I hope this guy is fired

[Chromatix]

The usual way of setting up a level crossing in Europe is as follows:

- There is a track circuit, or something else tied into the signalling system, which tells the crossing when a train is approaching.

- The crossing turns on lights and bells/sirens, and then lowers the barriers if it has any.

- The crossing detects that the barriers have lowered properly (and/or proves that the lights and sirens are working), and allows the line signals to show a proceed aspect (up to this point, they have been signalling the train to stop before the crossing). On some low-speed and single-track lines, there is a separate "crossing clear" signal.

- In some places, there is also CCTV so that the signalman can verify that the crossing is actually clear. This can prevent accidents when a car gets stuck on the crossing.

All of this means that if the crossing fails, the trains won't cross it. This obviates the need for buses to stop and check.

Here's a typical British crossing that uses the above principles. And here's what happens with a failed barrier on a German one.

In Finland, many crossings are not signalled to either the road or rail traffic. I don't know what the criteria for setting these up was, but they are clearly less safe than the signalled type. At these unsignalled crossings, *all* road traffic is supposed to stop and check the line is clear before crossing. Some crossings have enough visibility that you can check without actually stopping, but you still have to slow down. But people get used to just crossing the line, because there's only one train every other hour, so most of the time the lne *is* clear - and then the odd time that there *is* one coming, they don't see it.

[smileyeagle1021]

Chromatix, we have a similar system, at least on the transit system (I haven't really looked at how the freight system works with crossings). As the train approaches it trigures the gates on the tracks to come down across the road, as the gates are lowering lights on each side of the gate, facing the approaching trains, will flash to tell the operater the gates are decending, once down that light will turn to solid on to let the driver know that it is safe... that said most US municipalities prefer to ere on the side of caution and have the buses stop and double check just in case there is a fault with the gates (or a train operator not paying attention to that light and assuming all is well with the crossing).

eta, watching those 2 youtube links, the situation with the german one wouldn't work in the United States, at least not in rural areas, it would take much too long to come to a stop like that at the speeds freight trains travel... also thinking about it, Frontrunner uses the same signal system as Trax for crossings and I know there is no way they could come to a complete stop if a signal were to outright fail, all they could do is throw the e-brake and hope for the best

[JustADude]

Here's a typical British crossing that uses the above principles. And here's what happens with a failed barrier on a German one.

And here is a video I found by following the "Related" links. It's goofy, but the 'mini-van hit by a train' bit at about 3m in really drives home the point about why you be careful around crossings.

A fully loaded freight train can weigh up to about 8000 tons (~7254 Metric Tonnes), which means that one hitting a car at 12mph is about the same as dropping a 11-lb (2kg) weight from over your head onto an aluminum-foil 'box' with a couple grapes in it on the floor. Yeah, my Drivers Ed teacher told us the Imperial units for that and demonstrated it. The math checks out, too.

At a full 50mph... well... you'll be lucky if there's organs left to harvest for people smart enough to stay off the tracks.

[Chromatix]

Well, a failed level crossing barrier is a pretty rare event. And a freight train can in fact stop in a fairly good distance with the emergency brake - it's just rather difficult to get it moving again safely if it's on a steep hill, and the stopping distance is much greater than a car from the same speed. The stopping distance is probably most of the reason why freight trains run at a lower speed than passenger trains.

As an aside, there is an open (but signalled) crossing across a very wide and busy road in Helsinki, near the West Port. It is used by low-speed freight trains being shunted onto the docks. I've seen it being used a couple of times, and the train does come to a stop before attempting to make the crossing - presumably to make sure that all traffic has stopped clear of the tracks. But it does bring home the sheer size and bulk of a train - they use a small locomotive and only a few wagons at a time, but the Finnish loading gauge is among the biggest in the world, so they really do loom over the road traffic.

I'm fairly sure, however, that most crossings in the US are not linked to any track signal - metro systems are probably the main exception. There's just a sign telling the driver to sound the horn, and a track circuit to activate the crossing. Also - and unlike the Finnish system - there is nothing to tell road traffic that the crossing is functioning but the line is clear. (The Finns get a flashing white light when the line is clear, and a red one when it isn't - assuming the crossing has any signals at all.)

The Top Gear video is a well-known one, and it does illustrate very well what can happen if you're an idiot. The locomotive (a dead and decommissioned Class 31, propelled in the video by another loco which can be seen in the background) weighs about 100 tons, and hit at about 75mph - which is actually below normal express speed in Britain, but about right for commuter trains. The buffers hit the inside far wall of the passenger shell, and *then* started the car moving.

Unfortunately, somebody was even more of an imbecile than that, and ran a crossing used by fast expresses. The impact actually derailed the IC125 that hit him, and that resulted in noticeable consequences for the passengers on board. I don't think the IC125 was going at full speed at the time - as the name suggests, it is capable of sustaining 125mph.

Part of the trouble with crossings is that unless it's a full-barrier crossing (barriers on both sides of the road on both sides of the crossing, usually with skirts as well), people (idiots) just drive around the ends of the barrier, or simply ignore the light-signal if there is no barrier at all. But full-barrier crossings are more expensive, and take longer to activate which causes more inconvenience on a busy line.

The safest and most efficient crossing is one that doesn't exist (ie. a bridge). But full-barriers are a good step in the right direction. I'm surprised they aren't used more often.

[Gurndigarn]

We have one like that near home and the city has put up "TRACK NOT IN USE" signs on either side. The buses do not have to stop there. Seems a simple solution - change the law to say "unless not in use signs are erected" or something.

Either that, or rip the damn tracks out. At the current prices for scrap metal, you probably wouldn't have to pay anyone to do it. Though they should level the road afterwards, which might cost a small amount.

[Chromatix]

It appears that road traffic isn't always the only one to be ignoring signals. Sigh.

[pacman]

The bus driver in the OP should definitely be fired and/or charged with reckless driving - at the least.

To the LA crash, I'm sorry 'bout that but at the same time I wonder... What would have happened if there had been an automated warning / emergency stop system like here? That has transmitters between the rails and underneath the engine so that info can be passed via that wireless link and the driver can receive information on signals and speeds and future speed limits or such. And if the system notices something odd it just emergency stops the train with the driver being unable to keep the train going before it's brought to a full stop.

Actually, sometimes I wonder how this mankind still exists, thinking of all this idiocy happening everywhere...

[smileyeagle1021]

well Pacman, I can't speak for LA, but in most of the country we have a system that has been nearly fool proof... the rails have a slight current going through them, once the circuit on any particular section is completed by a train going over it the signal lights at either end will turn red which will trigure the signal lights one section away to turn yellow... this also causes a little lever type thing to raise up by the red signal, the lever serves no other purpose than to trip a trains brakes if it passes over it while raised... that emergency brake part though is a relatively new part of the system though so it's not only possible that LA didn't have it yet, but wouldn't be surprising in the least.

oh and automated systems like what you described can be downed by plain old fashion stupidity, the MARC system had something similar, every time a train drove over a transmitter the transmitter broadcasted information on what to expect ahead, it was also standard procedure to radio trains as you passed to give them a visual inspection... both used the same frequency... you can see where this is going...

ETA- the LA train crash pisses me off for more than just the useless loss of life, but also because of one idiot conductor all the work of several activist groups out there trying to educate people on how rail can be a perfectly safe and ecologically and economically beneficial way of travel has been set back, which will only slow our country's rail development leaving us even further behind the rest of the developed world.

[katie kaboom]

Actually, I think the bus at railroad crossing laws that smiley was referring to is the 'come to a complete stop & open the door to listen for a train even if the lights aren't flashing' thing.

Oh is that why they do that? I've been riding the bus to work for the past 4 months and i never knew why the driver always opens the door when we drive across the railroad.

[otakuneko]

They don't do the open the door thing here. Or at least, school busses didn't, back when I was of age to ride them. They did stop, of course.

[Chromatix]

The moving lever by the signal is called a "train stop" and is very old technology - it has been in use on the London Underground for many many years. It essentially knocks open a valve on the brake pipe, which applies the emergency brake (which is virtually guaranteed to stop a train even if the locomotive is at full throttle). This is also what the "communication cord" does.

On most other parts of the British system, there are two systems in use simultaneously - AWS and TPWS. AWS dates from the 1950s and triggers if the driver ignores a non-Clear signal - it is also present at many approaches to speed restrictions. TPWS is much more recent (circa 2000), and enforces specific speed restrictions and Danger (stop) signals explicitly. Both are based on near-field magnetic induction, so they can't be interfered with by normal radios.

TPWS was introduced precisely because there had been a series of serious SPAD (Signal Passed At Danger) incidents, some of which caused fatal accidents. The older AWS system had been found to be inadequate because trains frequently ran "under yellows" - where trains were so frequent that there was no more than one section between them - so drivers habitually reset the AWS without even thinking. The AWS's indication for a Caution (yellow, slow down) and a Danger (red, stop) signal is the same.

TPWS is only turned on for Danger signals, and has a much more involved reset sequence (it is supposed to never activate under normal conditions), so it is safer, but AWS is still used because it is a proven method of catching incapacitated drivers earlier than the Danger signal.

The American railway system is so vast and under-utilised that I'm not surprised that there are no AWS or TPWS type systems on most of it. But I do know that the high-speed lines are required to have such a system.

Edit: What the LA passenger train did have, however, was a forward-looking camera. What this helps with is determining whether the signals were functioning correctly and properly visible. Occasionally accidents have been caused by "wrong-side" signal failures (a "right-side" failure is when it shows a more restrictive aspect than warranted).

[smileyeagle1021]

The moving lever by the signal is called a "train stop" and is very old technology - it has been in use on the London Underground for many many years. It essentially knocks open a valve on the brake pipe, which applies the emergency brake (which is virtually guaranteed to stop a train even if the locomotive is at full throttle). This is also what the "communication cord" does.

oh and I had only heard about them a couple of years ago and assumed they were new
next time I'll do more research.

oh and after thinking about it, playing the devil's advocate against myself, there is the possibility that the bus was having mechanical problems and the driver wasn't intentionally being sucky... I doubt it, but just playing my own devil's advocate.

[Chromatix]

Don't feel bad about it, I'm a bit of a train geek as well as a computer one. Most people probably aren't aware of *any* of the automatic safety technologies that are now in use. And they may well have been "new" to your area.

The real reason why railways in most civilised countries are safe, is because professional Accident Investigators go over every accident and "dangerous situation" with a fine-toothed comb, and make recommendations (which are often binding) to ensure that accidents of the same type cannot happen again - or at least are a whole lot less likely to. The same is true of air travel.

I'll give a simple example from British history. Long ago, in the fairly early days of railways, a special excursion train, filled with children no less, was composed of a load far too great for it's locomotive to haul up the very steep incline some miles away from the starting terminus. The driver protested bitterly, but was forced to go ahead. Predictably, the train stalled on the incline.

At this particular point in time, continuous brakes had just been introduced on trains, and this train was so fitted. So every carriage had a brake, and furthermore there was a traditional brake van at the back, with a single manual brake. This was enough to stop the train from roling backwards down the hill. But there was not enough power to get the train moving up it either.

The only way forward was to divide the train, take the front half to a siding at the top, and come back for the rest. But there was a problem - while the train brake was continuous, it was not automatic, so there was no way of holding it on for the rear half of the train when the front half was disconnected. So the guard applied his handbrake as far as he could, and for good measure put stones under the van's wheels as chocks.

But this wasn't enough. When the coupling in the middle was disconnected, the carriages settled back on each other - and this pushed the brake van over it's chocks. The handbrake wasn't enough to hold it, and the train accelerated down the hill - towards a following express train.

The carnage was terrible. It was made worse by the carriages' wooden construction - which shattered and splintered on impact - and the gas lighting, which started a very fast fire. And did I mention this train was packed full of children?

Shortly thereafter, continuous brakes were scrapped in favour of automatic brakes. The difference is that continuous brakes require pressure (or vacuum) to apply them, whereas automatic brakes require pressure (or vacuum) to release them. So when a train is severed - deliberately or otherwise - the brake comes on full power.

The accident also prompted a change in legal policy - the Driver became responsible for the safety of the train. If he didn't think the train would be safe (eg. overloaded), he had the right to refuse to drive it. Management was no longer able to override the Driver's judgement.

[smileyeagle1021]

I'd actually heard that story before...

and I actually am something of a train geek... it's just that I like transit systems, not the long distance systems, ask me about TRAX safety systems, or Frontrunner, or hell, I might even be able to make a good stab at the NYC subway... but ask me about the Union Pacific trains or Amtrak and I'll just give you a blank stare.

[Chromatix]

It's a fairly well-known story. There haven't been a huge number of big railway disasters (in civilised countries), which makes them relatively easy to remember - but the reason for the low number is that safety equipment and policies were improved after each one.

FWIW, it was a railway disaster that caused the universal introduction of AWS, as well. It was caused by a driver missing a distant signal at "caution" in heavy fog, and not realising until too late that he had passed it's position. He braked hard when he did realise, but he ran into the back of another train in the station. Immediately afterwards, a train from the opposite direction hit the wreckage.

Part of the trouble was that the distant signal in question was mounted on the "wrong" side of the track, mostly because it was on a sharp curve. So in heavy fog, it could only be seen by the fireman - the driver's view being blocked by the long boiler of a steam locomotive. The fireman had, at that moment, been attending to the fire rather than watching for the signal.

But the AWS, if it had existed then, would have reminded both men of the signal's approach, and told them that it had a restrictive aspect. If they had then not acknowledged this warning, the train would have been stopped in time. GWR had a roughly equivalent system (using contact levers rather than AWS's magnets), from which the idea was developed - and to this day, the magnet housings in the track are called "AWS ramps" as a reference to the GWR system.