Train Graphic
Great Western Passengers' Forum Great Western Coffee Shop - [home] and [about]
Read about the forum [here].
Register and contribute [here] - it's free.
 21/11/2018 - First Bath Bus panel
21/11/2018 - Consultation end - Angel Road
26/11/2018 - TransWilts Board and Members
26/11/2018 - Bath Clean Air consult ends
28/11/2018 - Melksham RUG
28/11/2018 - WECA Scrutiny
Random Image
Train Running @GWR Twitter Acronyms/Abbreviations Station Comparator Rail News GWR co. site Site Style 1 2 3 4 Chat on off
November 18, 2018, 07:36:44 am *
Welcome, Guest. Please login or register.

Login with username, password and session length
Forgotten your username or password? - get a reminder
Most liked recent subjects
[97] Four track for Filton Bank - ongoing discussion
[87] Transport for London - the other new line
[65] IETs into passenger service from 16 Oct 2017 and subsequent pe...
[41] A welcome to XC from Bristol to Swindon. Delighted to have yo...
[38] Super Speed Camera
[29] Infrastructure problems in Thames Valley causing disruption el...
News: A forum for passengers ... with input from rail professionals welcomed too
 
   Home   Help Search Calendar Login Register  
Pages: 1 ... 24 25 [26] 27 28 ... 35
  Print  
Author Topic: Great Western Main Line electrification - ongoing discussion  (Read 47593 times)
YouKnowNothing
Full Member
***
Posts: 60


View Profile Email
« Reply #375 on: October 15, 2018, 10:39:41 pm »

Has there been any movement on when they expect the lines to reach Cardiff? It’s all gone quiet after they announced the delay....
Logged
Adrian
Jr. Member
**
Posts: 18


View Profile
« Reply #376 on: October 16, 2018, 09:21:37 pm »

Still a lot of masts to go up between Severn Tunnel and Magor.  Will the wiring taking place over Christmas just complete the English side?
Logged
grahame
Administrator
Hero Member
*****
Posts: 22500



View Profile WWW Email
« Reply #377 on: October 16, 2018, 11:20:54 pm »

Still a lot of masts to go up between Severn Tunnel and Magor.  Will the wiring taking place over Christmas just complete the English side?

The Christmas to New Year closure of the Severn Tunnel is to wire in the Severn Tunnel Junction area - thus the route via Gloucester will not be available.   GWR do not have enough crew / route knowledge / capacity to route Swansea trains via Malvern, so it's buses ...
Logged

Coffee Shop Admin, Member of Melksham Rail User Group, on the board of TravelWatch SouthWest and some more things besides
froome
Transport Scholar
Hero Member
******
Posts: 325


View Profile Email
« Reply #378 on: October 17, 2018, 08:00:02 am »

With today's dreadful disruption in mind, it seems timely to ask a question I've been meaning to ask for some time.

Just how susceptible are overhead wires to being damaged?

Whenever i travel along lines fed by overhead wiring, the cables look to me to be very susceptible to many sources of potential danger, from high winds and other weather related factors to damage caused by vandals or interaction with the trains themselves. What sort of risk analysis has been done on their use and what have they shown?

Obviously these are large questions that will have complex answers, but given the inflexibility of any sort of rail system, the susceptibility of a major part of that system, in this case, the prime energy source, must have been given much thought before introduction. Are there better ways to provide electricity that reduce substantially this susceptibility?
Logged
Timmer
Global Moderator
Hero Member
*****
Posts: 4844


View Profile
« Reply #379 on: October 17, 2018, 08:07:59 am »

The sad thing is all that has gone on these past few years on the GW mainline and now last night has given electrification a bad name yet it has been a huge success on the WCML and on mainland Europe. Not as successful on the ECML but that was because it was done on the cheap.

I still firmly believe electrification is still the right answer for all rail and not relying on diesel.
Logged
Electric train
Hero Member
*****
Posts: 3007


The future is 25,000 Volts a.c.


View Profile
« Reply #380 on: October 17, 2018, 08:09:48 am »

With today's dreadful disruption in mind, it seems timely to ask a question I've been meaning to ask for some time.

Just how susceptible are overhead wires to being damaged?

Whenever i travel along lines fed by overhead wiring, the cables look to me to be very susceptible to many sources of potential danger, from high winds and other weather related factors to damage caused by vandals or interaction with the trains themselves. What sort of risk analysis has been done on their use and what have they shown?

Obviously these are large questions that will have complex answers, but given the inflexibility of any sort of rail system, the susceptibility of a major part of that system, in this case, the prime energy source, must have been given much thought before introduction. Are there better ways to provide electricity that reduce substantially this susceptibility?


The area damaged is in the Hanwell area, this is in the most part still the older Mk3 "Headspan" system.  Headspan problem is when a wire is "ripped down" on one line it usually dislodges the other lines; the OLE used on the GWML west of Airport Jcn is independently mechanically registered with this system one wire being "ripped down" is very unlikely to effect adjacent lines, other than perhaps debris which can be quickly removed.


Its worth noting the OLE has quite a high (mechanical) tension on it, which has to be dealt with carefully when is dislodged
Logged

Mark Carne 26 June 2015 - "The challenges of delivering myriad improvement projects while still running a railway seven days a week were simply overwhelming".
froome
Transport Scholar
Hero Member
******
Posts: 325


View Profile Email
« Reply #381 on: October 17, 2018, 08:14:25 am »

With today's dreadful disruption in mind, it seems timely to ask a question I've been meaning to ask for some time.

Just how susceptible are overhead wires to being damaged?

Whenever i travel along lines fed by overhead wiring, the cables look to me to be very susceptible to many sources of potential danger, from high winds and other weather related factors to damage caused by vandals or interaction with the trains themselves. What sort of risk analysis has been done on their use and what have they shown?

Obviously these are large questions that will have complex answers, but given the inflexibility of any sort of rail system, the susceptibility of a major part of that system, in this case, the prime energy source, must have been given much thought before introduction. Are there better ways to provide electricity that reduce substantially this susceptibility?


The area damaged is in the Hanwell area, this is in the most part still the older Mk3 "Headspan" system.  Headspan problem is when a wire is "ripped down" on one line it usually dislodges the other lines; the OLE used on the GWML west of Airport Jcn is independently mechanically registered with this system one wire being "ripped down" is very unlikely to effect adjacent lines, other than perhaps debris which can be quickly removed.


Its worth noting the OLE has quite a high (mechanical) tension on it, which has to be dealt with carefully when is dislodged

Many thanks, that is very helpful. And I agree with all of Timmer's comments.
Logged
Bmblbzzz
Transport Scholar
Hero Member
******
Posts: 1618


View Profile
« Reply #382 on: October 17, 2018, 08:44:05 am »

What caused the wire this morning to be "ripped down", if that is what has happened? Something falling on it? Vandalism? Malfunctioning pantograph? ...
Logged

Day return to Infinity, please.
TaplowGreen
Transport Scholar
Hero Member
******
Posts: 4051


View Profile
« Reply #383 on: October 17, 2018, 08:49:07 am »

What caused the wire this morning to be "ripped down", if that is what has happened? Something falling on it? Vandalism? Malfunctioning pantograph? ...

Could it be Driver error? If so, I suspect someone is feeling rather uncomfortable this morning...…………….
Logged
broadgage
Transport Scholar
Hero Member
******
Posts: 2227



View Profile
« Reply #384 on: October 17, 2018, 09:30:17 am »

What caused the wire this morning to be "ripped down", if that is what has happened? Something falling on it? Vandalism? Malfunctioning pantograph? ...

Could it be Driver error? If so, I suspect someone is feeling rather uncomfortable this morning...…………….

I rather doubt it. All the driver can do is raise or lower the pantograph, perhaps in the wrong place.

Pantograph lowered when it should remain up--------------Train looses power and coasts. No contact with overhead, therefore no damage.
Pantograph raised when it should be lowered.-------------Pantograph liable to be knocked of  by a bridge or signal gantry. No overhead present to be damaged.

If the pantograph is improperly raised just before entering an electrified section, then no damage should be caused because the overhead is ramped at the entrance.

A defective pantograph seems the likely cause with defective overhead a distinct possibility. Either can result in the overhead getting caught UNDER the pantograph and pulling down the wires.
Logged

"When customers say that they want a seat, they dont mean they want to sit with their knees behind their ears so that 4 more can sit down. They mean that they want an extra coach so that 74 more can sit down"
"Capacity on intercity routes should be about number of vehicles, not compressing people"
a-driver
Hero Member
*****
Posts: 680


View Profile
« Reply #385 on: October 17, 2018, 09:35:06 am »

Wouldn’t be driver error, could be a whole manner of things... train fault, infrastructure fault, obstruction on the overhead or vandalism. 
Logged
ChrisB
Transport Scholar
Hero Member
******
Posts: 9729


View Profile Email
« Reply #386 on: October 17, 2018, 09:45:56 am »

Has there been any movement on when they expect the lines to reach Cardiff? It’s all gone quiet after they announced the delay....

This Q came up at the GWR Stakeholders Conference yesterday & Andrew Haines, MD, said next summer, if I remember correctly.

What caused the wire this morning to be "ripped down", if that is what has happened? Something falling on it? Vandalism? Malfunctioning pantograph? ...

Answered already in the disruption in Thames Valley thread....
An on test ECS 802 recently delivered was being moved from North Pole depot to Stoke Gifford depot....reportedly by a GBrF driver. What actually caused the failure will be under investigation still, I suspect.
Logged
SByers
Jr. Member
**
Posts: 18


View Profile
« Reply #387 on: October 17, 2018, 09:47:52 am »

With today's dreadful disruption in mind, it seems timely to ask a question I've been meaning to ask for some time.

Just how susceptible are overhead wires to being damaged?

The Swiss mountain railways are mainly overhead high tension line. The actual supports seem to be flimsy wooden poles. Yet it all works through most weathers.
Logged
Bmblbzzz
Transport Scholar
Hero Member
******
Posts: 1618


View Profile
« Reply #388 on: October 17, 2018, 10:38:13 am »

A defective pantograph seems the likely cause with defective overhead a distinct possibility. Either can result in the overhead getting caught UNDER the pantograph and pulling down the wires.
I'm struggling to see, in my mind, how that happens. All I can think of is the pantograph lifting, hitting the overhead line and not stopping but continuing, pushing the line to one side and getting it trapped underneath. Seems kind of complicated though.  Huh
Logged

Day return to Infinity, please.
Electric train
Hero Member
*****
Posts: 3007


The future is 25,000 Volts a.c.


View Profile
« Reply #389 on: October 17, 2018, 10:38:28 am »

Has there been any movement on when they expect the lines to reach Cardiff? It’s all gone quiet after they announced the delay....

This Q came up at the GWR Stakeholders Conference yesterday & Andrew Haines, MD, said next summer, if I remember correctly.

What caused the wire this morning to be "ripped down", if that is what has happened? Something falling on it? Vandalism? Malfunctioning pantograph? ...

Answered already in the disruption in Thames Valley thread....
An on test ECS 802 recently delivered was being moved from North Pole depot to Stoke Gifford depot....reportedly by a GBrF driver. What actually caused the failure will be under investigation still, I suspect.

I would not write anything into it being a GBrF driver most TOCs use a contracted in FOC to move new stock about, carry out test runs and mileage accumulation, they are no less able or skilled than a TOC Driver.
Logged

Mark Carne 26 June 2015 - "The challenges of delivering myriad improvement projects while still running a railway seven days a week were simply overwhelming".
Do you have something you would like to add to this thread, or would you like to raise a new question at the Coffee Shop? Please [register] (it is free) if you have not done so before, or login (at the top of this page) if you already have an account - we would love to read what you have to say!

You can find out more about how this forum works [here] - that will link you to a copy of the forum agreement that you can read before you join, and tell you very much more about how we operate. We are an independent forum, provided and run by customers of Great Western Railway, for customers of Great Western Railway and we welcome railway professionals as members too, in either a personal or official capacity. Views expressed in posts are not necessarily the views of the operators of the forum.

As well as posting messages onto existing threads, and starting new subjects, members can communicate with each other through personal messages if they wish. And once members have made a certain number of posts, they will automatically be admitted to the "frequent posters club", where subjects not-for-public-domain are discussed; anything from the occasional rant to meetups we may be having ...

 
Pages: 1 ... 24 25 [26] 27 28 ... 35
  Print  
 
Jump to:  

Powered by MySQL Powered by PHP Powered by SMF 1.1.2 | SMF © 2006-2007, Simple Machines LLC Valid XHTML 1.0! Valid CSS!
This forum is provided by a customer of Great Western Railway (formerly First Great Western), and the views expressed are those of the individual posters concerned. Visit www.gwr.com for the official Great Western Railway website. Please contact the administrators of this site if you feel that the content provided by one of our posters contravenes our posting rules (email link). Forum hosted by Well House Consultants