through. If they were wearing a 4-point harness, I guess? Do they build crumple zones into train cars? Or... just rely on utterly demolishing anything they hit so the deceleration is kept under control? (https://www.reddit.com/r/BitchImATrain/)

Some nice analysis of survivable deceleration here (with restraints): https://aviation.stackexchange.com/questions/16545/even-afte... (100mph=44m/s)

[user_7832]

Sure but buses and cars themselves are strong enough and use rubber tyres. Not that I think rubber's a good idea for trains, but still.

[TylerE]

You really don't want to see what a 90mph crash in a bus looks like. It ain't pretty. Those speeds are unreasonable for a bus, but common on commuter rail in many civilized places.

[woodpanel]

> strong enough

no car or bus survives a 150 km/h crash

[singleshot_]

Check out people movers at large airports: they look like trains, run on their own tracks, but have tires.

[hyperthesis]

Feynman on the turn-adapting bit https://youtube.com/watch?v=y7h4OtFDnYE