devon_metro
|
|
« Reply #15 on: October 09, 2009, 20:31:26 » |
|
I thought the program was reasonably balanced, and didn't try to dispute the view that rail safety has improved dramatically since Ladbroke Grove. (Only 1 passenger fatality due to an accident that was the fault of the railway since May 2002 is a remarkable improvement.)
Out of interest, how many HST▸ 's stop at Slough? Was the stop put on specially by any chance?
Varies between every half hour an hour. Mainly every half hour off peak
|
|
|
Logged
|
|
|
|
John R
|
|
« Reply #16 on: October 09, 2009, 20:57:30 » |
|
Thanks. I didn't realise that Slough was so well served by HST▸ 's.
|
|
|
Logged
|
|
|
|
Btline
|
|
« Reply #17 on: October 09, 2009, 22:27:56 » |
|
Thanks. I didn't realise that Slough was so well served by HST▸ 's.
Yep, Cotswolds and Oxford fasts stop (bar the peaks). I assume that Slough commuters jut have to get a stopper in the peaks!
|
|
|
Logged
|
|
|
|
Chris from Nailsea
|
|
« Reply #18 on: October 10, 2009, 16:51:06 » |
|
Some of the following post here were becoming rather 'off topic', so I have split them into a new topic on 'Slough commuters', at http://www.firstgreatwestern.info/coffeeshop/index.php?topic=5488.0 I felt this was appropriate, in view of the very sensitive nature of this particular topic. Thanks, Chris.
|
|
|
Logged
|
William Huskisson MP▸ was the first person to be killed by a train while crossing the tracks, in 1830. Many more have died in the same way since then. Don't take a chance: stop, look, listen.
"Level crossings are safe, unless they are used in an unsafe manner." Discuss.
|
|
|
Bulliver
Newbie
Posts: 1
|
|
« Reply #19 on: November 09, 2009, 19:54:32 » |
|
Two major facts were excluded from most media reports on the Ladbroke Grove collision, following a train passing a signal at danger.
In normal railway practice, where one running line joins another, there is a set of trap points (or derailer) which diverts an errant train away from the route it would otherwise have taken. Such trap points would be followed by a sand drag into which the train would plough and come to a very sudden but, depending on its speed, relatively safe halt. There were no such trap points (or derailer) at the end of the line controlled by Signal 109, either because they had never been installed, or they had been removed to save the maintenance cost of such a once universal safety feature.
On 23rd June 1999 at Winsford, Cheshire a train on a slow line passed a red signal, ran onto a fast line and was hit in the rear by another train ^ because there were no trap points at the end of the slow line. In this collision, just months before Ladbroke Grove, no one was killed or badly injured.
Both at Winsford and at Ladbroke Grove, the presence of such points would have averted the collisions
The other piece of normal railway practice missing was the way the facing points immediately beyond Signal 109 were set when 109 was at red. Had they been reversed to take any down train passing the signal at danger onto the track to the right ^ which was also a down line ^ then no head on collision would have been possible. As at Winsford, the worst that could have happened would have been two trains going the same way colliding.
Another question concerns the failure of the driver of the down train to respond to three AWS▸ (Automatic Warning System) alarms before accelerating past Signal 109. The driver of the train that passed 109 at red would have heard and cancelled those three warning horns telling him the signals he was approaching were at caution or danger. Instances of unconsciously cancelling AWS (and its decades old GWR▸ predecessor Automatic Train Control) warnings are legion; that is why ATP▸ (Automatic Train Protection) ^ which cannot be over-ridden in the same way ^ has now been installed on most if not all trains, even preserved steam engines, running on the national network.
As in most railway accidents, it was human errors that led to the Ladbroke Grove crash. Whilst some of those errors occurred on the day, others were built into the system waiting to be part of it. Even a fully automatic railway would still have been designed by humans.
|
|
|
Logged
|
|
|
|
Chris from Nailsea
|
|
« Reply #20 on: November 09, 2009, 20:06:23 » |
|
Welcome to the Coffee Shop forum, Bulliver - and thank you for posting such an informative summary. Chris.
|
|
|
Logged
|
William Huskisson MP▸ was the first person to be killed by a train while crossing the tracks, in 1830. Many more have died in the same way since then. Don't take a chance: stop, look, listen.
"Level crossings are safe, unless they are used in an unsafe manner." Discuss.
|
|
|
willc
|
|
« Reply #21 on: November 10, 2009, 00:22:38 » |
|
that is why ATP▸ (Automatic Train Protection) ^ which cannot be over-ridden in the same way ^ has now been installed on most if not all trains No it hasn't. ATP is only active on the HST▸ fleet on the Great Western Main Line and on the Chiltern Line's Turbo and 168 fleets. What was fitted nationally was TPWS▸ (Train Protection and Warning System) - which is an enhanced version of AWS▸ , offering many of the benefits of ATP up to 75mph or thereabouts, in terms of stopping a train passing a signal at danger, but full ATP it ain't.
|
|
|
Logged
|
|
|
|
JayMac
|
|
« Reply #22 on: November 10, 2009, 01:21:08 » |
|
|
|
|
Logged
|
"A clear conscience laughs at a false accusation." "Treat everyone the same until you find out they're an idiot." "Moral indignation is a technique used to endow the idiot with dignity."
|
|
|
paul7575
|
|
« Reply #23 on: November 10, 2009, 12:55:02 » |
|
In normal railway practice, where one running line joins another, there is a set of trap points (or derailer) which diverts an errant train away from the route it would otherwise have taken. Such trap points would be followed by a sand drag into which the train would plough and come to a very sudden but, depending on its speed, relatively safe halt. There were no such trap points (or derailer) at the end of the line controlled by Signal 109, either because they had never been installed, or they had been removed to save the maintenance cost of such a once universal safety feature.
This is called 'flank protection', and was discussed widely at the time of the original imquiry. Are you just pointing out that it wasn't mentioned by the media during the tenth anniversary reporting?Derailers or trap points seem to be more useful at the end of loops, where a train cannot be diverted onto another line. I'm not so sure about them being feasible in multi track bi-directional areas, except on the outer lines. I expect the Cullen Report covers it, it'll be online somewhere... Interesting point about ' GW▸ ATP▸ ', I believe that when the current kit it is life expired it will be removed and there are no plans for a like for like replacement. It is only on the GW as an experiment after all. So there may be a gap between ATP removal and ERTMS▸ roll out. I wonder if there'll be a public hue and cry? Paul
|
|
|
Logged
|
|
|
|
Tim
|
|
« Reply #24 on: November 10, 2009, 14:56:40 » |
|
Interesting point about 'GW▸ ATP▸ ', I believe that when the current kit it is life expired it will be removed and there are no plans for a like for like replacement. It is only on the GW as an experiment after all. So there may be a gap between ATP removal and ERTMS▸ roll out. I wonder if there'll be a public hue and cry?
Paul
Correct although we do have TPWS▸ into Paddington now (I assume that this was only installed because of anticipated ATP removal - it is currently not neccessary is it?) One point about TPWS is that although it is only works at up to 75 mph, an improved version TPWS+ works at up to 100 mph and has been installed at high risk signals. Also even if TPWS doesn't manage to stop a train completely, it will still manage to slow it significantly and thereby reduce the damage of any crash.
|
|
|
Logged
|
|
|
|
IndustryInsider
|
|
« Reply #25 on: November 10, 2009, 15:44:21 » |
|
Also even if TPWS▸ doesn't manage to stop a train completely, it will still manage to slow it significantly and thereby reduce the damage of any crash.
Yes, and that's a point that is all too often forgotten. The incident at Didcot North Junction last year is a prime example.
|
|
|
Logged
|
To view my GWML▸ Electrification cab video 'before and after' video comparison, as well as other videos of the new layout at Reading and 'before and after' comparisons of the Cotswold Line Redoubling scheme, see: http://www.dailymotion.com/user/IndustryInsider/
|
|
|
Tim
|
|
« Reply #26 on: November 10, 2009, 16:59:50 » |
|
Also even if TPWS▸ doesn't manage to stop a train completely, it will still manage to slow it significantly and thereby reduce the damage of any crash.
Yes, and that's a point that is all too often forgotten. The incident at Didcot North Junction last year is a prime example. IIRC▸ , NR» were critised after the Didcot North jnt incident because the site was "high risk" but TPWS+ had not been installed. I'd only be happy to see obsolete ATP▸ removed if proper risk assessment is carried out first and Didcot North Jnt type high risk signals are properly identified and addressed. With Didcot N. the risk assessment had been done and TPWS+ identified as a mitigating technology - BUT it had not yet been installed. It would be a great shame if we are only prepared to learn from tragidies like Ladbroke Grove and incidents like Didcot North (were an HST▸ was 13 seconds away from collission with a Turbo) are ignored.
|
|
|
Logged
|
|
|
|
devon_metro
|
|
« Reply #27 on: November 10, 2009, 17:38:26 » |
|
ATP▸ isn't particularly reliable and quite expensive to install. Not to mention the fact that it causes delays as it restricts the speeds drivers can drive at, even if a green aspect can be seen on the horizon, the driver cannot accelerate until passing the ATP loop (I think!)
TPWS▸ on vulnerable signals works on all other lines in the UK▸ !
|
|
|
Logged
|
|
|
|
Steve44
|
|
« Reply #28 on: November 10, 2009, 23:31:31 » |
|
Am i correct in thinking that a couple of Carriages from the Southall crash were involved in the Ladbroke Grove crash? or am i thinking of something else?
|
|
|
Logged
|
|
|
|
Tim
|
|
« Reply #29 on: November 11, 2009, 09:56:33 » |
|
TPWS▸ on vulnerable signals works on all other lines in the UK▸ !
But only if NR» installs the equipment which it didn't do at Didcot North Junction
|
|
|
Logged
|
|
|
|
|