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Your View | More Heathrow challenges

Cam 01 web cropped

In the December 2016 issue of New Civil Engineer, which highlighted our role in fighting floods, the editor rightly says that the elephant in the room is climate change and that the £1bn annual cost of flooding is similar to the cost of not having another runway at Heathrow. However, the benefit of a third runway is purely speculative, whereas the cost of flooding is almost bound to rise.

Moreover, the roundtable on airports headed “Can we deliver sustainable airports?”, states that airlines intend to cut carbon by creating forests or funding carbon reductions elsewhere. How many trees have airlines planted to date? As global warming is causing forest fires as well as floods, increasing flights may have dire consequences – an ethical dilemma for engineers who will be glad of the work entailed in building a third runway.

  • Richard Bloore (M) richardbloore@hotmail.com

 I was perturbed to read both the Comment and Lighthouse in the December 2016 New Civil Engineer. The editor is telling us “we must support Heathrow” and those who do not believe in this third runway project are “cynics”. Well, my engineering background has taught me to question and be rational, considering all aspects of schemes including the environmental and human aspects. 

 In a similar vein, Lighthouse talks about Heathrow, Hinkley and High Speed 2, and tells us to “come together to support a shared set of goals” and “get behind Armitt and support his work”.

The Heathrow area is already overheated; the M25 has five often stationary lanes of traffic in each direction, other roads are frequently severely congested, the area is already over the air pollution thresholds, killing and adversely affecting the health of many, and noise pollution is adversely affecting thousands of residents. The scheme is being pushed by big business, but opposed by most of the locally elected democratic representatives. On a practical operating point, how can this world class airport operate with night flying restrictions, or will those be overturned too?

Regarding Hinkley, do we want to tie in doubled electricity costs with foreign-owned companies, and also have design and financial control by a country which has been far from an ally? There was a chance to have an exemplar energy scheme with wind, solar and tidal power on the same site, at probably a fraction of the cost and with none of the controlling restraints.

I feel alienated by New Civil Engineer and the ICE’s positions on these subjects, and so will not be renewing my membership. My subscriptions may be better spent supporting more environmentally sound organisations.

  • John Lee (M) lee316@btinternet.com

It is difficult to believe that our profession appears to be supporting the architectural fancy being promoted for Heathrow. It is a wart of an airport outside an airport. The concept is impractical strategically, technically, operationally and financially. I do not need vast studies to support this position based on my experience of being charged with creating the concepts for Maplin, Terminal 4, North Terminal Gatwick, Stansted and Terminal 5. The perpetually overlooked answer has always been Stansted. I lay myself open to Parliamentary or any other challenge. Meanwhile the national interest is suffering and the planning blight is cruel because of the delay in finding a solution to the immediate and long term need.

  • H Pageot (F) Posted online on article headed “New Heathrow runway gets government approval”

The suggestion that the major airports could be joined together by high speed rail connections was dismissed by the editor on the grounds that they are in different ownerships

This has no validity. Companies frequently act in concert if they find it to be of mutual benefit. Early in the third runway discussion, spokespersons were heard being almost contemptuous in their dismissal of building the new runway at Gatwick and linking it by high speed railway to Heathrow, to create a four runway hub. At High Speed 1 speeds, this would take about 17 minutes. The dismissals of this idea, previously dubbed Heathwick, were doubtless made for narrow commercial interests rather than the national interest.

A serious examination of what appears to be a good solution would be interesting.

  • Ken Bowman (M) kandmbowman6@gmail.com

 

Resilience needed for population growth

I agree with your Comment on infrastructure renewal and resilience (New Civil Engineer December 2016). However, I think you missed the mark with your elephant in the room metaphor. Coping with climate change appears as a subject of topical interest in a wide variety of publications, including New Civil Engineer. The real elephant in the room is population growth.

  • David Crook (M) damel@shaw.ca

 Aberfan showed need for tip compaction

Letters in New Civil Engineer’s December issue discussed alternative explanations for the Aberfan disaster: the “sealed off” pore pressure below the spoil tip; and the build-up of pore pressure within the spoil tip. These suggest under drainage and/or pore pressure measurement as the respective precautions.

Both explanations are true but miss a third factor related to uncompacted or insufficiently compacted fill, which is not necessarily relieved by under drainage or registered by pore pressure measurement.

Excavation and tipping entrains 20% to 30% extra air voids which can mostly be removed by compaction. If left uncompacted, the air gradually seeps out (or is replaced by water) as the unstable voids very slowly collapse. The void collapse is a creep process known as collapse settlement which can be accelerated by shocks or stress and moisture changes.  Eventually the fill stabilises at a higher density and moisture content. However if the initial 30% extra air voids are fully flooded, and collapse is initiated locally, there is nowhere for the excess water to go to and static liquefaction spreads suddenly and rapidly through the fill, as at Aberfan. This sudden spread cannot be reliably predicted or detected by pore pressure measurement, or instantly relieved by under drainage.

The moral of Aberfan is to compact all major fills as they are placed, especially on sloping ground, or as possible future parts of a mining operation such as a tailings dam. The cost of compaction is minor compared to the excavation and transport, and the fill remains re-usable.

  • David Cox (M), david.cox37@btinternet.com

50mph Speed cut would save money…

I have a suggestion for saving High Speed 2 costs – drop the operating speed from 250mph to 200mph. That would guarantee a reduction in design and construction costs. However, I doubt HS2 Ltd engineering director Tim Smart and his masters would agree to anything so sensible – for obvious reasons.

  • David Watts, posted online on article headed “Technical challenges still to be faced’ on HS2”

 … But not that much

I don’t think you’d see much cost saving. The standard operating speed assumed for timetabling is 205mph, with a maximum design speed of 225mph to allow time to be made up if there is minor disruption. The alignment is designed to allow running speeds up to 250mph in the future. Seems like sensible future-proofing to me. As an industry we are quick to point out the bad consequences of penny pinching on previous infrastructure projects, yet when it comes to HS2 we can only see the cost and not the value.

  • Andrew Thomson posted online on article headed “‘Technical challenges still to be faced’ on HS2’”

Are we really such a bunch of doozers?

I read the ICE-led National Needs Assessment with interest to see what this high-powered group had produced and was not disappointed.

The document provides the government with a clear way forward. However, there is a major issue which demonstrates the mindset of ICE members – rather like the Doozers of “Fraggle Rock” we would rather build new things than look after that which we already have. Other than a few minor comments in the Welsh section, there is only one short paragraph relating to asset management, which I quote: “Much of the UK’s infrastructure such as sewer systems, rail network infrastructure and housing stock have been serving the UK for over a hundred years; much longer than originally designed for. Many of these assets now need replacement or investment to extend their lives. Given current economic constraints, a strategic asset management approach is required to provide clear prioritisation and better performance.”

Surely an issue which commands more capital investment than building new assets, should have been given greater prominence?

 

Carbon reduction questions

The UK has just signed the Paris Agreement on Climate Change with carbon emission reduction targets of 90% by 2050. The civil engineering profession has a key role in achieving these targets, and what we plan and build now is fundamental in delivering this.

 Is it an intelligent adaptable profession embracing change and engaging with the great issues of the day?

These are tectonic shifts in our lives. The transport sector is a vital part of the economy and contributes roughly a quarter of CO2 emissions; engine efficiency improvements are not going to deliver in the required order of magnitude. We have incredible computing power readily and cheaply available and working smarter and using spare capacity are fertile areas for change.

Cars are convenient and hugely popular. Being seen as anti-car is political suicide, yet how we achieve the Paris Goals with current car usage patterns is hard to see. But if we are taking people out of traffic jams and out of long commutes rather than out of cars it just might sell.

Meanwhile the aviation industry contributes 6% of UK’s CO2 emissions. How do we achieve sustainable CO2 emissions and air quality levels while expanding capacity? If we are to reduce emissions by 90% – and even if aviation emissions remain at their current level – my schoolboy maths tells me they will take up 60% of our quota: and this is mostly for leisure travel, mostly by wealthier citizens. Can someone explain the intelligent engaged thinking behind that?

  • Chris Edwards Chris.Edwards@carillionplc.com

Short sighted monitoring

Great points for debate. Box Tunnel presented a real opportunity to maintain the monitoring system in-situ. That opportunity was offered to the asset owner. A decision was made not to take up the offer. Short term funding seemed to be a driver rather than considering the benefits of using data to inform the maintenance strategy going forward. Brunel constructed Box Tunnel 175 years ago. It was subsequently lined and remained stable for 120 years and during the major track lowering in 2015. Other assets do not remain stable during major enhancement works, and assets deteriorate and impact performance, resulting in significant direct and indirect costs.

  • Paul Clarke, posted online on article headed “Digital: a matter of life and death”

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