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2015 Q5 Describe an accident
#1
DAP Module 1 Q5
 
You chose the Clapham accident; at the exam review the comment was made that almost everyone did and I think the examiners would have been more impressed if a candidate had offered something different as it indicates a wider knowledge.  Having said that, it was a good choice as it provides a rich seam of material.  However there are other major ones such as Severn Tunnel and Colwich that undoubtedly would qualify and a host of more minor ones.
 
Actually the situation at Clapham was the offending wire was not removed from one end but left live and the other end was removed, not cut back and was insulated only by reused green tape which subsequently fell off and the wire sprung back to rest intermittently against the relay terminal on which it had previously been terminated.  The actual work when this changeover happened was two weekends prior to the Monday of the accident; however there had been other work in the same relay room the day prior which presumably had subtly altered things as the shelf relays were probably disturbed slightly to facilitate further work for subsequent stages.  Hence whereas in concept the description was reasonable, it wasn’t entirely accurate.
Whilst accepting that you need to keep it brief, it would have been worth explaining that ironically the reason why the first train was stationary was that its driver had stopped to report to the signaller the irregular behaviour of a signal. It would seem that he was disbelieved and it was whilst the driver was returning to his cab that he heard the crash and his own train jolted forward as a result of the impact.  There was very nearly a 4th train ploughing into the rear of the 2nd train; the signaller had no means of replacing auto signals to protect the incident nor radio communication with drivers.   
 
 
It was good to distinguish between immediate cause, root causes and causal factors.
Again the descriptions gave broadly the right idea but we're not all 100% accurate; one of the factors was that the design was actually staged but one element had not been possible previously and was being combined into the weekend’s work to catch up programme as there was no spare weekend in the period up to the commissioning.  No such thing as correlation was done in those days and there was a general acceptance that the situation on site might be slightly different to that depicted and there was tacit acceptance that the installers could interpret the design in the context of what they discovered and implement slightly differently (nowadays we might call this “non-conceptual” design).  Although your answer did hint at the long hours culture, it did not mention the un-fillable vacancies situation and thus the need to get everyone “on the tools” with supervisors undertaking installation work themselves and thus there not being effective supervision, nor the lack of formal training courses to undertake specific roles or a formal competence management system.  Given this question was asked in module 1, these are particularly salient and would be the very things that would have made the Clapham accident such a good one to have chosen as the example.


Attached Files
.pdf   2015 mod1, Q5 Accident shts1&3 DAP.pdf (Size: 202.28 KB / Downloads: 52)
PJW
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#2
Hello PJW, is it possible to clarify whether level crossing accidents (associated with the signalling system rather than crossing user misuse) would be considered a suitable topic for the response to this question? In particular I am thinking about whether the Moreton-on-Lugg fatal accident would be considered appropriate by an examiner.

Many thanks.
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#3
Evening,

I've attached an attempt at the question- any comments, pointers or feedback would be very welcome.

I would welcome anyone unfamiliar with this incident to give their view on whether I have defined the incident well enough in part a) of the question (regardless of their experience).

Many thanks.


Attached Files
.pdf   Module 1 2015 Paper Question 5 Attempt.pdf (Size: 1.56 MB / Downloads: 8)
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#4
(11-09-2018, 07:12 PM)REMBrum Wrote: Evening,

I've attached an attempt at the question- any comments, pointers or feedback would be very welcome.

I would welcome anyone unfamiliar with this incident to give their view on whether I have defined the incident well enough in part a) of the question (regardless of their experience).

Many thanks.

Hello

Lots of good points raised but without the question, difficult to be specific in commenting.

The root causes could be considered for the circuitry not being in place to prevent the signal being put back.  However, the signaller made an error and was it actually human factors, i.e. workload, that caused the first error which was compounded by the lack of circuitry. Also, how familiar was the Bobby with the 'box and was this lack of approach locking normal for their 'box or 'boxes? 

One comment, in C it was written "route causes" where "root" was meant.

Jerry
Le coureur
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#5
(13-09-2018, 04:19 PM)Jerry1237 Wrote:
(11-09-2018, 07:12 PM)REMBrum Wrote: Evening,

I've attached an attempt at the question- any comments, pointers or feedback would be very welcome.

I would welcome anyone unfamiliar with this incident to give their view on whether I have defined the incident well enough in part a) of the question (regardless of their experience).

Many thanks.

Hello

Lots of good points raised but without the question, difficult to be specific in commenting.

The root causes could be considered for the circuitry not being in place to prevent the signal being put back.  However, the signaller made an error and was it actually human factors, i.e. workload, that caused the first error which was compounded by the lack of circuitry. Also, how familiar was the Bobby with the 'box and was this lack of approach locking normal for their 'box or 'boxes? 

One comment, in C it was written "route causes" where "root" was meant.

Jerry

Many thanks Jerry,

I've attached the relevant question paper for reference and any other interest parties.

I did indeed mean root, not route.


Attached Files
.pdf   Module 1 2015 paper.pdf (Size: 80.68 KB / Downloads: 4)
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#6
(13-09-2018, 05:15 PM)REMBrum Wrote:
(13-09-2018, 04:19 PM)Jerry1237 Wrote:
(11-09-2018, 07:12 PM)REMBrum Wrote: Evening,

I've attached an attempt at the question- any comments, pointers or feedback would be very welcome.

I would welcome anyone unfamiliar with this incident to give their view on whether I have defined the incident well enough in part a) of the question (regardless of their experience).

Many thanks.

Hello

Lots of good points raised but without the question, difficult to be specific in commenting.

The root causes could be considered for the circuitry not being in place to prevent the signal being put back.  However, the signaller made an error and was it actually human factors, i.e. workload, that caused the first error which was compounded by the lack of circuitry. Also, how familiar was the Bobby with the 'box and was this lack of approach locking normal for their 'box or 'boxes? 

One comment, in C it was written "route causes" where "root" was meant.

Jerry

Many thanks Jerry,

I've attached the relevant question paper for reference and any other interest parties.

I did indeed mean root, not route.

Based on what was in the paper, the accident wasn't a direct cause of the signaling system. It would possibly be better to focus on an accident where there is a single root cause that is clearly defined.

Clapham is slightly different in whilst the root causes were around fatigue / human-factors etc., it was the signaling system doing something other than it should that caused the first train to stop (arguably against the rule book) whereas MoL the signaling was working correctly albeit if modern standards were applied, the initial error from the signaler would have been mitigated!
Le coureur
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