Moreton-on-Lugg

[Peter]

The Rail Accident Investigation Branch (RAIB) has released its report into a fatal accident at Moreton-on-Lugg, near Hereford, 16 January 2010. The RAIB has made four recommendations.

There are several points in there that I found very interesting about the human factors issues which are cited as contributory to how the human error was made. Will you think the same way in the future if you are laying out an operations floor or designing a form for use in such an environment? Perhaps a bit more mod 7 Systems Engineering would help or do we discount the human from being part of the system.

Peter

[Jerry1237]

Pink fluffy SIL0 (PFS0) humans are the primary actors within a system. PFS0s make mistakes. Rules and processes don't stop PFS0s from making errors but provide a framework which when adhered too should provide 'a' level of safety.

It seems incredible how a function such as BGocc then BGclr and 42 replaced (BG is the track over the LX and 42 the relevant stop signal) which would lock 1 (gate lock) when 42 cleared had not been included in a fail safe system. The Hull Paragon accident (14th February 1927) details that system failure due to poor design can, and will, eventually occur.

For me, there is a fine line between the cost savings required by engineering versus the level of safety these systems must provide. Deadlines and timescales can also affect the delivered result. Savings are often short term 'gains' where the long term affects outweigh any reduction in costs. Human factors should always be considered and incorporated. However, the assessment should be based upon safety and system integrity.

My personal view is that the system failed the signaller. Whilst a mistake was made, the results were unfortunately fatal. The addition of electric locks to level 1 would have been minor changes but the rail industry often seems to choose not to question why something is the way it is. Many accidents of a similar nature have occured previously and yet a system that failed to identify predictable errors was commissioned and it took 34 years for the failure to occur/become apparent.

Jerry

[jaheen100]

The VW would have had a very poor view of the down line because the signal
box is in the way. On a related matter, has anyone ever been at a level
crossing with the barriers down and then they have opened without a train
passing? It's not something that I can recall happening.

[Peter]

The VW would have had a very poor view of the down line because the signal
box is in the way. On a related matter, has anyone ever been at a level
crossing with the barriers down and then they have opened without a train
passing? It's not something that I can recall happening.

Go to Topsham I. Devon, or any crossing where Network Rail has implemented Stowmarket Controls as a mitigation for a SPAD at a signal protecting a crossing where there is a station stop. The barriers automatically come down when the train is approaching and when it is proved to have stopped with the signal at Red, the barriers will go back up. I am very unhappy that this leads to a very different set if behaviours for users where they will see exactly what you are describing and hence may head to misuse.

Peter