Fifty years ago, on 18 February 1971, a group of friends – all of them tunnellers – met to form a society.
This was in response to a previous international conference on tunnelling that had taken place in Washington DC and which had suggested that each country should have a focal agency for tunnellers.
“Sir Harold Harding was the leading light. I think the committee more or less selected themselves,” says Ken Spiby (see article on p25) who is compiling a book of recollections to mark the anniversary. “Britain needed its own society in order to be affiliated to the International Tunnelling Association (ITA-AITES) which was then being formed.” Thus the British Tunnelling Society (BTS) was born.
In the half-century since then, the BTS has become central to UK tunnellers, for its expertise, and for improving knowledge and safety in the tunnelling community. Its monthly presentations and lectures, and the gatherings at the bar afterwards, have united tunnellers in a way that few other engineering disciplines enjoy.
The Society is also renowned for training – it is heavily involved with the nation’s only MSc course in tunnelling, at Warwick University; for setting standards for the UK and the EU that are frequently also adopted elsewhere; for publications and design and best practice guidelines; and for promoting awareness of underground space.
“The Society was founded as an affiliate of the Institution of Civil Engineers (ICE) and has always been based at their building in Great George Street [Westminster], a kind gesture on their part,” says Oliver Bevan, BTS chairman from 1981 to 1983. “Harding’s idea was that the BTS would have a range of members beyond that of the ICE. He particularly hoped that it would include the inspectors and foremen who are in many ways the backbone of our industry. I was pleased to have been in that founding group.”
“It is among the most active of the learned societies attached to the ICE – at least if the bar takings are anything to go by,” says Dr Myles O’Reilly, who is now 89. “It is a very friendly place.” But what makes it so special?
“It is special in part because tunnelling is a niche sector,” says Spiby. “It is an unusual career for engineers, which has made it just the right size: everybody knows everybody else, or at least has acquaintances in common.
“And tunnelling is a harsh environment, which makes for bonding among those who work in it. It was unpleasant thirty years ago. Tunnelling involves less physical work now; it is kinder on the body. There is more machinery and mechanisation, more concentration on safety.” Those changes are in no small part due to the BTS, which has promoted and encouraged new methods and which has campaigned tirelessly for improved practices and better health and safety underground.
At its founding, the Society had 60 corporate and 270 individual members. Today, those figures are 96 and 808 respectively. “The main activity of the society has always been its monthly evening meetings,” says Bevan. Then there is the Harding Prize, which is for a paper given by a younger engineer on a tunnelling subject; and the BTS also awards the annual James Clark Medal to an engineer either for work on a particular project or for lifetime achievement in the industry. And in recent years a group for younger members (BTSYM) aged 33 and under has been founded, running jointly and separately from the main group.” Bevan himself is the 1992 James Clark medal holder; Myles O’Reilly won his medal in 1998.
The society also has an official magazine, Tunnels and Tunnelling International (T&T) on which O’Reilly served for more than 20 years as chairman of its editorial advisory board. “Back in the 1960s, I was advising on a project on the India-Tibet border, which was then a closed area and more isolated even than it is now; I found copies of T&T on my host’s waiting-room table when I got there,” he says. “So the magazine really is read worldwide.” O’Reilly retired from that post in 2015, when he was 84; tunnellers do not skimp on their services.
Chunnel
The Channel Tunnel can be claimed to have been transformative for British tunnelling – not least in that it made politicians aware of the potentials and possibilities of going underground. At the founding of the BTS, it was slightly more than a visionary’s gleam, for Napoleon had contemplated building a tunnel back in 1802 to help him invade England.
The first trial excavations for a Victorian effort were dug in 1882; they used a 2.13m-diameter Beaumont-English boring machine driven by compressed air, and mined 1,900m from the coast of Folkestone; a similar distance was achieved from the French side, before the effort was abandoned.
One of the earlier functions of the BTS, and of Sir Harold Harding in particular, was advising the then Thatcher government on the outlines of the modern project. Margaret Thatcher disliked rail and was strongly determined it should be a road tunnel. As recounted in his memoirs ‘It’s warmer down below’, edited by his daughter Amanda Davey, Harding had forcefully to make the argument to Thatcher for rail rather than road. That he succeeded is a tribute both to the strength of the argument and to his persistence.
“Tunnelling was very different back then. TBMs were not in general use,” says O’Reilly. “And tunnelling has increased hugely in importance since those days. The amount being done in the UK now is colossal.”
HS2 is a high-profile project, as is the Tideway sewer project with its huge benefits to public health and control of river pollution: spoil is evacuated by river, reducing carbon emissions and road congestion.
Crossrail is the biggest infrastructure project in Europe, described by Ivor Thomas (BTS chair from 2018 to 2020) as open-heart surgery under the beating heart of London. Thomas was BAM Nuttall’s tunnel manager for the twin TBM drives on Crossrail between Paddington and Farringdon. Now, he is tunnel manager for the western drive of Tideway.
“Tunnelling is the most challenging of all civil engineering disciplines,” says Thomas. “Anything can happen underground. Things can change dramatically within a minute. The whole focus in tunnelling is on the face, and that is especially true of tunnel boring machines, so engineers down there have to act quickly. That is very challenging. “
“There are more high-profile projects than there used to be,” says Thomas. “There has been a constant demand for tunnels, a constant workload, but the projects have changed as techniques have improved. In tunnelling, as in most disciplines, all innovations are small step-changes. TBMs may seem a very dramatic change, but Brunel used a shield on his Thames Tunnel” [constructed 1825-1843] “and Greathead improved on it not many years later.” Greathead’s shield was used on the early London underground tunnels.
Developments in TBM technology have extended the nature of the ground that we can work with, and this has opened up space for different uses.
“Size has got bigger. Four metres in diameter would have been a large TBM at the start of my career,” says Thomas. “The proposed Lower Thames Crossing will be 16.5 metres. Shotcrete has made an enormous difference to [station] platform architecture. In London, that was demonstrated by the open nature of the platforms on the Jubilee Line, which opened in 1979; the public will be wowed by the platforms on Crossrail.”
Safe Practices
There is a continuity in tunnelling, and for the past 50 years BTS members have played a major part in new tunnelling innovations, contributing hugely to safe practices.
Hyperbaric tunnelling is an example. Donald Lamont is director of Hyperbaric and Tunnel Safety, but for over 20 years was head of tunnel and ground engineering for the UK Health and Safety Executive (HSE). He also is the James Clark Medal winner for 2009.
“The concept, of a ‘super sewer’ under the Thames, meant that it would have to go deep and would need to be dug under pressure at more than the 3.5 bar which was then – and still is – the legal limit. I knew we would have to find ways to safely, and legally, overcome that limit.”
Lamont was well placed to do so, being the HSE compressed air specialist. “Fifteen years on, HSE still had no guidance on high-pressure techniques and had no great interest in them”. However, in 2010 the ITA H&S Working Group, which Lamont chaired, decided to draft guidance on high-pressure techniques. The BTS, through its Compressed Air Working Group (CAWG), had the relevant expertise. He approached them and suggested they could work together. CAWG agreed. The first edition of the ITA/BTS CAWG report was published in 2012, and work started on a revision straight away. That first revision came out in 2014 at which time the technique was not much used.
“So, we at the BTS were leading the world in high-pressure compressed-air safety guidance and published the second revision in 2018”. Currently, CAWG is finishing a revision of the BTS ‘Guide to the Work in Compressed Air Regulations.’”
“Another health issue to be tackled by the BTS was Hand Arm Vibration Syndrome (HAVS). Jack Knights championed a BTS guide on it. Hand tools are less used in tunnelling now, so the problem has declined.
“However dust exposure is a problem that is not being tackled as seriously as perhaps it should be, given the increasing use of shotcrete, which essentially generates dust in the tunnel atmosphere, as does the use of spray waterproofing membranes. We need to ensure that current tunnel projects do not create a legacy of lung damage in the workforce.
“Over the years, the greatest change in the field of health and safety has been the change in attitudes,” Lamont explains. “Safety culture is something else that the tunnelling industry has done a lot to improve.”
Meetings and Prizes
Thursday evening meetings at the BTS remain an essential part of the values and the attraction of the Society. Once a year the meeting is devoted to the Harding Prize where young engineers (under the age of 33) present a paper on any aspect of tunnelling; the winner and finalists receive a cash prize and also have their papers published in Tunnels and Tunnelling International.
“A big thing for me is upcoming engineers,” says Roger Bridge, BTS chair from 2014 to 2016. “There is no established route into the profession. Like most others, I more or less fell into tunnelling. There is the Warwick MSc course, and some come as I did through the Cambourne School of Mines, which is now part of Exeter University, but we need to reach school leavers. So the BTS has produced a ‘teachers pack’ for STEM (Science, Technology, Engineering and Maths) aimed at school sixth-formers.” John Corcoran, the 1991 Harding Prize winner, has been responsible for setting up the evening meetings and arranging speakers; he also sorts out the sausage and chips in the bar afterwards.
“In a perfect world, presenters show what they have done, what the challenges were and how they were overcome. We balance construction with design; and I think it true that those informal sessions after the presentation are a huge part of the value of the BTS. Tunnelling is a quite small industry. You get to know most people within it.”
The other major accolade of the Society is the James Clark Medal, awarded for a contemporary achievement in tunnelling, for innovation or responsibility for a large project, or for a major contribution to the industry. Past recipients have included Alastair Biggart, John King and Colin Kirland, for the Channel Tunnel (1991); Roger Remington for the London Ring Main (1993); and Hugh Docherty for the Jubilee Line (1996). In 1994, the award went to John Bartlett, whose bentonite tunnelling machine, patented in 1964, was the ancestor of today’s pressurised TBMs and was the first machine to enable the excavation of non-cohesive soils safely and on a large scale. Donald Lamont won the award in 2009. The 2020 winner was Helen Nattrass.
A Future Role
What then of the future? “One big recent advance now in common use has been shotcrete, while one being worked on now is Hyperloop,” says Spiby. “That demands very straight, very smooth tunnels. We will need to increase the speed and lower the cost of tunnelling to make it work. Ideas for that are floating around with a BTS report and workshop.
“Less futuristically, TBMs move themselves forward intermittently, pushing against the last segment ring they have installed. Laying segments in a spiral arrangement might allow the TBM to move at a constant speed, more efficiently and saving energy. And finding ways of reducing concrete use and carbon emissions is of course vital.”
Green Tunnelling
The BTS has long been concerned with sustainability. As far back as 2002, BTS honorary life member Rodney Craig addressed the issue with a report produced for the ITA on Underground Works and the Environment. Benefits of tunnelling include preserving city space, rural environments and habitats.
“There is an ever-pressing need to reduce carbon input,” says Thomas. “I am a contractor and our desire is to drive down costs. That has a dual effect of driving down CO2 emissions; so there is strong incentive to use less concrete. Sustainable solutions are what it is all about.”
“Tunnels will develop” says Thomas. “What effect the pandemic will have on the future we don’t know. But I don’t believe it will reduce our appetite for travel; there will be more trains, more roads and more need for water. Surface space is limited, so we will need tunnels. The Society will still be needed and around in a hundred years.”
“The BTS is all about meeting people,” says Roger Bridge. “We are here to share knowledge. That is really what it is about.”
