Some time ago, probably in Model RR magazine they talked about "Constant
Lighting" for locomotives or even passenger cars. Anyone know how to do it?
Is there a kit of some kind or whatever? Even the style were the lights are
one even when not moving or parked.
Also I've noticed in my "B" units there are usually portholes. In normal use
would there have been any light showing from these "window" portholes?
There are a number of answers of varying complexity:
- DCC does the job automatically by applying 15-18 volts AC to the rails full
- A diode bridge in the motor circuit will provide 1.5 volts for head and tail
lights on DC powered locos.
- three extra diodes will provide directional lighting.
- Coaches and unpowered vehicles can have a reasonably simple capacitor and
voltage regulator circuit for (say) 6 volt bulbs.
The problem there is that more amperage has to be supplied to provide the
wattage at the lower voltage and some track voltage must be lost as heat.
- If your controller uses PWM (12 volts chopped to give the effect of lower
voltages) then a diode and capacitor in each vehicle will provide full voltage.
- I use either 12 or 15 volts PWM as above plus a zener and transistor to switch
coach lighting on and off. (12 volts off/15 volts on)
- High frequency AC superimposed on DC traction current.
DC motors have too much impedence to be affected by high frequency AC but light
bulbs don't mind at all.
A choke is required to block the AC from the controller and a capacitor in
series with a bulb will block DC traction current.
Most published circuits are near the top of the audible range, due to the
limitations of older transistors, but frequencies up to 30khz are quite
practical today. (drive the dog/cockroaches crazy!)
I doubt if A or B units would show light from the portholes normally.
The light can be on in the cab, but there is a door between there and the
machine room/engine room. That room, with the portholes, would have lights with
an on/off switch. The driver should have no reason to be in the machine room
while in motion unless he is confronted with an inevitable head-on collision.
Greg Procter wrote:
> The light can be on in the cab, but there is a door between there and
> the machine room/engine room. That room, with the portholes, would
> have lights with an on/off switch. The driver should have no reason
> to be in the machine room while in motion unless he is confronted
> with an inevitable head-on collision.
There are a number of *very* good reasons to be in the engine room of an
F-unit or other carbody diesels whilst the loco is in motion, none of
them connected with an imminent collision.
As one example, FTs had manually-operated radiator shutters in the
intake ducts, which could only be operated from inside the engine room.
The also had local control panels in the engine rooms, which included
alarms for low lubricating oil pressure, hot engine, wheel slip and hot
journals. These required periodic inspection by the fireman while running.
AFAIK more modern F-units had automatic radiator shutters, but the local
control panels remained much the same. At any rate, it was common
practice on US railroads, and elsewhere, for the fireman to go back and
check on the condition of the units while running.
Also, any carbody diesel with steam generators for train heating would
require the fireman to go into the engine rooms while running to
One other reason to go into the engine room while running - on carbody
units that's where the toilet was.
I can only guess that you rode in F units in the very late 70s or early 80s. Long
after they were gone from any kind of regular service on the nation's rail
They must have been rebuilt or refurbished machines like the MBTA F units that
rebuilt from GM&O F3s; the so-called F-10s. Federal law had mandated chemical
by that time, which could have been installed in the nose compartment. None of
units I ever rode in on several different railroads, had anything other than the
hopper that I described in another post. Every one of them was in the back
the loco. We were very Spartan in my day. If you wanted some water to drink,
better bring it with you, and so it was for almost everything.
More like the mid 60's and later. "F" units were in decline, but still
in service lots of places. It was certainly BEFORE holding tanks or
chemical toilets were common on the passenger cars (post Amtrak's
And, Yes, the F-units were certainly spartan by modern standards.
As regards the toilet, even the F-unit hopper was pretty civilized
compared to a steam loco ... THERE, you just used the coal scoop, and
heaved the waste into the firebox! Like I said, even the early Diesels
were a LOT more creature friendly than the steamers.
But also keep in mind that in the steam era, over much of the country,
there was NO indoor plumbing. Everyone used outhouses, or just 'the
bushes' as needed. It was a different time, with different standards of
It was on the engineer's side in the rear corner of the unit. E units had the
"hopper" as it was so euphemistically called crammed in among the train boiler
equipment. If you had to "use it" you found another way if you could.
Remember Peteski, the thing was a dry hopper. It was literally nothing but
galvanized steel, sheet metal cone, with the big end up, kinda like a funnel.
was something that was reminiscent of a toilet seat on the top of it, and the
end was a hole in the floor; that's right, just a hole in the floor, nothing more
than an outhouse on wheels. There was no partition, no door, no
You just plonked your butt down on the thing and did the necessary right in
anybody else that might be in there, or come wandering through.
Rather primitive, I always thought. Not only that, but you had better remember to
bring your own "accessories" or you would find yourself up s * * t creek without
paddle, so to speak.
In short, they were miserable and disgusting, and were relegated to use only in
direst of emergencies, which of course only made them even worse.
Road switcher type locomotives had the appliance in the short end, if they had
all, which some did not.
That sounds nasty! Actually, when I used to travel on Polish Railways
in the 70s, those had a slimilar toilets in the pass. cars. When you
"flushed", it opened up and you could see the roadbed moving under you.
Of course, there were signs which stated not to use the facilities
when stopped at the station...
When I used to walk the tracks, I sometimes came upon "gifts" left by
Ah, those were the days...
Maybe I was thinking of the more modern diesels (like F40PH).
That sounds about right for the very early units. Most of the "F" units
I was in had some form of chemical toilet (porta-pottie) in the nose.
It likely varied from railroad to railroad. This was even before many
passenger cars often had such. All the early passenger cars just had a
'hopper' for a toilet too, and this persisted on some cars into the
first Amtrak years.
I recall seeing passenger car trucks COVERED in human waste and toilet
It must have made working on the underneath running gear a real joy! I
suppose a good steam-cleaning would get rid of most of it. And, how
about the track and roadbed?
Different times, different values.
Sort of true, though routine running maintenance on the mechanism was
possible on the "covered wagon" carbodies, and was not uncommon. Also,
it was not at all uncommon for crew to pass through the units as needed.
On passenger trains the front doors on the "A" units allowed for direct
access to the train.
Thus the interior lights (quite dim) might well be on at times while the
train was moving .. not to mention just fogetting to turn them off.
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