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We've had murder cars, now we've got murder-trains in Florida of course 13
- Thread starter GregLocock
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Anyone without earbuds having a phone conversation might hear a 120 mph train in a no-horn zone. Too many wear audio compromising devices.
Also, Brightline uses cushioned wheels. In a video of the train leaving the station by far the loudest sound was the train's trolley bell sound - the sound of the locomotive engine and cars was barely audible. It appears to make a soft whoosh sound rather than the typical freight train squeal and rumble.
Also, Brightline uses cushioned wheels. In a video of the train leaving the station by far the loudest sound was the train's trolley bell sound - the sound of the locomotive engine and cars was barely audible. It appears to make a soft whoosh sound rather than the typical freight train squeal and rumble.
Brian Malone
Industrial
MintJulep and 3DDave thanks for the info and insights. I would like the quieter trains to roll where I live. I still do not understand the reasons or non-reasons some of these train strike victims. The presence of the tracks alone should be enough a signal of a hazard. Some train strike victims in the news are either alcohol or drug compromised and find the tracks a convenient location to lay down for a nap. Fencing may be the only viable option in urban / suburban areas. I have family in the East Bay area of California (Oakland/Richmond), next time I am out there I will have to observe what the BART system does for pedestrian exclusion. It must be minimal or non-obtrusive or I think I would have noticed.
@EdStainless,
I live in Denmark - and have travelled in Europe by train a lot and by road. And i have never encountered a road crossing for high speed tran (TGV, ICE etc.). And the number of train track crossings i know of is small. I live close to a central commuter RR track and even though its a 100 years old all crossings are bride or tunnel (viaducts). Just being curious, i tried to locate Gare Du Nord in Paris and follow one of the main trunks from that station going north that guess will carry TGV trains. As far as i checked: All viaducts. In some cases you could see old roads that had been closed of at a time - but no crossings.
--- Best regards, Morten Andersen
I live in Denmark - and have travelled in Europe by train a lot and by road. And i have never encountered a road crossing for high speed tran (TGV, ICE etc.). And the number of train track crossings i know of is small. I live close to a central commuter RR track and even though its a 100 years old all crossings are bride or tunnel (viaducts). Just being curious, i tried to locate Gare Du Nord in Paris and follow one of the main trunks from that station going north that guess will carry TGV trains. As far as i checked: All viaducts. In some cases you could see old roads that had been closed of at a time - but no crossings.
--- Best regards, Morten Andersen
BART uses fences for "pedestrian" exclusion.
I don't believe there are any grade crossings, pedestrian or otherwise, on BART.
Of interest might be that a motorcyclist slid out while making a turn, was then flipped over a fence by his motorcycle, then fell down about 16 feet onto the adjacent BART tracks (which emerge from a tunnel at this location), and was hit by an oncoming train. I'm not sure even Evel Knievel could have done that. September 16, 2022.
spsalso
I don't believe there are any grade crossings, pedestrian or otherwise, on BART.
Of interest might be that a motorcyclist slid out while making a turn, was then flipped over a fence by his motorcycle, then fell down about 16 feet onto the adjacent BART tracks (which emerge from a tunnel at this location), and was hit by an oncoming train. I'm not sure even Evel Knievel could have done that. September 16, 2022.
spsalso
electricpete
Electrical
Hell, Evel probably would've survived that and come back for more!
We have a mental model of what a train track means and what we need to do to remain safe around them. But unfortunately that mental model may not be as reliable if it was trained on slower, noisier trains. It seems like that could be one of the factors at work in this weird situation.
We have a mental model of what a train track means and what we need to do to remain safe around them. But unfortunately that mental model may not be as reliable if it was trained on slower, noisier trains. It seems like that could be one of the factors at work in this weird situation.
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Murph 9000
Computer
Here's a real video of a near miss at 125 mph by a level crossing in the UK, from CCTV on the front of the train. The incident train was an InterCity 225 (Class 91 electric locomotive hauled passenger express train) capable of 140 mph (225 kph), running at the maximum line speed of 125 mph (200 kph); the train is good for 140 mph, but the signalling limits it to 125 mph due to lack of investment in infrastructure. In this case, it was railway workers who almost came to grief, but it shows just how quickly high speed trains appear and how little time a pedestrian has to save themselves.
Video: One Second From Death: Rail Workers Narrowly Avoid 125mph Train
RAIB report: Report 11/2018: Near miss with a group of track workers at Egmanton level crossing
Video: One Second From Death: Rail Workers Narrowly Avoid 125mph Train
RAIB report: Report 11/2018: Near miss with a group of track workers at Egmanton level crossing
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Murph 9000
Computer
Network Rail's Safety playlist, which is mostly about trespassing and level crossing safety:
And the viral Australian safety video: Dumb Ways to Die
And the viral Australian safety video: Dumb Ways to Die
TugboatEng
Marine/Ocean
BART actually has a lot of fatalities. In past years, they've had a worker die in a collision and a woman get dragged under the train by a dog leash. However, the majority of on track deaths are suicides and those statistics are not publicly available that I know of. They have said there have been 30 deaths this year in the trains from drug overdoses.
Every worker safety training course that I have taken includes the following very simple statement:
A train may come on any track, from any direction at any time.
120 mph = 176 feet per second = 54 meters per second.
A typical commuter or inter-city train will have an emergency brake rate of about 1.3 meters per second per second.
That means 120 mph to zero takes about 41 seconds.
41 seconds x 54 m/sec = 2,214 meters or 1.4 miles.
To not hit a person on the track when travelling at 120 mph the train driver would need to see the person and apply the emergency brake 1.4 miles before reaching the person.
Think any train driver has good enough eyesight for that?
The numbers are not in your favor. Stay off the tracks.
A train may come on any track, from any direction at any time.
120 mph = 176 feet per second = 54 meters per second.
A typical commuter or inter-city train will have an emergency brake rate of about 1.3 meters per second per second.
That means 120 mph to zero takes about 41 seconds.
41 seconds x 54 m/sec = 2,214 meters or 1.4 miles.
To not hit a person on the track when travelling at 120 mph the train driver would need to see the person and apply the emergency brake 1.4 miles before reaching the person.
Think any train driver has good enough eyesight for that?
The numbers are not in your favor. Stay off the tracks.
That's assuming the driver even has a line of sight along a straight track section; any curve on the track nullifies even superhuman eyesight
TTFN (ta ta for now)
I can do absolutely anything. I'm an expert! faq731-376 forum1529 Entire Forum list
Murph 9000
Computer
The train in the RAIB report above slightly outperformed those numbers, braking from 125 mph to a stop in around 0.75 miles (1.2 km), but it's one of the more advanced trains on the network, with exceptionally good brakes that were designed for 140 mph+ (it's a derivative of the Advanced Passenger Train (APT), which had hopes of up to 155 mph (250 kph) in service).
RAIB said:
davidbeach
Electrical
If the engineer of a train operating at track speed sees something on the track ahead, said something will either remove itself from the track or the train will hit it. Stopping in time is rarely a viable option.
I’ll see your silver lining and raise you two black clouds. - Protection Operations
I’ll see your silver lining and raise you two black clouds. - Protection Operations
Seems that I've forgotten my basic equations of motion. This is not the stopping distance: 41 seconds x 54 m/sec = 2,214 meters or 1.4 miles.
It's the distance traveled at full speed during the time that the train could be slowing down.
Stopping distance from 120 mph (54 m/s) at 1.3m/s/s = 1,121 m. Pretty good agreement with the RAIB report.
If the brakes are fully applied 1,121 meters before the person, then the train will be at standstill when it reaches the person.
...exceptionally good brakes....
The limit to braking performance is adhesion between the wheel and rail.
As an upper practical bound, this limits instantaneous deceleration to about 1.5 m/s/s.
Try to apply more force than that at the wheel to rail interface will likely result in a slide, increasing stopping distance.
In ideal conditions adhesion might be as high as 0.25.
In poor conditions it might be as low as 0.01.
Adhesion is not friction - it behaves differently at the interface.
For stopping performance calculations however, it calculates like friction. That is, the maximum possible stopping force a wheel can provide is it's weight x the adhesion coefficient.
Bottom line, 1.5 m/s/s is a proven upper instantaneous limit compromise for performance during ideal adhesion and compromised adhesion.
High speed trains will typically have a lower brake rate at higher speed because for the same wheel and rail adhesion tends to decrease as speed increases.
If a higher deceleration is needed then:
Magnetic track brakes: Still rely on friction of the rail head, but the brake material can have a higher coefficient of friction that an steel wheel.
Eddy current brakes are independent of friction.
The APT appears to have neither of these - based on 3 minute of reading Wikipedia.
It's the distance traveled at full speed during the time that the train could be slowing down.
Stopping distance from 120 mph (54 m/s) at 1.3m/s/s = 1,121 m. Pretty good agreement with the RAIB report.
If the brakes are fully applied 1,121 meters before the person, then the train will be at standstill when it reaches the person.
...exceptionally good brakes....
The limit to braking performance is adhesion between the wheel and rail.
As an upper practical bound, this limits instantaneous deceleration to about 1.5 m/s/s.
Try to apply more force than that at the wheel to rail interface will likely result in a slide, increasing stopping distance.
In ideal conditions adhesion might be as high as 0.25.
In poor conditions it might be as low as 0.01.
Adhesion is not friction - it behaves differently at the interface.
For stopping performance calculations however, it calculates like friction. That is, the maximum possible stopping force a wheel can provide is it's weight x the adhesion coefficient.
Bottom line, 1.5 m/s/s is a proven upper instantaneous limit compromise for performance during ideal adhesion and compromised adhesion.
High speed trains will typically have a lower brake rate at higher speed because for the same wheel and rail adhesion tends to decrease as speed increases.
If a higher deceleration is needed then:
Magnetic track brakes: Still rely on friction of the rail head, but the brake material can have a higher coefficient of friction that an steel wheel.
Eddy current brakes are independent of friction.
The APT appears to have neither of these - based on 3 minute of reading Wikipedia.
Brian Malone
Industrial
Well the performance numbers everyone has posted indicate my observations of the garden variety Amtrak passenger and Union Pacific freight trains that pass near my house are nowhere equivalent to the higher speed trains! Pedestrians just need to stay off the tracks. Yeah, easier said than done. I just hate seeing technology skewered because of a subset of human behavior.
Murph 9000
Computer
I should possibly have said "as good as it gets for friction braking", rather than "exceptionally good". The APT-U (IC225) was designed with minimised unsprung weight, disc brakes, and per-axle ABS. The incident train above had 40 axles all essentially grabbing close to every last bit of adhesion practically available. Compared to more traditional passenger trains, it should have superior braking performance.
Here is a summary of a train accident:
Two trackworkers were killed. The train was traveling at 110 MPH. The main cause was mistakes in judgement by some of the maintenance workers.
Here is the cab video up to 1.7 seconds before the crash (I am astonished at the ignorance of some of the comments):
and here is the docket for this accident. There's a LOT of reading material.
spsalso
Two trackworkers were killed. The train was traveling at 110 MPH. The main cause was mistakes in judgement by some of the maintenance workers.
Here is the cab video up to 1.7 seconds before the crash (I am astonished at the ignorance of some of the comments):
and here is the docket for this accident. There's a LOT of reading material.
spsalso
electricpete
Electrical
Further to the point, I grew up in a residential area where the street in front of the house was our defacto playground. We played kickball and hopscotch there. We tossed around baseballs, footballs and frisbees there. No one got hurt or hit by a car on our street playground (even if a few of the neighborhood drivers were mildly torqued off by the situation). We had an intuitive feel for what kind of hazard the street represented, and how to play safely there (for example we didn't play in the street at night).
If someone who grew up in that environment was suddenly transplanted to another neighborhood where the houses and yards and streets all looked exactly the same, but every once in awhile an electric car whizzed by quietly at 65mph, their intuition would fail them, and the odds of that person getting hurt shortly after moving there would go waaay up.
For the most part, people don't intend to put themselves into life threatening situations. More often they just misjudge the risk (Sure, I can multi-task and read that text while driving on the highway.... besides, it's a cat picture!)
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