-- DerbyBorn wrote:
I was idly looking at the track as a steam loco went over a joint and
wondered why the joints in the track are not supported in some way by a
sleeper (and chair) arrangement. The cantilevered unsupported ends place an
incredible load on the strips of metal and bolts.
I realise the problem has gone away now - but has anyone any observations?


In the days when they still used fishplates and bolts, as well as wooden
chair keys, each joint and key was checked at least once a day by the
lengthsman, and you could see the wear at the joints on old rails in
sidings and suchlike places. The welded rail, as you say, doesn't suffer
from this problem.

However, as has been said, you'd need a special chair to support the
weight at the joint, which adds greatly to track maintenance complexity,
and given regular maintenance, there wasn't a problem. The old system is
still used at junctions, and they are still checked at least daily for
loose bolts. Modern rail expansion joints are every half mile or so, and
use overlapping horizontally tapered sections of rail which need regular
greasing. The keys on the chairs which hold the rail steady still need
regular checking with a hammer, too.

--
Tciao for Now!

John.