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Unanswered HS2 Questions

1st May 2019

Wendovers HS2 Questions to the Minister.

Our redline objective revolves around the first question

Will the Minister set up a face to face meeting where Wendover’s tunnelling experts and DfT/HS2/MWCC experts can establish the true facts surrounding this Wendover Mined Tunnel Proposal?

This meeting is crucial, for Wendover and for HS2, to moving the project forward.

Further questions are....

A. Why does the DfT continue to insist that the Wendover Mined Tunnel by OTB Engineering was examined in both Houses at the petitioning stage?

This is wrong. The high level concept of the Wendover Mined Tunnel was only briefly examined in the Lords, and they felt that their TOR’s meant that they could not recommend technical alterations of this sort in any case.

A detail proposal, by OTB Engineering, has evolved since that time with the full report being passed to government on the 15th of January 2019, through David Lidington MP.

This report was also shared with HS2 engineers and their feedback is that it is a doable scheme.

Small variations would be required to bring it inline with their in house engineering principles.

B. Why does the DfT insist that Wendover Mined Tunnel would be totally submerged under the water table for much of its length?

This is wrong. HS2 Ltd know that the horizontal alignment would in fact be above the water table for much of its length, and only the most northerly section would be partly below the water table.

The established fact is that the only dewatering problem is particularly applicable to the Bill Scheme cut-and-cover tunnel construction which the Main Works Contractor (MWCC) is now struggling to address.

C. Why does the DfT believe that Affinity water abstract water for human consumption in the Wendover area.

This is incorrect. The nearest Affinity Water extraction is adjacent to Great Missenden, and the Wendover Mined Tunnel proposal has no bearing on it.

D. Why does the DfT maintain that ground water would be a problem for tunnel construction?

This is wrong. The Wendover Mined Tunnel scheme will be free draining during construction and will have little effect on the aquifer and require straightforward water management.

After construction of the Mined Tunnel the water table will return to normal and the tunnel being totally sealed, will just require simple drainage.

In contrast the Bill Scheme cut-and-cover tunnel and large long cuttings will have a permanent effect on the water catchment in the area due to a phenomena called trench leakage. This will require active and costly intervention for the life of the scheme, particularly if assurances given to the DfE are to be met.

E. Why does the DfT repeatedly state that the geological conditions would be unsuitable for mining a tunnel?

This is incorrect. OTB Engineering, who design and build tunnels all over the world, consider that the ground conditions are completely suitable for mined tunnelling.

F. Why does the DfT fear that there are scheduling difficulties associated with the Tunnel proposal?

It’s late to be changing construction methods but not too late. The design is not complete and no irrevocably instructions affecting detailed design have been issued.

Any time pressure is entirely due to DfT/HS2 Ltd’s intransigence and a poor initial design.

In construction terms by simplifying the existing rather complex, viaduct 1, viaduct 2, green tunnel scheme into a simple mined tunnel alternative saves many months of construction time.

Driving the tunnel from 3 or 4 faces considerably reduces the timescale required to construct the fabric of the tunnel and provides early and essential access to the “trace” route for spoil and plant movement throughout the area.

G. Why does the DfT maintain that the Bill footprint limits would be exceeded by converting to the tunnel proposal.

This is wrong. Illustrations of how the Wendover Mined Tunnel footprint could be incorporated in the existing Bill Scheme limits have been provided repeatedly to DfT and HS2 Ltd in answers to various questions raised over the intervening period.

H. Can the Minister clarify how HMT and IPA do not appear to know about the tunnel costing model that appears in the HS2 Ltd document ‘Guide to tunnelling costs’ and which was used during the Petition Hearings?

HS2 documents in fact references the ‘model’ published by HM Treasury and Infrastructure UK which was produced for HMG by the British Tunnelling Society.

I. Can the Minister explain how such ugly, bog standard, viaducts are being imposed onto the Chilterns AONB in direct contravention of the expressed will of both Houses of Parliament.

See. paras 127 and 138 in the Lords Special Report, specifically mentioning the Ribble Valley Viaduct as a example of how good design can become part of the landscape.

An engineer for the MWCC introduced the Small Dean Viaduct to the community, in a public meeting, as follows. “I can’t sugar coat this, it’s a bit of a monster”. That’s the builders impression, you can guess what the Community thinks.

J. Can the Minister explain why so much of the social and fiscal capital of a Community and it’s Parish Council is needed to attempt to improve a flawed Government proposal and to highlight a major opportunity to save public money?

Why has that community’s efforts been repeatedly dismissed so patronisingly?

K. Can the Minister explain how if HS2 is an economic stimulus for the whole country, it is acceptable for it to strangle the A413, one of the most important economically strategic roads linking the Vale of Aylesbury, Milton Keynes and areas beyond to the M25, Heathrow, London and the Channel Ports?

The proposed Small Dean Viaduct as designed is certain to restrict the road for years during it’s construction and prevents any future improvement to the roads capacity permanently.


We are all intimately aware of instances where HS2 Ltd intransigence has caused local organisations considerable angst for the last 6 years before relenting and adopting more practicable solutions that had been suggested from the outset once real engineers came to the project. Indeed there are local instances were Parliamentary Assurances have been ignored by HS2 Ltd. The Wendover Mined Tunnel is another simpler, quicker and cheaper solution that solves many of the problems associated with the Bill scheme.

We don’t know what was reviewed but it wasn’t the WPC scheme.The review conclusions, clung to so desperately by Ms Ghani and Mr Grayling, contains so many major errors that it clearly wasn’t looking at our scheme. Wendover believes that this is as a result of the way that the review has been conducted. This was not an evidence based review. No requests for any documentation or clarification requests have been received by WPC or OTB Engineering from the IPA, SDG, Nichols Group or KPMG. That the review reports generated by these, quite erroneous reviews, are not being made available to Parliament or to us is particularly unhelpful.

We conclude that the Minister(s) may have been misled and that the only way of the benefits, to the project and to our community, accruing from the Wendover Mined Tunnel to be fully and fairly explored is if DfT host and chair a round table meeting between WPC, OTB, DfT, HS2, MWCC. If our experts meet their experts

Cost is often brought up as a reason to dismiss the Wendover Mined Tunnel. Our position is that any claims that we make are double checked. We have used industry standard costing models and retained Michael Byng, a world renowned expert on infrastructure costing to calculate our costs. Equally well known tunnelling experts OTB Engineering have designed our tunnel and crossed check the Byng costs. The variance is negligible. We are confident in our price.

HS2 have no idea how much their project will cost. Both the outgoing chairman and the new one admit to that as does the Chief Executive. They have not been able to substantiate any of the prices that they used in the Petitioning process. They were wildly inaccurate with their tunnelling costs at that time and seemed to have no idea of how much of anything that you get for your money today. The MWCC are getting to grips with the real costs and HS2 ltd are wriggling and shuffling and desperately looking for a way of reducing the scope and range of the railway to save money.

Tom Walsh, Chairman



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