Train GraphicClick on the map to explore geographics
 
I need help
FAQ
Emergency
About .
 No recent travel & transport from BBC stories as at 18:35 28 Apr 2024
Read about the forum [here].
Register [here] - it's free.
What do I gain from registering? [here]		 22/05/24 - WWRUG / TransWilts update
02/06/24 - Summer Timetable starts
17/08/24 - Bus to Imber
27/09/25 - 200 years of passenger trains

On this day
28th Apr (1996)
GNER franchise (Sea Containers) starts on ECML (*)
Train RunningCancelled
28/04/24 18:01 Severn Beach to Bristol Temple Meads
19:21 Reading to Gatwick Airport
21:16 Gatwick Airport to Reading
Short Run
15:31 Hereford to London Paddington
16:08 Weymouth to Bristol Temple Meads
18:44 London Paddington to Hereford
Delayed
13:00 Cardiff Central to Penzance
13:53 London Paddington to Penzance
15:00 Cardiff Central to Penzance
15:02 Plymouth to London Paddington
17:53 Weymouth to Bristol Temple Meads
18:38 London Paddington to Swansea
•
PollsThere are no open or recent polls
•
Abbreviation pageAcronymns and abbreviations
•
Stn ComparatorStation Comparator
•
Rail newsNews Now - live rail news feed
•
Train companiesSelect from:
GWR
SWR
XC
Chiltern
TfL
TfW
WMR
Southern
• Site Style 1 2 3 4
Next departures • Bristol Temple Meads • Bath Spa • Chippenham • Swindon • Didcot Parkway • Reading • London Paddington • Melksham
Exeter St Davids • Taunton • Westbury • Trowbridge • Bristol Parkway • Cardiff Central • Oxford • Cheltenham Spa • Birmingham New Street
April 28, 2024, 18:43:00 *
Welcome, Guest. Please login or register.

Login with username, password and session length
Forgotten your username or password? - get a reminder
Most recently liked subjects
[226] Clan Line - by Clan Line !
[56] Labour to nationalise railways within five years of coming to ...
[46] Misleading advertising?
[16] access for all at Devon stations report
[16] Who we are - the people behind firstgreatwestern.info
[6] Cornish delays
 
News: the Great Western Coffee Shop ... keeping you up to date with travel around the South West
 
   Home   Help Search Calendar Login Register  
Great Western Coffee Shop > All across the Great Western territory > The Wider Picture in the United Kingdom > Signalling shutdown - Croydon area - Wednesday night 18.12.19
Pages: 1 [2]
« previous next »
  Print  
Author Topic: Signalling shutdown - Croydon area - Wednesday night 18.12.19  (Read 4147 times)
Electric train
Transport Scholar
Hero Member
******
Posts: 4362


The future is 25000 Volts AC 750V DC has its place


View Profile
« Reply #15 on: December 21, 2019, 19:26:38 »
Quote from: ellendune on December 21, 2019, 13:38:31
Quote from: Electric train on December 21, 2019, 12:54:28
First the term power surge is used in the rail industry by folks in the operating department, a true power surge would fry a lot of equipment other than just the signalling. It was more likely to have been a short loss of power, just a few milliseconds is sufficient for the signalling system to go into a fail safe mode. 

Why would NR» (Network Rail - home page) say it was an over-voltage fault lasting 20 seconds or more then?

Typically the low voltage supplies derived form the 33kV will change over to a second or even third supply within 2 to 10 seconds, provided there was an actual supply failure, the change over equipment in the substations has a little hysteresis built. Also it can then take the signalling system can take many seconds to start to recover. 

The timings in the system are deliberate
Logged
Starship just experienced what we call a rapid unscheduled disassembly, or a RUD, during ascent,”
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 [2]
  Print  
« previous next »
 
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 customers 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 to report). Forum hosted by Well House Consultants

Jump to top of page • Jump to Forum Home Page