50 injured in German collision

[philthetube]

The ultimate source is the rule book itself, in this case module 408.2456, section 4:
The relevant bits from paragraph (1) and (4) are:
(1) The maximum permissible speed of a train movement on special orders is 40 km/h. [...] At block signals on the plain line - junctions and crossovers excepted -, this speed restriction applies until the front of the train has passed the signal.
(4) When a train passes a signal showing danger/a defective signal that is

• a colour light main signal with an unlit colour light distant signal (the arrangement used for Hv-type signals)
  
• a main signal capable of exhibiting a "caution" aspect (i.e. the German equivalent of a British three aspect signal, found with Hl and Ks-type signals, as well as the experimental Sk signals)

the driver must observe a maximum speed of 40 km/h until being able to recognise the aspect displayed by the next main signal or 2000 m have passed, whichever is shorter.

Ergo after passing a plain two aspect block signal, no further speed restrictions apply.

I must admit that I am struggling to follow some of this, one thing confusing me is the highlighted instruction, I would have thought that the block signalled would be at least a stopping distance forward of the signal, which could be a couple of miles if a high speed lime also used by freight. If I read this correctly then a failed train could be found a corner and a following train accelerating into it.

 

[edwin_m]

I must admit that I am struggling to follow some of this, one thing confusing me is the highlighted instruction, I would have thought that the block signalled would be at least a stopping distance forward of the signal, which could be a couple of miles if a high speed lime also used by freight. If I read this correctly then a failed train could be found a corner and a following train accelerating into it.

I haven't followed the detail either but I think it is exactly that issue that is a source of concern!

 

[Jan]

I must admit that I am struggling to follow some of this, one thing confusing me is the highlighted instruction, I would have thought that the block signalled would be at least a stopping distance forward of the signal, which could be a couple of miles if a high speed lime also used by freight. If I read this correctly then a failed train could be found a corner and a following train accelerating into it.

Paragraph (1) is basically there to deal with the fact that when passing a signal at danger, no speed signalling information is available and conveniently 40 km/h is the speed allowed by the smallest regularly employed points geometry. Where the speed is lower after all (e.g. for bay platforms, which are generally limited to 30 km/h, or some exceptional track geometry, or ...), either this speed is already noted in the driver's working timetable if it's a scheduled occurrence, or else the signaller needs to inform the driver when issuing the order to pass the signal at danger. For block signals that aren't protecting a junction or a crossover this is irrelevant, hence the speed applies only while actually passing the signal (and as I said the PZB trainstop override is only working up to that speed as well).

When the signaller can't ascertain that the section really is clear, the driver must be cautioned to drive on sight when passing through the affected section, which is handled separately in some other regulation.

 

[43096]

But of course a Tail Lamp is vital when a train running behind is under caution possibly looking for the back of the train ahead !

The tail lamp is, effectively, the last line of defence against a collision.