SIGNALS 101: 10 Levels of Train Signal Understanding 

You're absolutely correct, I'd had this explained to me before but I must have been conflating two types of track circuits. It appears there are high frequency AC track circuits that exist that operate the way I've described, but the ones we use that are lower in frequency utilize a vane relay that is looking for a certain amount of AC current to operate. Once the current drops off (due to the presence of a train), so does the relay. Learned something new today, thanks for calling me out!

@@Hyce777 Aren't Pwr. Freq. circuits the basis of grade crossing protection signals too? ?

@@mdavid1955 Depends; sometimes yes, sometimes no. Usually they are an overlay of some sort, be it audio or power frequency so that the approach circuits can be separate from train detection for signaling. But grade crossings are probably their own separate 101 video. lol!

Hey there is a video somewhere here on RU-vid where someone I was saying about is it possible to charge a cell phone from that track signaling circuit and I think it's a saved video that where they've got a lot of speaker connected to cross the rails and you can actually hear what type of signals are being send down the rail it's possible these are two separate videos possibly same RU-vidr don't know too long ago. Not sure which circumstances they were in and what type of signaling was used for that track circuit either. But you can clearly hear different patterns and in-between you'd hear something entirely different repeating on a regular basis. So just was not just a constant frequency again not sure what circumstances this was being used or how far a great Crossing or anything there was no reference to it and all you could see was the track at that point. In the old olden days or bad old days if you want to call it that? Almost everything was d.c. and frequently battery-operated either rechargeable batteries at in some areas or even long life primary batteries although some metal-air batteries were used and even the ones that just had two plates replaced and the electrolyte changed in some cases. Somewhere similar to what was used things like aids to navigation. Such as buoys and other other applications as well. And even what was referred to as a charge retaining battery which still unfamiliar with but I knew they existed. And even sometimes even in later buoys they would actually be powered by disposable batteries essentially. Think giant lantern battery! And I believe some systems as low as 4.5 Volt or even 6 volts. I know someone that had two strobe heads from a buoy that had been washed to a location the thing was basically kaput but the strobe assemblies have been salvaged. When it was found was barely even able to float anymore and had probably been out of commission for years! I was able to power up one of the strobe heads the other one the Xenon strobe lamp was truly spent electrodes that degraded so much that it wouldn't even flash at all. Also back in the day Way Way Back a some signals as in semaphores were actually powered by CO2. Back in the day it was called carbonic acid gas! Some signals were actually lit by oil candles even. But the interesting thing is there was some electrical equipment associated with that. Essentially a thermostat of course course relying on two different Metals expensing man Contracting. However are not a bimetallic strip like one might think. And there would be a series circuit that if one of the oil candles goes out the circuit would open since the thermostat but cool to the point that the circuit was open. And that would be relayed to either a signal Tower or otherwise to indicate that there was at least one signal aspect somewhere that was out! Even back in the day there a lot of track circuits. Most people think that all the lines beside a line of crack is Telegraph lines however back in the day a a lot of it was track circuits. Performing various functions not just signaling but various other things as well. As a matter of fact there was even a radio system at one time that was won the first since there was always overhead lines near the track essentially you could do short distance radio just having the receiving system on board the train and be able to just pick up the signals not sure of this was Prototype are actually putting into practice but have heard of it. Also there was actually a communication phone system that could use Telegraph ones for telephone purpose. That essentially the extended hooks over the telegraph line to connect it was an important box sort of thing essentially first portable railroad telephone of course this is before the Advent of Radio Systems. And even before really electrical and other things caught on there was a lot of purely mechanical systems that would operate signals and more. And also some generations of pneumatic systems. And if anyone has ever heard of the old Crossing beacons that just blinked at the Crossing and just had that sort of conical base with the Lantern on top. Those were actually at First at least let buy acetylene gas! Also at one time they let railroad cars by Compressed Gas! Lot safer than kerosene lamps

@@Hyce777 I believe the technique you were discussing applied to audio frequency track circuits in the multiple khz range. Utility frequency AC track circuits I believe worked like a simple DC TC, but could support electrification or DC overlays and just needed the AC relay technology to exist.

@ walterrogers359 what railroad did you work for?

@@northwestrailfanofficial CSX and predecessor lines to SCL from 1973-2017.

Shut

Silence

👍

Very pun-ny

*BA DUM TISS*

An axel counter does not weigh the train it just use an 8 bit value so you would zero for evry 2^8*n because you do modolu 2^8 to a binary value

Uhoh runaway bits!

@@TrapperAaron More like "Train? I've seen no train it says 0 axles passed" followed by kaboom.

It's an axle counter, uses a magnetic field to count wheels. You have one at the beginning and one at the end of the section. It counts +1 for each axle entering, -1 for each exiting 256 axles on the earlier versions made it think the section was clear

Hahaha the byte is full and goes "ah, its 100000000, its clear"

This explains the logic of US/Canadian signaling very well: web.archive.org/web/20160313144451/alkrug.vcn.com/rrfacts/signals/signals.htm Let me know how it works for you. I'm happy to answer questions you have.

Track Ciruits are not something that terrorist should know about, If you connect 2 Track Ciruits together with a pair of wires, cross them over, create a false feed, train is not detected, another train will crash into it.

@@ianburnett7333 the system is designed with numerous redundancies and fault detectors inside the trackside bungalows and at central Dispatch offices. any anomalous signals detected will send the block signal affected into Failsafe Mode. in Failsafe, the signal will display Red or no Indication at all an error detection will also be sent to Dispatch to send out Track Maintenance to find and repair the fault. Terrorists want to make a statement when they attack. derailing a train doesn't do that since trains derail without manual intervention due to an array of reasons railcars carrying Haz-Mat's are designed to remain intact if involved in a derailment.

@@ianburnett7333 "Terrorist" can't do much to a track circuit that mother nature hasn't already.

Yeah we could probably do a "special trackwork" episode. Maybe that would make sense before interlockings 101... We'll see. Lol

Signal code relays are very neat. It's how the signals talk to each other, so when a signal is at _Stop_ (no code, no clicking), the signal in front of it knows to show _Approach_ versus something better. It's also what the conventional cab signaling listens to.

That's awesome!

I totally understand that vibe, haha! Glad you enjoyed.

_“The most complicated thing I do now is trying to understand my navel.”_ ROTFL! I salute you, sir.

Agreed.

Yeah, that video came out and I about did a spit take. lol. It's awesome.

Yep I saw that one great video

You can still see the Lancashire and Yorkshire signalman training layout in use at the NRM in York.

Honestly, I was a little disappointed by his video. I was trained on one of those systems and there were just too many inaccuracies, probably quite a bit got lost in translation. Fortunately, for as far as I can tell, this video here is spot on in just about every aspect.

@@trainman2615 every aspect? Groooan

I think I'd really like the job! Except for the heights on those bridges and cantilevers...

Cheers Stuart :)

With the days of mechanical interlocking mostly forgotten, common railfan knowledge and understanding interlocking principles has sadly, err, fallen by the wayside. But it's just as critical to safety on the rails today as it was 100+ years ago.

That is why Call-on signaling has gotten more popular. I don't know of its status in Canada, but CSX uses it all over. It allows the dispatcher to signal a train past what would be a _Stop_ signal into an occupied block with an upgraded _Restricting_ signal. This maintains all the safety features of the interlocking plant while avoiding just talking a train past a _Stop_ signal.

@@jovetj we do have restricting signals as well - they are actually fairly common - however I’ve seen trains request permission due to signal malfunctions approaching a single track section. There are several ways to indicate restricting speed within the Canadian rules.

Railroad signals are great. It kinda baffles the mind that a little 8-inch light controls what a million-pound train does.

Searchlight outer roundels are 8 3/8 inches

So the real question is why are traffic lights upside-down, surely railroad signals came first.

@@Idaho-Cowboy hmmmmmm

Dallen9 said elsewhere that they mirrored the semaphores, which have the lights that way, but because engineers look for the physical high position when the RR went full color light they put the green up high... Lol!

@@Hyce777 Lamo

The Pennsylvania Railroad invented the _Position-Light_ signal. The idea was to use lights to mimic the arm positions of a semaphore. Originally they started with four lights in a row, but switched to the 3rd generation 3-light versions once they were found to be perfectly satisfactory. All of the lights on an original PL signal are a fog-penetrating yellow. At some point, after some kind of accident, some moron decided that Red for stop would be better, so the --- lights were changed to Red (which is actually much dimmer!). Modern position-light signals on the Amtrak Northeast Corridor are properly called _Position-Color-Light_ signals, since they have been completely colorized. The Norfolk & Western Railway also adopted position-light signals and colorized them themselves (including the dwarfs!).

The limes are an inside joke on the channel about people making dumb puns or saying dumb things. We jokingly throw them at each other. It's a silly tradition. Glad you enjoy the channel!

@@Hyce777 That's fun! Thank you for the explanation!

Google yielded good results :)

I took a hit seeing Michigan Milan (I knew that in the United States you have Rome and Venice, but not Milan), I kept thinking Milan Italy, the bad thing is that google maps for photos of the city also put the Castello Sforzesco and the Vittorio Emanuele II Gallery

That's also why I got into train simulators back in the day.

victoria in australia actually used GNR somersault signals and american style 3 position semaphores

Good :)

It's a complicated topic because of its diversity and the details are just not obvious. But railfanning is fun because there's always something to learn on the railroad!

And his voice is fantastic to listen to. Yes, I'd recommend folks watch his stuff :)

Cheers mate! Preemption is a neat thing. We're going to do a grade crossings 101 sooner or later here and we'll get into that.

@@Hyce777Cool. I'll be waiting. 👍

Actual train simulation software is much more fun than that.

@@jovetj except driving trains around is quite literally ALL you do in a game like TrainSim/Dreail Valley/RRO. Minecraft lets you use Trains for actual logistics. Wanna move spoil out of a mine, have someone else in another part of the server that needs a crapton of cobble for a build? Trains.

it's like getting the traffic flow mod for Cities Skylines as opposed to just running ATS/ETS or City Car Driving. It's a tool to meet goals. both are good, but they're very differant.

@@jovetj Shame all of the major ones are notoriously predatory with their business practises, not to mention poorly optimised with weak post-release support.