wrote:
In article , y () wrote:

On Tue, 28 Jul 2015 13:55:53 -0500
wrote:
There are no metre gauge railways of any significance in this country.
The DLR uses lots of docklands abandoned railway viaducts so it was
presumably thought to be simpler to stick to standard gauge which seems
to handle the curves without problems.

The trains handle the curves but they really don't sound happy about it
especially on the west india key to westferry curve. There's a huge
amount of squealing and shuddering even at single digit speeds. I
suspect its really on the limit of curve radius you can have with
standard gauge track.

Metre gauge trains aren't immune to this problem either.

They can handle tighter curves than standard gauge. That's why most
mountain railways are narrow gauge.

On Wed, 29 Jul 2015 08:34:59 -0500
wrote:
In article , y () wrote:

On Tue, 28 Jul 2015 13:55:53 -0500
wrote:
There are no metre gauge railways of any significance in this country.
The DLR uses lots of docklands abandoned railway viaducts so it was
presumably thought to be simpler to stick to standard gauge which seems
to handle the curves without problems.

The trains handle the curves but they really don't sound happy about it
especially on the west india key to westferry curve. There's a huge
amount of squealing and shuddering even at single digit speeds. I
suspect its really on the limit of curve radius you can have with
standard gauge track.

Metre gauge trains aren't immune to this problem either.

No, but the dragging effect of the outside wheel moving over the rail faster
than its turning (and similarly the opposite for the inside wheel) is lessened
because of the reduced distance between the rails.

--
Spud

On Wed, 29 Jul 2015 12:52:49 +0100
Recliner wrote:
On Wed, 29 Jul 2015 08:18:45 +0000 (UTC), y wrote:

On Tue, 28 Jul 2015 13:55:53 -0500
wrote:
There are no metre gauge railways of any significance in this country. The
DLR uses lots of docklands abandoned railway viaducts so it was presumably
thought to be simpler to stick to standard gauge which seems to handle the
curves without problems.

The trains handle the curves but they really don't sound happy about it
especially on the west india key to westferry curve. There's a huge amount of
squealing and shuddering even at single digit speeds. I suspect its really on
the limit of curve radius you can have with standard gauge track.

I assume all that noise is a sign of excessive track and flange wear
on the wheels.

Don't know TBH. But I imagine it doesn't do the wheels or track any favours.

--
Spud

wrote:
On Wed, 29 Jul 2015 12:52:49 +0100
Recliner wrote:
On Wed, 29 Jul 2015 08:18:45 +0000 (UTC), y wrote:

On Tue, 28 Jul 2015 13:55:53 -0500
wrote:
There are no metre gauge railways of any significance in this country. The
DLR uses lots of docklands abandoned railway viaducts so it was presumably
thought to be simpler to stick to standard gauge which seems to handle the
curves without problems.

The trains handle the curves but they really don't sound happy about it
especially on the west india key to westferry curve. There's a huge amount of
squealing and shuddering even at single digit speeds. I suspect its really on
the limit of curve radius you can have with standard gauge track.

I assume all that noise is a sign of excessive track and flange wear
on the wheels.

Don't know TBH. But I imagine it doesn't do the wheels or track any favours.

The DLR seems to make heavy use of its Beckton wheel lathe. It installed a
new one recently, and this was the required spec:

The new wheel lathe must be capable of turning at least 6 train axles in a
4 hour period and have a total capacity of no less than 1 650 train axles
per annum

http://www.sell2wales.gov.uk/search/...x?ID=NOV056317

In other words, it must be able to turn all six axles of one car in four
hours, and each car has all its axles turned about once every eight months.
That compares with about 54 months for LU trains, so DLR wheels wear at a
very high rate.

Also:

All DLR stock has wheels which have a more angled profile than that on
mainline trains, which is effective in dealing with the tight curves
encountered on DLR routes. However, a downside to this innovation is that
they are partly responsible for violent shaking as the train travels at
higher speeds on the straight parts of the route.

Another manifestation of the DLR's wheel geometry and tight rail curves is
that this setup generates noise. This noise is amplified by the use of
steel box torsion girders (e.g. Marsh Wall elevated road crossing adjacent
to South Quay DLR Station).

From
https://en.m.wikipedia.org/wiki/Dock...ems_suf fered

And, guess what, despite how new most of its track is, the DLR is already
on to a track replacement cycle on its twisty sections:
http://www.dlrlondon.co.uk/uploadedF...20FINAL(1).pdf

On Wed, 29 Jul 2015 15:32:39 +0000 (UTC)
Recliner wrote:
encountered on DLR routes. However, a downside to this innovation is that
they are partly responsible for violent shaking as the train travels at
higher speeds on the straight parts of the route.

I never did understand why they couldn't sort that. Presumably trams have the
same wheel profile yet they don't tend to shudder and shake at higher speeds
from my experience here and in france.

And, guess what, despite how new most of its track is, the DLR is already
on to a track replacement cycle on its twisty sections:
http://www.dlrlondon.co.uk/uploadedF...s/Upcoming_Wor
s_-_mobile/Closure_A5_Leaflet_8-9_June_2013%20FINAL(1).pdf

Can't say I'm surprised.

--
Spud

On 29/07/2015 14:34, Clive D. W. Feather wrote:
In message , Someone Somewhere
wrote:
Slightly off topic but if anyone is interested in metre gauge I can
thoroughly recommend the railways of Corsica

Speaking of which, can anyone advise on the railways (if any) of
Sardinia? Particularly at the southern end. Anything particularly worth
a ride if I can persuade SWMBO?

Yes!

The narrow gauge lines are well worth doing, not least in a "do them
while they are still there" sense. I did Cagliari - Isili in a little
railbus, and two of the routes from Sassari. The scenery can be quite
wild, vaguely Yorkshire Dales-esque.

The mainline network was standard Italian stock (though IIRC they've
since got some Spanish units), though in a perhaps slightly "unItalian"
landscape. The line up through the middle is scenic, and Sassari a nice
place.

There is a railway museum in the suburbs of Cagliari, accessible by tram
on the converted railway.

Top tip: don't go on a whim on a stormy weekend in March and book a room
overlooking the sea which has shutters but no proper glazed windows
between you and Barcelona.

--
Arthur Figgis Surrey, UK

On 29/07/2015 19:01, Arthur Figgis wrote:
On 29/07/2015 14:34, Clive D. W. Feather wrote:
In message , Someone Somewhere
wrote:
Slightly off topic but if anyone is interested in metre gauge I can
thoroughly recommend the railways of Corsica

Speaking of which, can anyone advise on the railways (if any) of
Sardinia? Particularly at the southern end. Anything particularly worth
a ride if I can persuade SWMBO?

Yes!

The narrow gauge lines are well worth doing, not least in a "do them
while they are still there" sense. I did Cagliari - Isili in a little
railbus, and two of the routes from Sassari. The scenery can be quite
wild, vaguely Yorkshire Dales-esque.

The mainline network was standard Italian stock (though IIRC they've
since got some Spanish units), though in a perhaps slightly "unItalian"
landscape. The line up through the middle is scenic, and Sassari a nice
place.

There is a railway museum in the suburbs of Cagliari, accessible by tram
on the converted railway.

Top tip: don't go on a whim on a stormy weekend in March and book a room
overlooking the sea which has shutters but no proper glazed windows
between you and Barcelona.


That sounds like experience speaking :-)

--
Graeme Wall
This account not read, substitute trains for rail.