In article ,
Tom Anderson wrote:

I think a whizzy high-tech moving block system can avoid these problems,
though; the system would (or should) have a battery of redundant sensors
and communications links, so it can keep accurate tabs on every train at
all times.

Until they fail or give contradictory results, in which case you have ...
a red signal (or in-cab equivalent) that trains must not cross !
Just like boltar2003[*] is whinging about.

Nick[*] isn't he a couple of years behind the times now ?
--
http://www.leverton.org/ ... So express yourself