. . . Immediately beyond the stop-block of the down loop the Oxford Canal passes under, pretty much at right-angles. The loop headshunt can't continue north unless the bridge is widened.
Noted. It looks like the abutments were built for a wider bridge if necessary.
I understood from local sources that the new platform 4 will be the whole length of the station and gobble up both north and south facing bays. I never heard of it being "short".
The 133m figure was from The Planner. I guessed it would be at the north end.
Knowing the site fairly well, I assumed that the up loops would describe a fairly smooth arc, not the wiggly ends you have shown. Bridge Street crosses the railway between the station and Banb. North S.Bx., and the goods loop swings wide to clear the bridge support pier. I know it's a diagram, but addition of the bridge (and the canal) would enhance the graphics I thought.
It's a fair comment, but some of the curves on loops and turnouts, especially on the up side, are 'false'. That is to say, they are not present in real life but are necessary for a straight line diagram to keep the loops parallel with the main lines. In reality, the curvature of the whole station site allows the tracks to splay apart around the platforms without such a wiggly approach on the loops. I could redraw the whole thing on a curve but that is time-consuming so I probably won't. I have shown the road, canal and river bridges.
There was, and may yet be, a siding (or two?) parallel to the up loop north of the station - "Engineer's siding?" Are we keeping that?
There is one siding north of the road bridge, called the middle road. It is to be removed according to The Planner.
There was an oil siding to the south-west of the station. Keeping it? (There are some storage tanks immediately west of the station). - I always assumed they were part of the same facility.
There's a headshunt for the mileage sidings there that projects towards the old steam depot site. It looks like the new depot reception roughly follows same alignment.
New version 3 : http://www.townend.me/files/banbury.pdf