"Tim Bray" wrote in message
.. .
Neillw001 wrote:
Excuse my ignorance, but why in the 21st Century are saftey-critical
devices on one of the most heavily-used urban metro systems in the
World reliant on a bit of string?

Maybe you are the kind of person who would fit a complex, unknown system
to a train saying `Its the latest hi-tech system`, it is what you need,
string is so 18th century?

If a piece of string works, then what is the problem?

Isn't the reason that the trains aren't running because the bit of string
DOESN'T work?

--
Brian