How Railroad Crossing Signals Work

I get this question often so I decided to tackle it in a video.

[@mikesmith4644]

I love how Danny says he is going to provide the most basic explanation of crossing signals and then produces the most comprehensive explanation of the different types of crossing systems I've ever seen. Best. KZbinr. Ever.

[@Harry-zz2oh]

Very nice explanation for the signaling system. Relatively goof proof.

[@briankeith2127]

very good explanation of how they activate

[@Bonzi_Buddy]

They need to clone this guy because he's got the perfect voice for train videos.

[@justiceleague4209]

On god

[@traderjoes8725]

I agree, his content is outstanding!

[@MrAnderson84]

*I remember being a young kid back in the late 90s playing on the tracks. We were curious on how the crossing arms knew a train was coming and would watch around at what point the train activated the crossing arms. We saw where the activation started once the train left we laid a bed frame across the tracks and sure enough it activated the crossing arms. Being young and dumb we kept activating them until the police came to see whats going on. They yelled at us and called our parents*

[@daeganj]

That’s awesome lol

[@rowan312]

does this still work? even if you just took a regular steel pole and touched either sides? and do all RR crossings work like this? or is it just some older ones because I'm not too sure if they updated it and changed how it worked

[@MrAnderson84]

@@rowan312 I think back then it was the joiner bars we laid the bed frame across. It’s been so long that it what I think it was. Because all we did was lay it across the tracks and a few seconds later it activated the crossing arms. I’m sure it’s different now with technology advances in that city Newark CA. I’m sure it’ll still work on other racks with that system. I’d say I’d go try it to see if it works still but I’m in my 30s now and know better.

[@rowan312]

@@MrAnderson84 ok. thank you!

[@cknorris3644]

We did the same thing with an old metal door frame. Set it off every time and they would just come and toss the frame to the side. Then of course being dumb kids we would just do it again on our way to school. They finally smartened up after 4-5 times and took it with them.

[@thecaptainredpants]

My man, you have THE voice for broadcast or documentary. I would learn literally anything if you narrated it. Edit: and some quick google-fu tells me you already have a career in radio announcement and production. I knew something sounded right here! Hats off to you, sir.

[@distantsignal]

Wow, thanks very much, Captain!

[@robertborchert932]

Hehe, Google-fu! Like that. Great announcers voice, I picked up on that.

[@ILikeWafflz]

Lol "google-fu" gave me a chuckle

[@billandrew4116]

Hes the Paul Harvey of railfans

[@ronaldpiper4812]

Look him up that's what he does.

[@blackhawks81H]

Hell of a voice, clear deliberate pronunciation + enunciation, good tempo/pacing.... This guy's got to be a radio dj, voice over artist, or something... Can't you just imagine him saying "This is a test of emergency alert system, this is only a test"? Lol. Love this, subscribing now.

[@distantsignal]

Wow! Thanks for such a nice compliment.

[@ColonelStraker]

11:48 as the engine's number is 911 and it's painted in the firefighter colors I assume it's a tribute not only to Firefighters but specifically New York City September event of 2001. MYPET GOAT yes we know the truth.

[@chrishuston4445]

@@distantsignal >> I would like to hear Danny do the History of the Turbo Encabulator kzbin.info/www/bejne/d5SaeGquhKxld8k

[@mikibihon8826]

I very much agree, he could be a good narrator of PBS documentary.

[@phillyphakename1255]

​@@chrishuston4445 he teaches us so well how the crossing system identifies the approaching train to lower the gates, I want to learn how the ambifascient lunar waneshaft effectively prevents side fumbling!

[@christopherlockhart2004]

You know its a good day when Distant Signal uploads.

[@DelcoImagery]

Yes

[@mr.g1136]

Indeed

[@unity3596]

Ya

[@dabulphilly]

It’s 83 degrees here in philly so it’s definitely a good day

[@nethoncho]

Same

[@TheChaosJohnson]

Whenever I hear that "Hello again Railfans" I feel like I can kick through a wall

[@fostoriadistrictrailfan3907]

Frickin SAME

[@steelcityrailfan4808]

Same

[@steelcityrailfan4808]

Da heck? 😂

[@TexasRailfan2008]

Same!

[@youraveragejoe2]

What did that poor wall do to you😂

[@christaylor7411]

Literally not even into trains at all but somehow watched this from start to finish. Great entertainment

[@wilf609]

This is what the internet and KZbin are great for - educating people in something that is interesting. Thank You.

[@TheRayterry]

As a retired Signalman/Signal Maintainer hired by the Southern Railway System and retired off of the Norfolk Southern Railway: I approve this video!

[@distantsignal]

Many, MANY thanks!

[@shrek7954]

As a signal maintainer for Canadian Pacific Railway. I also approve this video. Well Done.

[@TexasRailfan2008]

Woo hoo! Maintainer approved!

[@cherylsims5636]

As a CSX Engineer, I approve this video as well.

[@eitzhilfawx6804]

Could you come to Sweden and patch up crossings? We have some where the gates go up at the wrong time, so people start crossing the rails, only getting halfway across before the gates begin to lower again. It's a disaster waiting to happen

[@trackandtrail6874]

In a world gone wrong, Danny Harmon makes it alright. I learned something today. Thank you sir!

[@jeffcox9393]

Like your logo Track and Trail. Gotta be the old Chesapeake & Ohio!!

[@Mesa_Mike]

It's been a while since I was a software engineer at Safetran 25 years ago, but your explanation of the various crossing control sensor types and how they work is pretty spot on for the technology in use at that time. Basically, a transmitter injects an AC signal on one side of the crossing, and is monitored by a receiver connection on the other side of the crossing. The track between the 2 connections is the island. If a train is on the crossing -- the "island" -- the signal is completely shorted by the train's axles and the receiver sees no signal at all, so that's how the electronics know a train is on the crossing. Otherwise, the train presents a rolling shunt across the tracks, and the two rails and the train constitute a electrical loop which is an inductor, electronically. The closer the train is to the crossing, the smaller the loop and the smaller the inductance. The electronics monitors the amplitude and phase of the received signal - which is changing when a train is moving in the approach circuit due to the changing inductance - and can tell from that whether the train is coming or going, how fast and how close it is, and in the case of a GCP can use that info to predict when the train will hit the crossing, and drop the gates at a predetermined number of seconds beforehand. Things do get a bit more complicated when there are multiple grade crossings with overlapping approach circuits. I'm sure crossing control systems are much more sophisticated now though.

[@distantsignal]

That's a great explanation, Mike Thanks! I wish I'd had you along when I was making this video. Ha!

[@elevators_of_southern_ontario]

For many years, I had no idea how these signals knew how to activate for an impending train! You did a fantastic job explaining everything!

[@distantsignal]

Glad you enjoyed it!

[@Ricewarrior01]

I don't know why this was in my recommendations, nor am I a fan of trains, but this fascinated me and I ended up watching the whole video. This youtube algorithm is pretty scary stuff.

[@IstasPumaNevada]

I feel it's less that the algorithm is scary, and more that human patterns are fairly predictable. :)

[@NorthFloridaRailfan]

Once again when Danny Uploads a video we must stop what were doing and watch it!

[@michaeltaylor5786]

I've often wondered about the signals and how they work. A fast train activates a quarter mile away but a slow one just yards away. Thanks for the best explanation I could have recieved!

[@SchuminWeb]

Message art is so interesting. I've seen it before, and never realized that it originated with railroad employees as a way of communicating with each other. I always figured that it was just another tag like graffiti.

[@briankoski817]

We used to leave our initials near the Cotts Board to let our shop crew know who inspected the car for repairs. Now it's just on the work orders cover sheet.

[@idkreina]

this dude actually doesnt know what hes talking abt w this one.. its called moniker writing, originated w hobos & is still primarily practiced by either by hobos or plain ol graffiti writers... some rail workers *do* also write monikers - especially former rail workers - exact same as any other type of graffiti on trains.

[@justinstrickland5382]

Never knew about radio tones activating crossing signals. Thanks Danny!

[@SD40Fan_Jason]

In places where approach activation is not feasible, it's becoming more common now. But it's a technology that's been in use for at least 25 years!

[@neko7684]

It makes me curious if it's possible to use different tones to prevent the gates from ever coming down if a train is going to stop before the crossing. That way, traffic can keep going until the train actually does need to continue on.

[@SD40Fan_Jason]

@@neko7684 if the crossing is equipped with remote control activation and set up with no approach, then it would not activate unless the crew activates it or whenever equipment occupies the island. On the circuits that have an approach and remote activation, the crews are able to override the approach and deactivate the crossing remotely as well.

[@traindad77]

@@SD40Fan_Jason Or where road traffic doesn't allow a station delay to be used in the predictor.

[@CurtisMechling]

I've designed/installed DTMF controlled power switches for several Class I's in the last decade in non-signaled territory (no dispatcher control), CSXT included as a signal system engineer.

[@6777Productions]

Yay! A Danny video! - just one thing to add, whenever the gates are down, or the lights are flashing. Even if the crossing may be broken, NEVER drive around the gates. No matter what, even if the gates have been down for 2 hours, never go around because you never know what is coming!

[@nocontext4463]

Mhm!

[@bluegrassman3040]

I live next to the CSX Henderson Sub, and have seen people run past the gates several times. My parents were standing out side near my porch, and almost saw a pickup hit by the J731 local, one night...

[@clffliese26]

@@bluegrassman3040 It's either temporary insanity or a death wish. Either way, these people don't think about how this affects the train crews.

[@jovetj]

It is also _ALWAYS_ illegal to drive around lowered or raising/lowering crossing gates. Do not do it. This is above and beyond the mass ratio of a train to your car is like your car and an empty soda can. In many places it is LEGAL to stop and proceed with flashing lights but no gate. Obviously, Stop, Look and Listen, and be sure it's safe to do so before proceeding. But, also check with your local laws, because it varies from place to place in the US.

[@clffliese26]

@@jovetj You're right about it being illegal, but a lot of idiots do it, anyway. I said, elsewhere, it's, either, temporary insanity or a death wish. Either way, more often than not, it ends in death. DON'T DO IT!!!!!

[@Midnight.Shadows]

I'm really glad KZbin recommended your videos to me, they're very informative and very well done, from the information being well researched and presented in an easy to follow way, to how refined the videos are, this is high quality here, I could easily see this being part of a documentary series on TV or something about railways. Keep up the amazing work!

[@vernacular1483]

The technical content of this channel, as well as the amazing delivery, is some of the best on KZbin. Really well done! 😊

[@varrick1226]

This man is phenomenal, a great teacher and also has a great voice so he should be in Hollywood doing voice overs.

[@mikesmith4644]

He does! lol

[@varrick1226]

@@mikesmith4644 Hollywood, Florida? lol

[@joshsadventures1776]

How ironic, I was just out watching a Florida central RR train pass, and I see this. Really cool Danny!

[@johno9163]

I just found your channel..and it was fascinating and very educational. I always wondered how those signals work. Looking forward to seeing more of your great videos!

[@SilverThunder710]

Danny, your videos never cease to amaze. You have earned my subscription.

[@vrmntthb]

A gentleman - Mark Clay McGowen- has a channel of his experiences as a signalman for UP on here with some very detailed yet protected descriptions of the equipment and the duties it may do within the crossings he used to maintain. Great stuff to add to your collective efforts here sir and just another beauty from the Distant Signal world for us to watch and rewatch...and we always thank you...

[@jimrawls5509]

And he has a good channel too.

[@kevinheard8364]

@@jimrawls5509 agreed felt so sorry for him with the COVID ravaging his voice for so long

[@owenwoodall5642]

When you like the video even before watching it!

[@buckeyfan7623]

Love your videos man very informative! Been a huge CSX fan for many years I live about 15 miles from the A line in NC . And grew up a mile from the S line in Raleigh so love all the seaboard and acl talk in your videos.

[@DavidNSRailfan]

I just want to say thank you for some of the most informative informational videos I’ve ever seen and you give them in a classy way I enjoy watching your videos thank you

[@rickwatts7885]

As always, every time, the best, most professional rail fan video on the internet. Thank you very much for doing the hard work that enables we armchair fans to learn and enjoy. Stay safe!

[@southfloridarailfan6466]

it’s funny that he not only visited a railfan spot i frequently visit, but he also caught a dash 8 on an amtrak like I did about a week ago.

[@distantsignal]

We we're visiting family in Boca Raton last weekend so I snuck out Sunday morning to Deerfield and picked up that stuff.

[@tropicalrailroadproduction5028]

@@distantsignal I railfan at deerfield :O

[@christophercota2862]

@@distantsignal man the 3194 is such a beautiful engine im glad I caught him at plant city

[@scottdowney4865]

Could you please do a video on DPU's? Basically I am wondering why some are in the middle and others are on the bottom. Is it just logistics?

[@kyosuke19971]

I have one question that have been in my head for years now. How do the railway companies make locomotives speak with each other? Here in Norway diffrent types of locomotives can’t work as a pair. Then you gotta need a secound engineer to operate both locomotive. Only locomotives of the same type that are made to be multiple working together can be operated from the leader of the consist. But over in the US you guys is like connecting 70s SD40s with a state of the art ET44AC. Or an SD70ACe-P4 for an example.

[@Gidono]

Very nice production quality. The narration was clear and the information wasn't hard to understand to a majority of people new to the rail world. I learned something new today watching this video. I always wanted to know how these railroad crossings work. Good job Danny!

[@charlesbutler4646]

Thanks again Danny for another fascinating and educational video segment. I really enjoyed watching your reports.

[@Wrectem]

It was always something I sort of knew, but was always curious how they really worked.. thanks Danny

[@DanHPage]

Danny, this is a great explanation of how changing impedance is used to regulate crossing signals and gates! Thanks!

[@kathleenbarkan9888]

You have, by leaps and bounds, the BEST videos and explanations! Thank you!

[@miokujou]

I'm not even interested in trains yet I stayed and finished it because you made it so interesting and fun to watch. The way you explain it is so easy to digest. More power to your channel. We need more people like you that can make learning fun.

[@TrumpCardMAGA]

3194 sure is a pretty thing, but I sure do love that 911 fire engine red unit.

[@HughMartell]

Whenever I get a notification from a Danny video, it's like getting a wrapped Christmas present and can't wait to open it!

[@rgbrown90]

Another fine presentation of railroading information! Thank you Danny!

[@MesquiteBelt]

Another simple but incredible detailed explanation of how these systems work! Congratulations if a job well done Mr. Danny!

[@flyboy3ck]

I dont even need to see the video before I give it the thumbs up. I already know it's good because it's from Danny. Keep up the good content Danny. Hope you're well. Loving it from near Chicago.

[@alwillis9377]

Everything stops when Danny speaks. Great content!

[@GGRTL1]

I came across this video in the recommended. I've been curious about this for about 20 years. i'm 31 now lol This is very detailed yet simple. Very well put together.

[@qwertyTRiG]

There is a whole community of railfan KZbinrs, but Danny Harman stands out for excellent camera work and clear explanations.

[@GGRTL1]

@@qwertyTRiG I've been slowly digging into it. This looks like an awesome community already.

[@jamesford3648]

I just recently found & Subscribed to the this FANTASTIC channel. Thank you for all the work you do. I have a lot of “Catching” up To do and a LOT of “Like” hitting to do…

[@brianhickey5949]

I always enjoy the education that Danny gives us! Always enjoy learning about the train consists, the routes and timing and the track gear :)

[@TrainNut85]

Great video Danny, glad you caught the Pride In Service units!

[@Midnight-tw3gp]

Awesome video, thanks for the explanation of the message art left on cars by the car inspectors. I've quite often wondered what that was. Keep up the great work.

[@skitzoemu1]

I love how well he explains this stuff. I have started to use his videos to explain many of these things since I have trouble explaining these concepts to my kids.

[@cuffy69]

Was having withdrawals. Finally another DH Video to aatch. Lol

[@squirrelbazooka8033]

I’m actually trying to build a realistic functional Lego grade crossing signal as a project- this was a good video to watch for that!

[@Rwalt61]

I'm glad I found your videos Danny. Entertaining and informative. I see crossings every day and I always thought they were weight activated.

[@midwestrailfan134]

Even titles that sound dull are best watched and described with Danny always the best videos.

[@SD40Fan_Jason]

I feel it's necessary to mention that the first iteration of Motion Detectors were developed and distributed by "Harmon Electronics"

[@distantsignal]

Ha! Didn't know that one!!! Thanks!

[@qwertyTRiG]

That's really cool.

[@shrek7954]

they are called a harmon crossing processor. or HXP for short

[@SD40Fan_Jason]

@@shrek7954 the manual I have is for a Harmon Electronics PMD-1 and PMD-3

[@shrek7954]

@@SD40Fan_Jason ya its the same thing different name. if i remember from class i think it stands for Predictive motion detection. but we just called them HXP- 3 system. they are not installing those new anymore. the new system is called XP-4 .

[@JustarailfannerTrains]

Danny, You have no idea how excited I got when u posted this!!!

[@larrymccracken5396]

WOW! These videos are great to watch and your commentary is so informative.

[@KerryBARON]

I am captivated by your channel!!! Thank you.

[@cnhollysub6496]

Another Great video. I can remember when there was a tower in Royal Oak, MI that was manned 24/7/365 with someone who activated the crossings in town. Keep them coming Danny!!

[@stevelandry6387]

Thanks, Danny! I have been enjoying your work for years.

[@ChadAmI80]

This was the most expansive explanation I've ever seen on how the crossings work. Thanks for a great video!!

[@AlderKertor]

Honestly one of the most pleasant presenter voices I've heard. This has great production quality and skill

[@philsellers6003]

Seeing a video from Danny is always a good way to start a weekend!

[@amessman]

Awesome video, as both a railfan and electronics hobbyist, this stuff fascinates me.

[@jamesmulcare5321]

Very interesting piece. Explains in detail, but in a way that's easy to understand. And the narration is easy on the ears, great voicing!! Thanks!!

[@jeremiahrex]

Great video! Thanks. As an electrical and systems engineer it’s always fun and enlightening to learn a bit about other industries. This is just the right level of detail.

[@stephenwayland6676]

Well done, Danny. Big fan of all your videos. Have some fun out there on the high iron, and be safe!

[@BeyondtheRailz]

Yes! More Distant Signal. The railroad historian, I just started freaking out. Yessss

[@cadetkohr5508]

You give the most comprehensive explanation of things. Thank you.

[@rickchaidez5711]

Good video! From someone that was a track welder now recently becoming a signal maintainer. Well put video.

[@glenrummel4483]

One can always count on some very valuable information in a Danny Harmon video. Thanks Danny you filled some of my voids regarding signaling. Keep up the great work!

[@horroreader410]

Signal Maintainer here! Fun Fact many people may know, at 15:40 the signals deactivates after leaving the island block. In a normal Approach, Island, Approach (which is most of my territory) each of the 3 blocks have a stick relay. Basically, when the block is charged, the stick is up, when it's discharged, the stick drops. Most of these sticks have a timer as well. Once the train leaves the island and the signals deactivate at 15:40, the stick for the approach block that he's currently in, is still dropped. Once the relay realizes that the train is out of the Approach that it originated from and leaves the island (Both of those sticks return to their upward position) the stick for the block he's currently in will start a timer. It's called exactly what it is: A stick timer (Or block timer) Basically, after the train leaves the island, the stick timer for the approach block he's still in, will begin counting down. If that train doesn't get out of the last block after a certain amount of time (Typically 8-12 Minutes. I have my crossings set to 10 minutes) the signals will reactivate! So if you're ever near an Approach, Island, Approach signal, and you see the train leave the island but stop on the block after, wait about 8-12 minutes, and the crossing should reactivate!

[@shrek7954]

some of mine are set for 25 minutes.

[@horroreader410]

@@shrek7954 Mine are on a mainline that only sees 15MPH max so we have a lot of wiggle room. The only reason we keep it low is because there's an industry dock halfway in the north approach block, and since it's single tracked, we sometimes have to park flat cars there for the industry to unload. Our crossings are hodge-lodge though. We still have old RSI lights, an old Copper Dioxide GRS Rectifier, and lead acid batteries in a beautifully repainted silver battery box (We call it the toy box).

[@OliversElevators]

That’s interesting! Why would the signals reactivate if the train is stopped past the crossing, through? Is it expecting the train to reverse and go back through the crossing after it’s done its business at whatever is past the crossing?

[@horroreader410]

@@OliversElevators It’s more or less a failsafe feature for directional stick circuits. You have 3 blocks like in the video which are the 2 approach blocks and the island (road). When you’re talking about them in terms of direction, I was taught to call it, the origin block (the first approach the train enters), the island block (the road crossing), and the outbound block (the approach block the train enters after leaving the origin and island blocks). Whenever a train leaves the origin and island blocks, the signals deactivate. But if it’s still in the outbound block, the stick timer will expire (mine are set to 10 min) and the signals will reactivate. The 2 main reasons this would happen would be because the crossings uses both approach blocks to tell when a train is approaching. If one of those blocks is still occupied, it can’t tell if a train is approaching the crossings from that direction. So for all the crossing knows, a train could enter the island block at any moment which is typically only 50’ from the road which is not nearly enough time to activate the crossing to warn motorists

[@horroreader410]

@@OliversElevators And to your point, the only other most likely reason I was ever taught, was to prevent any equipment that was rolling backwards or reversing. A I’m sure there’s plenty of FRA reasons but that’s above my pay grade. My job is to install, inspect and maintain. I will tell you tho that a track predictor gets rid of a stick timer because like Danny says in the video, the circuit can detect direction and speed in the rails. So the train could stay in the approaches all damn day if it wanted to without a reactivation. So long as it doesn’t start moving toward the crossing at a certain speed that the Predictor circuit algorithm doesn’t notice as being a reason to activate

[@neilgandhi5565]

Howdy from the U.K. just really getting into watching trains as am more of an aviation enthusiast but a friend from my school days works for the railway/railroad here in the U.K. so am trying to understand it more and so watching your vlogs even though they refer to U.S railroad’s help me to understand how stuff works so keep it up boss

[@Aerospace_EdC]

As always very good video, very informative. There is a crossing near my home and many times I see the locomotive stopped back from the road because the operators make a visit to the convenience store nearby. It always gives me a little scare because the lights aren't activated (now I know why) and I see it in the corner of my eye. Even though the train speed isn't that fast on this track it still takes me by surprise.

[@TheMadness51]

I knew about the basic set up but the other set ups described today. Well done expanding my rr knowledge!

[@CNSD75I]

I was just in the middle of re-watching the juice train 1997 video when.. boom! New upload!

[@lethalogicax2474]

Super neat video, and definitely a subscribe from me ;) Railways and trains are absolutely fascinating to me and your content strikes a perfect balance of technical knowledge, real world examples and wonderful narration! Keep it up!

[@veinbanger9381]

Thank you so much for your Service! Love from Niagara Falls NY

[@dmorgan28]

That certainly was enjoyable Danny. You did a great job explaining these signal crossings 👍👍👍❤️

[@brucehansen4316]

Good to have you back Danny. 👍🏻

[@theangryfireball1023]

This video has no business being this engaging. I can't stop.

[@andrewmooney4562]

What an excellent video, Danny! I learned more interesting things about how these giants move about the land as they do. You're a great teacher, and I so enjoy your presentations.

[@jovetj]

He's the best!!

[@NEATrainsVids]

Thank you so much about the history of the Artistic messages! I am always glad to see a new video!

[@nightrider6769]

Danny enjoyed that little history on how the lights are activated thank you for doing it.

[@BernardBabin]

I regularly follow your videos which are very well done and informative. Many thanks for your excellent videos which I watch on my big screen TV. Bernard Babin - Railfan in Quebec - Canada

[@MrChappy39]

Pardon my gushing, but this chap has the best narration voice ever. And, the fact that I discovered this channel, has been a nugget of gold.

[@gatortrainchaser2080]

A most EXCELLENT and INFORMATIVE video Danny! Thanks for sharing!

[@NorthCountryTrains]

Alright! Another video from Danny, makes the week feel worth it.

[@fostoriadistrictrailfan3907]

Ya think? lol

[@paulgrodkowski5839]

Hi Danny. I would like to just quickly say thank you for posting "How Railroad Crossing Signals Work" I find this to be an informative KZbin video. It helps me ti understand what goes on in those grey metal huts or boxes that are near the tracks when I go for my walks. Thanks again.

[@wmjwell]

Thanks Danny. Really enjoy you sharing your knowledge!!!

[@phillipcudd5712]

That was the best explanation ive ever heard on crossings! Thanks for the info Danny.

[@VistanTN]

Excellent presentation, Danny. As an electrical engineer I compliment you for finding the balance between good detail and too techical.

[@drew25311]

I've always wondered how a stopped train at a station tells the crossing to activate. Thank you for the excellent explanation. This was a fantastic video!

[@garylbowler]

I’ve always wanted to know this information! Thank you! Very much appreciated!

[@bccarl88]

9:06 when you work on the railroad long enough to know by EAR what that DTMF tone was before even looking it up ( it was 6-4-2-*) 😉 Edit: I don't even work for CSX, but the Class II Railroad I work for has many power switches where we use DTMF tones to "throw" the switch. And with all Railroads, you use DTMF tones to get a hold of dispatchers and yardmasters on the radio. Basically they're just audio tones that the radio senses. So in theory you can "recreate" the tones if you can replicate the pitch of each DTMF tone.

[@AlRoderick]

I think each of them isn't a specific pitch, but a two-note chord. It sounds like it's the same as old touchtone phones, which means that what you have is a pitch for each row of the keypad and a pitch for each column, and every time you press a button it plays both of those notes on top of each other. So there's still 12 identifiable sounds but each one's made of two different frequencies.

[@bccarl88]

@@AlRoderick it's exactly the same. That's what DTMF is. Fun fact, you can basically do all the little goofy tricks you could with dial tones back in the day with the dial tones from the radio lol.

[@rickygonzalez3152]

Its actually 3-4-2-* but yes I can even tell by ear.

[@georgewheeler3731]

Thank You Danny for another excellent video, keep them coming!

[@scubaguy007]

Thank you, that was a great video. With my impatient nature I was worried I would not stick to the full 16 minutes, but you made it interesting, enjoyable, and very informative.

[@UnkleHeavy]

Excellent video, very well done!!! I've always wondered how these work. I remember as a kid, us jumping up and down on the rails before the crossing thinking that it was weight or pressure activated.

[@Garcansdad]

I learn something every day. I've always wanted to know the control circuitry. Now, I know. Thanks!

[@Railfanner2019]

Amazing catches as always! Thanks for teaching me something new today Danny!

[@dogatonic]

Wouldn't it be nice if all videos on KZbin were this well made? Great job guys.

[@KingTriton1837]

This is _THE_ best video explaining how this works! Thank you!!! Been curious all 32 years of my life!