2009 CTs on IRSE 2012 tables

[asrisaku]

Thanks Dorothy.

371D(S)
I am getting close nearly to understand opposing routes.
378B(S): calls 235R while 371D(S) calls 235N
382A(S): calls 234N while 371D(S) calls 234R

both routes require point different position. Why do we put 378B(S) as an opposing route?

Sorry for asking lots of things.

[dorothy.pipet]

You will probably find better explanations than I can give but this is how I think of it:
You want to set R371D(S), and need to ensure there are no other routes set which would cause a collision.
So we look at the other routes which might already be set -
* Directly opposing is where the other route is the reverse of 371D, thus no points calls already prevent the opposing route from being set. We use tracks clear conditions to ensure the opposing train is beyond signal 371.
*Indirectly opposing is where the other route starts from somewhere different; as this train moves through its route points become free to move because route locking only holds the route in front of the train.
Think about a train moving through R378B(S), once it clears track DR, P235 become free to move as the route locking clears behind the train. At this point the opposing move has not passed Signal 371 so we need to add opposing locking controls.
Now think about a train moving through R382A, it needs to travel until it clears track CF, before P234 are free to move and it's possible to set R371D, however the train has already passed signal 371 so it is no longer opposing R371D(S). Therefore it does not need to be included in opposing locking in this case.

Does that help? Perhaps PJW can provide a better explanation?

[asrisaku]

) I got it your point and clearly understood by your explanation. I'll think of it everytime I do the opposing routes

Happy to do more works in other years