> 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.

> So, how do you correct it?

The only way to "correct dynamiter(s)" is to find the offending car(s) and set them out of the train.

> 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.

>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.

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