
Double Saw Bye (2009) - concerto
http://www.sdmrra.org/Odds-n-Ends/saw_bye.htm
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woodruffw
Problems like these bear a lot of similarity to CS brain teasers, such as
exchanging N items without using N + 1 slots. [1]

I wonder if that contributes to why model railroad clubs (like the TMRC) and
early computer hobbyist groups intermingled so easily.

[1]:
[https://en.wikipedia.org/wiki/XOR_swap_algorithm](https://en.wikipedia.org/wiki/XOR_swap_algorithm)

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mannykannot
In the first section of his 1984 book 'Hackers', Stephen Levy wrote about the
Signals and Power Subcommittee of the MIT Tech Model Railroad Club, which
included quite a few computing pioneers among its ranks. Levy mentions that
one of the skills of the subcommittee was in disrupting any meeting through
creative use of Robert's Rules of Order.

[https://en.wikipedia.org/wiki/Tech_Model_Railroad_Club#Syste...](https://en.wikipedia.org/wiki/Tech_Model_Railroad_Club#System_layout)

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mannykannot
I did not get any hits on 'single saw bye' \- Is that the case where a siding
is connected to the main line at only one end? When I get a chance, I will see
if I can figure out that one (I guess there are two variants of the single-
junction siding, one with one and one with two switches.) Then there is the
question of the minimum-length siding for arbitrarily-long trains. There seem
to be some similarities to the Towers of Hanoi problem.

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falcolas
I love this kind of problem solving. Doing this safely is probably a time
consuming pain, yet less time consuming and dangerous than steaming several
miles backwards.

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thriftwy
I don't see why you won't have maximum train length for every part of track &
check that beforehand while routing.

Reminds me of the infamous MTU networking problems.

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PLenz
While through manifest trains are stable length locals pick up and set off
cars along the way - and historically there was no reliable way you'll know
exactly how many cars you'll switching in and out. Even today you can see
conditions change after a local leaves a yard and before it reaches say an
interchange between two railroads or a major shipper.

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thriftwy
Why don't they make an app to track trains' length?

Indeed I have hard time imagining an unaccounted car running on public rail.

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falcolas
Human error. These kinds of things happen all the time - packages going
through UPS/FedEx get lost, containers on ships are lost (i.e. put in the
wrong stack or fall off into the sea), containers in ports are lost/hidden...

There's a lot of rail cars in the US by itself. And while they are already
well tracked, mistakes happen.

