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Someone got rather lucky with how that has ended up!

10 hours ago, rogerpatenall said:

I have no insight into the Moorgate crash, but remember it well. Having sat in the front of numerous trains, I am convinced that there is such a phenonemen as 'sleeper hypnosis', and thought then that it was the most likely cause. In this case, with no one being injured it could be that it was empty stock, and it could again be a factor. All uninformed conjecture on my part - but nevertheless, and sadly, fascinating.

edit - just seen your confirmatory comment, Colin. 

Nothing is more fatigue inducing than slow speed movements - indeed maintaining concentration when there is very little to focus on or stimulate the mind is one of the hardest elements of train driving. I personally tend to stand up at such moments to heighten the senses a bit. 

 

8 hours ago, Pegpilot said:

 Back to the subject at hand, my spies tell me that the signalling system in Rotterdam would probably not have progressively checked the train's speed as it approached the arrestor because it was a shunt (non-passenger) move into a siding, whereas for a passenger move into a line-end platform such protection would undoubtedly have been required.  And the whale has apparently been called in for interview under caution - apparently its tail lights weren't working.....

Are we thinking like the metro equivalent of buffer stop TPWS grids here? Of course, one can still be under the trip speed (so no brake demand) and still collide with whatever (or not, as in this case!) is at the end of the line. 

Edited by AdamW
Corrected typo
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Hi Adam.  The system we put in on the Tube after Moorgate had a number of track circuits of carefully calculated length before each signal approaching a terminus.  If the train reached the next signal before a defined occupancy time for that track section then the signal would fail to clear and the train would be "tripped" to an Emergency Brake actuation at the following signal (we called it Approach Control).  So typically the speed would be confirmed as under 20 mph, then 15 at the next, then 10, then 5, and then there would be a fixed trainstop to halt the train if it went beyond its intended stopping position by more than a few feet.  Modern metro signalling - like the Thales system on the Jubilee and Northern Lines - have a reducing speed profile built into the "flight computer" and if the driver (in manual) or the driving computer (in Auto) exceeds this profile by more than a few mph them the Emergency Brake will intervene in the same way. TPWS was a cheap and cheerful system introduced on the mainline network to achieve the same goal, but wasn't absolutely fail-safe as I remember it.  By the way, when we started testing the new auto driving system on the Jubilee I was simply stunned at how accurately it could bring a train to a stand within a few inches of its intended stopping position time after time after time, although on outdoor sections at this time of year (lots of leaves falling) it was necessary to programme a more conservative braking rate into the system to avoid slipping the wheels and flat-spotting them all !  But even a 5 mph collision with the buffer stop can be fatal - in the early 80s a couple of standing passengers were killed when a train hit the buffers at 5mph at Cannon Street. Finally, a signal engineer's dream is to have a terminus with a very long overrun beyond, so you can bring trains in nice and aggressively and still have plenty of room ahead to stop if you get it wrong.  The nightmare platforms are those with a brick wall just a few yards beyond the stop position - then you literally have to crawl the train into the platform to be sure of not doing lots of damage if you get it wrong.  Hope that helps - Mark

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Hi Mark, really interesting stuff, so thanks for sharing.

The LU approach definitely has its advantages by ensuring that a profile of deceleration is observed as opposed to the 'crudeness' of TPWS which puts all the emphasis on being  under the trip speed at a given point - if you are that's it, you can keep going, but an incident is still very much possible.   

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14 hours ago, Pegpilot said:

Finally, a signal engineer's dream is to have a terminus with a very long overrun beyond, so you can bring trains in nice and aggressively and still have plenty of room ahead to stop if you get it wrong.

Unfortunately ferry terminals don’t have the luxury of a long overrun. I imagine the captain of Sirena Seaways (ex Baie de Seine) would have given anything for one when he got it slightly wrong back in 2013...😳

Chris
 

Photo taken from BBC website 

image.jpeg.0aebafbdc27657d5b45c354421064919.jpeg

Edited by Fine Whine
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This is of absolutely no relevance to BFE either but here goes:

It seems that in the US presidential election both parties have won, which sounds like a good compromise to me. Perhaps they could share the job, Trump on even weeks and Biden on odd weeks (assuming he can remember what he's supposed to be doing).  

The only real loser appears to be Piers Morgan but then we all knew that anyway. 

Ed. 

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