Why do railroads need special radios?

[BJ_NORTON]

Just looking through the forums today, and I saw the newest post here was about photos of clean cab radios. Just wondering why the engine's need a special radio. Seems like any commercial radio should work, and if it's noisy maybe a nice powered speaker would help.

I've never really listened to rail comms, but I think tonight I'll give it a try

 

[n5ims]

The power supply is different as well as some of the other specifications. They have specific channel assignments (with specific frequencies and PL tones, if any, assigned to those channels). Also the mounting and connectors are standardized to allow a fairly quick and easy swap when necessary. While the spec indicates use of the standardized mounting & connections, not everyone will use the standardized specs, of course.

This link can help explain the specifics --> Railroad Spectra

 

[pb_lonny]

Thanks for the information, very interesting reading.

 

[IrvingtonVFD43]

Not to mention, cab radios are also subject to vibration, wide temperature ranges, weather, etc., especially in older locomotives.

Specifications, such as channel selectivity (co-channel interference) ,sensitivity plays a big part too, especially the selectivity, as locomotives may operate in railyards with lots of radio activity happening over several frequencies, some close to the frequency the train crew is communicating on.

 

[burner50]

Just looking through the forums today, and I saw the newest post here was about photos of clean cab radios. Just wondering why the engine's need a special radio. Seems like any commercial radio should work, and if it's noisy maybe a nice powered speaker would help.

I've never really listened to rail comms, but I think tonight I'll give it a try

Because, we're special.

But locomotives are pretty much the only thing that gets a special radio.

As others have stated, there is a wide range of reasons for this, some having to do with tradition, some with functionality.

First, tradition: we still use engines and parts from as far back as the 1960s. And the radio is a mission critical piece of equipment. The railroads would not put up with proprietary mounting solutions... so really, even the tradition part is more about functionality.

Next, the way we use the radio is different. The radios are passed around from railroad to railroad and back again, so they have to work on a standard channel plan... to complicate things, many places use repeaters in and around yards. There is more combinations than there are memories of a modern radio. Our locomotive radios allow us to independently select our transmit and receive frequencies. Next, we have the physical way we operate... an engineer only has two hands, and often times they're both busy. A locomotive cab can be a busy place. An engineer can't hang on to a corded microphone while making constant throttle and brake adjustments, so he has a PTT button on the front panel of the radio. This enables him to easily use the radio without having to keep track of a microphone. Beyond that, most systems on a locomotive were designed to run on 74 volts... and as stated earlier, we still use ancient engines, so the modern equipment has to be interchangeable with the old engines. Also, our radios have extra microphone and speaker connections for other positions in the cab or for equipment that must operate on our voice channel such as the Man down feature on remote controlled locomotives.

Now we come down to durability. Cab radios are inserted, removed, dropped,thrown, kicked, and any other number of things that a modern mobile radio just won't put up with.

Once you add it all up, a standard mobile radio just won't cut it in the cab of a locomotive.

 

[jchappy]

Why is it called a "clean cab" radio? I've noticed that this term is not exclusive to Motorola.

 

[zz0468]

It's a Federal Railroad Administration term pertaining to locomotive cabs, and pertains to the human engineering aspect of the cab with an eye toward safety of the train crew and operational standards.

 

[imbruski]

Clean Cab Radio

I can remember when Motorola MoTracs were mounted to the side on the control stand with control head mounted to the radio. Banged head, shins, elbows and other body parts on the radio. That is part of the "clean cab" story.

 

[abbadabbado]

special radios ????? does any one remember the viberating mack trucks an cb radios that you had to reverse the polarity black would be hot red would be ground. i dont buy all the info on train cab engines. we hauld coal on dirt temperary roads cb radios viberated shook an ate dust every day still the cheapest cb stood the test of time safety facter was as bad as or almost as bad as trains these new systems is just a bunch of GOV BS so some gov connected contracted can encrease there greed livel just so you know WIFE in the 80s was a train engineer. she says the new reg is just BS she run for chesapeak an ohio to clinchfield in eastern ky to dante va now retired in florida. the freak show state does anyone remember the c/o kitten on there engines cars an cabooses

 

[burner50]

special radios ????? does any one remember the viberating mack trucks an cb radios that you had to reverse the polarity black would be hot red would be ground. i dont buy all the info on train cab engines. we hauld coal on dirt temperary roads cb radios viberated shook an ate dust every day still the cheapest cb stood the test of time safety facter was as bad as or almost as bad as trains these new systems is just a bunch of GOV BS so some gov connected contracted can encrease there greed livel just so you know WIFE in the 80s was a train engineer. she says the new reg is just BS she run for chesapeak an ohio to clinchfield in eastern ky to dante va now retired in florida. the freak show state does anyone remember the c/o kitten on there engines cars an cabooses

Okay, so older radios were rugged...


That doesn't change the main problem of the way we operate with them now.

With the standard plan we have now of 90 channels, there is 8,100 different combinations possible. In the near future when splinter channels start becoming possible there will be 180 channels with 32,400 possible combinations. In the area I work, we use simplex channels and nine different conventional repeaters.

Let me know when you find a modern mobile radio that has 32,400 memories available.

As far as the safety aspect, what exactly do you "not buy"? The hands free part? The standard mounting equipment? Please explain. Aside from being rugged,your CB back in the day had nothing that we would find of value in the cab of a locomotive.


Here is a typical day for me... start out on 26 to talk to the service track to find my power. Then go to 53-76 to talk to the bowl. Then to 44 to talk to the car department during an air test. Then to 19 to talk to another yard master, over to 42 to get a warrant to depart north, then to 78 to talk to the terminal dispatcher when ready. Then back to 53-76 for departure coordination while leaving the bowl, back to 78 after leaving the bowl while still in the terminal, then to 42 when we get out of the terminal. Next we need to talk to the BNSF to get a light at their inter locker, then back to 42.

And this is just at one yard.

 

[Jimru]

Hey guys,

So "clean cab" refers literally to keeping the locomotive cab clear of cables, etc. for safety reasons?

I've been all over Google and Bing trying to find the meaning of that term!

In light of this definition, wouldn't ANY radio installation have the same requirement? In aircraft cockpits, you certainly don't see cables all over the place, so that would be "clean cockpit"?

I just am scratching my head why something so self-evident needs a special classification in the railroad industry, when other transportation industries have the same safety need, yet no one seems to "require" it.

Just sayin'....

 

[AK9R]

"Clean Cab" may have just been a marketing term that Motorola made up like Private Line or Astro 25.

There are a bunch of photos of railroad radios in their natural habitat posted on DPD Productions' web site at:

DPD Productions - Railroad Gallery

One thing you may notice is that all of the radios are the same form factor whether they are made by GE, Motorola, or someone else. This makes it very easy for locomotive service people to swap out a defective radio. The radios are all the same size and shape, they all mount in the same hole in the console or in a box mounted on top of the control stand. And the connections on the back of the radio are all the same.

The bottom line is that the railroads have set the standards for their radios and they expect the manufacturers to conform to those standards in order to maintain interchangeability with their existing equipment. Motorola did it for years with their Clean Cab Spectra, but they got out of the market. GE is doing it with their 12R. Ritron and Kenwood are getting on the bandwagon. They may be taking one of their existing mobile radios and adapting it to the railroad specifications, but, to railroaders, they are all "Clean Cab" radios.

 

[burner50]

to railroaders, they are all "Clean Cab" radios.

For clarity, to railroaders, they are just radios...


Well, we do have different classifications of radio I guess...

Some radios are "Radios", and some of them (JEM) are "Junk".

 

[Jimru]

Thanks for the clarification. I have wondering about this for a good while!

Best,
Jim

 

[tomfassett]

One other aspect of railroad radios versus radios used by other forms of transportation is this; When I drove a truck, if my CB or company radio went out I could still operate safely (and I did have a few peter out on me due to the heat and dust of the desert). With a train, if your radio goes out you are in BIG trouble if you have shared work authority in the same block as another train. Stopping a truck in an emergency is a lot easier and less dangerous than putting a mile long train of tank cars into emergency. The ruggedness/reliability of railroad radios is not only dictated by the railroads, but also by the AAR and the NTSB (formerly by the ICC). This is a public safety issue and every precaution is taken to ensure that connections are not only standardized but as fool proof as possible as the radios are not only subjected to a harsh environment, but to constant removal and reinstallation. If you want to know how specific the safety requirements for railroad radios are, talk to someone who works for a railroad in the radio shop. The complete set of manuals are as big as the Los Angeles phone book. Why? To prevent a miscommunication that might cause a fully loaded LNG train from plowing into a train full of Anhydrous Ammonia cars in the middle of Chicago because of a radio failure. Railroad radios are just as complicated and as important as radios in that 747 landing at your local airport--for good reason...

Tom F

 

[Jimru]

These are some of the nicest, clearest cab shots I have seen anywhere! It has really illustrated the concept for me.

One question I have, slightly off topic, is this: if so much precaution is taken as to not have dangling wires in the cab, why are the controls for the train itself designed to stick out like that?

Seems to me that in a short stop, they could "put an eye out", as my Mom used to admonish me when I would run with a stick or something. Seriously, the controls also look like they could be easily moved by mistake. Wouldn't it make more sense to have had them designed in such a way as to not protrude in such a manner?

Again, great illustrations and thanks for the link. I'm traveling Amtrak today, on the NEC, from NYP to BOS. Will be monitoring all the way! I have always loved trains, but I am new to being a "rail fan". Even got my subscription to Trains mag a few months ago.

 

[radioman2001]

Most 2 way radio's use 12 volts DC, train cars have anything from 36 to 72 volts DC or even 110 volts AC, derived from 600 volts up to 13K, this then requires special switching power supplies to isolate the radio from the trains power source.
Clean Cab radios are for the most part locomotives only, but years ago you would find CC style radio's on revenue cars also, since they could easily be removed and relocated to another car. NYC Transit had about 2000 custom Motorola or GE radios (Motorola 1964 ish to 1986, and GE 1986 to ?) but over 6000 cars (now 8400+ cars), requiring the switching of radios daily. The engineer was actually issued a radio at the beginning of his shift, but now the days of doing that are over, The FRA now requires radios in all cars and locomotives whether they are being driven or occupied by an engineer or not. On our revenue cars we have a combination of GE Trans R12II, with an old AAR compliant control head, or GE Orion Mobile radios, some with dual head control, M-7100's, and now for the retro fitting of our older cars with radios that wouldn't narrow band (Mitreks) the M-7300 of which the Orion, M7100 and M7300 are actually controlled by cab control heads for TX/RX audio. There is no mobile mic or speaker.
Motorola made many custom radio packages from Motorola Motrac's,Motran's,Micor's,Syntors, and Spectra's, all with custom power supplies, and connections. The ones on the Motrac's and Motrans were really interesting, in that they had an oversize power supply, more power transistors mounted on the side rails and the AAR connector instead of the standard Motrac connector. I was able to salvage 2 of them that were meant for destruction.

 

[K4DHR]

It isn't uncommon to see standard commercial radios in short line locomotives. Unlike class 1 roads, most short lines may use one or two frequencies at most, some don't even use standard AAR frequencies.

 

[tomfassett]

Motorola made many custom radio packages from Motorola Motrac's,Motran's,Micor's,Syntors, and Spectra's, all with custom power supplies, and connections. The ones on the Motrac's and Motrans were really interesting, in that they had an oversize power supply, more power transistors mounted on the side rails and the AAR connector instead of the standard Motrac connector. I was able to salvage 2 of them that were meant for destruction.

Way to go! Just don't give your address to any railroad museums... ;- )

Tom F

 

[RadioGuy1951]

Controls

To the question of clean cabs & things that "stick out"...

Safe easy and predictable access is the short answer for the clean cab...

If you sit in your car with your eyes closed, you can still reach out and find all the important stuff (besides the wheel) like gear shift and headlight switch, right...??? It's because these are easy to find and you've memorized their locations...no matter if the knobs are pointy things or receased, or flat...

Modern cabs are almost like a desk, and the horn is activated by a button, not a lanyard, and if you bump into it not much harm done...kinda like when cars starting having recessed knobs & handles before airbags were invented...sharp pointy knobs made injuries worse...so they were replaces by non pointy knobs and switches


In an older loco cab, 3 things I **DO** want easily found are Throttle, Brakes, and whistle (horn)...reverser, bells, sander, transition switch are not quite as important...and the reason I didn't include reverser handle is because, it normally shound be changed only when at a dead stop...but the brakes are the most important, and there's TWO brake handles: Main (train) and Independant (Loco only)...and IF somehow I get injured by smacking into them, then I'm already doing something wrong and am probably in deep doo doo, and the brake and throttle handles will be the least of my concern (as in doing a Casey Jones)...


No matter what type loco cab I'm in, I need to be able to put my hand on the throttle or brake without looking, because my eyeballs might be busy looking elsewhere...whether a loco is a "clean cab" is secondary to me...