Hi All,
Attempted answer from 2012 Q6 permissive moves. This was done today in our lunchtime study group, please can we have some feedback. Plenty more posts are going to be coming over the next few weeks.
TF
tfly86 Wrote:Hi All,
Attempted answer from 2012 Q6 permissive moves. This was done today in our lunchtime study group, please can we have some feedback. Plenty more posts are going to be coming over the next few weeks.
TF
Couple of immediate thoughts for you to consider.
You mention in the use of call on that it may have different purposes, the use of one indication for multiple purposes could lead to confusion in the driver's mind and give rise to a risk (or is it a hazard, I can never remember). You could discuss the use affects the "target" that the driver assumes they have to stop at and could lead to a mistake. Also the indication can look very much like a shunt signal authorisation - are there any issues with a non passenger train being signalled in?
Another hazard you could mention is forgetting that one is on a permissive move - at some locations the signal is a long way from the platform (800m) and if the driver is brought to a stand there is a risk that they accelerate too much or forget that they are approaching an occupied platform.
Another hazard to consider is the stopping target - even if the driver is aware that the platform is occupied, where are they to stop. In some platforms there are mid platform stopping locations - the driver whether they need to stop there (to platform share) or stop ready to couple up to the train ahead.
You should remember that our binocular vision is quite good at establishing distance but poor at detecting movement away from us - the target (i.e. train ahead) needs to remain stationary as the second train approaches. If it starts to move away the driver of the second train may struggle to recognise this and follow the first train. If the first train stops (no brake lights) then you could end up with a rear end shunt because the second driver may not be able to visually detect the change in speed of the leading train. Huddersfield Controls.
An incident at Darlington (IIRC) was where a train was signalled into the curved platform with a short train at the far end. The driver was able to see the platform starter at green (beyond the train in the platform) and this led them to forget the call on aspect and proceed a little too fast meaning that when they saw the stationary train it was too late to stop - bump. Huddersfield Controls also address this.
Thought of another issue to be considered - the second train is longer than the available platform leading to either operational challenges or passengers attempting to disembark outside the platform.
Good Morning, thank you for your replies. Within the assumptions we added that we would be using UK signalling and interlocking principles, this was intended to address Huddersfield and Lime street controls, so within the answer we concentrated around the risks outside of these interlocking controls. Should we have been more specific in our assumptions in order for the examiner to understand that we were concentrating on the risks that still exist even with certain interlocking controls being applied?Additionally, the other risks you mentioned were valid, but we found once we started digging, we came up with a lot of hazards and mitigations for the risk stated, and this consumed all of our time. Should we have spread our time out over alternative risks, or would concentrating on one suffice, in order to gain necessary points. ThanksTF Wrote:wealdbrook
Thought of another issue to be considered - the second train is longer than the available platform leading to either operational challenges or passengers attempting to disembark outside the platform.
Hi TF,
If you said you were applying "Outer Mongolian" railway principles how would the examiner know what they were and which hazards you had failed to mention because those principles addressed a Yak on the track?
The purpose of Module 3 is to test your understanding of why things are done not what you do - so it could be expected that you would identify the hazards which, for example, Huddersfield controls manage and discuss whether the controls are effective.
Hazard identification is always a challenge - I suggest for exam purposes you concentrate on those hazards you think are likely to happen or those which have very large consequences.
The mark allocation should also give you a clue - about 1 minute a mark.