Date: Tue, 25 May 2004 17:57:20 -0600

Author: "David Kardelis"

Subject: RE: trains

Post:

Something I have heard is there is an old mining or forestry law from
the Late 1800's that requires rails in the US to be laid on wood
sleepers whereas in Europe they use concrete sleepers. This is part of
the reason US trains do not reach the speeds of European or Japanese
trains. dave

David Kardelis Ph.D.
Chairman; Dept of Chemistry and Physics
College of Eastern Utah
451 E 400 N
Price, UT 84501

david.kardelis@ceu.edu
435-613-5258
435-613-5125 (lab phone)
435-613-5996 Fax

> -----Original Message-----
> From: owner-tap-l@listproc.appstate.edu [mailto:owner-tap-
> l@listproc.appstate.edu] On Behalf Of Paul Nord
> Sent: Tuesday, May 25, 2004 7:27 AM
> To: tap-l@listproc.appstate.edu
> Cc: Paul Nord
> Subject: Re: trains
>
> Could be that European rails are much better maintained than those in
> the US.
>
> My "back of the envelope" calculation says that a mile of track will
> expand (or contract) 6 feet over a 100 degree temperature change. I'm
> a little doubtful that the track information that Jerry found is the
> whole story. If the tracks have "pressure relief points" at intervals
> of several miles, the rails would need to slide back and forth at
those
> end points by tens of feet. Can the rails be attached to the ties so
> carefully that they allow this much movement?
>
> I'm also imagining that it is unlikely that several miles of track
> would see uniform temperature changes.
>
> Paul
>
> On Monday, May 24, 2004, at 08:14 PM, Chuck wrote:
>
> > If the rails were joined in a diagonal lap joint it would account
for
> > the
> > lack of noise. This was standard many years ago in Japan but has
since
> > seemingly given way to the 90 deg butt joint also. What joint
> > construction
> > details did you observe?
> >
> > cheers,
> > chuck...
> >
> >
> >
> > -----Original Message-----
> > From: owner-tap-l@listproc.appstate.edu
> > [mailto:owner-tap-l@listproc.appstate.edu] On Behalf Of Beth
Stoeckly
> > Sent: Monday, May 24, 2004 4:50 PM
> > To: tap-l@listproc.appstate.edu
> > Subject: RE: trains
> >
> > My understanding of the continuous (welded)rail is this: If long
> > pieces
> > of rail are not under tension, then as they heat up on a hot day,
they
> > will try expand. If they have no room to expand they will go into
> > compression and eventually buckle. However, if the temperature at
> > which the rail would be neither in tension nor compression is well
> > above
> > the expected range in service, and the rail is held stretched (in
> > tension) at normal temperatures, then all that happens as the rail
> > heats up is that the tension is reduced.
> >
> > Beth Stoeckly
> >
> > -----Original Message-----
> > From: owner-tap-l@listproc.appstate.edu
> > [mailto:owner-tap-l@listproc.appstate.edu] On Behalf Of Jerry
DiMarco
> > Sent: Monday, May 24, 2004 3:45 PM
> > To: tap-l@listproc.appstate.edu
> > Subject: Re: trains
> >
> > I don't understand how laying tracks under tension helps the
> > situation. Below is an excerpt from a history of trains webpage.
> > Guess
> >
> > you should have watched the track a little longer...
> >
> >
> > Jerry
> >
> > "British Railways purchases rails in 60 ft (18.3 m) lengths which
are
> > shop-welded into 600 ft (183 m) lengths and then welded on site into
> > continuous welded track with pressure-relief points at intervals of
> > several
> > miles. The continuous welded rails make for steadier and less noisy
> > ride
> >
> > for the passenger and reduce the tractive effort."
> >
> > At 11:01 AM 5/24/2004, you wrote:
> >> I went to NYC yesterday on the NJ Transit train, as I have several
> > times
> >> in the past. The ride was very smooth. So smooth that it got me
> > thinking
> >> about heat and expansion joints. There wasn't that "clickety-clack"
> > noise
> >> one would expect to hear. It was as if each track was one
continuous
> >> piece. So I looked at adjacent tracks and noticed what appeared to
be
> >> track joiners, with basically NO space in between the track
sections.
> > This
> >> puzzled me. We've probably all seen expansion joints on steel
bridges,
> > and
> >> photos in texts of railroad tracks buckling during extreme heat
> >> conditions. Does anyone know how engineers account for the
temperature
> >> effects on these tracks? I know Jersey does things a little
> >> differently
> >> sometimes, but the laws of physics should also apply in this state!
Or
> > am
> >> I missing something here?
> >
> >
> > <><><><><><><><><><><><><><><><><><><><><><><><><><><><><>
> >
> > Jerry DiMarco
> > Manager of Lecture Demonstrations and Instructional Labs
> > Montana State Univ., Physics Dept.
> >
> > Bozeman, MT
> >
> > Our Motto: "There's a demo in there somewhere."
> >

From chuck.patten@verizon.net Tue May 25 22:31:55 2004

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