Colin Rosenstiel wrote:
In article ,
() wrote:

"Richard J." wrote in message
m...

The answer is that the line is fitted with TPWS as well as the
LUL trainstop system. At each signal, there is a TPWS loop and a
trainstop.

I thought there might be something like that. I'm also guessing
that it would be illegal to have tracks not equipped with some sort
of redundant saftey system in potential revenue service.

I thought TPWS was installed on a risk-of-SPADs basis, so not on all
stretches of all passengers lines?

That is correct, in fact a number of TPWS installations are being removed as
some overkill occured during the original fitting.

Paul

In article ,
(Paul Scott) wrote:

Colin Rosenstiel wrote:
In article ,
() wrote:

"Richard J." wrote in message
m...

The answer is that the line is fitted with TPWS as well as the
LUL trainstop system. At each signal, there is a TPWS loop and a
trainstop.

I thought there might be something like that. I'm also guessing
that it would be illegal to have tracks not equipped with some sort
of redundant saftey system in potential revenue service.

I thought TPWS was installed on a risk-of-SPADs basis, so not on all
stretches of all passengers lines?

That is correct, in fact a number of TPWS installations are being
removed as some overkill occured during the original fitting.

Does that mean that AWS is then counted as the redundant safety system?
Or is even that not necessary? After all, not all lines have AWS.

--
Colin Rosenstiel

"Colin Rosenstiel" wrote in message
l.co.uk...

Does that mean that AWS is then counted as the redundant safety system?

How doe we understand the term redundant? I understand it to mean that
something to back up the human factor in operating safety if that fails.

Or is even that not necessary? After all, not all lines have AWS.

Where are there areas that are not equipped with AWS?

In article ,
() wrote:

"Colin Rosenstiel" wrote in message
l.co.uk...

Does that mean that AWS is then counted as the redundant safety
system?

How doe we understand the term redundant? I understand it to mean
that something to back up the human factor in operating safety if
that fails.

Or is even that not necessary? After all, not all lines have AWS.

Where are there areas that are not equipped with AWS?

Not many in London I expect, but it is not universal.

--
Colin Rosenstiel

"Colin Rosenstiel" wrote in message
l.co.uk...
In article ,
(Paul Scott) wrote:


That is correct, in fact a number of TPWS installations are being
removed as some overkill occured during the original fitting.

Does that mean that AWS is then counted as the redundant safety system?
Or is even that not necessary? After all, not all lines have AWS.

IIRC they are mostly TPWS overspeed warnings associated with speed
restrictions rather than signals.

Paul

"Paul Scott" wrote in message
...

That is correct, in fact a number of TPWS installations are being removed
as some overkill occured during the original fitting.

They will nonetheless remain at terminals, will they not?