How Railroad Crossings Work (2024)

How Railroad Crossings Work (2024)(practical.engineering)

37 points by at1as 2 days ago | 20 comments

cmiles8 2 days ago |

“Let me show you how this works in a real demonstration. On the left, I’ve hooked up a power supply to the tracks, putting a voltage between the two rails. On the right side, I’ve attached a relay.”

The problem with publishing “articles” that are just the script from a video is that the reader doesn’t understand a bunch of what’s written because it’s talking about something not being shown.

I like these videos, but if they’re going to be turned into articles at least put pictures and figures in or rewrite the text to stand on its own. Heck AI could probably fix that in a minute these days.

MysteryTramp 2 days ago | |

I appreciate the script being there. I can quickly scan it and decide if the video is worth watching, or go to the part I am interested in. I skim podcast transcripts as well.

gwbas1c 2 days ago | |

It's not an article. It's the video with the transcript below.

vorticalbox 2 days ago | | |

I know it says that at the top but my brain completely skimmed that when I start reading.

gumby 2 days ago | |

This is the only way I’ll refer to a video, so I hope it starts to happen. I know some people like them but personally I skip them, and skip HN submissions that are obviously links. Unfortunately this was was washed through a URL.

TL;DR: IV;WW (It’s Video, Won’t Watch).

telesilla 2 days ago |

I can't remember the last time I crossed a train track in western europe - trams yes but not trains. Is this being engineered into bridges and tunnels in this part of the world or is this increasingly common. I suddenly feel very safe.

bluGill 2 days ago | |

Grade crossings exist all over - they are so much vastly cheaper than the alternative that other options are often not reasonable. There are many possible reasons you don't see them where you are anyway.

I would guess that the reason you never cross them is that you rarely travel outside of cities. Within a city the population density makes the cost of not having a grade crossing (bridges are typically an order of magnitude more expensive) worth it. Often tracks converge into cities as well, so a grade crossing every half hour turns into the crossing closed more than open in a city thus splitting the city into parts: unacceptable.

I've personally crossed train tracks at grade in Western Europe so I know the crossings exist (or did 15 years ago when I was last there...) Though the freight train network in Western Europe is terrible by world standards (for both good and bad reasons), and that is going to drag down your sample size.

1718627440 2 days ago | |

The actual rules are different per-country, but the trend is the same. In Germany you aren't allowed to have crossings for lines permitted for over 160km/h. Also the former national railway company decided to not build new crossings at all. They have downsides for both participating transportation modes: less capacity, annoying waiting times, slower velocity, safety, security and availability issues. The only downside of bridges is space and cost.

iggldiggl 1 day ago | | |

> Also the former national railway company decided to not build new crossings at all.

At least partially that's actually the law as well – the default mode for new rail-road crossings is mandated to be grade-separation, with exceptions to that rule decided on a case-by-case basis, though primarily only in cases of low traffic (which in case of roads means ≤ 100 vehicles/day). Plus in actual practice the federal railway authority also having a reputation for a strict interpretation of that paragraph and tending to not grant exceptions has also done its thing, so in practice new level crossing on the federally-operated railway network (i.e. DB) are indeed a total rarity.

b3orn 2 days ago | |

I know about quite a few in Hamburg, Germany. Most level crossings are in the relatively low speed cargo rail system in the port, most of these only have traffic lights, but some don't even have that so you have to check if a train is coming and there were a few deadly collisions in the last few years. There aren't that many level crossings in the regular rail system in the city, but even there last year a deadly collision with a lorry happened.

mlaretallack 2 days ago | |

Loads of them in the UK. Especially in villages where it would be too expensive to install a bridge. Just look at the Southampton to Weymouth line.

glitchcrab 2 days ago | |

There's two level crossings alone in my small UK town (~150k people)

robrain 2 days ago |

(2024). This week’s video is about stopping trains at the end of lines. The channel is always an interesting watch.

NuclearPM 2 days ago |

I used to be a railway signalling guy. AMA

bell-cot 2 days ago | |

In what country?

How much (if you know) do the details vary by country?

If you were ever involved in a grade crossing fatality case, what was that like? (Professionally - not prying at your personal feelings. Answering optional.)

NuclearPM 1 day ago | | |

Canada

Same system as US. Similar operating rules. Other countries have different rules including track gauges (width). Canada’s:

https://tc.canada.ca/en/rail-transportation/rules/2022-2023/...

“Fun” fact, the rules were metaphorically written and blood, and grew to include things like “don’t microwave your clothes to dry them”.

Everyone who had worked in the rail industry (especially conductors and engineers) for more than a few years has horrible stories. PTSD is real. Suited by train is fucking selfish and disgusting.

euroderf 1 day ago | |

In the USA ? I ask because the EU is putting effort into harmonising signaling (and all railway comms) across the union and it seems to be a fairly imposing task.

NuclearPM 1 day ago | | |

Canada.

at1as 2 days ago | |

for how long were you in this career? How did your job change (if it all) during that time?

NuclearPM 1 day ago | | |

Almost 10 years, split between apprentice, journeyman, supervisor, project manager.

It’s an amazing job when young and you can see lots of remote beautiful locations. Very high divorce rate…

Moved to Nuclear which is similar in that small mistakes can have catastrophic consequences. Nuclear has more layers of redundancy (technical and administrative). Railway has half the people doing 1.5 times the work as it did 30 years ago - nice profits though, Things changed when Hunter Harrison gutted/streamlined. https://en.wikipedia.org/wiki/E._Hunter_Harrison