[andbberger]

incredible almost everything you said is wrong!

> Note that if you travel from The Netherlands to Spain you might be traversing 6 different railway electrification systems that vary in critical stuff like voltages (and by more than a factor 10!) and possibly Hz, and some are AC and some are DC (not kidding). Also there will be at least 2 incompatible track gauges involved. And I bet other stuff like communications and routing systems are incompatible and safety critical too.

none of this is nearly as problematic as you seem to think it is. modern powertrains traverse various electrification schemes without difficulty. signaling systems are trending towards ETCS, trains that traverse incompatible signaling systems (eg the eurostar) simply carry a set of onboard signaling equipment for each standard. gauge changes are the most challenging technical limitation in your list, but are a solved problem. spanish talgo's regularly change gauges at speed [1]

[1] https://www.youtube.com/watch?v=ZiH4kt14yGw

[ATsch]

> modern powertrains traverse various electrification schemes without difficulty.

Indeed, however the majority of currently existing stock is only fitted for operation in at most one or two countries

> signaling systems are trending towards ETCS

"trending towards" is doing a lot of work here, ETCS rollout has been stalling for ages. New train sets are still being delivered today that do not really support it. Most countries have somewhat understandably not been in a hurry to make the huge investments required to replace their current, working systems with ETCS.

> trains that traverse incompatible signaling systems (eg the eurostar) simply carry a set of onboard signaling equipment for each standard.

Yes, which is extremely expensive and also requires full re-certification for every country, which means that in practice most trains are only certified for one or two countries at most.

None of these would be unsolvable with some more willpower of course, but they are still absolutely an issue today.

[emn13]

Exactly - the issue isn't that any of this is unsolvable; these problems are solved, even today. The issue is that those solutions aren't free, and that they do impose limitations on the quality of service.

[m2fkxy]

I believe you could get from the Netherlands to Spain in just two trips: Amsterdam > Paris in Thalys, and Paris > Madrid in AVE (seasonal) or > Barcelona in TGV (neither involve track gauge change). You could do that in the span of a day and still have spare time, depending on how well the schedules match.

[emn13]

Of course technical hurdles can be worked around - the issue is that those workaround often have limitations and consequences. Trains won't be as interchangeable as they might be. Not all trains and all routes will be chosen because they're ideal from the perspective of traveler's logistics, but to stick to technically more feasible routes. There's going to be cost involved in making trains support multiple systems. Electrical systems can convert between voltages, but doing so efficiently, cheaply and robustly isn't that easy, and they'll take space and weight in the train too.

All those factors reduce the overall efficiency of the network, and they help explain why it's so slow and costly to travel large distances by train - much more so than you'd naively expect given modern train speeds.

For instance, I just tried looking for a connection between Groningen,NL and Murcia, ES. The train connection takes 29-30 hours. Adding busses into the mix reduces that time to 23-24 hours. Avoiding high-speed rail entirely and using a car would take ~21h - despite the trains going much, much faster for long stretches of the trip. By contrast, if you take long trips within e.g. France or Germany countries, it's pretty common for the train to be the fastest option.

The interconnections just aren't great, and I bet part of that poor connectivity is due to the fragmentation in the standards involved.

When you assert that these hurdles aren't impossible to take you're of course correct - but that doesn't mean the hurdles are irrelevant either.