24-09-2012, 10:24 AM
I must confess that I have a difference of opinion here over the provision of AWS and TPWS on your layout.
The question says "signal" the layout...... - does this mean that there are no marks for shunt signals, limits of shunts, route indicators, and indeed for showing that a lightly -used line would use a staff instead of physical signals?
Equally, you can't say "I will provide ERTMS level 2 which uses no signals, please can I have 60 marks?"
We are railway signal engineers in the widest sense, and I believe that the verb "to signal", which is the instruction in the question, is to provide appropriate signalling in the widest sense of the word.
Putting it another way, signalling causes trackside devices (signals, AWS, TPWS, eurobalises, coded track circuits, GSM-R base-stations) to transmit various types of radiation, which is received by trainborne receivers for train advice, train protection, ATO etc. Why should the question be limited to the devices which emit only in the visible spectrum?
I strongly believe that AWS and TPWS are an integral part of the current UK main line signalling philospohy, just as much a part as eurobalises in an ERTMS system or coded track circuits which transmit a speed code in other systems. Therefore, showing the examiner that you understand these integral parts, and how to correctly apply them, is an essential "signalling" skill.
I don't hold with the view of writing a general comment "all main signals fitted with AWS...." - the question asks you to do it, not write an essay about it!, and crucially, you miss the opportunity to show that you can correctly identify the signals which do not have AWS, and those which do not have TPWS.
Finally, you'll never have time to create a complete layout in the exam. In this context, i strongly beleive in showing that you can do " a little bit of everything" : main signals, route indicators, controlled signals, automatic signals, shunt signals, limits of shunt, local manouevres etc. This shows much more breadth of knowledge compared to just having time to do all the main signals and running out of time. Bolting- on AWS and TPWS when appropriate adds to this picture of breadth of knowledge which you can use to impress the examiner.
Reuben
The question says "signal" the layout...... - does this mean that there are no marks for shunt signals, limits of shunts, route indicators, and indeed for showing that a lightly -used line would use a staff instead of physical signals?
Equally, you can't say "I will provide ERTMS level 2 which uses no signals, please can I have 60 marks?"
We are railway signal engineers in the widest sense, and I believe that the verb "to signal", which is the instruction in the question, is to provide appropriate signalling in the widest sense of the word.
Putting it another way, signalling causes trackside devices (signals, AWS, TPWS, eurobalises, coded track circuits, GSM-R base-stations) to transmit various types of radiation, which is received by trainborne receivers for train advice, train protection, ATO etc. Why should the question be limited to the devices which emit only in the visible spectrum?
I strongly believe that AWS and TPWS are an integral part of the current UK main line signalling philospohy, just as much a part as eurobalises in an ERTMS system or coded track circuits which transmit a speed code in other systems. Therefore, showing the examiner that you understand these integral parts, and how to correctly apply them, is an essential "signalling" skill.
I don't hold with the view of writing a general comment "all main signals fitted with AWS...." - the question asks you to do it, not write an essay about it!, and crucially, you miss the opportunity to show that you can correctly identify the signals which do not have AWS, and those which do not have TPWS.
Finally, you'll never have time to create a complete layout in the exam. In this context, i strongly beleive in showing that you can do " a little bit of everything" : main signals, route indicators, controlled signals, automatic signals, shunt signals, limits of shunt, local manouevres etc. This shows much more breadth of knowledge compared to just having time to do all the main signals and running out of time. Bolting- on AWS and TPWS when appropriate adds to this picture of breadth of knowledge which you can use to impress the examiner.
Reuben