Thanks for providing an answer to that, it was something I intended to ask ages ago.
No doubt the extra platform faces were provided for demand that never materialised from the town itself.
No worries, just happy I was helpful
That line passed very close to the 'never used' platform at Hertford North, but not through it. Everything I have seen says that the platform in question never had any track. As I understand it, despite the impession that might be gained from old maps, Hertford North never was an interchange between the two line.
The line in question in question used to run from Welwyn Garden City under the Hertford Loop at the point where the viaducts are south of Hertford North then run alongside the Up Yard before veering towards Hertford East at the point just past the existing relay room which is where Hertford North signalbox I think used to be.
In fact the abutments which supported the line towards Hertford East are still in place although obviously the bridge and track etc.. have all long gone.
If you look directly across the road from the station entrance, you will see one of the abutments, there's some old stairs towards the side from the car park leading onto the former trackbed up above where a mobile phone transmitter now resides on the former trackbed.
The line itself closed in the 1950s so can't really be blamed on Dr Beeching which is a shame as if the line was cut back but left in place between Welwyn Garden City and Hertford, it would have proven to be so useful in today's age and time.