Re: TALGO tilt trains

[McFergus@my-dejanews.com]

In article <75khk8$m4v$1@reader1.reader.news.ozemail.net>,
  "David Proctor" <daproc.spambait@umpires.com> wrote:
> David Bromage wrote in message <75kera$om6$3@news.mel.aone.net.au>...
>
> >That was a problem with the short lived British APT, or so is popular
> >belief. The problem was actually that the tilting was so soft that there
> >was no sensation of the tilt, yet you could see the horizon move.
>
> Sort of - it wasn't that the tilting was so soft, but that it perfectly
> compensated for the curve that the train was going around - the sensation
> that you mentioned was correct - the middle ear detected that the body was
> level, but the eyes picked up that the body was tilted, hence the conflict.
>
> Current tilt systems get around this by compensating for all but 2-3% of the
> forces - so both the middle ear AND the eyes pick up that the body is not
> level, and the nausea does not occur.

I was aware of the APT's tilt problems, but what I was referring to was
almost the exact opposite! Whilst the APT provided near perfect compensation,
AFAIA passive tilt trains have been criticised for providing not enough
compensation, and for having a lag time between the 'detection' of a curve
and the transmission of that 'detection' into tilt action. Isn't this one of
the reasons why active and more recently pre-emptive active systems were
developed.

>
> David Proctor
> daproc.spambait@umpires.com
>
>


Rob

Sydney (Australia)

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