bb21
Emeritus Moderator
- Joined
- 4 Feb 2010
- Messages
- 24,151
Yes I agree. Just some additional information for reinforcement.
Because it's not that simple.
Even here in the UK where you might be required to run with the TPWS temporarily isolated, there is no single maximum speed imposed and it is still possible to exceed certain limits. For example, you can proceed through a Temporary Block Working section (for which the TPWS will need to be temporarily isolated) at up to 50mph, but you must still slow down to 15mph for any unsecured points, switch diamonds or swing-nose crossings. But then if you have to isolate it because it has become defective you may still proceed at linespeed provided another competent person is available (unless there is fog or falling snow), otherwise you're down to 40mph.
So you see, one system and so many different permitted speeds.
O L Leigh
I have heard a slightly different version which is that the first train had been cautioned through a "dark" section of line (20km/h) but that the signaller was under pressure to run the second train through the same section. So he sent that one into the same "dark" section before the first train had emerged at the other end and failed to caution the driver. Travelling much faster than the train ahead he quickly caught it up and was unable to stop before colliding with the rear. There has also been some discussion that the trains were running in the wrong order due to them both being delayed, which may have added to the confusion.
O L Leigh
I would imagine that the signaller would instigate some form of temporary block working where only one train at a time is allowed into the section, and only once it has been confirmed that the train ahead has cleared the section. This would undoubtedly require a reduction in speed and the driver to control the speed of the train such that it can be stopped in the distance that the driver can see to be clear. What appears to have happened is some failure to instigate such a method of degraded working, whether through ignorance, negligence or someone further up the chain requiring it.
O L Leigh
The driver had no warning of the stalled train and activated the emergency brakes seconds before impact slowing the train such that only 4 carriages were knocked from the viaduct which if at full speed would have resulted in 6 carriages being thrown off. The driver was sadly impaled by the brake lever at the moment of collision.
There has also been some discussion that the trains were running in the wrong order due to them both being delayed, which may have added to the confusion.
... so perhaps patience will be rewarded.
According to Wikipedia the trains were built as a joint venture between Bombardier and CSR.
Chinese government now saying theres 'A serious design flaw' in the signalling, a green light failed to automatically turn red to alert the following train to the stalled preceding train. The signalling equipment was designed and installed in September 2009 by an unnamed Beijing design and research institute. At the same time staff at Wenzhou station 'failed to respond properly' to the malfunctioning signalling, switching to manual operation.
They dug up and moved some very muddy crushed carriages a couple of days ago, after the burial outcry. They wernt buried for crane access however, the line was reopened 24 hours after the crash and they didnt start burying the carriages until 48 hours later. The total destruction via backhoe of the driving cars I think was the greatest tragedy as the passenger cars are relativley intact.
Looks to me that the track circuit did not 'fail safe' in the interlocking. This then allowed the signal to still show proceed.
They are using some sort of ETCS derivative probably level 1 ETCS with errors.
So did the first train stall or was it proceding under caution?
Now lets assume this new story is true (and his little bit about red and green signals is just added in to make it easy to understand). What was the signaller doing? It should have been noticed that the second train was not slowing down enough. Also, as this first train has now just stalled, it should have been visible to the signaller (in fact the signaller should have known full well about it anyway), so why has it not been passed onto the following train?
Still too much doesnt make sense.
An accident is good for the mainland so that they could know '' fast '' is not everything, it is nothing compared with the japanese one, their levels just not the same.