I was wondering how the DOT device hooks on to the last car. Does it hook into the coupler, or to the car itself. What is meant by arming it? I heard one the other day making a whining sould as the last car went by - what causes this?
thanks,
marshall
Well the newer devices hook to the air hose, and they are held by the coupler.
Arming it basically means turning it on. They are battery powered and a friend of mine that used to work for Conrail used to complain that they went dead before the train reached its destination because they used cheap batteries. In addition to the flashing light facing back, it also transmits brake line pressure (reason it’s connected to the brake line) and motion sensor output (to tell if the back end of the train is moving or not) to the engineer. Some do more, but not sure what or which railroads use them.
The EOT hooks into a pocket on the coupler. Arming it is more than just turning it on, its setting up communication so that the engineer can dump the air from the hind end.
The whining sound was an air powered EOT that uses brake pipe pressure to turn a turbine to power the marker instead of using a battery.
I was just going to suggest that someone should find a way to use the train movement or air to generate the electricity needed for that. Guess I’m a day late and 2 cents short. [2c] Thanks for the info. Interesting.
eots, grumble…replace cabooses, consarn boxes…
As at least one has mentioned, arming an EOT means setting up communication between the cab and the EOT. This is done on a little “box” in the cab, where the four digit(I think) number found painted on the EOT is entered in. This works like programming in a Radio Frequency on a scanner, listening only to the EOT with that number.
Noah
Here is a head end device commonly called mary. the 5 thumbwheels at the right determine what fred it’s tied to.
Here is a Santa Fe one that is a combo head-end device and radio
Yes, and when the “fine” workers for CN have nothing better to do, they listen in and get your EOT number and dump your train on you. Hey, not my fault their company sold the DT&I from Diann south…
Ryan
lol…now that is fun to do if your trying to skin your friend that is called only a mins ahead of you…or you are a prankster and one of your buddies is on that train… lol
csx engineer
Interesting… I didn’t know there was a combo unit available. Who makes that?
Dave
-DPD Productions - Featuring the TrainTenna LP Gain RR Scanner Antenna-
http://eje.railfan.net/dpdp/
Sorry Dave, I don’t know who makes them.
we don’t use the HED feature of this radio.
So how do they do that? Do they have a data reader to decode the number? Does the headend device post a list of numbers within transmission range?
I’ve heard the conductor read the number to the engineer over the air… Wouldn’t be that hard to spot the number if it’s stencilled or otherwise plainly marked.
You can find an EOT with the HOT. Here is an excerpt from one of Al Krugs essays:
Another use for these buttons is to find the I.D. number of an unknown Fred. By pressing and holding both the Test button and the counter button the combination of the counter display and the pressure display will show the I.D. number of the last Fred transmission this Mary has recieved. By repeatedly doing this you might be able to find your own Fred number before the carman radios it to you. Or you can find the Fred number of a train ahead of you on the road. This is handy. If he is stopped ahead of you and it is 3am you can search and find his Fred. Then dial it into YOUR Mary. Now YOUR Mary monitors HIS Fred. Take a nap. When he finally releases his air or starts to move, your Mary will beep at you waking you up. Now you can re-dial in your own Fred and continue. This is another feature that the modern computerized locos with their built in software Marys don’t have. (Yes your Mary is still armed to your Fred when you return).
They would do it if we gave the EOT number to the engineer over the radio. I no long give it over the radio, I just walk the air slip to the head head before going to the rear.
Thanks Ryan, I did not read your first post to mean it was spoken by a crewmember over the radio. I took it as though they were decoding the data stream on the EOT frequency. Another case of an engineer thinking too high up the ladder and missing the obvious.
The newer generation air turbines are a pain in the butt to work with and are not as reliable as the battery units.