Because of signal sighting rules in the UK, we experienced a lot of trouble upgrading lines to higher speed. All of a sudden, that signal that you could see for 10 seconds could now only be seen for 8 due to a bridge or whatever. Muchos dollars relocating signals and in some places not being able to increase the line speed at all.
Boring but very real reasons why we "can't just update things"
Dunno why they don't just go ahead and bite the bullet and go to 100% in-cab signaling. The technology has worked for decades and has been deployed on many lines, including a few in the UK.
Cab signaling requires a different set of standards in order to provide the necessary level of safety.
Cab signals are (usually) transmitted through the rail and picked up by a special receiver on the leading axle of the locomotive. Each locomotive has to be equipped and the rails themselves have to be checked and blocked. This also means the rails have a higher maintenance requirement as opposed to lineside signals which can be more easily maintained.
However, some countries (Brazil predominantly) have embraced a GPS based cab signal system where lineside signals are almost totally eliminated. However, this was done with federal subsidies to cover the expense iirc.
Another example is the US Northeast Corridor where cab signals are used along with lineside signals to provide a level of redundancy at speed.
Unfortunately there’s no easy solution, but I lean towards the Brazilian GPS based systems from Wabtec.
Realistically, in the UK, it's going to be ETCS with balises: all new build stock at this point either has ETCS in-cab signalling fitted, or is designed for its fitment.
That said, the rollout of the infrastructure side of ETCS is somewhat delayed, but it is happening in places (Thameslink is ETCS Level 2 with conventional signal overlay, albeit with shorter blocks in ETCS; Crossrail is ETCS Level 2 with no overlay).
As a random piece of trivia, in cab signaling was pioneered in the 1920's and implemented commercially by Pennsylvania Railroad the 1930's while upgrading their main line between New York City and Washington D.C. You can see in this photo that the engineer had one indicator that would light up for each signal aspect: https://i.pinimg.com/originals/31/85/83/3185833fba11b79498ff...
The locomotives, not all the rolling stock. I'm not saying it wouldn't be hard/expensive, but it seems better to spend money on things that will be useful for decades rather than stopgaps that just kick the can a little further up the road.
If you remove the block signaling system and use in-cab signaling, you still need to know where the back of the train is. Otherwise a train could run into the back of another in the fog or heavy rainstorm. Currently, railroads use FREDs (flashing rear end device) on the last car of the train. Some FREDs are more intelligent than others but would benefit from being able to send out their ___location via GPS.
Longest trains are under five miles so you could use that or whatever the limit for that line is as a safe baseline. Unless you're worried about trains separating.
That's not an actual problem. You simply have 2 trains each broadcasts it's ___location. It's unexpected separations that might be a problem, but those are currently very rare and dealt with seperatly than static signals.
It's like you need to design a nuclear reactor to deal with an aircraft hitting it. You don't need to automate the response becase that's a rare situation.
Well, I read about one instance where it happened, and the brakes didn't apply. (Not sure how that could happen other than a mess-up in building the train. You'd just about have to have both angle cocks closed.) Both fragments continued, for miles.
Can't cite a source (I think I read about it on the Altamont Press discussion board). And that's only one instance. And it could have been reported incorrectly. But it appears to be possible for this to happen.
Most British passenger trains are multiple units (and most British trains are passenger trains), so there's effectively little distinction between locomotive and rolling stock.
But when the people who hold the pursestrings are looking no further ahead than their next election, "useful for decades" means nothing at all to them.
And of course there's the whole discussion in the UK about having a second safety-critical person on the train (e.g. "guard", "train manager" etc.) versus driver-only operation.
I got a chance to drive a couple of different engines at the Plumas rail museum. And one of the things that does is help you internalize the amazing amount of mass and momentum a train carries around all the time. The engineer who was with us spoke of freight trains that were a hundred cars of iron ore that, even though they were travelling at only 5mph would take nearly 1000' to bring to an "emergency" stop. While I don't know how true that is, just driving around the engine gave me some insight into how far ahead in time the engineer has to be thinking if they are operating a full train.
My experience is largely with bicycles (you're very aware of the energy input/output), automobiles, and boats, but thinking of moving vehicles as momentum systems, to which energy can be added or removed, is useful.
On a bike, you maintain a steady speed by matching drag losses with the energy you're putting into the pedals. Braking and other actions cost you energy you've put in.
For automobiles and trucks, added mass has a significant change to momentum, and I feel that. Boats, from a row or sailboat to a 30m+ power vessel, have their momentum, drag, and interaction with water, waves, currents, and wind.
Nothing is redundant on a bike, if anything it is the other way around, e.g. the brakes are the wheels, the frame is the suspension, the gear mechanisms are also there to keep the chain on, the passenger is the power source. Nothing can be taken away.
Bikes also pioneer high tech lightweight materials, only recently have 'bicycle grade' aluminium and carbon fibre been used on those boxy car things.
It is a whole different world of 'body on frame' engineering. I sometimes wonder what a train would look like if it was designed from the ground up by a bicycle designer with a Lotus engineer - 'add lightness'.
Some modern 'Tesla truck' tech could be thrown in too.
Imagine having half the amount of wheels, all of them actively powered and actively steered so no screeching on corners. The seats could be 'bus stop grade' and the monocoque being some extruded tube with the hand rails and luggage racks being structural elements, like a rally car roll cage.
The idea of Brunel's wide gauge was to have the wheels at the side of the train rather than have the train sit above the tracks. Imagine if you had independent suspension and stepped a metre down into the train for some super low centre of gravity. Or if that extra space below the train was a massive parcel area so goods were shifted on/off trains with some standard pallets that just slotted in, aircraft style. Think how much traffic could be shifted off the roads particularly if you ran the trains in mixed freight mode through the night.
Rollercoaster style tracks, particularly in tube lines could be used to slow down trains at stations and speed them up afterwards.
As for the doors, these could be integrated into the compartment ends, so rather than there being the normal interconnect between compartments the doors would slide back/fore to keep the train enclosed on corners without the usual rubbery bendy bit needed.
Add airbags and seatbelts, windows that open, a bit of wifi and you could have comfort and actual passenger safety.
> On a bike, you maintain a steady speed by matching drag losses with the energy you're putting into the pedals. Braking and other actions cost you energy you've put in.
As does the frequent mistake of putting weight on the rear pedal. Realising this made me understand how little energy it really takes to keep a bicycle going, given the correct gear.
I think he means making sure to actively bring your rear leg forward while pedaling, so that your downstroke doesn't have to push against the weight of your rear leg too.
On a bike, you maintain a steady speed by matching drag losses with the energy you're putting into the pedals. Braking and other actions cost you energy you've put in.
Which is exactly why bicycles are so fond of rolling through stop signs. When you're riding one, it is obvious to you that going from 20 mph down to 10, then back up to 20 is reasonably safe and only takes half the effort as going from 20 mph down to 0 and then back up to 20.
Yes really. I'm sure you know power is velocity * force. For a long range, force output is pretty constant for humans, so power output must be lower: http://users.frii.com/katana/biketext.html
>> 5mph would take nearly 1000' to bring to an "emergency" stop.
That seems far fetched. 1000' is a long way at 5mph. The number of engines doesn't matter. Each car has its own brakes in an emergency. Cut pressure in the line and every car will brake itself. Perhaps they meant situations involving hills, not uncommon for ore trains heading from mines.
"Shortly after 08:00 hrs on 8 November 2010, a passenger train running from London Charing Cross to Hastings failed to stop at Stonegate station in East Sussex. The train ran for a further 2.45 miles (3.94 km) with the emergency brake applied, passing the level crossing at Crowhurst Bridge before coming to a stop 3.22 miles (5.18 km) after first applying the brakes."
There's a whole sequence of events behind this, from the work to remove slippery leaves from rails, to the sand applied during braking if wheels are slipping, to the IT systems and management processes identifying why the train didn't have any sand. It's a fascinating 151 page report.
True, but the last part of the graph shows what I think is fairly normal braking from 24mph to 0.
Counting pixels, the distance covered from 10mph to zero is about 350 feet. With this distance for a lightly loaded passenger train, 1000 feet doesn't seem impossible or even unreasonable for a heavy freight train at 5mph.
A train's emergency braking system is somewhat sacrificial (using it can damage engines, cars, etc.) so you're probably correct. I'd say that in either case, most people who are not "train people" will dramatically underestimate the required stopping distance. The mass of a fully loaded train is surprisingly large.
Car drivers tend to underestimate the amount of space it takes for a semi to stop. Heck, every time I load up my car or attach a trailer, it takes time to become accustomed to the decreased braking performance.
Drivers likely could not give an accurate estimation for how many feet it takes to do anything on the road, such as come to a stop in an SUV going 50. Given the extreme mass of a cargo train, I wouldn't be surprised if the distance figures sounded high.
> how many feet it takes to do anything on the road, such as come to a stop in an SUV going 50
Isn't knowledge of stopping distances for vehicles at various speeds and different road surface conditions a requirement for obtaining a driving license? (At least, in the UK I believe it is, and I think the Highway Code tables probably over-estimate these distances for safety purposes)
Yes, but I don't think it requires or correlates to real understanding of what the distances are. I doubt that people understand how it varies with speed, or what that number of feet really looks like on the road. The process I have experienced is I read what a theoretical distance is in the booklet the state gave me for the exam, and then select their indicated answer on a multiple-choice test.
The Highway Code tables are based on an average family car in the 1960s (IIRC) when the tables were first introduced. They're ridiculously long distances for modern cars, though AIUI the "thinking time" part is nowadays thought to be too low.
Still, that's not a bad thing, per se. If we underestimate based on a vaguely remembered overestimated value from the highway code based on 1960s cars, then the effects cancel out and we're basically correct for modern vehicles?
I /think/ I recall seeing something that claimed with longer reaction times it actually ended up worse overall.
That said, I think often the bigger problem is people not realising especially in more unusual conditions (like snow in much of Britain) quite how much longer braking distances become.
This is true. A buddy of mine works for the engine and brake systems of trains. I was helping him install the new skid plates and bumper he ordered from 4WheelOnline for his Jeep when he mentions the critical points and headaches of maintaining the brake system of trains.
You don't want to lock up the wheels in an emergency. Locked wheels will skid on the rails, creating flat spots on the wheel. Later, if not repaired, the rotating wheel can hammer the rail at the flat spot, causing the rail to break.
I agree, but the optimal achievable situation might be to be on the edge of locking wheels like ABS. Anyway, my point was that damaging the wheels is not the issue at hand.
Electricity wouldn't scale. Solenoids on each brake system would take current. Adding new cars would increase the load on whatever is providing that current. To ensure that cars could be swapped in and out, the cables on all cars would have to be large enough to provide current for even the longest train.
Air brakes, once pressurized, don't take much to maintain. Relatively small pipes work on even very long trains. You can add cars all day without increasing the steady load on the compressor. A longer train will take longer to pressurize, but once there it would not need the compressor to run constantly. Air is also not as dangerous as running large electrical cables the length of a train.
I meant electricity just for the triggering, not for the action. A small electric signal could for example open a valve in the air tube. Thus all cars would break at the same time.
Some trains already to this, where they put in electronic valves in the air lines for in car. Basically, the electronic valve controls if the existing brake is vented or connected to the central air line. This still allows for the fail-safe behavior of being able to brake the train from the central air line by venting it.
This lets them start easier/quicker from a stop, as they don't have to re-air the entire train and less wear on the brakes of the trains in the front of the train as all the cars start braking at the same time. This is particularly useful for trains that have to start on a hill as taking minutes for your brakes to fully turn off can complicate things.
Passenger trains have used electropneumatic brakes for decades. A few freight trains use them. Trains with distributed power (locomotives spaced along the train) have sectionally controlled braking. Sometimes, there are "repeater air cars" with air compressors and a radio link to the locomotive. Those are used mostly on flat terrain, where more braking power is needed but not more engine power.
Because the pneumatic system is fail-secure, since a break in the line causes the pressure to drop and brakes to engage. I suppose you could have a system which required constant power to hold the brakes open, and loss of power would cause them to engage, which would have the same result?
There are lots of assumptions in that entry-level physics exercise, for instance that all the energy can be dissipated without destroying anything (that the brakes are able to utilize the full friction available) and also that the entire weight of the vehicle rests on top of the wheels performing the braking.
Weight and ground pressure cancel each other out in the friction equation. The issue is where all that heat goes. Heated brakes will fade, glaze, fail, break, burn or a combination of the above, so there are limits on how much braking force you can apply to wheels
The fireman debate, where management argues that a position is no longer necessary due to technological improvements, while the people actually doing the work think or understand differently, should be familiar to almost anyone in any field of work.
We're currently fighting a whole genre of fire at work that boils down to the fact that a particular system, with many many finicky integrations both inside the company and with rickety old 3rd-party systems, was designed with the assumption that there was a so-called "junior QA" team who would be manually looking for trends in error logs and failed task logs. This position was eliminated with a corporate reorganization, and the many many moving pieces are slowly getting rewritten with different assumptions about monitoring, alerting, and logging, but in the meantime there is not anybody covering this function. This means that we typically only have a chance to fix things after they've started to be an actual nuisance to someone and they complain, whereas with the old team in place we had a better shot at identifying problems before they became a major nuisance and fixing them before anyone complained.
The title (Dangers of Train Yards) reminds me of a story told by an acquaintance who worked in a yard many years ago. He said they would fuel the engines by inserting a hose and letting it run. It would take a long time to fill the tanks and so they would walk off to complete other tasks. They would return and more often than not, the tank would just be overflowing diesel into the ground. He didn't think they would ever be able to remediate rail yards because of the contamination.
Culture is just "what people do". It's interesting that train drivers have to be coached through it feeling uncomfortable but necessary for safe operation. If there's a "national character" element to it, I'd say it's the acceptance of the uncomfortable but necessary.
The two are one and the same thing, I'd wager. The act of translating abstract thought processes into physical action (whether that's speaking or just pointing) forces you to examine it in a different way, just in order to make it concrete enough to express.
In North America, there is no longer a "Fireman" position on diesels. You have the Engineer and the Conductor in the lead engine, and a "FRED" Flashing Rear End Device on the rear to control the air brakes, report speed and acceleration back to the head end.
More often these days, trains have extra engines on the end (and middle) that are controlled from the front in Distributed Power Units (DPU's). By spreading power out, you have more control, less stress on the couplers, can run a longer train, and the air brakes respond faster (closer to each engine for pressure changes and recharges).
Many of the photographs feature gnarled old railroad bridges because of the hills and rivers in the region. Because of the region's steel industry, many photograph also feature smoke stacks and dirty skies.
Here is how the collection is described:
"""The Pennsylvania Railroad collection, held by the Archives Service Center, includes 345 (nearly all of which are 8x10 in size) gelatin dry plate images of railroad infrastructure dating from 1907-1917. Many of the images depict construction and repair projects to the company's lines, both within the city of Pittsburgh, as well as across the Midwest. Featured prominently in the collection is the renovation and construction of the second track for the Ohio Connecting Railway Bridge, located just north of downtown Pittsburgh. The collection also includes numerous views of track re-grading operations which occurred in Pittsburgh, as well as other major cities including Cleveland, Chicago, Cincinnati, Indianapolis, and Detroit."""
> the union had more than 30 railroad employees take photos of their workplace in an effort to demonstrate the hazards firemen could help navigate around.
suggests that the presumably union workers may have tended to
choose to take photos of the more (or most) dangerous locations.
I loved those videos too, but it was pointed out to me how much blame they put on the employee for unsafe working conditions. Safety isn't just about telling your employees to be safe and punishing them when they aren't.
When I worked for BNSF I heard a story about a guy crushed between two cars in the knuckle because he lost line of sight with his engineer and they were using hand signals instead of a radio.
They were able to keep him alive long enough to cover him with a tarp and bring his family in to say goodbye. He died immediately upon separation of the knuckle.
This is an old urban legend. Feel free to Google it, and you will see everyone who has worked near trains knows a guy who knows a guy who this exact thing happened to.
That particular story is an urban legend, but fatal shunting accidents are sadly not. See https://www.gov.uk/raib-reports/fatal-accident-at-grosmont-n... for a recent example (an amateur on a preserved steam line in this case; the mainline railway in the UK minimises manual shunting as much as possible)
It's hard to understand why Snopes has this marked as a myth. The specific anecdote structure with the wife showing up is clearly a meme but that doesn't make it a mythical type of event.
We're much better at dealing with this situation in developed countries now. It's still a serious hazard. Around the turn of the 20th century it was very difficult to handle.
This seems to involve patients being 'crushed' for an extended period of time. Like more than 15 minutes, where tissue dies and basically creates a poison, that enters the blood stream when the patients get released.
That doesn't seem to describe a situation like the ggp was talking about.
Note that I'm addressing the Snopes conclusion more than the comments of the HN poster, except insofar as he/she used Snopes as a source.
The key elements of the Snopes article are these:
-Victim was crushed by machinery.
-Victim is still alive.
-Victim is not in much pain.
-If the machinery is removed the victim will probably die quickly.
-There's time to have them communicate with loved ones, a priest, whoever.
There are literally videos of this situation on liveleak. It happens with trains, with elevators, with forklifts and freight, and most commonly with car accidents.
The reason you don't remove the person at first is that they'll bleed out. The crushing material is an effective tourniquet so the person just sits there, alive and moving.
By the time that emergency responders get there to address the blood loss crush syndrome is a definite possibility. The person is generally going to faint the moment the equipment is removed because of the sudden loss of blood pressure. If they don't die of blood loss then they may have kidney failure and die on the way to treatment.
Everything about this is shockingly common except bringing the victim's family down to say goodbye or bringing in a priest.
To suggest that this has not happened in any of the hundreds or thousands of crushing cases since the industrial revolution occurred is ludicrous. It used to be that companies provided housing for workers near the factory/trainyard/loading dock. It would often have been the case that the victim's family could get there before an emergency responder.
The sense in which this is a "legend" is that people claim it happened to a friend-of-a-friend or whatever, and it's true that's an urban legend channel, but the actual events are documented except for the dramatic last kiss. I wouldn't even be sure that isn't documented. I just haven't seen it.
I got within a hair. Stupid, stupid, stupid. In a nutshell: I was working with a backhoe that was older than I was, early 60's model and a hydraulic line developed a very small puncture, enough that I could see the line start to sweat. Instead of backing off I got closer to see if the drop I saw on the line was really oil or maybe water. Fortunately before I could reach for it but after I got way too close the line exploded. Blinded me for about 15 minutes completely, the oil got infused into the fabric of my sweater so deep that even 12 years later (yes, I hate throwing stuff away) you can still clearly see where it hit. And that was just a hydraulic line bursting, we're not into accidents with buckets and blades territory.
A Reddit thread this week said if you put your finger over a leak in an oil line the pressure will drive it through your skin and they basically have to do surgery to scrape the pockets away from your bones.
Do you get joy from just making up stories and pretending you were there?
I've heard this story perhaps as frequently as I hear about people who go cow tipping. But then I ask and it back tracks 'Oh, did I say I went cow tipping? I meant I sat in the car while some friends went cow tipping. And no, I guess I didn't see any cows. And we were parked in a taco bell parking lot.'
Historical, not current ones. I was talking to some friends about it just yesterday and was looking forward to the driver's point of view.
Also, cookie wall. So the TLDR is that in the past, more people needed to be employed on a train. The diesel came and they could redesign the locomotives so no big boiler was in front which blocks visibility. Problem solved for the railroads, but people unemployed. Apparently there are some historical pictures that they took on rail yards to prove the visibility issue.
Interesting story. In Italy trains still require two engineers, although on modern high speed ones the second engineer has to sit away from the windshield and the controls.
Boring but very real reasons why we "can't just update things"