What does that mean?
With that term, the locomotive engineer is reporting to the rest of the train crew that the brakes have been set and the reverser lever has been “centered”-moved to the neutral position. It tells the crew that it is safe to move between cars to hook up air hoses, center couplers, turn air valves or perform any other work between, at the ends or under cars.
So, the use of the term is part of the protocol for radio communication between the engineer and other crew members on one part of the safety rules.
Brakes are “set”
Reverser is “centered”
Some railroads like CP and us use 3 point protection which in addition to the above…the generator field is turned off
“Set and centered” is the same thing as “three point protection”. The third “point” is communication that the first two have been done.
Obviously im not going to disagree with you, as you are a proffessional rail, but here 3 point means 1. Brakes 2. Reverser 3. Generator Field.
I asked the “3-point” question years ago in the “Ask Trains” column. As I recall, it was: 1) air brakes applied; 2) reverser centered; 3) generator field disabled (or off).
Now maybe I’m thinking too much like driving a car or truck, but shouldn’t the throttle position be part of this as well ? I realize that technically it doesn’t matter if the reverser is centered (= transmission in “Neutral”) - the loco isn’t going in either direciton, and if the generator field is off it can’t generate any power to move itself with the traction motors (no easy automotive analogy, other than being another version of Neutral - the engine can run all it wants, but no power will be transmitted into the drive train to move the wheels). But still, I’d be a little uncomfortable going between the cars on the basis of “3-point protection” from a loco thats 20 cars away and out of sight around a curve roaring away in the “Run 4” throttle position. As a practical matter, I suppose that never happens unless the air is being pumped (I understand there’s a special setting for that, which won’t move the loco), and these days the Road Foreman of Engines would get on the engineer’s case for wasting fuel if that would ever happen. But maybe it should technically also be that the throttle is in “Idle” position, so it’s “4-point protection” ?
I just know this is going to come back to haunt me sometime . . . [:-^]
- Paul North.
Three step (per NORAC) or three point protection is sufficient. If the generator field is off and the reverser is centered, it doesn’t matter where the throttle is set. In fact, the engineer may advance the throttle in order to more rapidly charge the trainline (for engine driven compressors).
A key point that everyone has missed here is that three step must be specifically requested by a crew member. The engineer acknowledges that crew member specifically, and only that crew member may cancel his/her own three step.
I’ve had times when the engineer has anticipated my request (such as when we’re setting up to do the standard series of moves for a runaround) and has already applied three step before I request it. If there are no moves to be made immediately (say, I have to go between cars to check a connection for the PA system but we aren’t doing any moves) he/she may not actually take the three step down when I’m in the clear and request that three step be cancelled or “taken down.”
I’ve also had times when I forgot to release my own three step and thus had the engineer patiently wait for me to do so before moving.
Something I was curious about, though, and had a chance to ask about first hand last summer, was how it was handled for steam engines.
Some simply blue flag the train, especially those operations that rarely have call to go between cars.
The other answer I got was that in steam circles they use “four step” - IIRC:&nb
Throttle could be in 8, but if the genny field is off and your reverser is centered, nothing is gonna happen.
Larry -
Do you remember the Trains article about the late E-L / early Conrail / NJ Transit commuter passenger operations in North Jersey, with the GE U34CH’s (if I remember right ?) Like yours, the engineer was - properly - a stickler for procedure, and that train wouldn’t move until the proper signal was provided. I recall that there was a delay of some kind, which everyone was wondering about, and it came to a head when the engineer said over the PA system, "Somebody give me ‘two’ and we can go ! - which then immediately happened. [“Drawbar flagging” [:I] I think the author called it.]
I too was wondering about the relationship between the traditional “blue flag” protection and the “3-point” or “set & centered” version. I suppose one could describe the latter as a “short-term” or very temporary blue flag, or blue flag “light”, because the intent and a lot of the rules are the same.
Finally, thanks for saving my dignity with the steam engine reply ! The cylinder cocks are analogous to the generator field switch on a diesel - all that energy (in whatever form) isn’t going anyplace then where it could c
Paul - Doesn’t ring a bell (pun intended).
Not quite sure I’d go so far as to refer to three step as blue flag “light” - but it’s an apt comparison. The chief difference is that if I blue flag a train it’s me and me alone. Three step is a team effort which provides protection for the worker ‘on the fly,’ if you will.
same with cp
I remember hearing that some of the modern locos have the option of a four point, though I don’;t recall what that was? Or am I losing it? Also redundant to the generator et al, but still another piece to try and keep the train where it should be.
Merely opening the cylinder cocks on a steam locomotive won’t prevent motion. It is standard operating procedure to open the cylinder cocks of a standing engine prior to starting and to leave them open until after the locomotive has moved for a sufficient distance to expel all condensation from the cylinders and prevent any more condensation from collecting there where it might cause a hydraulic ramming effect that would destroy the cylinder head or piston.
If the locomotive is sitting, opening the cylinder cocks will prevent any steam that leaks around the throttle valve (which frequently didn’t seal completely) from causing the locomotive to move. If the cylinder cocks were left closed, even a bit of leakage could eventually cause the locomotive move with considerable tractive effort, albeit slowly.