[SystemSafety] Tram Accident in Croydon

[Mike Ellims]

"unless the operator operates the equipment correctly, all the protective
systems in the world will not help".

 

1.       Driver says he blacked out, if so he was therefore was not
operating the equipment. It is of course possible that he had an epileptic
fit or similar i.e. just froze for a few seconds, I assume that it is
possible for this to exist undiagnosed.

2.       If there were *adequate* safety systems then it shouldn't have
mattered if the driver blacked out, or whatever; as they would presumably be
designed to override an over speed condition. My understand (which could be
wrong) is that's the sort of things safety systems are supposed to do...

3.       Peter has noted that the trams were equipped with a dead man's
handle, if so it doesn't seem to have been adequate in that it did not
prevent the accident. If that is the case then we could expect a number of
similar systems will need to revaluated. It's also  possible that the dead
man's handle was activated to too late to be effective.

 

Blaming the driver is possibly simplistic and what Reason terms the "the
person model" which he notes is "deeply rooted in folk psychology". One
possibility (i.e. I'm speculating)  is that at a system level the time table
was too tight i.e. if there was a delay or even a series of very minor
delays and the drivers were expected to make up time then there exists a
situation where the drivers have an incentive go as fast as possible for as
long as possible to avoid potential penalties or sanctions.

 

 

 

From: systemsafety
[mailto:systemsafety-bounces at lists.techfak.uni-bielefeld.de] On Behalf Of
Andrew Banks
Sent: 17 November 2016 08:34
To: dick at ntcom.co.uk; systemsafety at lists.techfak.uni-bielefeld.de
Subject: Re: [SystemSafety] Tram Accident in Croydon

 

>> 
>> Quote from train driver's union:
>> 
>> Aslef, the train drivers' union, said it was "clear that the lack of
adequate safety systems were at the root of this dreadful accident".
>> 
 
I guess the ASLEF spokesman is unlikely to admit "This accident was clearly
caused by our member being incapable of driving the tram within the speed
limit" and will try and pass the buck.
 
The investigation is in its early days yet, and we can talk all we like
about system issues, but unless the operator operates the equipment
correctly, all the protective systems in the world will not help!
 
Andrew


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