Railroad Signaling Explained: How Wayside Detectors Work

[@NiceMuslimLady]

I have some old SP timetables (1987 and 1989). They had talking detectors already in 1987. "Type E" and "Type F" series. A Hot Box - Letter "H" Indicator with Digital Readout C Hot Box - Numerical Display Board with Indicator Lights D Hot Box - Remote Readout at Terminal E-1 Hot Box - Talker E-2 Dragging Equipment - Talker E-3 Hot Wheel - Talker E-4 High/Wide Load - Talker E-5 Loose Wheel - Talker F-1 Dragging Equipment - Talker F-2 High/Wide Load -Talker G-1 Dragging Equipment - Revolving Red Light G-2 High/Wide Load - Revolving Red Light

[@tomharris8263]

I remember the old number message board system. The engineer would call out "white light scanner coming up" over the radio and after passing, the conductor on the caboose would call out "highball the scanner" with a 000 display. The scanners were also connected to the dispatcher's office so they knew as well. Great videos. Thanks and be safe.

[@MarkClayMcGowan]

Thanks for checking it out!

[@markbell9742]

Thanks Mark: just found your channel and I don't know if there is anyone else interested in railroad operations, maybe I am the only one (yuk-yuk), but getting many question answered I have had. You have a great persona and delivery. Cheers, another Mark !

[@BrilliantDesignOnline]

At the hardware store buying a charcoal lighter: "Having a BBQ?" "Nah, railroad test equipment..." :-) super interesting. Thank you.

[@MarkClayMcGowan]

My pleasure! Thanks for checking it out!

[@dunsmuir238]

Excellent Mark...Thank you for the behind the scenes look...

[@MarkClayMcGowan]

I'm glad you enjoyed it and hope you check out more of my stuff plus what's on the way! Thanks for checking out my channel!

[@cambridgebob8953]

I liked learning about this. Back in the 70's I remember driving along a B&M rail line in Western Mass early in the morning heading to my favorite fishing spot when I started to see a series of fires along the rail. I stopped at one and the railroad guy there told me a passing train lit them from a hot box. Small fire, didn't spread, but I never heard about hot boxes until then. Mark, your video quality is great, like being there.

[@MarkClayMcGowan]

Thank you! I'm glad I could expand your understanding of how some of this stuff works! Thanks for checking it out!

[@vgolla]

Good job Mark. Thanks for taking time to share this with us. Keep it coming...

[@MarkClayMcGowan]

Thanks for the compliment and for checking it out! More to come!

[@MarkJoseph81]

This kind of stuff is absolutely fascinating to me. I love it!

[@d2sfavs]

i sure miss the rail scanner going off before and after the train passes telling us the axle count and speed then announces the temperature.now only the track number is announced.thanks for sharing

[@MarkClayMcGowan]

You're welcome and it's my pleasure to share them. Yeah, now you only hear information if there's a problem. Thanks for checking it out!

[@michaelnapier3221]

I remember those big black boxes that usually had greenish yellow numbers in them and I always wondered what it was. Those were placed going into the CSX (the old C&O) yards at Russell, Kentucky . Thanks so much for the insight and your efforts. I know this is a long time after the video post, but glad to see you’re getting along better now.

[@mikekantor453]

Great video! I had no idea trains were so technical. I learned a lot from this video. Thanks.

[@MarkClayMcGowan]

My pleasure! Here are links to a couple of "How Things Work" playlists. Enjoy, and share with your friends! kzbin.info/aero/PL6ge3RoxmyvqBUZL-pzdFNCD9ZwWeAxwA kzbin.info/aero/PL6ge3RoxmyvpcyRZPKJKl6W4l5IdiC-Ps

[@BoxcarJerry]

Very interesting video thanks for sharing it .

[@MarkClayMcGowan]

Glad you enjoyed it! Thanks for checking it out!

[@mikedavis7733]

Love these videos very educational for Model Railroaders

[@MarkClayMcGowan]

That's great. Never considered the information for modelers. Thanks for checking it out!

[@367cuba1]

I am guessing with 40 years under your belt in this field, you have also giving classes for the company you work for. You speak clearly and break things down like ABC which make it easy to understand and learn. Thank you, be safe and God Bless.

[@MarkClayMcGowan]

I never officially taught classes but did give many presentations in meetings and in the field. Thank you for the compliment. I don't know if you saw the videos I did on the tunnels but I'm doing a presentation based on them at the Tehachapi Depot Museum next week. Should be fun! Thanks for checking it out!

[@LouT1501]

Thank you for the look inside and explanation! The line I worked on (ex-SP line, spun off to a shortline) originally had simple draggers with rotating red lights that lit up if something hit the paddle. And the trains had to have a manned caboose. Story goes of a big derailment and the guy in the caboose swears that the dragger was dark. Managers highrail back to the dragger and it's still lit up. Guy who was in the caboose got 'promoted' to maintenance of way and the draggers very shortly were equipped with radios. I swear I was not involved in that...

[@MarkClayMcGowan]

Sounds like the Bart Simpson defense! LOL

[@PowerTrain611]

@@MarkClayMcGowan I didn't do it!

[@johnhansen6112]

Very interesting. Always wondered how the hot boxes were detected. You will see a car off by itself on a siding and now I know.

[@peteohm]

At one time in my career I was on southern Pacific owned rail detector which ran between Colton and Lordsburg on a 3 month cycle. The good old days!

[@MarkClayMcGowan]

They still run them regularly. Thanks for checking out my channel!

[@Mrruneight]

Thank You Mark for all the trouble you go to to make these videos. I know you don't have to do this but I'm sure glad you do!

[@MarkClayMcGowan]

I'm glad I did them. It can be so difficult to try and explain it in conversation. Thanks for checking it out!

[@railspike7057]

Does the UP have WILD detectors? Wheel Impact Load Detectors? For flat spots, out of round wheels and unbalanced loads or overloads? Any acoustic hot box detectors? Uses microphones to hear the defined sound of a bearing failing

[@MarkClayMcGowan]

Not around here, but that doesn't mean they don't

[@johnblair8146]

I believe those were invented by UP.

[@johnblair8146]

Back in the days of friction bearings on the Erie Lackawanna there were two items that were stocked in cabooses for dealing with hot boxes. One was "Texaco hot box coolant sticks" which were 1" square cross section sticks of very heavy grease about 7" long that came 3 to a box, IIRC and the other item was the company branded "Erie Lackawanna hot box fire extinguisher" These were 2"Dia. x 6" high cardboard tubes filled with baking soda. The extinguishers were used to put out any burning waste. As for the coolant sticks which were sort of like the Alemite sticks used on steam locomotives, they were used to lubricate hot journals until the car could be set out.

[@geac9100]

Great inside look that we'd never see otherwise.

[@MarkClayMcGowan]

My pleasure! I'm glad you enjoyed it and thanks for checking it out!

[@taavinen]

Really informative. Appreciate you putting in the time to explain the system 👍🏼

[@kaylynm4193]

Great video. I love hearing what things are and how things work. 😀

[@BBT609]

Great video! I always had an interest in DDs and how they worked. The DDs didn't talk until the early 1960s when the Seaboard Air Line invented the innovative talking defect detector. For the first time in history, crews could hear a readout of their train in the locomotive and caboose. They ran on a number of tape to play recordings in a sequence. The message took a bit long but yet innovative. For every number spoke out, it took 1 1/2 seconds for it to play. The speechless DDs many railroads had were of course as your mentioned large digital display number boards that flashed 000 is no defects were found but flash a number if one was accompanied with a light on the top or bottom of the board. Many were printed on stylus graph paper in interlocking towers or dispatcher offices where ever axles appeared as a spike on the graph. A high spike was a defect, hotbox or dragging equipment. The most common one was white lights, some railroads had white and red lights. A solid white was no defects, a flashing white light or a red light means something was wrong. At that time, youd have to go into the bungalow to identify your defects. The invention of SALs talking DD made way for other railroads to implement talking DDs thought not as fast until the late 1980s when it was more feasible to have that technology which has greatly improved. From systematic tape readouts to now microprocessors and computers, it's all interesting! Love the videos! Definitely subbed!

[@MarkClayMcGowan]

Thanks for the comment! It's always interesting to know how things have worked and changed over the years in different places! I'm glad I was around long enough to see modern signaling come into play. Thanks for checking out my channel!

[@leeroth5604]

I think it was early to mid 70's and saw the "big board" defective axle display system in action near Circleville, OH on the C&O. Rows of incandescent bulbs made up each of the numeric "7 segments", and there were 3 digits. The black display board was dark unless there was a passing train. A RR maintenance guy told me they would sometimes test the detectors with a lit cigarette.

[@ebnertra0004]

Erie Mining in northern MN had draggers that just had a light on top of the box, along with a radio transmitter that just beeped if something hit it

[@BobbytheBongoPlaya]

Nice video! 😊🐸 Like the history lesson and the in-depth tour! I like and appreciate videos like these lol. Very knowledgeable! 😀

[@geohig01]

Outstanding video - I learned a lot about a subject I thought I knew something about.

[@MarkClayMcGowan]

Thank you. I'm glad I was able to explain it without complicating it. Thanks for checking it out!

[@garyfiber3525]

I was the HBD technician for some of the N&W / N&S railway in the 1980's. We had Servo 7707D, Servo Model 87 retrofits on the 7707D detectors, GE HB290 and GE HB 300 detectors, and 2 GRS detectors. Some were upgraded to Servo 9909 during my time. All were read out of strip chart recorders using ink as the recording on a paper strip chart read out in millimeters. My position was abolished and i was replaced by 2 BoRS electronic technicians, as my job was ending we were just starting to install what we called track side Analyzers made by Ensun corp. We paralled them with the Servo 7707D detectors. Only saw one "working" we had it installed at Casad, In which was an incoming yard detector for Ft Wayne, IN from Fostoria, OH. WE saw a train over it and the analyzer said the train was traveling at 657 MPh and was over 100,000 feet long. We had a very big laugh, obviously we had a few false triggers from the wheel detector circuits. We consolidated a few dispatchers offices during my time on the railway and used Allen/Bradley PLC 2/30 industrial Programmable Logic Controllers (PLC) to switch the analog output of the many detectors into a limited amount of strip chart recorders. In Ft Wayne, In we had over 20 detectors coming into 10 strip chart recorders. The PLC would switch the recorders in sequence, we even included a switch we could cycle through the recorders to take one off line for paper change and ink service. Most of our detectors at the time was over wayside pole line on the signals code line. Spent time chasing low signal levels, using a Selective Voltmeter for dB levels made by Harmon Industries, we also used Harmon Industries Line overlay carrier for our detectors at the time.

[@garyfiber3525]

I forgot to say I was the technician on 45 Hot Box detectors in parts of 5 states. I was a regional technician. My railway title was General Inspector - Signals , an ARASA position, that was to get the salary up as at the time i was almost never home. Thanks Mark for a nice series.

[@tomy6917]

Hello Gary, I had one tower that used a Gould brand ink chart recorder & my other towers used a huge bulky Sanborn brand chart recorder (it said "Hot Box Detective" on the sides with a Private Eye holding a magnifying glass) that used thermal pens & back in 1983 those "pens" were $125 each. 3 thermal pens per recorder were used, one for each rail & the 3rd was used for "the event marker" to show the axle that had alarmed. Tower operators had to count by hand all of the "pips" (lines drawn for each axle) & our rules were the train crew had to check 2 additional axles on each side of the "alarmed axle" in case a counting error was made by the Tower Operator. Back then, we also used Harmon brand transmitters & receivers to send the data to the towers. All of wires were in underground cables (Amtrak NEC territory) with center core telephone pairs we used to transmit the HBD data from the field to the tower. The Harmon Frequency Selective Voltmeter was another instrument we had, too. Take care :)

[@bali2516]

@@garyfiber3525 Gary, do you have anymore information on the Trackside Analyzers? Was it the talker component that was made by Ensun?

[@peterwise9900]

Thanks so much for this video. Well enjoyed. Have a background in Safety Systems, and always happy to learn more.

[@MarkClayMcGowan]

Thank you! I'm always happy to know I've informed someone about new stuff! Thanks for checking it out!

[@MikeInPlano]

Mark, how accurate is the axle number provided by one of these detectors when it advises of a problem? What about the accuracy of total axle count of the train when it provides that?

[@MarkClayMcGowan]

They're dead on. They give the problem axle and total axle when there's no problem and also give time, temp and speed. There are some that only talk if there's a problem.

[@markschroeder2578]

They do give an opening message (railroad reporting marks [initials] "detector, milepost [nearest tenth of a mile]") just to say "I'm working". At least the ones around San Antonio Texas do. Stay safe and healthy.

[@WhereAreTheTrains]

An interesting use for a charcoal lighter! :-) Thanks for the information!

[@stocktonrails9279]

Thanks for this video, really enjoyed it! Question: What happens if a detector is completely offline and no longer reporting- do you guys have a way of seeing that on the backend (via ping tests/health checks sent to the detector, etc)? Can detectors also report that they themselves have a defect?

[@elkhartgary9675]

Thanks for the video! Nice job!

[@michaelmorgan7893]

You're talking about the old "scoreboard detectors" where a revolving red light would come on above that scoreboard that would light up the number and an H to indicate a "hotbox". I hadn't seen them since around 1984, and they were about where you're standing now. Both SP and Santa Fe had those across Arizona and NM.

[@MarkWilliams-tb3ks]

Are there freight rail physical security requirements for houses and cases? Access control systems? Thx!

[@MarkClayMcGowan]

Other than they must be secured with locks requiring no less than specialized tools, not really. Most cabins are now equipped with "puck locks". They have two steel halves surrounding a heavy flat lock and are very difficult to overcome but the thieves still figure out ways to defeat them! Many locations in cities are now surrounded by heavy steel mesh fences and concertina wire. Thanks for checking it out!

[@markgiuliano8014]

Great video Mark. Learned a lot from it. However, how do the train crews determine if a journal is to hot to where the railcar has to be set out. Does the RR still use tempilstiks? Perhaps the conductor uses some type of handheld electronic device to determine the temp of the journal?

[@MarkClayMcGowan]

That I do not know but I will find out! Thanks for checking it out!

[@leeroth5604]

Guessing these days they carry the IR thermometer "gun" with appropriate temperature range. Squeeze trigger, point the LED laser spots to what you want to measure, check the readout. "Home grade" ones are about $25 these days.

[@jameswyatt1304]

You ought to see what we can detect with high-speed imaging on the wayside and on geometry cars nowadays, Mark. The systems aren't cheap, but if we're to keep injuries and disruptions down and the public's trust in our carrying hazmat, they are worth it, IMO. Seeing a small wheel crack at 60mph+ in all lighting, weather conditions, and across wheel types before we lose a load is quite a capability.

[@MarkClayMcGowan]

I rode on one from Stockton to Bakersfield a few years ago. It was pretty impressive!

[@valentinehemmer7521]

Can they detect a flange height of 25/16 or a flange thickness of 12/16? I doubt it.

[@lmenestrina]

High Tech! Very informative! Thanks!

[@MegaJohnhammond]

my sister in law set off the wide detector

[@PowerTrain611]

A lot of older EMD locomotives have a hotbox detector built into the bearing housing on the axle - if the axle got to hot, it would essentially set off a stinkbomb!

[@MarkClayMcGowan]

Eewww! I did not know that!

[@annahogsett3967]

thank you - always wondered how those worked!!

[@tomy6917]

Excellent video, Mark, thank you. Is that a Southern Technologies HBD system? Also, I had noticed track wires near the scanners, are you using an audio frequency overlay (AFO) system for the HBD's advance start, since you hadn't pointed out any advance start transducers in your video? Do you follow a 3 month schedule for HBD calibrations? I had maintained HBD's on Amtrak's Northeast Corridor when I was promoted in 1983 (I'm now retired). Back then, we had DD sites that still used the older Servo Model 7707 HBD systems that had ballast mounted scanners and vacuum tubes & even a vacuum tube was inside the scanners for the infra-red sensor's ciruitry. Next, we had advanced to Servo's model 8808 with rail mounted scanners & transducers that were clamped to the rails instead of having to drill holes thru the web of the rail. We also had a hybrid system, the Servo 7708, where the 7707 equipment rack remained the same & the big boxy ballast mounted scanners were replaced with the 8808's more modern & rail mounted HBD scanners. The problem with the older 7707 ballast mounted scanners would be missed or inaccurated infra-red samples due to track pumping (time to get the Tamper machine to the site). The Servo corporation had patented the rail mounted HBD scanner technology. Later, the Harmon Corporation had bought Servo and their latest & greatest HBD was the Cyberscan 2000 (I didn't like it). Then, Harmon sold their HBD rights to GE & then later Progress Rail bought the rights (their HBD systems we liked).

[@MarkClayMcGowan]

To be honest, I don't remember whose those were. We used an overlay to turn on the scanners but the transducers are right at the location. Calibration is an annual item.

[@tomy6917]

@@MarkClayMcGowan Thank you, Mark :)

[@mikedavis7733]

Amazing how a human mind created such equipment

[@MarkClayMcGowan]

A better mind than mine for sure!

[@raylouis]

In switching yards. Do they light fires on the switches to keep them working?

[@MarkClayMcGowan]

In colder climates. It doesn't get that cold at any of the yards in California!

[@SETX_Sirens_and_Rail_02]

So I've heard that wayside detectors are usually placed anywhere from 20-30 miles apart but that it's usually railroad preference. About how far apart are UP detectors placed?

[@MarkClayMcGowan]

Draggers are about every two to five miles (usually at intermediate signals), hot boxes every 10, AEI about every 20-25 miles. Thanks for checking it out!

[@SETX_Sirens_and_Rail_02]

I did actually find a dragger nearby at an intermediate. I still never hear it on the scanner

[@MarkClayMcGowan]

@@SETX_Sirens_and_Rail_02 they only talk if there's a problem

[@SETX_Sirens_and_Rail_02]

I didn't know if it they just came on and said "No defects" if there weren't any issues

[@ronnebinger9133]

Really unique to see this. Explains alot.

[@pacset2]

Very cool Thanks Mark Make it a safe day

[@MarkClayMcGowan]

I'm glad you enjoyed it. Now I just need to be safe shooting videos without having to tolerate mindless job briefings!Thanks for the comment and for checking out my channel!

[@Samanthareneeheart1]

Ok now with the crossing gates why do the high rail trucks /vehicles (i.e. . Section gang, weldeing gang, signal matainer trucks, road master & track inspector vehicle) not triger them? I have seen it countless times. Is it they are not heavy enough or they travel faster then the impulse? Pr is it the ruber tires?

[@MarkClayMcGowan]

Hy-rails have shunts that can be lifted from the rails from the cab. By rule they cannot count on the gates to protect them at crossings. In areas where there are multiple adjoining crossings they are required to raise the shunts while running and wait for traffic to clear before proceeding. In any case they are required to stop and clear even if the gates are down.

[@Samanthareneeheart1]

@@MarkClayMcGowan thanks Mark that explains a lot

[@markschroeder2578]

I remember reading a Denver & Rio Grande Western VP of signal practices saying that on-track equipment had to shunt detection circuits continually or not at all. Intermittent shunts drive the circuits crazy. Trains with their weight will shunt continually, but lighter weight equipment is usually insulated from the detection circuits. This is usually why hi-rail vehicles approach every grade crossing prepared to stop for motor vehicle traffic because without special shunt circuits they will not activate crossing signals. And not many people will expect to see a pickup or SUV driving down a railroad track, in spite of the headlights (and if equipped, a strobe light) on, so SAFETY FIRST. Stay safe and healthy.

[@kens.3729]

Very Interesting Info. Thank you! 👍

[@epacm50]

The UP guys shut down the outcome results of the detector(unless there was a defect found). Our detectors will announce the outcome followed by the end announcement("out"). Our detectors must have three types of detection.

[@MarkClayMcGowan]

Some of the UP detectors announce all trains. It was decided on joint track not to do so.

[@peteohm]

Are they still running UP owned detector cars?

[@MarkClayMcGowan]

Yes but they also have a contracted company whose name I can't recall right now.

[@valentinehemmer7521]

Can you do a video of track department gauging frog depth and any other rail equipment that may be hit by high flanges. Thanks.

[@MarkClayMcGowan]

The track inspectors are responsible for checking the frogs, and I don't recall having seen them doing it since I retired. Should I see one out there while I am filming, I'll then try to catch the welders doing buildups/repairs, but I don't often see that happening either. Other than at diamonds or transducers at wayside detectors, there isn't much to be affected by flanges, and rail is generally replaced long before that becomes an issue. Thanks for the idea, and for checking it out!

[@richardsmith4187]

Another great video !!

[@MarkClayMcGowan]

Glad you enjoyed it and thanks for checking it out!

[@grvolans]

How do detectors "open the mikes" of the radios to broadcast the message? Is it tone activated?

[@MarkClayMcGowan]

Detectors are connected to radios inside the cabin. Some are programmed to talk on train, others are talk on defect only. In either case, when a train or defect is detected, the radio is activated automatically and the information transmitted on the road channel. The message will generally talk over any other communication on the channel. I hope that helps.

[@EyeOnVenture]

Wow. Just saw this oldie but goodie and that was cool info.

[@MarkClayMcGowan]

Glad you enjoyed it! I have many more on how things work!

[@JoeG-firehousewhiskey]

this is great information, thanks for the video

[@MarkClayMcGowan]

Awesome! I'm glad you enjoyed it and especially that you found it informational, which was my hope in making it. Thanks for subscribing and for the comment! Merry Christmas!

[@55tmilam]

I have a CSX mainline that borders my property, there is a detector close by and I want to get a scanner and listen to it

[@MarkClayMcGowan]

The frequencies should be on record. I know many railfans who use them.

[@malcolmmarzo2461]

Your opinion on the East Palestine disaster would be a good topic. An ex-signal guy has shown detector cabling laid out on the ground rather than being buried. And detectors 20 miles apart.

[@MarkClayMcGowan]

Cabling not being buried for short periods of time is not uncommon and would likely have no effect on the operation of the equipment it served, whether a detector or other apparatus. I'm doing an opinion piece on it, but it will shed zero light on what happened, because until the investigation is complete, anything anyone has to say about it is speculation.

[@malcolmmarzo2461]

@@MarkClayMcGowan The cabling shown on the East Palestine section shows a sloppy safety culture. The railroad does not want the expense of properly installed work. Like train crews, maintenance of way crews are being pressured to do more with less. Independent journalists are doing the real investigations because the so-called regulatory agencies don't work for the public. The last three years have amply demonstrated this.

[@DAVISM-i4y]

In late 70s early 80s either Southern Railroad or Illinois Central had hotbox detectors that triggered a paper tape graph in headquarters. Someone in the office had to scan the graph, notice the peak being higher than normal, look at its neighboring peaks -- 4 high in a row could be a roller bearing car that ran hotter in normal service than a plain journal car -- and then count the peaks to determine the axle count to radio the engineer. Perhaps this was in addition to the local display of axle counts or prior to local display being implemented. When the Southern ran steam locomotives in the 1980s a special instruction in the timetable allowed engineers at their discretion to ignore hot box warnings that they thought were triggered by the locomotive.

[@MarkClayMcGowan]

at SP, we just turned our detectors off in advance of the 4449 or 3751 coming though.

[@rickygonzalez3152]

For anyone wondering, this detector is located at MP 364.3 on the UP Mojave Subdivision in Tehachapi, CA

[@MarkClayMcGowan]

There are two locations shown here. 364 and 377. The high/wide detectors have been removed from service. Thanks for checking it out!

[@markhayes6407]

Technology abound. Great information. Like the video

[@MarkClayMcGowan]

Thank you. I'm glad you enjoyed it. Thanks for checking out my channel!

[@oldmaninthemirror]

Why do the dragging equipment detectors have what appear to be hand written numbers on them ?

[@MarkClayMcGowan]

So they're replaced in the same place they were taken off. The outside two are a different width than the others. If I recall correctly, the inside ones are the same, but maybe the gang who did it just wanted to make it easy. Thanks for checking it out!

[@kdubb288]

With RFID being a thing on all North American rail cars, do you see a day where "defect near axle # [ ]" becomes a thing of the past? Given the ability to fetch and exchange high speed data in modern times, seems like maybe the detector could immediately fetch the data (owner, identification, car number, stock type, cargo within, etc.) from central office based on the RFID that the scanner simultaneously reads. A conductor having to "count axles" on a stopped train to establish what car has the problem seems so prehistoric. (Or does the train's manifest have all that data already, so he knows what car to look for?) I can't imagine having to walk 3/4 mile along a train in 5 degree winter to count up to axle number 219 if a "stop train" order was issued.

[@MarkClayMcGowan]

I don't know what's coming down the technology pike but if it makes economic sense and will do the job more easily the railroads will do it. No matter though, someone has to physically look at the car in question and yes, the computer manifest identifies the car. The AEI system checks the train about every 50 miles. Thanks for checking it out!

[@gdrriley420]

seaboard on the east coast had speaking detectors in the early 60s. interesting to know SP took so long to get them

[@donalfinn4205]

Good stuff.

[@hj-mr5gg]

these videos are going the be gold in 50 years when the railroad doesnt use any of this

[@MarkClayMcGowan]

I wish I'd had the foresight to capture the older equipment on film! Thanks for checking it out!

[@CurtisMechling]

@@MarkClayMcGowan Same here. so much over the years I wished I captured. I had the opportunity, but missed it, to document when we were retiring a bunch of old US&S 5xx Code system units for CSX. This was probably the oldest equipment I've ever seen still in service. It was a few year phased project where first phase left the relay interlockings and we interfaced the existing field units w/ the newer packets switches to get rid of the pole lines. Then came back a few years later and slowly upgraded to microprocessor-based.

[@derail14]

i recall on conrail when i hired on they had a device called a loose wheel detector at a few locations--LWD it was a series of metal fins on the inside of both rails and a bit off set you could only go 10 mph over those things any faster would trip them off, thankfully they did not last too long they took them all out, to many delays going at 10 mph. they were wired to the next signal that would drop to stop when you tripped one of them and many times the crew could not even find the loose wheel.

[@MarkClayMcGowan]

Cool info. I'd never heard of them. Sounds like I'm glad we never had them! Thanks for checking it out!

[@davidschoonover5171]

I was in telecommunications for almost 40 years and at huts along the railroad lines. This series is so informative thank you for sharing these aspects of your business

[@MarkClayMcGowan]

My pleasure!

[@harps1974]

I heard one CN detector here in Canada, with an axle 577 instead of 576 or 578

[@MarkClayMcGowan]

Perhaps single axle articulated flats.

[@rickvia8435]

Local dragging equipment/ hot box detector 160.905 Mhz: "NORFOLK SOUTHERN MILEPOST 1-5 POINT 5 - NO DEFECTS".

[@kimfeilgood]

current ER in Ohio with vinyl chloride control release ...guess wayside not enough?

[@MarkClayMcGowan]

Although the cause has yet to be determined, I read they are looking into a possible broken axle on one of the cars. There are no wayside detectors that will warn of that. Axles and wheels are inspected at regular intervals at what are called "one spot" car facilities at most major yards. Wayside detectors will spot hot journals, hot wheels, dragging equipment, and in some cases, high and/or wide loads. Thanks for checking it out!

[@kimfeilgood]

@@MarkClayMcGowan thank you. I lived close to a track and there was a syrup derailment that I got lucky on in downtown Arlington TX

[@jimdoyle6065]

There is a picture of an old caboose era Canadian Pacific numeric display scanner half way down the page in the link that follows. I believe that if a fault was found, the numeric display would start counting up from zero for each subsequent axle that passed after the first fault was found. The conductor in the caboose would notify the crew of the results after passing the display. 000 meant no faults. The lights above and below had different meanings. I believe the center low light would flash indicating that the detector was working. The top left and right lights would indicate the side of the train a fault was on. The other two I am not sure about. www.trainweb.org/oldtimetrains/CPR_Trenton/History_changes.htm

[@DougGrinbergs]

4:48 equipment room interior

[@RailfanNetwork]

Excellent!!

[@MarkClayMcGowan]

Many thanks!

[@clfhnt]

well done!!

[@barrybickle7992]

How does it work in snow country?

[@MarkClayMcGowan]

The equipment is heated but many times it is overwhelmed and they will have maintainers on duty 24/7 to keep them clear. Check out my playlist called "Just Trains" for a video I shot on just such a storm watch at night!

[@grado142]

why does you hard hat has written on it former signal maintance foreman just wondering?

[@MarkClayMcGowan]

I was a maintenance foreman for 22 years. With nine months until retirement they cut my job so I bumped a maintainer rather than another foreman with the new extended territories. I did a video on my thoughts about it.

[@grado142]

@@MarkClayMcGowan okay, I was just wondering. I seen written on your hard hat it was written former. Your videos are very interesting to view. They are very infomative for someone that has never seen or been around equipment like you work with. It is an enjoyable videow to watch. Who would of thought it takes all that type of equipment that could be controlled from great distances and tell what the train is doing from a far.

[@djjamar]

I live near here. Hundreds of trains a day. And wind wind

[@SOU6900]

I thought you were Steve Austin for a second to begin with...😅

[@sceu25]

Austin 3:16

[@ef66kenken]

👍👍👍👍👍👍👍👍

[@ooglek]

Charcoal starters are your test equipment??? Ouch. Seems like there might be a better, more predictable way to test the hotbox detectors. You can't know how hot the charcoal starters are, so if the hotbox is reporting 50-100ºF below the actual temperature, a train might continue in an unsafe situation with a hotbox failure!

[@MarkClayMcGowan]

The detectors are very high tech, and are calibrated regularly with very high tech equipment. They either work, or they don't. The equipment knows when things aren't working correctly and if certain parameters are exceed, one way or another, the location will announce an integrity failure, and the crew will have to stop the train and inspect it. The starters are simply to ensure the equipment sees the difference in temperature, not to test to any specific temperature. Thanks for checking it out

[@ooglek]

@@MarkClayMcGowan Thanks Mark! The scary thing is when "they don't" work, and they just announce that it is broken, or remains silent, rather than reporting the issues. How does central operations find out when a Defect Detector is not working correctly, and what is the amount of time it might be left inoperative before operations can get out there to repair it? The other challenge that I can see is related to the Ohio derailment. The bearings or wheelbox temperatures were reported, as an offset to the current ambient temperature. If the only test mechanism that you have is electric charcoal starters, then it is possible that the detector could be reporting an inaccurate temperature, either low or high, which then could cause a train to stop when it doesn't need to, or cause a train to continue when it should absolutely stop. For example, I think I read that above 170ºF reported the train needs to stop. Let's say Ambient temp is 60ºF, the actual wheel temp is 180ºF (10ºF above the threshold where the train needs to stop), but the Defect Detector reports 80ºF (which plus ambient would be 140ºF), which is below the threshold. Or maybe the threshold is 170ºF above ambient, so the Defect Detector reports 150ºF when the actual temperature is 180ºF, which means the train doesn't stop, but it is actually unsafe. That's why the fact that these detectors are not tested with calibrated test equipment regularly, beyond the charcoal starter, is scary!

[@MarkClayMcGowan]

Any time the detector isn't working correctly, the "integrity failure" announcement goes out on the Road Channel for that area. The train stops and reports it to the dispatcher, who reports it to signal ops, who dispatch a maintainer or tech to look into the problem. Once a failure occurs, there are multiple actions crews may take based on train type and dispatcher instructions. Those range from stopping and inspecting the entire train (which is not generally what happens), slowing to restricted speed, or depending on train type, continuing to next defect detector at maximum authorized speed, which is usually 20 miles. If I remember correctly, the temp above ambient to fire off a HBD is 250 degrees, but there is another parameter that measures the difference between each journal on each axle. I don't know what that difference is. The ignitor gets hotter than 250, so it is plenty hot to do the job. If the system tries to fire at a lower temp, or doesn't fire t a higher temp, it will cause an integrity failure. As I said, these systems know when something is not right and will simply fail. We've been using this testing system for decades, and nothing has ever gone wrong. In Ohio, the detectors did just what they were programmed to do. The NTSB, FRA and NS have already said that, nd those numbers don't lie.

[@ooglek]

@@MarkClayMcGowan Awesome detail, thank you! Could we agree that the "integrity failure" announcement could be missed at any one of the relay points? 1. If the engineer did not receive the message, due to a signal issue or radio issue 2. If the engineer "forgot" or failed to report to the dispatcher 3. If the dispatcher failed to relay/document the problem for the maintainer/tech 4. The tech/maintainer did not have the proper equipment to ensure that the HBD is reading the correct temperature (e.g. the axle or wheel is 300ºF but the HBD reports that as 180ºF) If the Defect Detector is not properly calibrated, it could be saying everything is fine when it is not, which is why it surprises me that the only calibration tool used is an electric charcoal starter, where the actual temperature of the resistive element is unknown. Charcoal starters can take 15-20 minutes to get to max temp. If the HBD triggers on a Charcoal Starter at 150ºF and says 300ºF, a LOT of trains are going to be stopped needlessly. If the opposite, a LOT of trains may be in danger and nobody knows it. The sensors in the system are only relaying what they measure. The sensors do not know if they are calibrated, and the sensor is the single thing that is measuring the temperature. If it is not accurate, there is no way the Defect Detector could or would know, because there isn't a 2nd temperature sensor to compare the first measurement against, AFAIK. Nothing has ever gone wrong? I'd argue that the Ohio derailment went wrong, and there are probably many other situations where a defect detector failed to catch an issue that caused a failure. And don't forget about all the times where things have gone wrong and nobody knew it, because the defect detector said everything was fine, even if it might not have been. If you put a thermometer in your mouth, and it says 107ºF or 76ºF, and you aren't mostly dead, you might realize that your thermometer might not be accurate. There is no 100% accurate sensor. All NIST standards are checked against many other things to ensure that the measuring tools are as accurate as possible, and they do these calibrations often (daily even). The US DOT / FRA guide on "Implementation for Wayside Detector Systems" assumes a +/- 10% margin of error for some measurements! How do you KNOW (not assume, but actually test) that your HBD temperature sensor is accurate within +/- 10% if you don't test it? railroads.dot.gov/sites/fra.dot.gov/files/fra_net/18667/Wayside%20Detector%20Implementation%20Guide.pdf This 2020 Research into Wayside hot-box detectors (HBDs) found that "HBDs tend to underestimate the temperatures of bearings in field service operation" -- exactly what I'm trying to say. > Generally, wayside HBDs tend to underestimate the temperatures of bearings in field service operation, which is not surprising given the simple one-point calibration procedure that is used to calibrate these devices. Underpredicted temperatures can have disastrous consequences, especially if a defective bearing goes undetected by a wayside HBD. The latter has occurred on numerous occasions in the past two decades in the U.S. and Canada and has resulted in catastrophic derailments. "Nothing has ever gone wrong" seems like some important data points are missing in your picture of the railroad industry! www.utrgv.edu/railwaysafety/_files/documents/research/mechanical/ijrt_wayside-hbd-investigation.pdf

[@MarkClayMcGowan]

I dealt with the realities of railroading in my corner of the world. You are speaking in hypotheticals and a whole lot of IFs. Railroads utilize failsafe systems. It's the best they can do. I keep telling people I only speak for MY corner of the world. Maybe you have time to deep dive into everything that has ever gone wrong on every road in North America, but I don't. I deal in the absolutes I spent 40 years dealing with.

[@georgew.5639]

I wish the media talking heads would shut up and watch videos like this. I’m sick and tired of their disinformation about anything they think they are reporting about.

[@MarkClayMcGowan]

I have my thoughts about the Ohio issue coming up tomorrow in which I talk about just that.

[@lmsubman243]

...just like on a toy railroad! oNLy biggerer!!

[@NorthernChev]

So, I just watched a different Hot Wheel Detector video and they said the opposite boxes were for each duty. They said the hot wheel detector was the one on the right and the hot bearing detector was the one on the left.

[@misterexponential]

Very interesting information that I’ll never use in this lifetime. Your lilty hi-lo voice pitch is a bit extreme to be subscribing to.

[@MarkClayMcGowan]

You should hear it since covid left me with a paralyzed vocal cord. You wouldn't even click on my stuff!