Thank's Bob2 for the most appreciated UDE explanation.


Dr Zarkoff Wrote:
-------------------------------------------------------
> > Thanks, I was interested in this dynamiter
> thing; never had such a thing on our Government
> Railway(they may nowadays?).
>
> If NZR, by whatever today's name is, uses ABDX-NE
> control valves, there can be no dynamiters because
> the ABDX-NE has no vent valve in its emergency
> portion.
I(we) was never instructed on Car&Wagon Brake components other than the Triplevalve and location of the Cut-out cocks. The older versions were AF triple's and Loco service be about locos and train handling.

> > Do you put it in Emergency and then Release, or
> do you just have to wait it out?
>
> Not sure what you're getting at here.

I was trying to reason a reset(such as with the Vigilance device(Alerter) penalty brake application if tripped.
So if you make a reduction, and the ude happens, would you not place the ABV handle into Emg and then Release? Once you'd brought the speed down to a D/B holding speed? I guess because the rules say you have to stop an walk, but you know you caused the ude by application, eh!
But the rules also say you must have control the train eh. Now we all know things get "bent" to suit, like running a dip, but in Bob2's example, if there was opposing traffic....


> >The signal clearance sequence sounds interesting;
>
>
> Is sounds to me like an effect of how far ahead
> the DS has cleared the A signals for the train.
Thanks, there wasn't anything like that here, unless one described the old Searchlights rotating through the sequence on clearing.

> > nothing like that here apart from a non-clearing
> indication(if you were over a certain speed) at
> the end of doubleline, just before a major
> downgrade, in my former area. was taht the reason
> for the odd clearing indication there, or was that
> standard everywhere?
>
> It also probably depended on whether the signal at
> the end of DT was automatically approach-cleared
> (which would be tied into a similar signal
> -govering in the opposite direction- at the other
> end of the single track section).
In this PukeruaBayCabRide video, the three Signals can be seen at Pukerua: from what I remember; the first is a Starting Signal, stop&stay always displaying Yellow. Next is a Directing stop&stay at Muri, showing Yellow over Green. Back in NZR days this was the timing section, staying at Yellow over Red if you were going too hard and the next signal is the Departure Signal stop&stay with the Medium speed reduction displayed at Green on the bottom. If you were not getting it stopped here, the Departure stays Red over Red, the Points don't reverse and you end up on the catch track. Good luck there Mate. This was going from Double-Track Automatics to Single-line CTC Automatics for the steep hill section South of Paekakariki(Sands of Iwo Jima fame).


> On the other hand, NZR probably followed UK signalling
> practices (i.e. speed signals) more than US ones.

We had both: Two position(both Semaphore and Colourlight) route signaling areas and Automatic three-position (Colourlight) speed signaling areas.

Thanks for your participation Dr.


Chris
in New Zealand