HS2 is about to enter an interesting phase. “Interesting? It’s always in an interesting phase!” The surprised interjection was by Andrew Coombes, HS2 Ltd’s head of specification and assurance.

It is a great way to start an interview and find that the latest part of this massive project is indeed just one small part of a truly interesting whole. No wonder the repost – a point well made.

So, what’s happening now? HS2 Ltd is in the process of compiling the submission for the hybrid bill for the first phase of the network, whilst continuing to progress the development of the more northern second phase. So is this hybrid bill really engineering or just a vast paper exercise? Well, it’s certainly engineering on a grand and detailed scale – although there’s plenty of paper involved too.

Parliament – that collection of our elected representatives (bless ’em) – has to satisfy itself that the new railway line between London and the West Midlands is adequate and appropriate and that, through it’s component parts, it will be usable, affordable and operable. All these are stringent tests and through a process of petitions and queries HS2 Ltd’s work will be put under the microscope. HS2Tunnel

Andrew looks back at the previous ‘interesting stages’ to see what has gone on before. Right at the beginning was the route optioneering work carried out pre-consultation. Curving and alignment rules coupled with service and passenger assessments gave the basic positions of various options for the railway. The consultation process which followed and which was completed in January 2012 fixed the core alignment.

Land required

The hybrid bill is all about establishing the land requirement – how much land either side of the core alignment is needed to accommodate the railway and all its associated equipment. It’s also about how much is required for the railway to be built and to enable suitable environmental mitigations. So there are both permanent and temporary parcels of land involved. All this presupposes a high degree of construction detail.

The submission may not contain many of what a railway engineer would recognise as working drawings but, supporting the formal submissions, these are almost exactly what have been prepared. This level of detail is needed so that the full complexity of the project can be understood.

Looking at it in a different way, the bill is a railway proposition for something that could be built in a certain way but without stating that that this would be exactly the way it’s going to be built. “We know how it could be run. We know how it could be built. We know how it could be operated but we’re only homing down on the land issue initially.”


The bill submission recognises the need for reasonable construction access, how it is going to be used and then how it would be returned. Another example of why land is required is for environmental landscaping. Quite a bit was learnt from HS1 when it was found necessary to negotiate additional lands for landscaping after the bill. “Our environmental colleagues are encouraging us to think about this now rather than later, so that we try to ask only once for land rather than going back again.

“Bill submission should be just the once – you don’t go back. But it’s a tricky call between affecting people and properties that, in the end, you don’t need to involve versus having to approach them later.”

The environmental effects are a major part of the submission. In fact the largest part deals with the effects that the construction and operation will have on the environment and what is being done to mitigate these.

Of course, at this stage it would be prudent to build in a degree of future proofing. So the maximum number of trains that can be accommodated is known, as is the maximum speed of trains – higher than today. All of this reverts back to a mix of basic physics, anticipation of future demand and technology developments. The constraining envelopes are to do with acceleration and braking capabilities along with noise constraints.

Power and other third party utilities

Part of the test of the bill is that the railway has to be usable, affordable and operable. “So if we are promoting an electrified railway we need to demonstrate that power can be fed into it in adequate quantities!”

There are two aspects to this. One is a power requirements analysis which leads to power feeding arrangements. Then there’s the engagement of National Grid so that there’s an understanding that they can actually supply sufficient power at the feeding points. Within the bill itself, land is sought so that the supply points and the feeder stations can be built.

All the third party utilities have to be discovered and the effects on them understood. And that’s everything – power lines, telecoms, sewers and even a whole range of high pressure oil pipes. All the utility companies need to be involved to minimise the affects on their businesses.

So what was the starting gun?

The starting gun was the Secretary of State’s announcement of the results of consultation and of the preferred route for the first phase. This ‘post-consultation route’ is a line on an Ordnance Survey map and in the station areas it’s a box.

The stations are at London Euston, Old Oak Common (interchange with Crossrail), Birmingham Interchange (NEC/Birmingham Airport/Birmingham International station) and Birmingham Curzon Street (next to Birmingham Moor Street). The railway is non-stop throughout the rest of the route. This aligns perfectly with the policy that this is a high speed line which releases capacity on the conventional network to better serve the core conurbations.


Part of the detail includes a maintenance proposition which means understanding where maintenance loops and recesses are needed. Washwood Heath, Birmingham will be a rolling stock depot and there’s a maintenance depot at Calvert (near Aylesbury) which is approximately halfway along the route.

It was initially thought that there would be maintenance access roads throughout, but this was discounted in the review process. “By the time you’ve gained access to your autotransformer sites, your track feeder sites, crossovers and signalling locations you’re actually quite well provided with access.” HS1 doesn’t have a road throughout – just to the major facilities. But it mustn’t be forgotten that a major access need for HS2 is to tunnels for emergencies.

A single version of the ‘truth’

Detailed Map showing the Calvert Infrastructure Maintenance Depo

Proposed infrastructure maintenance depot near Calvert (Claydon Junction) Bucks.

At consultation, there was a shared cost estimate and that was set against the benefits case for the scheme. This provides an envelope for the cost expectation which has been apportioned to each area of the route. Each area has a target cost or indeed target saving. The design is all being conducted collaboratively between the teams with experiences being shared. “We have focus groups sharing the expertise and understanding. For example, how you build a good high speed viaduct? How you provide ground treatment for a high speed railway? This consistency of approach is very important for choices that directly affect our land requirements – take, for example, slope angles.”

There is a single version of the ‘truth’ – building a CAD infrastructure model which can be shared so everyone is contributing to one design. Pulling up the design for one part of the railway will have the same descriptors as any other part. There’s been a lot of work into consistency to ensure that the design is right first time.

“Going through to future design stages we need to build on this design instead of starting from scratch at each new stage. It’s important to ensure the best design is retained both in terms of a good railway and also in terms of a railway we can afford.”

Using BIM (Building Infrastructure Modelling) techniques, the design feeds off the large projects like the Olympics and LUL but takes the processes further than anyone has taken them before. This gives one block of data from which savings can be made right the way through to commissioning and driver training.

Before and after Royal Assent

The first sod is due to be cut in 2017 although other things can be started officially when Royal Assent is given in 2015.

“Softening up (ancillary) works are trickier as you’re very limited in what you can do before you get Royal Assent. You have no scheme and so you’re expending public money on something that might not exist.” HS2 Ltd is currently working on understanding what early works they could do such as establishing ground clearance in preparation for the major works starting in 2017.

“It’s important to provide major work continuity to people who will be finishing Crossrail and some of the major elements of Thameslink at that stage. In terms of the big picture of construction there’s quite a bit involved in enabling a continuity of effort, the retention of skills and enabling people to keep contributing to the economy.”

The design team

HS2 Ltd has expanded considerably. It has gone from 60 people at the start of 2012 to roughly 300 in their Victoria offices. These include core HS2 Ltd staff, development partner CH2M HILL and smaller teams from TfL and Network Rail. But then there’s the design team of about 500 – 600 beyond that. The design consultants involved include:
•    Ove Arup International who are involved in the civils preliminary design, the systems preliminary design and the environmental issues;
•    Mott MacDonald Ltd – civils preliminary design;
•    Atkins – civils preliminary design and the environmental issues;
•    Capita/Ineco JV – civils preliminary design;
•    Parsons Brinkerhoff Ltd – systems preliminary design;
•    ERM/Temple/Mott MacDonald Ltd JV – environmental issues.

Supporting the hybrid bill

What’s coming up next is a process of supporting bill readings and addressing the concerns of petitioners. Once the first reading has gone through it’s pretty much established that the country wants the high-speed railway line and that it has government support. In terms of day to day involvement, HS2 Ltd will have to keep providing supplementary evidence that things are correct and appropriate.

At the moment, it is vital that everyone understands the reasoning behind the designs. Again, this is why this single design record and evidence is so important because of the coming challenges.

There are exciting times to come from late 2013. So that will be another ‘interesting phase’?

“Of course! Just yet another!”