It wasn't?
but Wellingborough to Northampton would form a very useful link between the northern part of the Midland Main Line, South Yorkshire, Nottingham and Milton Keynes and places served by East-West Rail, Oxford and beyond.
I'm sure others would have other nominations, but I'd say the closure of Wellingboro - Northampton was the worst single closure of the 1960s. It was a short route (12 miles?), so what were the savings? And it offered such potential for connectivity. Much better than Bletchley - Bedford, especially considering that did not run into Bedford Midland at the time, and was also likely expected to close.
BR & the Ministry of Transport must have known, even in 1964, that the GC would be closing north of Aylesbury, and could have insisted keeping Aylesbury to Calvert, running a DMU Aylesbury - Bletchley - Northampton - Wellingboro' - Kettering - Corby - Oakham - Melton - Nottingham. (Single sections north of Corby as appropriate.)
And, of course, Milton Keynes was also in the planning stage, though I'm not sure it was announced by the time the GC closed. Nonetheless, it would clearly need new connections.
Nobody would expect to use Aylesbury - Nottingham throughought (faster to Nottingham by changing at Wellingboro), but this would have maintained a service northwards from Aylesbury (actually, better than anything previously offered, at least in terms of connections), a service to Corby and north thereof.
As there are not any important places on the line and those that might be are bypassed by the line, trains could run non-stop at least at 100mph from one end to the other making the service much quicker than the existing alternatives.
You mean between Northampton and Wellingboro? You could have kept Castle Ashby open. Don't think Northampton Bridge Street would make the grade.
90 mpn or even 75 mph line speed would have been fine.
The line was originally Northampton-Peterborough, and became an LNWR route. There was a spur built to link to the Midland at Wellingborough but this has been been partially built on in Wellingborough. The connection also came up on the wrong side as well - to the Fasts rather than the Slows, which would have been better if still open as a freight route.
Northampton-Peterborough would have been an interesting freight route given how busy the A45/A605 is today and could have provided an alternate for Freightliner traffic from Felixstowe. However, despite being an early route (built by London & Birmingham railway) it was done cheaply in the sense that all road crossings were on the level.
Agree that longer term Wellingboro' - Peterboro' would have been good, but I suspect the financials at the time would have been very poor. And, of course, it ran into Peterboro' East, not North.
Was Oundle station well located for the settlement? If so, might have provided some local traffic, I suppose. There was the school, of course.