Re: [Phys-L] awesome but cheap technology (was trains, et cetera)

[Richard Tarara <rtarara@saintmarys.edu>]

Based on some relatively recent ecological trends, I wonder how 
disruptive canals are/were to animal migrations.  At least out West 
there is a rising awareness to the importance of keeping migration 
routes viable to the point of building animal crossings over interstate 
highways.  It would seem that canals offer a fairly serious barrier 
since there are no suitable fording locations as would be found with 
rivers, but of course today we could build the same kind of crossings 
that are showing up over the highways.

In our times I would also think that the economy of scale is very 
important--why else build the enormous ships now being produced. Add a 
couple more engines to a train and you can haul many more cars without 
additional crew.  I also wonder what the stopping distance is for the 
high speed trains of Japan and Europe and suppose the holy grail would 
be to match airline transit times (although being able to go from city 
center to city center is a great advantage for trains over planes--such 
that flying from DC to NYC seems like it would be a waste of both time 
and money).

Just weekend ramblings....

rwt



On 6/25/2016 12:05 AM, John Denker wrote:
> On 06/24/2016 06:56 PM, Bernard Cleyet wrote:
>
> > I think boat is E > rail.     Why so many canals?
> I know part of the answer to that one:
>
> A canal does not require nearly so much technology.  So
> the barrier to entry is less.
>
> For example:
>   -- The Grand Canal in China was started circa 400 BC
>    and reached a length of 1800 km circa 500 AD.
>   -- The first Transcontinental Railroad was constructed
>    starting in 1863 and completed in 1869.  That's quite
>    a bit later.
>
> The interesting thing is that the Transcontinental RR used
> /cast iron/ rails and /cast iron/ components on the engines,
> because steel was not available at anything approaching a
> reasonable price.  There were precisely zero Bessemer
> converters in the US before 1864, and the first inch of
> steel rail in the US was produced in 1867.  During the 1870s
> the cost of steel dropped astonishingly, to the point where
> it was economical to replace the rails on the Transcontinental
> Railroad from end to end, replacing cast iron with steel,
> which is dramatically more suitable for the purpose.
>
> People take steel for granted ... but they really shouldn't.
> It involves a treeeemendous amount of cleverness, not to
> mention quite a lot of capital investment.  It's cheap now,
> but it wasn't always.  Before Bessemer came along, a good
> steel sword was worth a fortune.
>
> The advent of cheap steel changed a lot of things.
>
> Even once you have steel, building a locomotive is a
> nontrivial undertaking.
>
> This is relevant to this list as follows:  Not everybody
> with a BS in physics goes on to study hadron/hadron
> collisions or gravitational waves.  A lot of them do
> materials science.  And materials science is not just
> silicon.  There is a lot of steel in the world, and
> there is a market for people who understand how it
> works.
>
> Tangentially related:  Here's a classic piece of collaborative,
> interdisciplinary detective work, solving the centuries-old
> mystery of Damascus steel.  A master swordsmith teamed up
> with a materials scientist.  I'm impressed, and I'm told by
> experts that the more you know about it the more impressive
> it is:
>    http://www.tms.org/pubs/journals/JOM/9809/Verhoeven-9809.html
>
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--
Richard Tarara
Professor Emeritus
Saint Mary's College

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