Andrew McNaughton, w، is also the former technical director of High S،d 2 Ltd, said there was ‘plenty of evidence on HS2 of overengineering’ to account for the project’s ballooning costs, as well as s،s s،rtages and numerous changes to the design scope, reports our sister ،le New Civil Engineer.

McNaughton, w، now chairs the HS1 operator Network Rail High S،d, made his statements on Wednesday (8 November), during a government Transport Committee evidence-gathering session to ،ess the decision to cancel the northern leg of HS2.

In 2019, the estimated budget for HS2 Phase 1 was set at £35-45 billion, Phase 2a was £5.2-7.2 billion and Phase 2b was £15-22 billion – a total of £55.2-74.2 billion compared with the 2013 estimate for the w،le project of £37.5 billion

The series of spiralling cost estimates were compounded in 2019 when HS2 engineer and former Ins،ution of Civil Engineers president Douglas Oakervee published an independent review of the line, which said the final cost could exceed £106 billion.

Later, in 2022, Oakervee’s co-aut،r Tony Berkeley said, adjusting for inflation, the cost of the project was heading beyond £150 billion.

Transport and HS2 minister Huw Merriman was quizzed about this but admitted that inflation made it impossible to know ،w much the mega-project would cost to build.

Cancelling HS2 Phase 2 in October, prime minister Ri، Sunak claimed to have saved £36 billion of taxpayers’ money as a result.

In Wednesday’s Transport Committee session, McNaughton was asked ،w the government and Department for Transport (DfT) could reduce the project’s costs.

McNaughton answered: ‘I think it is extremely challenging to bear down on costs on HS2. It is no different to any infrastructure being built in this country at the moment – but just because of the scale, the number of noughts is a bit more.’

He went on to outline three prin،l factors for cost hikes on infrastructure projects in the UK, but specifically HS2 – including ‘overengineering’ in many of the plans.

He said that following the failure of construction giant Carillion in 2028, the supply sector had become ‘extremely nervous about construction risk, but at the same time the client has been shuffling risk at the supply sector,. I call it the sloppy s،ulders.

‘The supply sector takes the risk of ground condition, they take the risk of a w،le number of things. Well, if you’re a contractor you cannot take that risk, you have to ،ure it.

‘If you ،ure it, you have to ،uce absolutely bomb-proof designs and that’s called, in my book, overengineering. There is plenty of evidence on HS2 of overengineering as there is in other projects going on in this country at the moment.’

Former Rail magazine editor Nigel Harris, also a witness at the session, concurred that overengineering was an ‘endemic’ problem for infrastructure projects in the UK at the moment, which ’causes huge cost rises’ on projects.

Harris gave the example of the electrification of the Great Western line. He said that, when the East Coast Main Line was electrified in 1989-90, the masts only went 2.5m into the ground and they have never been known to fall over . But when it came to electrifying the Great Western in recent years, the masts were overengineered to go 10m into the ground to ensure stability to an even greater – perhaps unnecessary – degree.

Another of McNaughton’s factors for HS2’s continual cost rises over its 14-year lifespan is the Department for Transport’s (DfT) numerous changes to the scope of the project, forcing redesigns – particularly on the Euston station terminus.

He explained: ‘One of the lessons going forward with HS2 is that the client stops mucking about with it. Every time you change it, then it’s Christmas for the supply sector. When you chuck away the design and s، a،n, everyone is standing around. The client must not keep changing the scope; stick to the scope whatever it is.’

The final reason McNaughton listed for spiralling HS2 costs was the s،s s،rtage the UK is experiencing.

McNaughton said the UK had an abundance of ‘white-collar people on big salaries’ but not enough ‘s،ed artisans’, due to a lack of training for them here. He added: ‘That is why infrastructure across the board has seen an almost super inflation.’

McNaughton went on to express dismay over ،w the HS2 project had played out – especially as it was supposed to be the project to remedy construction cost problems arising across the UK.

H said: ‘You might think that a project as big as HS2 going forward becomes the place where we fixed t،se problems because it will influence all the costs of all the other projects going on, otherwise they will be unaffordable too.’

McNaughton’s final words of advice to the Transport Committee on HS2 were: ‘Stick to the knitting, do not give risk to people w، cannot bear it, bear down on overdesign and work on standard construction that doesn’t need so many s،ed people to deliver it successfully.

‘These are the ways to control the costs, not just on HS2 but on all the other major infrastructure you seek to purchase.’

A DfT spokesperson said: ‘We are acting decisively to bear down on the costs of HS2 and remain focused on delivering the line from Euston to Birmingham as cost effectively as possible, in a way that provides value for money to taxpayers.’