Chris Osment wrote:The Churston backing arm was 42 - you must be reading the small thumbnail image!
According to the SRS locking table info, it could be pulled regardless of the position of the up dock siding points 13. It did not require the ingoing disc 42 to be off if the siding points were reverse. My suspicion therefore is that you could go all the way back down the up loop if so required, as with 13 normal it locked the up loop facing points 10 normal and the Up Home, so the 'limit of shunt' presumably would have been the Down Advanced Starting 44.
Great - very handy to have the details - so I revised the plans in the folder here to accommodate much of this commentary.
I looked at doubling the line to Pwhelli, but it was not practical in modeling terms - it just cluttered up the area too much. So single passing station it still is.
I have allowed for an express to pass a stopping passenger train that was being "banked" using the normally Up line, but assumed that in that these trains would never stop at TYG (double headed) so also removed calling-on for that line. The rationale for the one-handed nature is that although stopping trains coming down the bank will have to detach a banker at TYG it will be quickly done and then they can rapidly go downhill. But on the way up they will be slow because of the bank and so having a bypass is more important.
For banking I did keep the middle road - its such a nice feature - but made the entrance and exit to it suit the arriving and departing bankers without requiring additional run-around moves. I changed the goods entrance as John suggested and fixed the gunpowder works signaling.
I now have two signal boxes, one for the station proper and one for "the bank". This led me to add extra distants but I have required that they be interlocked - I assumed "slotted" - so if the express sees the first distant is off in either direction it means that the route is clear all the way through the station and onto the bank for down express and all the way through on the up for all up trains.
I do still have a backing signal ala Churston that is used both to back a down goods train down into the yard because the entrance is near the end of the loop as well as to support any "try the bank again" activity.
Although it breaks the illusion of steepness and banking, because one line is signaled bi-directionally, we can switch out the two boxes for when we are short-handed and operate PD to Pwhelli as one single section, I hope.
I realize that all these things did not exist in one place and that there is a bit of disagreement about how common other features were - but what I want is to be broadly within the bounds of 1 inch to the foot reality and not needlessly frighten the horses.
So remaining questions -
- Did I get the distants right and are they all needed?
- I have discs 43 and 44 for goods yard and down platform backing. But Churston doesn't - was it common to have implicit permission like this on the GWR->WR ( i.e.,pass a red disc for the divergent route and have no disc for the non-divergent)?
Hopefully we are converging,