Issue number 16                                                                                                                                      
September 2017
Nothing stands in the way of progress — not mountains, rivers, railways ... or traffic jams. No-one knows this better than engineers, who for centuries have been working to derive better, safer, quicker and more cost-effective ways of getting round problems by going underneath.

Consider the immense range of these subterranean structures: the catacombs, aqueducts, mines, sewers and waterways, railways and roads, to name but a few. There's a whole world under our feet — so let's try at least to scratch the surface.
A celebration of tunnels and all who bore them
This issue is inspired by the much vaunted re-opening this month of the Post Office's network of underground tunnels in London. These were used from 1927 until 2003 for the distribution, by battery-powered train, of incoming mail from mainline railway stations to London's sorting offices. Along the way, in the 1930s, relics of an even older, pneumatic Victorian system were discovered abandoned.
A replica of London's original underground mail train — which was not designed for passengers and thus only sufficiently comfortable for sacks of mail — travelling along its well-preserved route. Visitors can now ride the route in slightly less teeth-rattling style from the Postal Museum at Mount Pleasant.

photo : copyright The Postal Museum
Read the story here, including the lovely tale of how three dedicated engineers ensured the disused tunnels were preserved.

Visitors can ride the route in replica mail trains &mash; if you can get a ticket, for public interest has been phenomenal.

If the story of the newly-reopened mail tunnels has piqued your interest in what other little-known subterranean routes you might find in the capital, you're certainly not alone. London blogger Thinking Bob (he's not called Bob but let's assume he IS thinking) has published a fun "top ten" list of London tunnels to explore. Bob's site declares his association with, which returns to the theme of London's tunnels frequently: if you don't want to join in with the delving yourself, you could still enjoy these crowd-sourced snaps from June this year.

Finding an actual map to guide you through these hidden pathways is a harder job - perhaps for security reasons, engineering timelines surmises. Artist Stephen Walter, clearly a lifelong fan of worlds underground, has taken steps to fill the gap.  But it may be that the most accurate mapping of some of London's underground networks is still to be found in the work of  investigative journalist Duncan Campbell (pictured below), clearly a man not frightened of getting himself into trouble ...
Investigative journalist Duncan Cambell takes to the tunnels below London in researching his 1983 publication, War Plan UK.  It's still available via his website, which also publishes — for free — some of the tunnel systems he explored.
photo : copyright Duncan Campbell at

Further afield, the best possible source for would-be moles across the nation is the incomparable Subterranea Britannica (note also the society's links to similar associations across Europe). You can spend literally hours down that particular hole... but maybe unravel some thread as you go, so you can find your way out again.

Readers may already know of the well-established Ramsgate Tunnels project, (re)opened to visitors in 2014 and, like many heritage projects, always in need of volunteers. Details of the original engineer(s) elude engineering timelines at present but you can read an account of the history published by online magazine Urban Ghost, together with a fine array of photos of disuse.

On a similar theme, engineering-timelines would love to know what has become of the Runcorn Hill tunnel project in Cheshire. From October 2014, quarry tunnels below Runcorn Hill Park, used as air raid shelters during WWII, were being investigated for possible opening to the public. Yet after a much-reported open day on 10 January 2016, although the renovation of the park itself seems to have gone ahead with the support of National Lottery funding, about the tunnels we hear nothing ...
It's boring, yet they're interested! Young(er) visitors study a Lego model of a boring machine at the Institution of Civil Engineers' Tunnel Engineering exhibition before getting to grips with some Lego modelling themselves.
Even for the non-professional enthusiast, there's more to tunnels than just running about in them. For those who want to dig deeper, the Institution of Civil Engineers is on hand with Tunnel Engineering, a comprehensive exhibition on the subject. There's plenty for the professional, the interested amateur and even for children, thanks in part to the involvement of Lego. It runs until November, and a visit to the dedicated website will give you a good idea what to expect.

Additionally, also at ICE but administered by Construct, the Peter Campbell Lecture on 16 November features Bill Tucker and Howard Smith of Crossrail (obtain tickets through Construct). As Central Section Delivery Director and Operations Director respectively, their topic is wider than the extensive and complex tunnelling involved ... But you can't build Crossrail without tunnelling, as any visitor to the existing (and recommended) Crossrail exhibition at the Museum of London Docklands will tell you.
The Tunnelling Shield devised by Marc Brunel to protect workers during construction of the first Thames Tunnel. As historian Mike Dash puts it, writing in The, "His insight led him to invent a device that has been used in one form or another in almost every major tunnel built during the last 180 years." A model of the shield is on display at the Brunel Museum in Rotherhithe.
photo : sourced from Today In Science History / extracted from Google Books free eBook; Stories of Inventors & Discoverers by John Timbs
Not all tunnels lead to Brunel, but when a history of engineering website talks tunnelling in London, it's literally impossible to move on without at least making mention of the Brunels' pioneering Thames Tunnel of 1825-43 (featured here on engineering timelines).

Rather than go over - or under - old ground, those familiar with the Thames Tunnel might like to read through an intriguing collection of historic reactions to the tunnel, both celebratory and satirical, compiled by For anyone inclined to be cast down by public reaction to innovation in our own time, they're certainly worth reflecting on: it was ever thus.

On a related note, the wonderful offers a reasonably-priced facsimile of a 1829 publication, Rotherhithe Tunnel Sketches. Altogether, the site is a great and somewhat dangerous resource for fans of transport heritage — visit at your own risk. The out-of-print books it features are all downloadable for between 50p and £5.00, and they mount up faster than you might imagine.

Could Marc Brunel have dreamed of the Channel Tunnel when he completed his Thames crossing at Rotherhithe? Probably so, knowing the ambition of the Brunels. But several of the world's longest tunnels were built to transport water to the people, rather than people under water.

The longest of all, the 137km Delaware Aqueduct which delivers more than half of New York City's drinking water, was constructed between 1939-45, much of it by boring through solid rock. Photographs are helpfully provided by the New York local government, here.

A billion dollar project is currently underway to repair two massive leaks to the aqueduct that have caused increasing problems since the 1990s. Engineering timelines was happy to read that in March this year, the new, state-of-the art boring machine being used as part of this essential work has been named after one of America's very first female civil engineers - read the full story. And what a name she had: Nora Stanton Blatch de Forest Barney. You'll be relieved to hear that the boring machine which celebrates her achievements answers to the simpler version: just "Nora".

You can see the original press report of Ms Stanton Blatch de Forest Barney's success reproduced on this fabulous blog, An Engineer's Aspect, which is the work of engineering graduate and former Miss Idaho, Nanette South. Treat yourself.
Nora Stanton Blatch de Forest Barney: not just a pretty name, but the first woman ever admitted to the American Society of Civil Engineers.
photo : copyright Coline Jenkins via

As anyone who's going on a bear hunt will know, if you can't go under it and you can't go over it, you've got to go through it. But what if it's blocked?
Fritchley Tunnel, completed in 1793, is the work of railway pioneer Benjamin Outram and believed to be the oldest surviving railway tunnel in the world. Although it looks far from dramatic in its buried state (above), the photographs of the uncovered sandstone blockwork tunnel are beautiful.
Four years ago, in Derbyshire, a short railway tunnel believed to be the oldest surviving example of its kind was recovered after 36 years, reportedly hidden behind a rockery. The rockery itself is undocumented, which seems a shame to judge by the scale of the blockage — it must have been quite a feature in someone's garden. A dedicated website tells the full story, with pictures and a fly-through video clip.

The excavated artefact was duly listed by Historic England.

Meanwhile, illustrating how far (in some ways) we've come since 1793, last year saw the opening of the Gotthard Base Tunnel in Switzerland - the world's longest and deepest rail tunnel (below). That's a title the Swiss have claimed three times during their tunnelling history, including with the first ever Gotthard Tunnel, far nearer the summit of the mountain, which was completed in 1882 and is still in use.
The Gotthard Base Tunnel, which opened in June 2016, is — at 57.09km long — currently the longest and deepest rail tunnel in the world.

No whistle-stop tour of historic tunnels could end without even the briefest of visits to the sewers. Alas, there is not the space or time now to dive into those malodorous depths and view the fatbergs wedged therein!  Our narrower focus is on the appropriately named Shirley Gut syphon — a 79m length of immersed, entrenched, segmented tunnel that forms but a small part of the waste water system of Boston, Massachusetts. It has, however, the distinction of being the first immersed tube tunnel in the world. The Drew Archival Library website gives details, including rare photographs of its construction, drawn from the family collection of one of the facilitating engineers.

The Shirley Gut syphon was installed in 1893. Seventeen years later, US engineer William J. Wilgus, fresh from completing New York City's Grand Central Station railway terminus, installed the first immersed tube tunnel for rail, the Michigan Central Railway tunnel, under the Detroit river. Shorpy's Historic Photo Archive includes a nice, illustrative photo of the launch. Unfortunately, tunnel construction doesn't feature among the free iPhone wallpaper images on the same site, but you might find something else you fancy.

Britain's first immersed tube tunnel, under the River Conwy in North Wales, was completed in 1991, almost 100 years later than Massachusetts' pioneering sewer pipe. It is described here on engineering timelines.
If the French surrealist was able to trick us all in 1929 with his The Treachery of Images (depicted), the British Tunnelling Society would be digging (boring?) circles round him now. The difference between a tunnel and a pipe becomes less and less clear as techniques and technologies are refined and borrowed - pipe-jacking and micro-tunnelling, here we come.
photo : copyright
For those interested in more details about immersed tube tunnel construction, there are hosts of videos on YouTube. Engineering timelines enjoyed this informative, 8-minute example from Sweden: An immersed tunnel under Söderström.

It's a truism in engineering progress to say that the biggest project is yet to come, but in this case the result is already predicted. The sometimes-controversial Fehmarnbelt link (or Femern Sund Baelt, depending which end you stand at) between Denmark and Germany is intended to be an 18km long immersed tube rail and road tunnel that will smash previous records for its kind. The project still awaits final approval on the German side, pushing back prospective completion to 2028. 

It may then one day take its place in the Case Histories of the International Tunnelling and Underground Space Association — definitely worth a read for their immense historical span, beginning with the Neanderthal mines of Swaziland.

Which brings engineering timelines — and you, the reader — to the proverbial end of the tunnel, and into the light.