On 16/11/16 23:13, Michael R N Dolbear wrote:

"MB" wrote

It's too easy just to check you can see a picture from the camera and
assume it is recording.

Which is why there needs to be a system in place to check at some
regular interval that they are recording and that the recordings are
archived properly with that being logged.

The interim report says
Initial analysis of the tram’s OTDR indicates that some braking was
applied in the 180 metres before the 20 km/h (12.5 mph) speed
restriction board, but this was only sufficient to reduce the tram’s
speed from 80 km/h (50 mph) to approximately 70 km/h (43.5 mph) by the
time the tram passed the board and entered the curve on which the
accident occurred.
==
And
The RAIB’s ongoing investigation will include consideration of:
{. . .}
l any previous over-speeding incidents at Sandilands Junction;
==

Does this mean that trams' OTDR (and CCTV) data are archived so, eg,
any report of possible over-speeding can be checked against real data
on this and on normal running?http://www.bbc.co.uk/news/uk-england-38003934

The OTDR may not be downloaded regularly for review but providing the
units retain enough data I would expect that some, if not all, have been
downloaded to examine driving habits before this accident.