Railway track (OT)
 

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?

Railway track (OT)
 

On 10/28/2013 11:55 AM, -- 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?



I guess it simply wasn't found necessary and avoided the need for
specialised chairs. The join also allowed for expansion, which would
have been an additional complication.

Railway track (OT)
 

On 28/10/2013 11:55, -- 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?


Not quite as much load as you might think. Remember that the loco weight
is distributed over several pairs of wheels so that once the joint
"flexes" the load is redistributed over the other wheels. Different for
carriages where there is suspension on the bogies.

Railway track (OT)
 

But isn't the load spread well to either side of the actual joint? Even a
Stirling Single loco, with just two massive driving wheels (that is, one on
each side) has leading and trailing wheels to take some of the weight.

Railway track (OT)
 

-- 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.

Railway track (OT)
 

Fishplates?

I guess as it worked nobody cared much.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"-- DerbyBorn" wrote in message
2.222...

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?

Railway track (OT)
 

In article ,
newshound scribeth thus
On 28/10/2013 11:55, -- 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?


Not quite as much load as you might think. Remember that the loco weight
is distributed over several pairs of wheels so that once the joint
"flexes" the load is redistributed over the other wheels. Different for
carriages where there is suspension on the bogies.

They can't be supported normally as they have things called Fishplates
lumps of flat metal quite thick and are what holds the lengths of rail
together..

Course thats on olde world sections of line, most all the time elsewhere
its long lumps of rail that get welded together...
--
Tony Sayer