My current commute (West Hampstead - Crouch Hill) requires me to take both the North London line and the Goblin line with a change at Gospel Oak. On a personal level, changing at Gospel Oak is a slight inconvenience (particularly towards West Hampstead as it requires going up and down lots of stairs). It also seems that the single Goblin platform at Gospel Oak is preventing higher frequencies. However, my personal entitlement aside, it seems that this affects lots and lots of people. Now that trains are getting busier again, a full train load of people has to transfer through the way too small underpass (it seems that 99% of people arriving at Gospel Oak via the Goblin line transfer to the North London line westbound.
This leads me to my question: Would through trains from Barking onto the North London line be feasible? The track connection seems to exist and seems to be functioning, but does the capacity exist on the North London line? Is building a 4th platform at Gospel Oak feasible? Thought it might be an interesting discussion to have.
Although there are obviously bigger priorities and bigger worries for TfL right now, it would make the commute for thousands of people slightly easier.
You exaggerate. About 85% of passengers alight from the GOBLIN and change to the west-bound Richmond or Clapham Junction trains. About 5% change to the east-bound trains and 10% leave the station.
The track connection does exist and is used several times a day in each direction by freight trains.
The current GOBLIN platform isn't on a through route which would prevent trains from Barking through to Richmond calling at Gospel Oak. This was the case with the extra service that used to run through to Willesden Junction in peak hours
This major change to the GOBLIN service would undoubtedly incorporate a revised track layout at Gospel Oak including a reshaped platform.
There isn't capacity on the NLL west of there, right now there are ~12 trains in each direction per hour, including freight (not all of which actually runs but it is timetabled). That's pretty much as many trains as can be run. Added to which another flat junction is not going to help timings either
Any scheme to extend GOBLIN trains onto the North London Line (NLL) would also involve sending some NLL trains via Primrose Hill to Willesden Junction low-level instead of Clapham Junction or Richmond.
You would need two new platforms since neither of the through tracks has a platform and the terminus line can't be extended. I doubt a business case for two new platforms at Gospel Oak exists, and suspect that Hampstead Heath would become the new junction instead.
Hampstead Heath would be the "junction" for east-bound passengers changing to the GOBLIN. No need for any new platforms.
Not sure there would be any chance of that without the entire link being on a flyover over the Midland Mainline. Moreover, are there likely to be any relevant traffic flows?
I've been advocating such a flyover for decades! However, Bald Rick has explained in the past that electrifying between the MML and GOBLIN is extremely difficult.
My pet speculative project is Goblin to Ealing Broadway via Willesden Junction. It's a real pain getting to Ealing from N / NW London even though it's not far. Know it's not on with the frieght situation. What if some NLL trains went via the Primrose Hill line to Willesden, giving Goblin trains pathways via Hampstead Heath? The highest demand on the NLL seems to be east of Camden Rd.
An interesting idea. Two points: 1) The trains should terminate in the bay platform at Hayes & Harlington instead of Ealing Broadway. 2) Although NLL trains are most heavily used east of Camden Road, at peak periods they are also full and standing east of Willesden Junction. Regular passengers will complain if the service is thinned-out.