Train technology

Yes, I know, technology is not particularly interesting.
Neither are men who do the whole Jeremy Clarkson bit and get obsessed with it for its own sake.
To understand the options for the AB&T though a little bit of information about the technology options and the history of the technology will help.

The East Coast Mainline is electrified via overhead wires carrying 25kV AC.

The Metro system is electrified voa overhead wires carrying 1.5kV DC.

The AB&T is not electrified in any way.

All three networks have different signalling systems, but most Network rail trained drivers are competent to travel across the ECML and the AB&T.

If you ask some people they'll tell you these technological and systems differences are insuperable.

They're not.

The biggest obstacles to wider and more useful passenger services in the north east are political and historical, not technological.

Train companies in the UK have routinely run dual voltage trains. Here's one and here's another.

The Metro was electrified before the East Coast Main Line. The divestment of the Metro network by British Rail, as was, was a classically short sighted decision. So was the decision not to electrify the AB&T as a relief route for the ECML, and to lift some of the line at the south of the AB&T. None of those decisions were fatal to the return of passenger services to the BA&T though. It has always been possible to commission rolling stock that could link the Metro network to the ECML; the obstacle to, say, Durham to Tynemouth or Berwick to Newcastle Airport services is not technology.

How does that observation help people in Blyth or Seaton Valley? Simple. Other nations, and even other parts of the UK, are experimenting with dual power diesel electric rolling stock. It works quite simply. In addition to the electric power system on the train, a generator pack is fitted to provide electricity to the motors when overhead lines aren't available.

With rolling stock like that, suddenly the divide between British Rail and Metro is simply an artificial divide, a set of contracts and rules that can be changed if anyone wants to badly enough. The key to that is desire. not technology.