Richard J. wrote:
Clive Coleman. wrote:
In message , Tom
Anderson writes
Makes sense. What's the advantage of conventional construction
over this, then?
The railway as laid down by Brunel wasn't level but sagged between
pillars down into the earth to prevent movement. Frequent
sleepers stop this and hold the gauge correctly.

Interesting. Was this true of all Brunel's broad gauge lines? That
would have meant that high(ish) speeds on broad gauge wouldn't have
been compatible with the comfort (and possibly the safety) of
passengers. Do you know if Brunel realised that later?

Apparently he did. I've just realised that Brunel died (in 1859) four
years before the Met opened, so it's probably wrong to attach credit or
blame to him for the Met's tracks. I then discovered that there is
evidence that Brunel himself had modified the track design some years
previously:

"To rectify the shortcomings of the track, Brunel adopted the expedient
of cutting through the piles which supported the track-work, allowing
the track assembly to be supported by the ground, then re-packing with
ballast as necessary. When this work was done the track behaved as had
first been expected."
(from "The Broad Gauge Story" at
http://lionels.orpheusweb.co.uk/Rail...dG/BGHist.html )

--
Richard J.
(to e-mail me, swap uk and yon in address)