Northern Ireland set to get 200kmph train line west of the Bann as part of all-Ireland rail blueprint

That is equivalent to about 124mph and is far, far faster than any trains which currently run in Northern Ireland.

A speed of 124mph is roughly the same as the famous Japanese bullet trains when they began operating in 1964 (though they have since become speedier still).

There is a Dublin-Cork service which can travel at roughly that speed, but nothing close to it in Northern Ireland.

For example, the current maximum speed of the Dublin-Belfast Enterprise service is 90mph, though in reality it averages out at about 50mph when all the stops and speed restrictions are taken into account.

The new 124mph train – or trains – is slated to travel between Portadown and Londonderry via Omagh (where there currently is no line) as part of a wider plan for the whole island.

A professor with expertise in transport has said that the idea of creating a new line from Portadown to Londonderry at such a high speed is not plausible:

• Idea of super-high-speed railway line for the west of Ulster is 'ridiculous' overkill says transport professor

It is understood that 124mph would be the top speed, not the average speed, of the new service.

It would be a huge change to the country’s train network, which is almost entirely concentrated in the more prosperous half of the country, east of the Bann River.

Such a blueprint has been talked about for a long time.

But now that Stormont is up-and-running once again, the minister is signalling his intent to press ahead with it.

More from this reporter on the current revamp of Northern Ireland’s rail network:

• WATCH: First-ever footage of the colossal replacement for Great Victoria Street Station in Belfast – now renamed Grand Central Station and due for completion in one year

• IN PICTURES: Plan to raze one of Belfast’s main train stations to the ground

The 200kmph speed was mentioned almost as an aside in a Q&A session on the floor of the Stormont Assembly yesterday.

The infrastructure minister Mr O’Dowd (whose main area of responsibility is transport, and represents Upper Bann for Sinn Fein), was asked by fellow Sinn Fein MLA Padraig Delargy (Foyle) to “provide an update on the speed of the Portadown to Derry railway line”.

Mr O’Dowd responded: “Yes. In a previous debate, I said that it was around 200 kilometres per hour.

"It is a high-speed rail link between Portadown and Derry.

"It is part of the all-island strategic rail review. It is an ambitious plan that gives connectivity, tackles climate change and promotes public transport.

“Those projects are medium- to long-term projects, but they are important.

"It is crucial that they include tackling regional imbalance and correcting the mistakes of the past.”

His mention of an earlier debate apparently refers to comments in the chamber on February 27, when he had said: “About the speed of the Portadown to Derry connection, to clarify, it is planned for that rail network to have a 200kmph speed, so it is a high-speed connection.

"There will also be cross-border routes from Derry to Letterkenny and Portadown to Mullingar; reinstatement of the railway line between Lisburn and Antrim, which will enable Belfast International Airport to be connected to the rail network; and improvement of existing rail connections at George Best Belfast City Airport.”