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Post by superteacher on Mar 31, 2018 21:03:02 GMT
When performing a mainline shunt, trains are required to proceed as far as a “limit of shunt” board, where the driver changes ends and takes the train over the crossover to the other line. Do trains proceed to the limit of shunt in ATO?
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Post by aslefshrugged on Apr 1, 2018 3:14:24 GMT
On the Central mainline shunts have to be done in Coded Manual, in ATO the train would carry on past the limit of shunt until it reached the next signal at danger or a Block Marker Board with a zero code.
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Post by up1989 on Apr 2, 2018 17:33:28 GMT
The Seltrac ATO will go to the limit of shunt ok, on the Northen and Jubilee
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Post by superteacher on Apr 2, 2018 17:47:57 GMT
On the Central mainline shunts have to be done in Coded Manual, in ATO the train would carry on past the limit of shunt until it reached the next signal at danger or a Block Marker Board with a zero code. And would that be classed as a SPAD? |
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Post by North End on Apr 2, 2018 17:59:38 GMT
On the Central mainline shunts have to be done in Coded Manual, in ATO the train would carry on past the limit of shunt until it reached the next signal at danger or a Block Marker Board with a zero code. And would that be classed as a SPAD? No, but it would be recorded as an error by the train operator for failing to select the correct operating mode, albeit a performance error not a safety-related error. |
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Post by Deleted on Apr 2, 2018 18:00:34 GMT
On the Central mainline shunts have to be done in Coded Manual, in ATO the train would carry on past the limit of shunt until it reached the next signal at danger or a Block Marker Board with a zero code. And would that be classed as a SPAD? Certainly not, the train will have gone precisely as far as the signalling allows. The LU limit of shunt is just a stop marker, like a stopping diamond, marking where a right direction movement should stop in order for the rear of the train to be clear of the points and signals and so on in order to then shunt back onto the other line. There are no wrong direction movements whose limit is marked by a limit of shunt, it will always be a fixed red light. Having said that, it's possible in some cases that perhaps you will begin a wrong direction movement, cross over onto the right line and ultimately stop at a limit of shunt at the end of your movement, but trains always approach limit of shunt boards in the right direction. They are not stop signals. So yeah on conventional lines the signal will always clear you onto the next signal and it will be safe to proceed that far and it will be up to you the driver to understand that you're supposed to stop at the limit of shunt to go back, but it'll be safe and legal to proceed to the next signal, it just won't help you to carry out the move you're meant to be carrying out and might make someone cross with you  Same principle on the Central, although of course it might be a block marker board somewhere up the line you're being authorised to. On Seltrac, I guess the movement authority might well end at the limit of shunt, in which case trying to carry on your merry way would be a problem. |
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Post by North End on Apr 2, 2018 18:12:08 GMT
And would that be classed as a SPAD? Certainly not, the train will have gone precisely as far as the signalling allows. The LU limit of shunt is just a stop marker, like a stopping diamond, marking where a right direction movement should stop in order for the rear of the train to be clear of the points and signals and so on in order to then shunt back onto the other line. There are no wrong direction movements whose limit is marked by a limit of shunt, it will always be a fixed red light. Having said that, it's possible in some cases that perhaps you will begin a wrong direction movement, cross over onto the right line and ultimately stop at a limit of shunt at the end of your movement, but trains always approach limit of shunt boards in the right direction. They are not stop signals. So yeah on conventional lines the signal will always clear you onto the next signal and it will be safe to proceed that far and it will be up to you the driver to understand that you're supposed to stop at the limit of shunt to go back, but it'll be safe and legal to proceed to the next signal, it just won't help you to carry out the move you're meant to be carrying out and might make someone cross with you Same principle on the Central, although of course it might be a block marker board somewhere up the line you're being authorised to. On Seltrac, I guess the movement authority might well end at the limit of shunt, in which case trying to carry on your merry way would be a problem. Anyone with local knowledge able to give a view about how JB92 at Harrow-on-the-Hill is treated? IIRC this is a shunt signal that reads towards a LOS board. |
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Post by aslefshrugged on Apr 3, 2018 7:40:38 GMT
There was one occasion quite a few years ago where someone missed the limit of shunt board west of Liverpool Street and got all the way to Bank in Coded Manual. They had to come back in Restricted Manual until they picked up codes for the shunt signal (LIS 5065) but apart from having an IOp in the cab to show them where the LOS board was I don't recall there being any other action taken (other than much urine extraction for the rest of us).
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Post by superteacher on Apr 3, 2018 8:20:38 GMT
There was one occasion quite a few years ago where someone missed the limit of shunt board west of Liverpool Street and got all the way to Bank in Coded Manual. They had to come back in Restricted Manual until they picked up codes for the shunt signal (LIS 5065) but apart from having an IOp in the cab to show them where the LOS board was I don't recall there being any other action taken (other than much urine extraction for the rest of us). Just allowing for a greater margin of error so he was sure the rear of the train was clear of the crossover!  |
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Post by marri260 on Apr 3, 2018 10:49:48 GMT
JB92 is a shunt reading towards a LOS board yes, slightly unusual. Sits under JB3 which is a normal semi auto starter. Authorises you up to the LOS board (just at the foot of the supports for the Pinner Road bridge north of the station) where you'd then change ends before shunt JB98 sends you over 95 crossover into platform 2.
Believe that you wouldn't be able to get JB98 to clear having accepted JB3 if cleared in error for a train making the shunt move. Not sure why the location is signalled in this way but I'll ask next time I see the person who'd know the reason behind the set up.
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Post by MoreToJack on Apr 3, 2018 11:36:08 GMT
JB92 is a shunt reading towards a LOS board yes, slightly unusual. Sits under JB3 which is a normal semi auto starter. Authorises you up to the LOS board (just at the foot of the supports for the Pinner Road bridge north of the station) where you'd then change ends before shunt JB98 sends you over 95 crossover into platform 2. Believe that you wouldn't be able to get JB98 to clear having accepted JB3 if cleared in error for a train making the shunt move. Not sure why the location is signalled in this way but I'll ask next time I see the person who'd know the reason behind the set up. JB98 should clear if JB3 was originally cleared - the only complication comes if the LoS is missed under JB3 which would then require a wrong direction move back to JB98 from the next running signal, JB7. The limit of authority for JB92 is the Limit of Shunt board, whilst for JB3 it is JB7. Theoretically if you passed the LoS it would be a SPaD, but whether that's how it would actually be treated (considering that there's technically no signal involved) is probably down to the discretion of the investigating manager. Similar arrangements also exist at Amersham with the mainline shunt there. |
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Post by North End on Apr 3, 2018 12:28:39 GMT
JB92 is a shunt reading towards a LOS board yes, slightly unusual. Sits under JB3 which is a normal semi auto starter. Authorises you up to the LOS board (just at the foot of the supports for the Pinner Road bridge north of the station) where you'd then change ends before shunt JB98 sends you over 95 crossover into platform 2. Believe that you wouldn't be able to get JB98 to clear having accepted JB3 if cleared in error for a train making the shunt move. Not sure why the location is signalled in this way but I'll ask next time I see the person who'd know the reason behind the set up. JB98 should clear if JB3 was originally cleared - the only complication comes if the LoS is missed under JB3 which would then require a wrong direction move back to JB98 from the next running signal, JB7. The limit of authority for JB92 is the Limit of Shunt board, whilst for JB3 it is JB7. Theoretically if you passed the LoS it would be a SPaD, but whether that's how it would actually be treated (considering that there's technically no signal involved) is probably down to the discretion of the investigating manager. Similar arrangements also exist at Amersham with the mainline shunt there. I suppose it *could* be treated as a SPAD as there’s certainly provision in the policy for that situation. Would be a bit harsh though. |
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Post by davethewomble on Apr 27, 2018 9:45:32 GMT
If the train passes the shunt limit, can the driver still perform the reverse maneuver, or must they proceed to the end of block in the direction of travel?
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Post by aslefshrugged on Apr 27, 2018 10:03:41 GMT
If the train passes the shunt limit, can the driver still perform the reverse maneuver, or must they proceed to the end of block in the direction of travel? On the Central Line if a train is in ATO it will ignore limit of shunt boards and continue until it reaches a block marker board or signal with a zero code but if the train is in coded manual the driver can stop anywhere. If the driver passes a limit of shunt board they have to change ends and either wait until the shunt signal clears to get codes or move up to the signal in restricted manual. If you switched the train into reverse and brought it back to the limit of shunt board you'd be sacked (as happened with a West Ruislip driver who reversed in Northholt sidings a few years ago). The only time we're allowed to use reverse (restricted manual) is within platform limits with the assistance of station staff but most of us change ends regardless |
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Post by spsmiler on Apr 27, 2018 11:20:50 GMT
There was one occasion quite a few years ago where someone missed the limit of shunt board west of Liverpool Street and got all the way to Bank in Coded Manual. They had to come back in Restricted Manual until they picked up codes for the shunt signal (LIS 5065) but apart from having an IOp in the cab to show them where the LOS board was I don't recall there being any other action taken (other than much urine extraction for the rest of us). Hopefully not in the rush hour! Simon |
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Post by aslefshrugged on Apr 27, 2018 11:57:10 GMT
There was one occasion quite a few years ago where someone missed the limit of shunt board west of Liverpool Street and got all the way to Bank in Coded Manual. They had to come back in Restricted Manual until they picked up codes for the shunt signal (LIS 5065) but apart from having an IOp in the cab to show them where the LOS board was I don't recall there being any other action taken (other than much urine extraction for the rest of us). Hopefully not in the rush hour! Simon No, that was during engineering works, we were shut down west of Liverpool Street |
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Same principle on the Central, although of course it might be a block marker board somewhere up the line you're being authorised to.
