Perhaps one of the greatest of the railway inventions is the humble points. In the USA they are called switches, which is more descriptive. Because with points you can switch a train from one track to another. Points allow you to create a network. The earliest trains were A to B. Now the same train could go to C afterwards, maybe even get to D on a good day. 

HS2 will not be a point-to-point railway line, it is part of a network.

Most of the HS2 publicity is around the onwards connections that will be possible when HS2 joins the classic railway, for example at Crewe, where trains will continue running north but more slowly. But there will be network connections at the southern end of HS2 as well, and not least will be the connection to HS1, the existing high speed line from St Pancras to the Continent.

HS2 to Paris, via HS1

What could go wrong? Well, a worry I have is based on the Regional Eurostar debacle. It was 25 years ago when we wasted an opportunity to have trains running from all parts of England, Scotland, and Wales through the Channel Tunnel to Paris. A timeline is given here (final page of pdf).

This new service almost started – the new trains had been delivered, the staff were qualified, the tests runs were underway – but the project spectacularly fell apart, with Parliamentary enquiries for years to come. And to this day everyone involved seems to have a different reason to give for the Regional Eurostar project failure. My suspicion is that all the railway companies that bid for the franchise cherry-picked the London route alone, and with railway privatisation coming in a few years the government gave way. I have written previously on the practicalities of re-instating the Regional Eurostar project aims ahead of the completion of HS2, here.

We need to learn from the past attempts and look forward to making it happen this time.
And in the world of railways the devil is in the detail. A project can have twelve elements, and if only one element fails then the whole project fails.

At the moment the critical factor seems to be immigration systems. Immigration controls for HS1 are done by British officials working in on the railway station platforms in Paris (and in Brussels and Lille). That way, there are minimal difficulties once in the UK, and the British tabloids don’t need to worry about migrants pressing the emergency stop button and running away through the fields of Kent. 

But following Brexit and the Calais migrant camp issues, the French government has said this working arrangement is now in doubt, and will be thrown into the big pot of Brexit negotiation issues. Worse, because it is a bilateral agreement and not an EU agreement, it could be terminated by the French government anyway, even if lawyers might complain about the abrupt process. 

Would this be a bad development? Consider some alternatives:

1. UK immigration checks happen in Dover. Every train stops, people get out and are checked, then they get back on the train. This process already happens (in Lille) for the winter special ski trains from the south of France.
2. UK immigration checks happen at the arrival station. This would start with St Pancras and Ashford, but would need to also happen in Manchester (for example) if Continental trains ran on to HS2. But will the British tabloids and politicians accept the risk of people running off?
3. UK immigration checks happen on the train while it is moving. This was the suggested approach for the Regional Eurostar service, but was rejected at the time. It might actually be the least disruptive option now, especially using newer technologies.

All of these options are solutions, the question is which one is to be followed?

So to summarise, at the moment it is: 

HS2 to Paris … via HS1 … via the Home Office.