Entry point

Entry point Jun 25, 2014 19:52:19 GMT

Post by punkman on Jun 25, 2014 19:52:19 GMT

Jun 25, 2014 17:03:45 GMT tut said:

Hi, I assume it's the same on the Jubilee line as well, but I'm gonna ask here since a lot of the recent TBTC discussion (understandably) has been about the Northern.

There is a piece of TBTC signage which consists of a hexagon with the letters EP printed in the middle (and another which is identical, but with a red cross through the letters EP). I understand that 'EP' stands for Entry Point and the sign with a red cross is a 'clearance point sign'. What do these signs mean? I think I once read somewhere (possibly here) that the entry point marks the boundary between 2 TBTC loops (no idea what the clearance point sign is for) but I don't really know much else.

What I'd really like to know is what these signs are supposed to convey to a T/Op and what (if any) action is supposed to be taken and in what circumstances.

---

And while I've got you - what is the 'end of route secure' (RS with a red cross through it) sign for?

Thanks

As you correctly say they are Entry Point and Clearance Point (in common parlance E-P-X) repectively and the EP is indeed at a TBTC loop boundary. Basically if a train is driving in RM for whatever reason it shows the driver when he or she goes into a new loop after which the VOBCs should start to communicate after a VOBC reset. Similarly in the event of a loop failure it shows the driver he or she is now in a new loop section, but in this case the VOBCs would not communicate until the next loop ("good loop to good loop" rule). The Clearance point sign is at least a train length after the EP indicating that the whole train is in that loop section and both VOBCs should be "on loop." At this point the train can be stopped and reverted to ATO mode. The reason (I think) that it is sometimes more than a train length from EP to EPX (sorry, Clearance point) is because of areas where ideally trains should not stop e.g over large rail gaps.

R-S-X is similar; after having to pass a route secure (for points) in RM, it shows the driver that the rear of the train has fully passed those points which had been secured.

Post by Deleted on Jun 25, 2014 17:03:45 GMT

Post by punkman on Jun 25, 2014 19:52:19 GMT