View Single Post
  #206   Report Post  
Old April 16th 21, 02:14 PM posted to uk.railway,uk.transport.london
Tweed[_2_] Tweed[_2_] is offline
external usenet poster
 
First recorded activity at LondonBanter: Aug 2020
Posts: 12
Default Test tracks

Roland Perry wrote:
In message , at 11:26:45 on Fri, 16 Apr
2021, Recliner remarked:
Anna Noyd-Dryver wrote:
Anna Noyd-Dryver wrote:
Recliner wrote:
Marland wrote:
Recliner wrote:
Marland wrote:


There are more up to date ones which would have been a better
choice such
as this one from the cab of an S stock train under test.

https://youtu.be/ZL8xZrY9SeU

Thanks, that was interesting. From the conversation, the 4th rail test
track is 4km long, and includes virtual stations and virtual tunnels. The
train has to do 500 miles (800km) of testing, so a 100 cycles.


One thing that strikes me from the various videos of the old Dalby test
route is that it is mainly straight. As more trains like the S stock get
constructed with full width connections between cars
or even articulations that could be an achilles heel.
The law of sod if you are testing something says it will be the bit that
wasn’t stressed that shows up an unexpected snag.

I know they have test rigs to repeatedly stress those connections to
destruction, with more violent movement in all directions than you'd want
to put a real train through.

Real service often shows up problems which testing hasn't; the latest
example is cracks in the yaw damper mountings of Northern's CAF units.
Several units are out of traffic, the rest being visually checked daily,
and some 319s are apparently being readied for a possible return to
service.

https://twitter.com/garethdennis/status/1382968339870408707?s=21


That looks like a pretty basic flaw that should have been found and fixed
long ago, particularly as it's happened before, in Ireland!


Or similar failure modes on the Comet aircraft. Don't they teach this on
the first week of engineering courses, any more?


It’s what happens as the result of “efficiency”. In days gone by there
would be a core of long serving engineers in an organisation with the
corporate memory of what not to do again. These days it’s fashionable to
talk up changing jobs every few years and easing out the older experienced
staff because they are expensive. The modern practice is to claim that
everything can be captured in a specification or a standard. Unfortunately
that’s not the case....

Many outfits are doomed to keep on repeating the same mistakes because of
high staff turnover.