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