[ih] Speaking of layering and gateways

[Bob Hinden]

John,

Very nice article!

I have taken a train  Hamburg to Copenhagen in the early 1980s.    The train cars went onto a ferry from Rødby Sogn to Puttgarden.    The networking analogy is, of course, encapsulation.

Bob

p.s. I see this is no longer running, the current route is a mix of land and bridges.





> On Apr 15, 2024, at 11:28 AM, John Levine via Internet-history <internet-history at elists.isoc.org> wrote:
> 
> Back in the 19th century there were a lot of railroads built in a lot
> of incompatible ways. The most obvious incompatibility was track gauge
> but there were others including the couplers between the cars and the
> ways they did (or sometimes did not) ensure that there was only one
> train at a time on each piece of track.
> 
> These days most of the world has converged on standard gauge but there
> are still places like Spain and Russia that use broader gauges, and
> mountain railways and trams that use narrower. When a passenger or
> freight train crosses a border there's a variety of approaches, some
> of which may seems kind of familiar.
> 
> The conceptually simplest approach is a gateway, at the border
> everyone gets off one train and gets on another.  The Canfranc
> station in the Pyrenees at the France-Spain border was famous
> for this.
> 
> https://en.wikipedia.org/wiki/Canfranc_International_railway_station
> 
> Another approach is layering. At the border, equipment lifts the car
> bodies off the bogies of the old gauge and puts them onto bogies of
> the new gauge. This is better since passengers don't have to get out
> (often from sleepers in the middle of the night) and goods don't have
> to be unloaded. This technique was patented in 1876.
> 
> Here's the Prague-Moscow train changing gauge in Brest, Belarus.
> 
> https://youtu.be/2nI467sc-Eo?si=w783HVwUGXAmQD7_
> 
> Yet another approach is parallel operation, dual or triple gauge, with
> three or more rails allowing trains of different gauge to run on the
> same route. In Japan the Shinkansen are standard gauge but older
> railways are mostly 1067mm so there's a fair amount of dual gauge in
> and out of cities.
> 
> This is a very old solution. The Niagara Falls bridge in 1855 had four
> rails for three different gauges, although now it's down to two.
> 
> Here's a video of a dual gauge Shinkansen route:
> 
> https://youtu.be/0d0XAaqEZ0s?si=ZYo27gNoAAXibtVq
> 
> Another approach is switching on the fly. Some trains have variable
> bogies that can change gauge as the train is moving, which is pretty
> cool.
> 
> Here is a Swiss train doing that:
> 
> https://youtu.be/H0gj2LWe-SI?si=7zpZFc-jQPTIv8TX
> 
> And a tutorial in Spanish:
> 
> https://youtu.be/y8N7Ikw87tM?si=bCwrx5ph3SpgrevM
> 
> The last approach is a flag day. One of the reasons the south lost the
> US Civil War was that they had a fragmented rail network, which
> continued to inhibit recovery and development after the war. So over
> two days, May 31-Jun 1, 1886, southern railroads regauged 11,500 miles
> of track to the Pennsylvania's gauge (1/2" wider than standard but
> close enough) and changed the bogies on the rolling stock.
> 
> Here's a video about it:
> 
> https://youtu.be/4v81Gwu6BTE?si=Yi9JDSU0onABpWju
> 
> R's,
> John
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