(26-07-2010, 07:52 PM)PJW Wrote: (26-07-2010, 10:50 AM)cgallafant Wrote: This question was recently set at the York Study Group June session. Any comments would be gratefully received.
There has been an accident. A three-car electric multiple unit, travelling at about 80km/h, has derailed on a set of facing points approaching a station stop. The unit was in passenger service and has remained upright and coupled, clear of the points. There are no serious injuries. The leading bogie has remained on the rails; all the remaining bogies have derailed.
You are responsible for undertaking the initial investigation into the cause of the accident and you arrive on site within minutes of the accident occurring.
On arriving at the scene, what are the initial actions you should take? [15 marks]
How should the cause of the accident be determined? [10 marks]
It'll take me some time to respond to this batch of questions; however I tackled this question in a London Study group session some years ago and the attached Powerpoint presentation was what I used to talk around an answer to this question.
I have read the four attempts and generally I feel they were in the right direction. One thing to be careful of though is presuming the points have moved under the train.
Train failures can account for accidents with wheels breaking, suspension collapsing, seized axle bearings, overspeed. There are also operational problems such as SPAD, overspeed, driver mistaking their location, mis-read route etc.
The important parts, I feel, to this question are ensuring the evidence is not destroyed and the root cause is sought. To answer specifics:
Part 1:
1) Ensure you are safe to access the site - speak to the signaller and ask them not to move anything and record what actions they have taken post-accident;
2) Check no other trains will arrive at the scene by stopping them away from the incident - to avoid changes in the equipment, even inadvertantly (flank protection for example);
3) Keep everyone away from the rear of the train and assist, if necessary, getting the passengers and staff to a place where they can be interviewed;
4) Record the scene, the train, the points, the weather, viewable aspects etc;
5) examine the train for anything loose, displaced, missing etc;
6) Is the point machine's lid on and padlocked;
7) state of the rodding, stretchers, the gauge at the S&C etc;
8) anything trapped in the pointwork or lying around that appears out of place;
9) cable conditions, troughing lids in place, damage to cable routes etc;
10) obtain what records are available on site including the train's fault log, records in locs and for the PM;
11) speak to the driver and reexamined anything if necessary and walk the route to check for damage to rails, sleepers, chairs/baseplates, displaced balast, anything out of the ordinary (reason I would speak to the driver at this point is their view may predudice your judgement if you speak to early but their testimony many give you a clue to when the train started to behave inappropriately);
12) interview the passengers and other eye-witnesses;
13) interview the signaller;
14) attend the 'box and take copies of the appropriate records, i.e. the data recorder tape (or register);
15) check you have everything you may need, if not revisit site, interview people again but do not release the equipment and train until you are sure you've capturered what you may need.
In some of the answers, reference was made to RAIB, ensuring everything is to standards etc. Well, in this case I think the question tells you that you are the investigator so that will not get you a mark. To standards is not really worth a mark either as you need to specify that you would check maitenance is apt, to standards and within the timescales specified. S&C may not be designed or installed to some revised standard but that does not mean it is not fit for purpose.
I would like to add, note the spread of the marks for the question. The first part is 15 marks - hence my fifteen bullet points. Less will likely loose marks but writing a similar number of points as an essay is also acceptable.
The answers:
I feel all had merit but JF, RB and JBs answers were not long enough for part 1. IPs answer was longer but I certainly would not suggest pulling relays nor worry about an RIO (the question makes that role yours!). There are set procedures for the emergency services, I don't feel there is value is mentioning them.
Your purpose on site is to gather evidence, make a high level judgement into the cause and record the site. Don't presume the obvious is at fault, let the evidence lead you - not all derailments at S&C is due to the S&C!
I'll answer part 2 later.
Jerry
