I have been asked:
These are quite specialised questions for relatively unsual scenarios; I woouldn't worry about them for IRSE exam purposes- however since oyou asked.....
1. You just would not believe quite how difficult updating a standard in the UK now is; for one thing you have to demonstrate a "business benefit" of undertaking a change and there are many parties to get to agree.......
Note that GE/RT is a Railway Group Standard (administered by the RSSB but "owned" by all the relevant parties forming the railway industry) whereas NR/GN/SIG/11004 is Network Rail's
own company standard; I don't expect you to understand the nuance, but just know that two completely separate organisations...... The former are supposed to set the high level goals whereas the latter should give more of the detailed manner of implementing a compliant solution.
2.The diagrams could be clearer but the first depicts where the unfitted line ends and converges with a fitted line, then the distant and stop signal at the end of that line are actually fitted. The second diagram shows the unfitted line continuing but there being a junction with the fitted line. In this case can't fit a couple of signals with AWS as would apply to those trains continuing on the nominally unfitted line; therefore can only put an AWS immediately beyond the junction signal and suppress it for those moves along the unfitted line.
3. Standards have varied but nowadys should always be placed at 180m on the approach, except when speed of over 100mph when are placed at the greater distance. Does give issues re consistency when parallel running lines of different speeds, so sometimes there are non-compliances- in this sense there are "other factors" sometimes.
4. Nowadays, not a lot (although historically it was felt best to reduce distance in accordance with linespeed). However there are places where placing AWS is not sensible- placing withing S&C is not easy for example. Not sue there is any absolute tolerance- just get as close to the nominal distance as reasonable- generally 20m gives enough flexibility
Quote:Dear sir,
Please clarify,
1.In the AWS GE/RT 8035 standard:
The symbol of AWS from unfitted to fitted line (Page No. 35) shown without suppression.
But in the typical circuit T02018, AWS symbol shown correctly as per NR/GN/SIG/11004.
Why so far standard not been updated?
What is the necessary action to be taken for the small scale changes in RGS?
2.Please see GK/RT 8035 page 35 re convergence of unfitted line and fitted line- why difference
3.Does the position of AWS depends only on Speed or is there any other factor ?
4. While positioning AWS how far we can deviate from the standard distance [Non Standard distance] ?
These are quite specialised questions for relatively unsual scenarios; I woouldn't worry about them for IRSE exam purposes- however since oyou asked.....
1. You just would not believe quite how difficult updating a standard in the UK now is; for one thing you have to demonstrate a "business benefit" of undertaking a change and there are many parties to get to agree.......
Note that GE/RT is a Railway Group Standard (administered by the RSSB but "owned" by all the relevant parties forming the railway industry) whereas NR/GN/SIG/11004 is Network Rail's
own company standard; I don't expect you to understand the nuance, but just know that two completely separate organisations...... The former are supposed to set the high level goals whereas the latter should give more of the detailed manner of implementing a compliant solution.
2.The diagrams could be clearer but the first depicts where the unfitted line ends and converges with a fitted line, then the distant and stop signal at the end of that line are actually fitted. The second diagram shows the unfitted line continuing but there being a junction with the fitted line. In this case can't fit a couple of signals with AWS as would apply to those trains continuing on the nominally unfitted line; therefore can only put an AWS immediately beyond the junction signal and suppress it for those moves along the unfitted line.
3. Standards have varied but nowadys should always be placed at 180m on the approach, except when speed of over 100mph when are placed at the greater distance. Does give issues re consistency when parallel running lines of different speeds, so sometimes there are non-compliances- in this sense there are "other factors" sometimes.
4. Nowadays, not a lot (although historically it was felt best to reduce distance in accordance with linespeed). However there are places where placing AWS is not sensible- placing withing S&C is not easy for example. Not sue there is any absolute tolerance- just get as close to the nominal distance as reasonable- generally 20m gives enough flexibility
PJW