TORR always requires-
a) signal disengaged so replaced to danger by the passage of a train (generally by berth and first tracks simultaneously occupied),
b) signal free of approach locking by the passage of a train (often 1st clear with 2nd still occupied after a time when 1st and 2nd simultaneously occupied)- this is the TISP. Approach locking release by TIME is NOT utilised (as that is for the situation in which a train has not taken the route and therefore cancelling the route in front of it would be highly inappropriate!)
c) Something else that gave an independent input that the intended train movement had really taken place. That something else was in the early days quite usually the equivalent to release of approach locking by "lookback"- so not only had the train entered the route but also that it was no longer on the approach. This fell out of favour (generally for wrong reasons in my humble view as it was said to take to lomng to test, but where comprehensive A/L lookback being provided anyway it actually was ahuge timesaver as the MAP file could be tested so much faster using the TORR functionality that the A/L functionality) and typically became another sequence- such as "2nd track occupied with 3rd track clear followed by vice versa". Sometimes it was just "2nd track occupied for a minimum time needed to traverse then clear again- typically when a short route entered sidings and not enough tracks to play with. Occasionally there could be an added treadle to be proved operated etc. as the independent item, but that is normally because of a late change etc and that was the only solution.
So TORR that is said to be UNCONDITIONAL actually means only conditions a) and b) are applied; there is nothing "extra". I am very surprised that you have met whole schemes like this as I thought it was only applicable to non-passenger routes. However I must admit that it has been at least 10 years since I had day-to-day dealing with Control Tables or Principles testing and things do change. Certainly TORR is not as novel and nowadays can be undertaken within the SIL2 control system rather than SIL4 interlocking and hence it my be that with greater familiarity and experience that there has been some "lowering of the bar". The old rules were that there had to be something additional to the basic interlocking that would have been in situ if there had been no TORR and the signaller themselves cancelling the route and hence applying an element of thought before they did so- the TORR controls were to add something in to compensate for removing the human from the chain.
It may be that someone (Dorothy?) may be able to comment who is more familiar with current standards.
PJW
a) signal disengaged so replaced to danger by the passage of a train (generally by berth and first tracks simultaneously occupied),
b) signal free of approach locking by the passage of a train (often 1st clear with 2nd still occupied after a time when 1st and 2nd simultaneously occupied)- this is the TISP. Approach locking release by TIME is NOT utilised (as that is for the situation in which a train has not taken the route and therefore cancelling the route in front of it would be highly inappropriate!)
c) Something else that gave an independent input that the intended train movement had really taken place. That something else was in the early days quite usually the equivalent to release of approach locking by "lookback"- so not only had the train entered the route but also that it was no longer on the approach. This fell out of favour (generally for wrong reasons in my humble view as it was said to take to lomng to test, but where comprehensive A/L lookback being provided anyway it actually was ahuge timesaver as the MAP file could be tested so much faster using the TORR functionality that the A/L functionality) and typically became another sequence- such as "2nd track occupied with 3rd track clear followed by vice versa". Sometimes it was just "2nd track occupied for a minimum time needed to traverse then clear again- typically when a short route entered sidings and not enough tracks to play with. Occasionally there could be an added treadle to be proved operated etc. as the independent item, but that is normally because of a late change etc and that was the only solution.
So TORR that is said to be UNCONDITIONAL actually means only conditions a) and b) are applied; there is nothing "extra". I am very surprised that you have met whole schemes like this as I thought it was only applicable to non-passenger routes. However I must admit that it has been at least 10 years since I had day-to-day dealing with Control Tables or Principles testing and things do change. Certainly TORR is not as novel and nowadays can be undertaken within the SIL2 control system rather than SIL4 interlocking and hence it my be that with greater familiarity and experience that there has been some "lowering of the bar". The old rules were that there had to be something additional to the basic interlocking that would have been in situ if there had been no TORR and the signaller themselves cancelling the route and hence applying an element of thought before they did so- the TORR controls were to add something in to compensate for removing the human from the chain.
It may be that someone (Dorothy?) may be able to comment who is more familiar with current standards.
PJW
(01-09-2014, 09:56 AM)jenni.joseph9 Wrote: Hi,
Recently I have seen a scope where the TORR is being done unconditionally for all the Routes, in that scheme.
Does the route release happens with Approach locking timing and TISP(Train in section proving) sequence or there is someother form of releasing the each route.
Can some one please clarify.
Thanks & Regards,
PJW
