[SystemSafety] Tram Accident in Croydon

Fri Nov 18 15:22:53 CET 2016

Many thanks Dick,

A link to an interesting initial status report.

I agree with comments that we should always be looking to maximise safety
and minimise the need for human intervention to provide safety.

However we also need to be aware of the operational requirements of the
society in which we live and the commercial realities of transport systems
such as the Croydon Tramlink. I recall that when the Docklands Light Railway
first opened in the late '80s, its passenger stock had bus/tram doors that
swept across the carriage floor on the inside. This was corrected with the
replacement stock in 1992 given that the passenger loading levels were
higher than originally planned for. Different rail systems achieve a
tolerable level of safety in different ways in alignment with their size,
speed, passenger numbers etc. Tram systems are a case in point; much of
their running is open to the public and road vehicles. The creators/managers
of a tram system will have produced their budgets on the basis of tram
safety, not mainline or high-density metropolitan railway safety. What I
would assume, subject to the alternative coming out, is that the Croyden
Tramlink follows the standard UK safety practice for tram operations on the
basis that the Railway Inspectorate will have approved their operation (and
HMRI is not known for approving poor systems).

It may be that safety improvements in the provision of "Tram" services will
be required following the inquiry but these should be well thought through
not knee jerk.

My understanding of driver competence is that drivers are required to know
the route to a level that includes knowing just what the speed limit is and
where it starts even if the sign has gone missing. There are also small
points such as: we should be able to assume that the speed limit was signed
in the same units as the tram speedometer. I would hope that the inquiry
also looks at whether the tram was behind schedule and the driver under
pressure to recover that schedule - management causes.

If we want to be non-pragmatic then we should take motor vehicles off the
road - the reason that the derailment is news is that it is unusual. Modern
society needs tolerably safe transport and the task before the engineering
community is to provide the systems that society needs at a tolerable level
of safety.

Robin Cook

From: systemsafety
[mailto:systemsafety-bounces at lists.techfak.uni-bielefeld.de] On Behalf Of
Dick Selwood
Sent: 16 November 2016 16:26
To: systemsafety at lists.techfak.uni-bielefeld.de
Subject: Re: [SystemSafety] Tram Accident in Croydon

This is the press release from RAIN and it links to the interim report

https://www.gov.uk/government/news/interim-report-fatal-tram-accident-croydo
n

On 16/11/2016 15:45, Andreoli, Kevin (UK) wrote:

Train was doing 43.5mph in 12mph zone.

See: http://www.bbc.co.uk/news/uk-england-38003934 

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".

District organiser Finn Brennan said a system to make sure trams travelling
too quickly in a potentially dangerous area can be slowed down and stopped
should be put in place, as on the mainline railway and London Underground. 

"If it had been then this awful event could have been avoided," he said.

Kevin
--
Usual disclaimers.

-----Original Message-----
From: systemsafety
[mailto:systemsafety-bounces at lists.techfak.uni-bielefeld.de] On Behalf Of
Peter Bishop
Sent: 11 November 2016 09:39
To: systemsafety at lists.techfak.uni-bielefeld.de
<mailto:systemsafety at lists.techfak.uni-bielefeld.de> 
Subject: Re: [SystemSafety] Tram Accident in Croydon

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Re 12 mph / 20 kph limit

Could this be an issue of the wrong speed units?
I.e. driver thinks the limit is 20*mph*?

Peter Bishop

On 10/11/2016 11:45, Peter Bernard Ladkin wrote:

On 2016-11-10 09:36 , Andreoli, Kevin (UK) wrote:

I suspect the reason rail type safety is apparently not installed 
will be down to the thinking that Trams are Buses on rails and not Tram =
Train. .....

The engineering involved will all have been by professional light-rail 
people well acquainted with the hazards of rail operation, of which 
overspeed in a changing track configuration is a very well known one, 
as is driver incapacity. I don't expect any comment on this list from 
UK rail engineers, but I wouldn't be surprised if at least one person
reading this is thinking "you know, we did say......"

The trams themselves are (first batch) Bombardier Flexity Swift CR4000 
sets built in Vienna. They apparently do have a "deadmans's handle" 
https://en.wikipedia.org/wiki/Bombardier_CR4000

The second batch are Stadler Variobahn sets 
https://en.wikipedia.org/wiki/Variobahn Stadler The Variobahn is a 
Bombardier design (originally called Variotram), manufacture of which was
taken over by Stadler in 2001 (according to the Wikipedia page).

I wrote:

It is the first fatal accident on UK rail/tram lines in 12 years,

This is not so. It is maybe the first one in that time not involving 
system-external agency (even that is questionable - see 2016.08.07 
below). The Wikipedia page on TfL Tramlink
https://en.wikipedia.org/wiki/Tramlink says:

On 7 September 2008, a bus on route 468 travelled through a red 
traffic signal and collided with tram
2534 in George Street, Croydon. The impact caused the death of a 
passenger who was reported to have been thrown through the upper front
window of the bus.......

On 13 September 2008, tram 2530 collided with a cyclist at Morden 
Hall Park footpath crossing between Morden Road and Phipps Bridge tram
stops. The cyclist sustained injuries from which he later died.

And I read on the RAIB WWW site of four other fatal accidents in 2016 
alone 
https://www.gov.uk/government/publications/raib-current-investigations
-register/rail-accident-investigation-branch-current-investigations

2016.02.23 a pedestrian was struck by a train on a pedestrian level 
crossing
2016.08.07 a passenger on a train struck his head on a signal gantry
2016.08.15 a pedestrian was struck by a tram
2016.10.05 a mobility-scooter user was struck at a level crossing

I also said:

The corner is apparently posted at 12 mph = 19 kph

I took that figure from the newspaper report. The RAIB says it is 
posted at 20km/h 
https://www.gov.uk/government/news/fatal-tram-accident-in-croydon

PBL

Prof. Peter Bernard Ladkin, Bielefeld, Germany MoreInCommon Je suis 
Charlie
Tel+msg +49 (0)521 880 7319  www.rvs-bi.de <http://www.rvs-bi.de> 

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