379 110mph testing

[DXMachina]

I shall await the news coverage

"Train disintegrates near Rugby"

 

[asylumxl]

I shall await the news coverage

"Train disintegrates near Rugby"

Far too nice a way to describe what would happen.

Considering a 379 managed to weld itself to the wires on the GEML, I'm not looking forward to seeing how many delay minutes a 379 will create on the WCML.

 

[ert47]

I thought the reason for the re-designed windows on the recent Class 379/172/378s had something to do with the suppliers of the original ribbon glazed windows going out of business. Or was that just a rumour?

 

[bronzeonion]

I thought the reason for the re-designed windows on the recent Class 379/172/378s had something to do with the suppliers of the original ribbon glazed windows going out of business. Or was that just a rumour?

I've heard that too.

 

[asylumxl]

I've heard that too.

Do you reckon the current windows cheaper?

Has the price per carriage been reduced, remained the same or gone up?

 

[jon0844]

Quality down, price up?

 

[asylumxl]

Quality down, price up?

Probably . This is Bombardier after all.

 

[HSTEd]

NR's plans for the next 30 years do seem to include raising the archetypal prevailing linespeeds for each type of service.

I will go back to imagining 110mph flat fronted units on all regional services then.....
Especially if we get mass electrification.

 

[boing_uk]

Converting these magic numbers in to metric for one second.. is there a massive difference in the outcome from a head on collision at 161kph from one at 177 kph?

Or are things being decided on arbitrary round numbers in an obsolete (from an engineering point of view) measurement system..?

 

[jopsuk]

Whilst I'm in favour of metrication too, any cut offs in metric would be equally arbitrary. It's just we'd probably be talking about 160km/h versus 175 or 180 km/h.

 

[bronzeonion]

I don't know why everyone is so bothered about the crashworthiness of the thing! Trains are not like cars. Trains run on a fixed set of rails, are stopped by safety systems if it passes a red signal, signalling is interlocked so you pretty much can't signal conflicting moves. The only thing that would cause a train to crash these days is maintenance cuts in the pway or rolling stock. Besides, modern trains are heavy enough as they are adding even more crash worthiness will just make them heavier.

 

[edwin_m]

Today's designs have far more crashworthiness features than a few decades back when Mk1 coaches and the EMU derivatives were routinely run at 90-100mph. These features include crash-friendly interiors (eg plastic mickey mouse ears as seat grab handles instead of the old metal cubes), which probably cost very little more than the old designs if fitted from new.

There are also structural crumple zones at car and unit ends, which do increase costs quite a bit, and also reduce passenger space. They are only relevant in end-on train-to-train collisions, and the risk from these has already fallen by 60-70% due to TPWS. My personal view is that these structural crashworthiness measures are no longer necessary (if they ever were in the first place).

Recently European standards have included energy absorption in unit ends, which is one reason why the noses of recent designs are a bit longer. These may have some value in level crossing collisions but are probably not very significant in collisions between trains.

 

[jopsuk]

Rather odd claim from the GA Twitter with regards this in response to someone's query:

Hi, just spoken to my colleague from Bombardier. This is not for some time yet and it won't be using our trains

 

[Class377/5]

Rather odd claim from the GA Twitter with regards this in response to someone's query:

Could be the 377/7's.

 

[317666]

I shall await the news coverage

"Train disintegrates near Rugby"

I'm very surprised we haven't had "Train disintegrates near Broxbourne" yet! They're certainly rattly and cheap-looking enough.

 

[notadriver]

I don't know why everyone is so bothered about the crashworthiness of the thing! Trains are not like cars. Trains run on a fixed set of rails, are stopped by safety systems if it passes a red signal, signalling is interlocked so you pretty much can't signal conflicting moves. The only thing that would cause a train to crash these days is maintenance cuts in the pway or rolling stock. Besides, modern trains are heavy enough as they are adding even more crash worthiness will just make them heavier.

Trains are not always stopped by 'safety systems' if a red signal is passed. Please get your facts right.

 

[bronzeonion]

Trains are not always stopped by 'safety systems' if a red signal is passed. Please get your facts right.

Alright calm down...

Why would a train fitted with TPWS or ATP running on a line with TPWS or ATP not be stopped if it passes a red signal? Apart from if the driver overrides the trainstop before passing it.
--- old post above --- --- new post below ---

Today's designs have far more crashworthiness features than a few decades back when Mk1 coaches and the EMU derivatives were routinely run at 90-100mph. These features include crash-friendly interiors (eg plastic mickey mouse ears as seat grab handles instead of the old metal cubes), which probably cost very little more than the old designs if fitted from new.

There are also structural crumple zones at car and unit ends, which do increase costs quite a bit, and also reduce passenger space. They are only relevant in end-on train-to-train collisions, and the risk from these has already fallen by 60-70% due to TPWS. My personal view is that these structural crashworthiness measures are no longer necessary (if they ever were in the first place).

Recently European standards have included energy absorption in unit ends, which is one reason why the noses of recent designs are a bit longer. These may have some value in level crossing collisions but are probably not very significant in collisions between trains.

I agree.

 

[edwin_m]

TPWS isn't intended to stop a train at a red signal. It is designed to apply the brakes on a train passing a red signal or in some cases approaching it too fast, with the aim of stopping a certain degree of overspeed before it can come into head-on or sideways conflict with another train. Gross overspeeding can still cause these types of collision but at a reduced speed, and TPWS isn't generally fitted to automatic signals where the only collision risk is head-to-tail.

Despite all these limitations, TPWS has about 70% of the safety benefits of a full ATP or ERTMS system.

 

[455driver]

Why would a train fitted with TPWS or ATP running on a line with TPWS or ATP not be stopped if it passes a red signal?

Because the vast majority of signals are not fitted with TPWS would be one reason.

Also ATP is only in use in one area.

 

[jopsuk]

And we come back to no signalling being able to prevent a head on in the manner of Great Heck- or the recent crash in the US.

 

[asylumxl]

Because the vast majority of signals are not fitted with TPWS would be one reason.



Also ATP is only in use in one area.

I thought it was on the Chiltern Main Line too?

Not sure I'd define GWML and CML as one area...

 

[A-driver]

Alright calm down...

Why would a train fitted with TPWS or ATP running on a line with TPWS or ATP not be stopped if it passes a red signal? Apart from if the driver overrides the trainstop before passing it.
--- old post above --- --- new post below ---

You seem to be misunderstanding what tpws actually is and what it does.

Tpws won't prevent a signal being passed at danger-it is there to reduce the consequences of a SPAD.

As has been said not all signals are fitted with tpws, infact in some areas very few actually are.

Plus, if tpws stop loops are in place at a signal (no overspeed on approach which is fairly common at places) then a collision is still very possible if a spad happened. If you pass a red at 110mph and the tpws kicks in you could easily run into another train stopped just past the overlap at a fairly high speed.

Head on collisions are very rare of course, but there is nowhere near as much preventing them as you seem to imagine. Plus, as has already been said, the is nothing preventing incidents like collisions with cars/tractors/lorries on the track.

 

[bronzeonion]

Oh right fair enough, I always thought TPWS was more widespread, it's a shame ATP never took off really.

 

[A-driver]

Oh right fair enough, I always thought TPWS was more widespread, it's a shame ATP never took off really.

ATP still wouldn't prevent all head on collisions, plus I think its fair to say that its not needed all over - even without it and without 100% TPWS coverage head on collisions or any kind if 'serious' incident following a spad is very rare and unlikely. Obviously steps will still be taken but I can't really see a case for ATP all over.

 

[notadriver]

ATP still wouldn't prevent all head on collisions, plus I think its fair to say that its not needed all over - even without it and without 100% TPWS coverage head on collisions or any kind if 'serious' incident following a spad is very rare and unlikely. Obviously steps will still be taken but I can't really see a case for ATP all over.

Agreed : there's no real need for ATP and it was calculated that it has little cost benefit over TPWS. Anyway ERTMS will come in years to come.

Bronzeonion maybe you are more familiar with the tube which on conventionally signalled lines has trip cock at every signal.

 

[bronzeonion]

Agreed : there's no real need for ATP and it was calculated that it has little cost benefit over TPWS. Anyway ERTMS will come in years to come.

Bronzeonion maybe you are more familiar with the tube which on conventionally signalled lines has trip cock at every signal.

Youre right am alot familiar with that.