Re: Independence Day

D  <nospam@example.net> wrote:

On Mon, 22 Jul 2024, Scott Dorsey wrote:

Amtrak buys trains from Europe but because the tracks are graded and
configured for freight, they wind up having to pay a lot for design
modifications to accomodate the tracks.  Those modifications do not
always perform as planned.  The freight companies have no motivation
to change their tracks for passenger service.

>
If memory serves, I think that sweden has a different track width
compared with the rest of europe. This makes international travel with
train from sweden to europe a bit more painful, since you need to change
in denmark. But this could be something I've dreamed. I'd say I'm 60%
sure.

Nope, Sweden and Denmark uses the same track width (Standard Gauge),
they do use different voltages and signalling but these days it's
trivial to get triple or quad-capable trains (usually 1.5/3/15/25kV,
or 750V/1.5/3kV). And simpler 15/25kV (and 1.5/3kV) capable trains has
been in use for many decades.

Denmark do have a LOT of non-electrified tracks though - basically
it's just the mainline from Helsingor via Copenhagen to
Padborg/Germany, the spur from Sweden to Copenhagen, the
Lunderskov/Esbjerg line and the S-train & Metro (near and inside
Copenhagen respectively).

But the Sweden to Germany route do use electrified lines, changing
voltage and signalling twice - if they use the land route, as opposed
to the ferry route which include a ferry changeover between Denmark
and Germany - I assume this will go away too once the new Fehmarn Belt
fixed link is done.

The Sweden to Denmark transition is done in the tunnel at full speed
and no one even notice, I don't know how the Denmark to Germany
transition is handled but there's no technical reason why it couldn't
be seamless as well. The trains have been been running over the
Oresund bridge+tunnel since 2000 so I expect they're probably "only"
15/25kV models.

Perhaps you're thinking of Finland, they DO have a different track
width [3] from the rest of Europe. It's similar to what Russia uses
(shows it's origins) but the width was modified so that Finish train
can work on Russian tracks but NOT the other way around (they're a bit
paranoid about Russia, for good reasons). And they use 25kV @ 50Hz
while Russia is 3kV, they probably considered that difference a bonus
too (old Russian transports definitely wouldn't be multi-voltage
capable!).

IIRC Spain has gauge-changing trains (changing requires a slow section
for the change over) so the Sweden to Finland gauge change could have
been bridged without a train change but I think Sweden/Finland handle
passenger traffic via "deboard on train, board another". It's not THAT
much passenger traffic near or above the polar circle.


More technical details for those that want those:

Basically modern trains mostly doesn't care that much about the type
of electricity they run on except the available traction power may be
different (affects top speed and acceleration), and the signalling
side is mostly a question of which of the available signalling card
have you installed. It used to be a big thing though.

Sweden uses the same 15kV @ 16.7Hz [1] that Germany, Austria and
Switzerland uses. Denmark was very late at electrification so they use
the newer 25kV [2] system used in France and various other countries.


1. https://en.wikipedia.org/wiki/15_kV_AC_railway_electrification
2. https://en.wikipedia.org/wiki/25_kV_AC_railway_electrification
3. https://en.wikipedia.org/wiki/Track_gauge