In the stream of the 6 January a new german system appeared aboard TSW 2: GNT. Does anyone know what it is and how works?
It allows tilting trains to travel faster through curves. To this end, it overrides PZB magnets if necessary and monitors your speed continuously - similar to LZB. As far as your input is concerned, you can imagine it as a simpler form of LZB. Brake for speed restrictions and a red G GNT light on the dash will warn you that you’re getting close to the required braking curve. You don‘t have any complicated procedure for the end like LZB does.
So, if this is a simpler LZB system, it means that when the red "G" appears i won't must press PZB acknowledge and that if the red "G" keeps lighting, the emergency brake will not be activeted, right?
From what I saw last night: G dimmed (not lit) - no upcoming speed restriction G lit steady - upcoming speed restriction, apply brakes G lit flashing - brakes applied to slow down for speed restriction If G remains steady when braking - you need to apply more brakes to meet the new speed limit
GNT isn't actually "like" LZB in the way it works, but from a driving point of view you can treat it like manual (no AFB) LZB: it has its own speed limits, it signals braking curves, and while it is in effect you don't have to acknowledge PZB above 70 km/h). Below 70, the system disengages and you are back under PZB rules.
I'm not entirely sure about that. I was just looking through the real manual on GNT and found these two passages interesting: (page 21 of the pdf / page 15 in the document) Suppressing the supervision of PZB in the case of permanent speed restrictions (page 25 of the pdf / page 19 of the document) The PZB supervision is active in the case of distant signals and main signals as well as temporary speed restrictions, these need to be acknowledged. Judging by the document, it seems like GNT suppresses the PZB magnets as long as it's not signal based - meaning you'd need to acknowledge signals like Vr 0, Vr 2, Ks 2, but not speed restrictions like an Lf 6. There's no mention of GNT disengaging based on speed. It would be nice if one of our experts could have a look at it.
This seems likely; it could be that along the modeled route there are no permanent limits 70 and below, and all of those are signalled. However, it's my understanding that the tilt mechanism, and thus presumably GNT, doesn't engage until the train is doing at least 70.