Coal Train Helpers

[Mookie]

We have tons, literally, of coal trains. They sometimes have an engine on the front and a helper at the rear.

My driver wants to know how the helper is controlled by the headend. Radio signals?

Jen

[wabash1]

yes they are controled by radio signals what ever the engineer does they do except for dynamic braking. if it was a radio train working from the middle of the train it work alittle differant. but the distributed power is used differantly.

[Mookie]

I will print this off and show him.

Thank you

Jen

PS - The old engineer said the same thing you did - he told his fireman that if someone ran in front of a train, not to go into emergency and flatten the wheels - just hit them and then go into emergency. Makes sense to me!

[CShaveRR]

Radio is correct...the name for these helpers nowadays is Distributed Power. Trains had an article on the workings of the various systems a year or so ago (might be longer than that... couldn't find it). Anyway, this trailing unit (and it doesn't have to be at the rear; it could be in the middle) can be independently controlled from the lead unit, or (usually) just do what the lead units do.

What's really neat is to stand somewhere that a DP train is coming out of a speed restriction (such as leaving the yard) and listining to the rear unit suddenly lean into the train--knowing that nobody's in there and the front end is controlling that, too.

If the next issue of Trains inspires you and your driver to come to the Chicago area, let us (spouse and I) know! We'll make a point of seeing that.

[wabash1]

i could argue with you on terms you used such as the distributed power not being at the rear. on the old southern we had radio trains mid-train power then they put it to the rear and called it distributed power. it operates differantly, but i still call it a radio train. in the same fasion you woould call a radio train distributed power.

[Mookie]

I always hear the end unit "Power Up" a notch as it goes by - it is just leaving the yards. That was what he heard and asked me - I said radio, but said I would ask. Now I can give him some details.

Let's see - I have down Houston, Rochelle & Chicago, maybe a trip to Michigan. We will have to take early retirement and tour the USA!

Thanx

Jen

[Jackflash]

Jen the locomotive on the rear or in thr middle of the train is controled by radio, with the brake pipe serving as back up in case of comm. failure, if a radio break occurs while the DP units are under power they will continue to load
for 90 minutes, if the engineer needs to knock them back to idle he can do so by making a brake
application, radio breaks are not common and
if they happen they do so usually at the same place each time such as a tunnel.

there are two methods to operate in DP
1 is synchronous mode where the remote locos.
do exactly what the lead engine is doing
power, brake, and dynamic brake in the same incerments that the lead loco is doing.
its like the engine is hooked up multiple unit.

2 is independent mode. where the engineer has
seperate control over the remote locos.
he can have the lead units in dynamic brake and
the remote units still in power, this is real good
for controling slack action when cresting a hill.
you can also throttle back the remote units, for instance, have the lead head end unit in run 6
and maybe have the remotes in run 2 or 3 or idle,
or they can be set for the same as the lead
the remote engines also feed the brake pipe, and
make brake reductions so stopping a train is faster, also releasing a brake application is faster too, you're adding air from both ends.
hope this helps Jen. jackflash

[Jackflash]

Jen the locomotive on the rear or in thr middle of the train is controled by radio, with the brake pipe serving as back up in case of comm. failure, if a radio break occurs while the DP units are under power they will continue to load
for 90 minutes, if the engineer needs to knock them back to idle he can do so by making a brake
application, radio breaks are not common and
if they happen they do so usually at the same place each time such as a tunnel.

there are two methods to operate in DP
1 is synchronous mode where the remote locos.
do exactly what the lead engine is doing
power, brake, and dynamic brake in the same incerments that the lead loco is doing.
its like the engine is hooked up multiple unit.

2 is independent mode. where the engineer has
seperate control over the remote locos.
he can have the lead units in dynamic brake and
the remote units still in power, this is real good
for controling slack action when cresting a hill.
you can also throttle back the remote units, for instance, have the lead head end unit in run 6
and maybe have the remotes in run 2 or 3 or idle,
or they can be set for the same as the lead
the remote engines also feed the brake pipe, and
make brake reductions so stopping a train is faster, also releasing a brake application is faster too, you're adding air from both ends.
hope this helps Jen. jackflash

[Jackflash]

Jen the locomotive on the rear or in thr middle of the train is controled by radio, with the brake pipe serving as back up in case of comm. failure, if a radio break occurs while the DP units are under power they will continue to load
for 90 minutes, if the engineer needs to knock them back to idle he can do so by making a brake
application, radio breaks are not common and
if they happen they do so usually at the same place each time such as a tunnel.

there are two methods to operate in DP
1 is synchronous mode where the remote locos.
do exactly what the lead engine is doing
power, brake, and dynamic brake in the same incerments that the lead loco is doing.
its like the engine is hooked up multiple unit.

2 is independent mode. where the engineer has
seperate control over the remote locos.
he can have the lead units in dynamic brake and
the remote units still in power, this is real good
for controling slack action when cresting a hill.
you can also throttle back the remote units, for instance, have the lead head end unit in run 6
and maybe have the remotes in run 2 or 3 or idle,
or they can be set for the same as the lead
the remote engines also feed the brake pipe, and
make brake reductions so stopping a train is faster, also releasing a brake application is faster too, you're adding air from both ends.
hope this helps Jen. jackflash

[Jackflash]

Sorry folks, I didnt mean to do that, my bad jackflash

[Mookie]

Jack - you answered his next question - what if you are going up a grade and down a grade at the same time - your 2nd part answers that!

He will be so pleased!

Thanx

Jen

[CShaveRR]

Thank you, Jackflash--this sounds like what the Trains article said, and covers it nicely.

[Jackflash]

J, I know what you speak of when you say radio trains, I realy dont know if there is a difference
,in this day and time electronics has been shrunk
down 10 fold from just a few years ago, remember
the "control cars" that use to have be coupled to the radio engines, well now you probably could pick up the "control equipment" and walk off the engine with it, its been shrunk that much.
the control software will allow more than one
distributed power locomotive in the train, some software versions will allow 4 engines (consists).
some versions will allow 6 engines (consists) to
be placed into a train , they can be anywhere in the train, one time I had to move a DP engine off
the tail end of the train and put it the third
engine in the head consist (for a total of three
engines at the head of the train) I just left that
engine in DP mode and didnt bother with the MU hoses and cable, just hooked up the walkway chains
If you do have more than one DP engines in the train such as if you had two, one engine in the middle and one engine on the rear, they dont have
to be in sync with each other, you could have the
head end in dynamic brake, the middle engine in
run 5 and the rear engine in run 8, what you CANT
DO though is have the head end in power and the
remote(s) in dynamic brake, probably pull it apart
or at the very least you would waste fuel, so the
software wont allow it, if the head end is in dynamic brake or in idle you can put the rear remotes in dynamic brake, if the remote(s) are in
synchronous mode they are going to follow the
throttle setting of the head end, dynamic brake too. jackflash

[Anonymous]

Can anyone tell me what frequency the transmitters operate at. Do they operate off a standard PL tone? Can someone tell me who makes the transmitter and receiver? Who maintains them?
Thanks
TIM A

[Jackflash]

The freq. is UHF about 457 Mhz I think, there are
two radios, one is a back up, they look like motorola mobile units (25 watts I suspect) I would
guess if you could hear the signal it would sound
like a paket signal (digital) I dont think there
is a true PL tone, when you link up to remotes
you dial in the lead unit number, during the linking process you enter the remotes number
(a digital handshake between those two and those
two alone)(sortta like an addressable TV box the
cable company gives you) hope this helps, jackflash