2017 Q5 Train Control / ATP

[tfc82]

All feedback welcome. Hopefully my suggestion of CBTC without ATO functionality wouldn't have annoyed the examiners, in retrospect may be over-engineered.

A new train control system is being specified for a mixed-traffic railway. The safety authority
requires that some form of automatic train protection is provided, but the railway has not yet
decided if the signalling will be multiple aspect colour light signalling, in-cab signalling, or some
combination.
a) Briefly describe a suitable system design. [5 marks]
b) For the system you have described, explain the most significant risks that may lead to an
unsafe event during normal operation. [8 marks]
c) For each of the significant risks you have explained, describe how the system may be
designed to mitigate their effects. [12 marks]

[hayesip]

Moving Block CBTC may be a bit extreme as a proposed train protection system onto an existing mixed traffic railway. Consider real world examples where ATP is being put onto mixed traffic lines eg ETCS level 1 type ATP systems using existing lineside signals (eg NSW), or ETCS level 2 type ATP systems (eg Thameslink,) with cab signalling for the ATP area and retaining lineside signals outside of this area.

[tfc82]

Thanks for the tip - in retrospect  an ETCS L1/2 style system would indeed seem like the way forward for this question.