Can you get pulled under a train?

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SUMMARY

The discussion centers on the aerodynamic effects of high-speed trains and whether they can exert enough force to pull a person standing close to the tracks under the train. It is established that while a train traveling at 30 m/s can create a low-pressure area due to air displacement, the force generated is insufficient to pull a 100 kg person under the train, especially if they are aware and braced. The conversation also highlights the potential for being nudged off-balance by the bow shock of the train, which could lead to a fall, but not a direct pull under the train. The Bernoulli equation is referenced to explain the pressure dynamics involved.

PREREQUISITES
  • Understanding of Bernoulli's principle and its application in fluid dynamics.
  • Knowledge of aerodynamic effects related to high-speed vehicles.
  • Familiarity with concepts of pressure differentials and boundary layers.
  • Basic physics principles regarding force and motion.
NEXT STEPS
  • Research the Bernoulli equation and its applications in real-world scenarios.
  • Explore the aerodynamic effects of vehicles, particularly trains and large trucks.
  • Study the boundary layer effect and its significance in fluid dynamics.
  • Investigate safety protocols and risks associated with standing near train tracks.
USEFUL FOR

Individuals interested in physics, engineers working on transportation safety, and anyone concerned about the risks of standing near high-speed trains.

  • #31
.Scott said:
That last statement does not apply to US Navy carriers - since they can only be supplied this way on their starboard side.
But what if one of the carriers is running in reverse? Then two right sides are available.
 
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  • #32
jbriggs444 said:
But what if one of the carriers is running in reverse? Then two right sides are available.
Okay. We'll make you captain.
 
  • #33
jbriggs444 said:
But what if one of the carriers is running in reverse? Then two right sides are available.
Very difficult to reverse a straight line. The driver has to lean too far out of the bridge window to see behind him.
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Plus, the prop walk is brutal.
 
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  • #34
.Scott said:
Okay. We'll make you captain.
"Wrong Way Peach Fuzz" at your service.
1763071800809.webp
 
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  • #35
DaveC426913 said:
The driver has to lean too far out of the bridge window to see behind him.
All the Captain can do is to try to keep a steady course; he can't see a thing from the bridge. It's up to the Pilot boat helm to chase the boarding ladder. I imagine they have radio communication so the captain can stop (or start) worrying after the event.

PS Is it possible that Naval craft use commercial pilots? I guess they have no option in non-naval ports (Left hand down a bit)
 
  • #36
sophiecentaur said:
PS Is it possible that Naval craft use commercial pilots? I guess they have no option in non-naval ports (Left hand down a bit)

Decades ago, I worked with a Navy veteran with experience in this area. He reported a story about a particular instance of using a Maritime pilot - and his mention suggested that this was typical.

Of course, the Navy would not always opt for the services of a local pilot. The approach to the beach at Playa Girón, Cuba comes to mind as an example.
 
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  • #37
dextercioby said:
Kurz gesagt: Ein praktisches Problem beim Aufenthalt in der Nähe von Bahngleisen. Kann/Sollte man das tun? Was wäre, wenn der Zug in Hanoi 100 km/h fahren würde?

Angenommen, ein 100 m langer (wahrscheinlich irrelevanter) Zug mit einer Geschwindigkeit von 30 m/s und einer Masse von 100.000 kg fährt an einer 100 kg schweren Person vorbei, die 1 m von den Gleisen entfernt steht. Da der Zug die Luft massiv verdrängt und so ein kleines Vakuum bzw. einen Unterdruckbereich erzeugt, übt er vermutlich eine Anziehungskraft auf alles aus, woran er vorbeifährt – in diesem Fall also auf eine Person. Meine Frage ist ganz einfach: Lässt sich diese Anziehungskraft durch eine Kraft quantifizieren? Reicht diese Kraft aus, um die Person unter den Zug zu ziehen? Was wäre, wenn der Abstand 50 cm betrüge?
First there is a pressure surge, then a weaker suction at the end. Only if you are standing very unsteadily could this cause you to fall over.
In Austria, a stroller once rolled under a train. The slight jolt was enough to set it rolling. Since then, there have been straps on the platform to secure strollers.
 

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