#tunnels — Public Fediverse posts
Live and recent posts from across the Fediverse tagged #tunnels, aggregated by home.social.
-
Plasma Tunnels Reveal How Dying Satellites Fall to Earth
https://spectrum.ieee.org/space-debris-atmosphere-burn-up
Comments: https://news.ycombinator.com/item?id=49062120
#HackerNews #Plasma #Tunnels #Satellites #SpaceDebris #EarthScience #SpaceTech
-
Plasma Tunnels Reveal How Dying Satellites Fall to Earth
https://spectrum.ieee.org/space-debris-atmosphere-burn-up
Comments: https://news.ycombinator.com/item?id=49062120
#HackerNews #Plasma #Tunnels #Satellites #SpaceDebris #EarthScience #SpaceTech
-
Têtus et déterres. À Bloxham, paisible village de l’Oxfordshire, entre Birmingham et Londres, les vieilles rumeurs de tunnels souterrains chuchotées entre deux pintes au pub du coin se révèlent tout ce qu’il y a de plus réel.
#insolite #tunnels
https://www.lesmotsontunsens.com/des-rumeurs-a-la-realite-des-tunnels-secrets-decouverts-sous-un-village-anglais/ -
Located near the entrance to the #Nazi Underground City complex at Osówka (Podziemne Miasto Osówka) in the Owl Mountains, #Poland.
Most likely, a foundation for a heavy equipment or service infrastructure supplying the #underground #tunnels.
-
“Inside Gaza’s Tunnels: Al-Qassam Documents Commander’s 50-Day Battle”
by Palestine Chronicle Staff
@[email protected]
@[email protected]
@[email protected]
@iran
@iraq
@palestinenews“Key Developments:
- Al-Qassam published a new installment of its ‘Flood Moons’ documentary series.
- The footage follows field commander Ahmed Salim al-Ghamari and his fighters inside a combat tunnel for more than 50 consecutive days.
- The video documents battlefield operations, military training and al-Ghamari’s final months before he was killed in combat in December 2024”#Press #SocialMedia #Gaza #Tunnels #Qassam #Ghamari #PalestinianGenocide #Zionism #SettlerColonialism #Resistance #EradicateZionism #DecolonizePalestine #GlobaliseTheIntifada #Iran #War #Trump #Israel #Lebanon #Hezbollah #MoU
-
“Inside Gaza’s Tunnels: Al-Qassam Documents Commander’s 50-Day Battle”
by Palestine Chronicle Staff
@[email protected]
@[email protected]
@[email protected]
@iran
@iraq
@palestinenews“Key Developments:
- Al-Qassam published a new installment of its ‘Flood Moons’ documentary series.
- The footage follows field commander Ahmed Salim al-Ghamari and his fighters inside a combat tunnel for more than 50 consecutive days.
- The video documents battlefield operations, military training and al-Ghamari’s final months before he was killed in combat in December 2024”#Press #SocialMedia #Gaza #Tunnels #Qassam #Ghamari #PalestinianGenocide #Zionism #SettlerColonialism #Resistance #EradicateZionism #DecolonizePalestine #GlobaliseTheIntifada #Iran #War #Trump #Israel #Lebanon #Hezbollah #MoU
-
🚀🌀 Behold, the riveting saga of big, empty #tunnels where air goes whoosh! Because who doesn't want a photo album of NASA's oversized hairdryers? 📸💨 Surely, nothing screams relevance like peering into the void! 🙄
https://www.theatlantic.com/photo/2018/05/historic-photos-of-nasas-cavernous-wind-tunnels/560660/ #NASA #Airflow #Photography #Engineering #Humor #HackerNews #ngated -
🚀🌀 Behold, the riveting saga of big, empty #tunnels where air goes whoosh! Because who doesn't want a photo album of NASA's oversized hairdryers? 📸💨 Surely, nothing screams relevance like peering into the void! 🙄
https://www.theatlantic.com/photo/2018/05/historic-photos-of-nasas-cavernous-wind-tunnels/560660/ #NASA #Airflow #Photography #Engineering #Humor #HackerNews #ngated -
Historic Photos of NASA's Cavernous Wind Tunnels
https://www.theatlantic.com/photo/2018/05/historic-photos-of-nasas-cavernous-wind-tunnels/560660/
Comments: https://news.ycombinator.com/item?id=48787124
#HackerNews #NASA #Wind #Tunnels #Historic #Photos #Aviation #Engineering #Innovation
-
Historic Photos of NASA's Cavernous Wind Tunnels
https://www.theatlantic.com/photo/2018/05/historic-photos-of-nasas-cavernous-wind-tunnels/560660/
Comments: https://news.ycombinator.com/item?id=48787124
#HackerNews #NASA #Wind #Tunnels #Historic #Photos #Aviation #Engineering #Innovation
-
🚀🥱 "Let us bore you into submission with #the riveting world of #SSH tunnels!" This never-ending opus by #Ivan #Velichko is the equivalent of watching paint dry, but with more technobabble and less excitement. Pro tip: you might need a SSH tunnel to #escape from this tutorial! 🎉🔓
https://labs.iximiuz.com/tutorials/ssh-tunnels #Tunnels #Boring #Tech #Tutorials #Mundane #HackerNews #ngated -
🚀🥱 "Let us bore you into submission with #the riveting world of #SSH tunnels!" This never-ending opus by #Ivan #Velichko is the equivalent of watching paint dry, but with more technobabble and less excitement. Pro tip: you might need a SSH tunnel to #escape from this tutorial! 🎉🔓
https://labs.iximiuz.com/tutorials/ssh-tunnels #Tunnels #Boring #Tech #Tutorials #Mundane #HackerNews #ngated -
A Practical Guide to SSH Tunnels: Local and Remote Port Forwarding
https://labs.iximiuz.com/tutorials/ssh-tunnels
#HackerNews #SSH #Tunnels #PortForwarding #Networking #Security #Guide
-
A Practical Guide to SSH Tunnels: Local and Remote Port Forwarding
https://labs.iximiuz.com/tutorials/ssh-tunnels
#HackerNews #SSH #Tunnels #PortForwarding #Networking #Security #Guide
-
I emerged safely at the far end.
-
I emerged safely at the far end.
-
Traffic jams? Consider underground tunnels to ease congestion on the hot roads
Elon Musk "really profits from a kind of terra nullius environment, where there’s as few regulations as possible, and he can quickly move into a relatively empty space and dominate it,” Slobodian says. Just as he achieved that with SpaceX’s rockets and Starlink’s low Earth orbit satellites, so Musk doubtless saw the underground realm as territory for the taking."
We urgently need an uncongested tunnel underneath Hyde St in car-dependent #Bellingen >>
https://www.theguardian.com/technology/2026/jun/17/neoliberal-nightmare-my-ride-on-vegas-loop-elon-musk-answer-to-traffic-jams
#cars #congestion #traffic #cardependent #MobilityDesign #TerritoryforTheTaking #tunnels #climate #ExtremeHeat #EmptySpace #UndergroundRealm #TerraNullius #environment #deregulation -
Traffic jams? Consider underground tunnels to ease congestion on the hot roads
Elon Musk "really profits from a kind of terra nullius environment, where there’s as few regulations as possible, and he can quickly move into a relatively empty space and dominate it,” Slobodian says. Just as he achieved that with SpaceX’s rockets and Starlink’s low Earth orbit satellites, so Musk doubtless saw the underground realm as territory for the taking."
We urgently need an uncongested tunnel underneath Hyde St in car-dependent #Bellingen >>
https://www.theguardian.com/technology/2026/jun/17/neoliberal-nightmare-my-ride-on-vegas-loop-elon-musk-answer-to-traffic-jams
#cars #congestion #traffic #cardependent #MobilityDesign #TerritoryforTheTaking #tunnels #climate #ExtremeHeat #EmptySpace #UndergroundRealm #TerraNullius #environment #deregulation -
Ukraine has built 822 kilometers of anti-drone road tunnels. Each kilometer means safer evacuations and faster supply
" In May alone, the State Special Transport Service rebuilt 115.5 km of conventional road, Defense Minister Mykhailo Fedorov said.
Ukraine has built 822 kilometers of anti-drone protection along frontline logistics routes since the start of 2026 and has restored more than 170 kilometers of damaged regular roads in frontline oblasts, Defense Minister Mykhailo Fedorov says. In May alone, Ukraine's State Special Transport Service built 211 km of new anti-drone protection. "
#WarOfAggression #Ukraine #AntiDrone #tunnels #drone #FPV #roads #warfare #army #war #Russia #WarCriminal #invaders #occupiers
#перемогаYкраїни -
Ukraine has built 822 kilometers of anti-drone road tunnels. Each kilometer means safer evacuations and faster supply
" In May alone, the State Special Transport Service rebuilt 115.5 km of conventional road, Defense Minister Mykhailo Fedorov said.
Ukraine has built 822 kilometers of anti-drone protection along frontline logistics routes since the start of 2026 and has restored more than 170 kilometers of damaged regular roads in frontline oblasts, Defense Minister Mykhailo Fedorov says. In May alone, Ukraine's State Special Transport Service built 211 km of new anti-drone protection. "
#WarOfAggression #Ukraine #AntiDrone #tunnels #drone #FPV #roads #warfare #army #war #Russia #WarCriminal #invaders #occupiers
#перемогаYкраїни -
“Tunnel und Unterführungen” / Tunnels and underpasses
Chirk Tunnel, 1990 (Scanned from 35mm Negative)
https://en.wikipedia.org/wiki/Chirk_Tunnel
Edit: added a few keywords
#Tunnel #Tunnels #Canal #Canals #Boat #Boats #NarrowBoat #NarrowBoats #River #Rivers #ChirkTunnel #LlangollenCanal #Wales #Cymru #UK #Britain #British #Photo #Photography #BNW #BlackAndWhite #BlackAndWhitePhotography #Monochrome #History #Historic #Historical
-
“Tunnel und Unterführungen” / Tunnels and underpasses
Chirk Tunnel, 1990 (Scanned from 35mm Negative)
https://en.wikipedia.org/wiki/Chirk_Tunnel
Edit: added a few keywords
#Tunnel #Tunnels #Canal #Canals #Boat #Boats #NarrowBoat #NarrowBoats #River #Rivers #ChirkTunnel #LlangollenCanal #Wales #Cymru #UK #Britain #British #Photo #Photography #BNW #BlackAndWhite #BlackAndWhitePhotography #Monochrome #History #Historic #Historical
-
💁🏻♀️ TIL: 🏛️⚽ Students at #Rome’s Cavour High School, just steps from the #Colosseum, had long whispered about hidden rooms beneath the gym floor. 🤫
After they explored the #tunnels and alerted #Latin teacher Claudia Marino, archaeologists confirmed a 2nd century Roman villa called #Domus Liceo Cavour with frescoed walls, #mosaics, and even older #graffiti. 🏠
#archaeology #history #ancientrome #teens #excavation #italy #highschool #discovery
-
💁🏻♀️ TIL: 🏛️⚽ Students at #Rome’s Cavour High School, just steps from the #Colosseum, had long whispered about hidden rooms beneath the gym floor. 🤫
After they explored the #tunnels and alerted #Latin teacher Claudia Marino, archaeologists confirmed a 2nd century Roman villa called #Domus Liceo Cavour with frescoed walls, #mosaics, and even older #graffiti. 🏠
#archaeology #history #ancientrome #teens #excavation #italy #highschool #discovery
-
Does an ethical #alternativeTo #Cloudflare #ddos protection and #tunnels exist?
-
Does an ethical #alternativeTo #Cloudflare #ddos protection and #tunnels exist?
-
🧵 1/3: This latest @standupmaths video about tunnel height limit signs in the 🇬🇧 #UnitedKingdom is in the best kind of geekery / nerdery there is. Who knew that metric and imperial measurements do not have to be 1:1 convertible to the other? 🤷
#StandUpMaths #MattParker #math #maths #mathematics #bridges #tunnels #transportation #roads #highways
-
🧵 1/3: This latest @standupmaths video about tunnel height limit signs in the 🇬🇧 #UnitedKingdom is in the best kind of geekery / nerdery there is. Who knew that metric and imperial measurements do not have to be 1:1 convertible to the other? 🤷
#StandUpMaths #MattParker #math #maths #mathematics #bridges #tunnels #transportation #roads #highways
-
Become the bombshell #enby #femby #trans #genderfluid #tattoos #piercings #tunnels #lgbtq
-
@RxBrad here is the thing you setup ssh passwordless to various machine and then to ssh fwd a drive
ex: (one of these may work automagically for your user and hosts once you get passwordless going - you issue the ssh to fwd the local drive to remote host and it shows up in the fs just like any other device #tunnels #keygen #sshcopyidhis works! mounted sshfs on server from remote...entire drive
dpipe /usr/lib/openssh/sftp-server = ssh root@wiki369 sshfs :/media/chad/wd500/ /mnt/sshfs -o slave
dpipe /usr/lib/openssh/sftp-server = ssh root@vps2 sshfs :/media/chad/d58f499e-ef19-490b-a9fc-41e6fcb6985a/ /mnt/sshfs -o slave
dpipe /usr/lib/openssh/sftp-server = ssh root@vps3 sshfs :/mnt/nvme1/ /mnt/sshfs -o slave
-
The thread about the building of the Scotland Street tunnel, a challenging – and occasionally fatal – engineering endeavour
This thread was originally written and published in September 2023.
In this thread from the other day I covered why Bellevue House in the centre of Drummond Place was demolished so as to allow the Scotland Street Tunnel to run directly beneath it. There’s a lot been written about the Tunnel: some of it’s even true! Despite a service life of just over 20 years and despite being defunct as a transport route for over 150 years, it still captivates the local imagination. The 1,052 yard long tunnel climbs from its entrance beneath Scotland Street to its terminus at the long gone “Canal Street Station” (beneath the Waverley Market) at a significant gradient of 1-in-27, directly beneath the axis of the New Town streets of Scotland Street, Dublin Street and St. Andrew Street so as not to undermine any buildings. But have you ever stopped to wonder how it was built?
An Edinburgh & Northern Railway map of c. 1849 with the short section south of the Forth, that ran under the New Town beyond Scotland Street, highlighted.The tunnel was planned by the Edinburgh, Leith & Newhaven Railway, which soon changed its name to the Edinburgh, Leith & Granton when the terminus on the Forth shifted to the latter harbour. Within a few years, this small railway was absorbed by the larger (but as-yet unbuilt) Edinburgh & Northern Railway in and changed its name one last time to the Edinburgh, Perth & Dundee in 1849 to better reflect the destinations it planned to connect.
When it came to construction, it wasn’t simply a case of starting at one end and digging towards the other, or even trying to meet in the middle from both. No, in fact they dug from both ends and also sunk 5 shafts along the route and dug out from all, at once. The process was to dig a narrow guide mine or drift , 6 x 6 feet wide and tall, linking all the shafts together and then widen that out into the 24 x 24 feet tunnel section and line it. The aerial view below shows the locations of these shafts, from the southern edge of St. Andrew Square (top right of image) to the southern edge of the Drummond Place garden (bottom left of image).
Google Earth image of Edinburgh’s northern New Town, overlaid with the route of the Scotland Street Tunnel and the shafts sunk along it during construction.The shafts are not spaced equidistant along the route but are concentrated in the central section between Drummond Place and St. Andrew Square. This is because of the underlying geology; the hardest rocks to dig through are located here. From the northern portal and under Scotland Street to the north of Drummond Place was easy going through sand, clay and gravel but beyond this they struck multiple bands of sandstone, freestone, hard freestone, very hard freestone, whinstone, hard sandstone and blaes (mudstone and shale). Beyond St. Andrew square, going got easier again as the freestone is interspersed with multiple bands of clay. An excellent geological section map is available on Canmore, but the terms of its licensing don’t allow me to reproduce it here. So I went one better and re-drew it and re-coloured it to make it clearer for you.
Section of the Scotland Street Tunnel showing geology, re-drawn from the engineer’s original. © SelfThe sources tell you the tunnel was constructed between 1844-47, but the newspapers confirm that the drift was actually started by the contractor James Mitchell (of Ross & Mitchell, who was father in law to James Gowans of Rockville) in February 1843 when the company was still known as the Edinburgh, Leith & Newhaven Railway. It was largely completed by February 1844, with the exception of the hardest section beneath Drummond Place and Abercromby Place. Much of the ground that was cut through here was water bearing and drainage was a problem before the whole drift was completed. A particular difficulty, which you can see in the above diagram, was the strata being cut through were thrusting upwards at an angle of around 20-30 degrees to the tunnel and so formed “walls” which held back the water. When the miners breached these, they could suddenly and unexpectedly release the water built up in the next layer. To counter this, the contractors bored out “jumper holes” (pilot holes) ahead of the excavations. When the jumper hole breached a geological wall and struck water, this could then be tapped off and drained away in a controlled manner before the whole drift advanced into the next strata.
19th century railway tunnel excavations – note this does not specifically show the Scotland Street Tunnel, but is one of a roughly equivalent scale and overall appearance © Science Photo Library Limited 2023This approach was quite successful, but disaster struck early on Friday 29th November 1844 when the nightshift workmen of No. 3 Shaft, digging away below the vicinity of Albany Place, bored out the jumper hole off the planned angle in error and breached a significant subterranean pocket of water which flooded the workings. This shouldn’t actually have been a surprise, the Thursday shift had noticed unusual springs of water in the workings and one of the miners had insisted to his mates that they were digging off of the intended route. Mr Mitchell, the contracting engineer, was informed, and made known his intention to go down with the morning shift at 6AM, to inspect the workings for himself. He asked the workmen to call him before they went down, however when the shift arrived they workmen called not on Mr Mitchell the engineer, but his brother Peter Mitchell, who was employed as a superintendent “but was not conversant in the business of mining“.
Instead of getting his brother, Peter Mitchell took it upon himself to do the inspection and went down with the gang. A short time later, a 14 year old boy – Jack – was being lowered into the shaft and was almost at the bottom when he heard “a loud roar of thunder” and yelled in a panic to be hauled back to the surface. Jack only just made it to the surface before a “huge wave came surging up the shaft” behind him and rose to a height of 80 feet, before “falling back again… almost as quickly as it had risen“. A second explosion of water occurred near the entrance to Broughton Markets out of No. 4 shaft, this one caused by the compression of the air in the tunnel by the flooding finding a route out and propelling the water before it. The basements in this area were flooded up to a depth of 4 feet. Once the initial torrents had subsided, the men at the surface found the drift and shafts were flooded and choked up with rocks, clay and debris from the onrush of water. The majority of the water however drained down and out of the tunnel mouth at Scotland Street “where it flooded the terminus of the completed portion of the railway to a considerable extent“: for a short period, the Canonmills Loch resurrected itself.
Canonmills by Mary Webster, 1836. This view looks from approximately where the tunnel portal is, across the Canonmills Haugh (meadow) towards the ancient loch.The men on the surface soon followed the receding water down the shaft to look for their mates. A ganger – Erskine – and a miner, Blair from Liberton – were soon found, “as might be expected, quite dead“. The body of another miner – Philips – would not be recovered until later. Tragically, he and Blair should not have even been there, their relief had overslept and were still putting their working clothes on on the surface when the disaster happened. Philips wife “resorted to the scene in the course of the forenoon and her wild shrieks and cries exhibited a spectacle to touch the coldest heart“. His body was found at around 3PM that day and that of Peter Mitchell, who should never have gone down the mine, was found at 4PM. Their bodies had been washed down the tunnel and were stopped beneath Drummond Place by a barrier of rock that had been left across the drift to help control the flow of water down the hill.
A public subscription was raised for the “families of all these poor men” who (with the exception of Mitchell the superintendent) would be “left destitute” by the loss of the breadwinner. The Edinburgh Evening Courant implored the directors of the railway to contribute generously.
The tunnel was finally completed and ready in mid-April 1847, when the company was known as the Edinburgh, Leith & Granton Railway. Captain Coddington, RE of the Railway Board inspected it and gave it the all clear on 10th April. It opened on Monday 17th May after “the most formidable difficulties“, on the same day as the Edinburgh & Glasgow Railway opened their extension from Haymarket to a (for now temporary) terminus underneath the new Waverley Bridge.
A watercolour painting by Joseph Ebsworth was completed a couple of months later, and from its vantage point of the Scott Monument we can clearly see a train emerging from the Scotland Street tunnel into Canal Street Station below Princes Street. There is a further thread here about that station, if you fancy reading some more on the Edinburgh, Leith & Granton Railway. The tunnel was too steep for the railway engines of the day when it was built, so trains were hauled up it on a rope by a static winding engine and ran downhill by gravity from Canal Street to Scotland Street, were a locomotive was attached for the onward journey to Granton or Leith.
“A watercolour showing an east view of Edinburgh taken from the Scott Monument”, Joseph Ebsworth, 1847, © Edinburgh Museums & GalleriesDespite the effort of its construction, the tunnel ended up having a very short life and was closed to traffic only 21 years after it opened. You can read more about the various crimes and illicit goings on that the tunnel attracted during this time in this thread. In this time it also gained a reputation for accidents and the newspapers record many – it proved particularly dangerous for the men employed to work it:
- In December 1853, Thomas Cleghorn, a railway guard, was killed instantly in the tunnel when he struck his head on the wall after leaning out of the luggage van in which he was riding.
- In August 1855, a carriage left unattended at the top of the tunnel and without its brakes applied, ran down the incline and collided with a passenger train, causing multiple injuries, some severe. The shunter, Thomas Wells, pleaded guilty to “culpable neglect of duty” and was imprisoned for 9 months.
- In September 1857, a goods train emerging from the foot of the tunnel at Scotland Street did not stop and ran into the back of a slow-moving coal train. The driver of the latter train jumped from his engine but forgot to shut off the steam and apply the brakes in his panic. His engine ran off towards Granton at a speed of 30mph and crashed into a train of carriages which was fortunately almost empty, demolishing the lot. The few passengers on board had already jumped clear when the runaway train was seen to be approaching. The Glasgow Sentinel newspaper recorded that at Scotland Street station the damage was limited to 2 barrels of whisky, which broke and their “mountain dew scattered on the ground“
- In October 1859, John Adam, a railway labourer, was fatally injured after being struck by a train coming out of the tunnel. He had gone to fetch a lamp to work with and found himself caught between the train and the tunnel wall.
- In October 1859 also, the haulage cable snapped at 930AM in the morning, preventing use of the tunnel for the whole day.
- In June 1863, James Samuel, a carriage driver employed to move coaches around Canal Street Station by horse traction, caught his foot in the mechanism of a turntable and was run over by a train coming out of the tunnel on the haulage rope. His injuries proved fatal.
- In July 1865, a train of 13 carriages, 2 trucks and 3 brake wagons was moving downhill when it separated into two portions. The forward portion moved ahead, but was then hit by the rear portion when it began to slow as the brakemen, in the pitch dark, could not even see that the train had separated. There were no serious injuries.
- In September 1867, a train ran away down the hill from Canal Street Station and overshot the station at Scotland Street at the foot of the tunnel, the brakemen – one on every third carriage – had to resort to applying the emergency “drags”, stout pieces of timber that were shoved into the spokes of the wheels to bring them to an immediate (and violent) stop. There were no serious injuries.
- In November 1867, William Reid, a brakeman, was killed when he jumped from his train at the foot of the tunnel and fell, being run over by his own vehicle.
Ultimately, the tunnel was never a practical transport solution. Beyond its lack of engine traction, the platforms at Canal Street station were far too short to allow longer trains, and were at 90 degrees to the larger Edinburgh & Glasgow and North British Railway station, making connections clumsy and impractical. In 1863 the line’s then owners, the North British Railway, gained powers to construct a new line diverting around the tunnel via Abbeyhill. Construction began in 1865 and it opened (and the tunnel closed) on May 22nd, 1868. It has been abandoned as a transport corridor ever since, but has seen use variously as a car garage, industrial mushroom farm, air raid shelter and emergency railway control room for at least some the intervening years. Every so often a plan is mooted to re-open either as a tram or metro route, or as a cycleway.
Closure notice of the tunnel, advertised in the Edinburgh Evening Courant, 21st May 1868Footnote. In February 2023, the Broughton Spurtle local newspaper broke the story that Dublin Street was subsiding – a “sinkhole” hole had appeared in the middle of the road. Coincidentally, this was right on top of No. 4 shaft, the one that flooded Broughton Markets in the 1844 disaster.
Note to readers: unfortunately in April 2026, a third-party plug-in more than exceeded its authority and broke many of the image links on this site. No images were lost but I will have to restore them page-by-page, which may take some time. In the meantime please bear with me while I go about rectifying this issue.
If you have found this site useful, informative or amusing then you can help contribute towards its running costs by supporting me on ko-fi. This includes my commitment to keeping it 100% advert and AI free for all time coming, and in helping to find further unusual stories to bring you by acquiring books and paying for research.
Or please do just share this post on social media or amongst friends and like-minded people, sites like this thrive on being shared.Explore Threadinburgh by map:
Travelers' Map is loading...
If you see this after your page is loaded completely, leafletJS files are missing.These threads © 2017-2026, Andy Arthur.
NO AI TRAINING: Any use of the contents of this website to “train” generative artificial intelligence (AI) technologies to generate text is expressly prohibited. The author reserves all rights to license uses of this work for generative AI training and development of machine learning language models.
#Lochend #Logan #Restalrig #StMargaret -
The thread about Edinburgh’s 1970s Interceptor Sewers – the great untold engineering feat that cleaned up the Firth of Forth
- Part 1 of Edinburgh’s sewage history was the Thread About the East Foul Burn and the Irrigated Meadows.
- Part 2 of Edinburgh’s sewage history was the Thread About the Sewage Problems of Victorian Edinburgh and How to Fix Them.
- Part 3 of Edinburgh’s sewage history was the The thread about the Interceptor Sewers; how Victorian Edinburgh cleaned up the Water of Leith. Twice.
This is part 4 – the final instalment – of my threads on Edinburgh’s sewer story – the great untold engineering feat of the 1970s Interceptor Scheme. We left off part 3 at the end of the 19th century, when Edinburgh and Leith had finally managed to clean up the polluted Water of Leith by the construction of two “interceptor” sewers to prevent waste getting into it. However none of the sewage that was diverted by these sewers and prevented from entering the river was simply piped below the low tide level and discharged, raw, into the Firth of Forth where it was hoped for that the tide and currents would move it offshore and out into the estuary. As the city grew in the 20th century, this same basic system was expanded to cope; new sewers were added to keep other rivers and streams such as the Almond, the Jordan / Pow Burn, the Figgate Burn, the Braid Burn etc. clear, but these all just diverted the effluent out into the Forth. hoped for the best that the tides and currents would carry it out to sea
The principal sewers of Edinburgh by the middle of the 20th centuryIn 1951, the Rivers (Prevention of Pollution) (Scotland) Act made provision for the establishment of river purification boards to begin to tackle the issue of discharge of raw waste into tidal waters. This saw the Lothians River Purification Board created. This had the power to make the Forth subject to a “Tidal Waters Order” and in 1960 such an order was made. A follow on act gave the Board the power to make the Edinburgh Corporation, as it was, take action through the licensing of discharges and making that subject to conditions.
River Purification Authorities and Boards in Scotland as set up in 1951The clock was ticking now for the Corporation to take action. Initial planning of what should be done started in 1966 and was agreed with the Purification Board in 1967, to be completed by 1976. The fundamental challenge was Edinburgh’s hilly topography that divided the city up into different water catchments – and had caused the sewage network to develop piecemeal following the natural drainage. As such the system was in no way integrated and had 9 separate discharges into the Forth, none of which were treated.
Most of the existing older sewers were “interceptor” sewers, the new system had to “intercept the interceptors”. It then had to consolidate all this waste somewhere for treatment; the natural “centre of gravity” of the city’s drainage is in Leith Docks. It had to run East-West along negligible gradients and yet still be gravity worked, to avoid the expense of pumping. It then had to treat all of the waste and discharge the treated primary effluent somewhere beyond the gently shelving seabed, where the weak tidal flow made natural dispersion tricky. And lastly it had to do something about the sewage sludge leftover from primary treatment. So there was a huge amount to do.
The 1970s Interceptors (green) intercepted all the existing sewers (brown) to prevent them from discharging directly into the ForthAt the centre of the scheme would be a new primary treatment works near Leith Docks at Seafield and requiring land reclamation. This would dispose of the treated effluent through a single 2.8km long outfall that reached far out underneath the Forth and it would capture the primary sludge to be disposed far off in the other reaches of the Forth by means of a disposal tanker. The works would be fed with the sewage of the city by two vast new interceptor sewers, one each approaching the works from the east and the west, tapping off all of the existing raw discharge outlets into the Forth.
Schematic of the 1970s Sewage Disposal Scheme. Credit ICEThings moved remarkably quickly. The council approved the scheme in 1970 and got approval from the Scottish Development Department for the necessary financial loans, some of which came from the European Investment Bank. The project was valued at over £35m (£181m in 2023) and was “a massive civil engineering undertaking involving more than 30 main contracts.” Shovels began to enter the ground in 1971 for exploratory works associated with the land reclamation at Seafield and the first construction contract followed within months. The new interceptors were to be 15.3km long in total and of a large diameter, getting wider as they went. The western sewer started at 1.4m diameter and grew to 3.1m. The eastern sewer started at 0.7m and grew to 2.3m. They intercepted the old network at 26 separate points. It was not possible to work entirely under gravity and 6 pumping stations were required to lift the waste uphill via rising mains from parts of the coast that would not naturally drain themselves.
A huge engineering challenge was the sheer range of geological conditions to be dug through; coals, sandstones, mudstones, clays, shales, geological folding, jointing, the Pentland Fault and all sorts of impressively named features like the “Midlothian Syncline“. Most of the route ran under built up areas and therefore 73%, or 11.6km, of the route would have to be tunnelled. The geology required the use of explosives, limited by the presence of the buildings overhead. Much of the excavation was done by compressed air at high pressure, this pressure helped hold back the ground water given how shallow the tunnelling was through fairly wet ground. In some places the ground had to be artificially drained in advance and in others, where there was no other option due to the ground being saturated fine silt and sand, liquid nitrogen was injected into the ground to freeze it, making it stable enough to dig through. As if these weren’t challenges enough, the western sewer also had to cross the Water of Leith at some point. The location was in St. Mark’s Park, which required an inverted syphon on the river bed. This was constructed by building a cofferdam, diverting the river around it, and draining the river within.
The new treatment works was reclaimed out of the East Sands of Leith – home of the Pennybap Stane and the bogle Shellycoat – by extending the existing sea wall of the dock railway yards and then filling in behind it; there was still no shortage of demolition rubble from clearances in the city in the early 1970s, plus an almost endless supply of colliery waste.
Semi transparent overlay of early 1960s OS map over modern aerial photograph. The white line shows the sea wall line prior to the construction of Seafield Sewage Works.The sewers and works were calculated to treat the waste of a population of 470,000 within its drainage catchment – 250,000 cubic meters of flow a day. It allowed for an increase to 600,000 people and 336,000 cubic meters a day. While the works has grown since to make use of this built in capacity, the core of it is still the 1970s construction.
Plan of the Seafield Sewage Works as it opened in 1976 overlaid on modern aerial photography. Credit, after ICE.There are a couple of great pictures here of the Seafield works in the later phase of construction from Beqi’s Flickr:
In the second picture above, notice the 3 concrete sewage inlets rising out of the ground into the screens, just below the big white shed building. These screens separated insoluble solids and flotsam out of the sewage, which were scraped off the screens, collected in skips and taken to the Corporation incinerator at Powderhall for disposal. Grit was also removed, washed and disposed of and storm tanks collected any excess inflow for later treatment.
After screening, the waste was pumped into one of the 8 sedimentation tanks (the large concrete circles) where the solids settled out into a sludge on the base of the tank. The treated liquid effluent was then drained off for disposal at the outfall. The concentrated sludge was collected and pumped to two storage tanks at Leith Docks. The sludge tanks at both Seafield and Leith Docks were fitted with a deodorising system, whereby Ozone was generated in a high voltage discharge, dissolved in water and then sprayed over the stench. I can’t comment if that worked! From the docks, the sludge would be collected by the Corporation’s new, purpose-built sewage tanker, the amusingly named MV Gardyloo.
The Gardyloo at Leith, c. 1995. CC-by-SA 2.0, AlljengiTwo or three times a week, the Gardyloo would carry it out to the outer reaches of the Forth between the Bell Rock and St. Abb’s Head (depending on the season) and then dump it overboard. In a typical display of 1970s municipal pride, the vessel was painted in the Corporation colours of maroon and white and was licensed to could carry passengers; the city would “treat” school children and pensioners to a 7-hour day trip on the boat, complete with a lunch of fish and chips from the vessel’s cafeteria. The paying public could also take this offer up for a small fee. You can see an amateur cine film of one of these trips at the National Library of Scotland’s Moving Image Archive.
This just left the liquid effluent to get rid of. This was (and still is) by means of a gigantic outfall shaft, 7m in diameter and sunk 52 meters straight down into the ground before turning through 90 degrees, reducing in diameter to 3.7m and heading out to sea for 2.8km.
Sinking the outflow shaft. Credit; ICE.The outfall tunnel was constructed according to standard colliery practices. This makes perfect sense; the miners and engineers of the Lothians coalfield had been digging roadways under the Forth in this manner for a hundred years or more. During construction, the outfall tunnel had a double track narrow-gauge, battery-powered railway in it to bring the excavated spoil back to the main shaft for disposal. The tunnel was made wider at this point to accommodate a siding of the railway for spoil wagons. The diffuser outlets were drilled down into the end of the outlet tunnel from above the surface by the jack-up rig GEM126 moored overhead in the Forth.
GEM 126 drilling piles for the Immingham oil terminal in 1970Work on the whole scheme proceeded remarkably quickly and efficiently, slowed down mainly by restrictions on spending. The scheme was transferred from the City of Edinburgh Corporation to Lothian Regional Council during local government reorganisations in 1975. The initially completed part of the scheme started operation in the autumn of 1976, with most of the parts of the wider scheme in place by 1978, when the Gardyloo started operations. The estimated cost in 1975 was £26.04 million, or about £224 million in 2021 money.
The construction of the sewers was relatively incident free, however I have read that a mistake during blasting in one section caused two houses above to become so damaged they had to be demolished. I haven’t yet found out where they may have been. Update, October 2023. The houses have been found! There were in fact two different instances of subsidence as a result of the tunnelling, both in the eastern section between Seafield and McDonald Road. The first occurred in November 1972 when a sinkhole appeared in the back green of the tenement at 20 Dryden Street in Pilrig, jeopardising the stability of the tenement in front of it which was home to 6 families. While the City Engineer, Gerard Pakes, said that they were merely taking precautions, the Scotsman suggested that the tenement was “in danger of collapse” – it is still there to this day however.
Workmen remove the front garden fence at 20 Dryden Street to allow the waiting crane behind access to lift shoring timber over the tenement to the sink hole behind. Scotsman, November 16th 1972.The second incident occurred in August 1973 when two bungalows on Prospect Bank Crescent near Seafield began to exhibit dangerous cracks and had to be braced with a forest of scaffolding. Robert and Nellie Taylor at no. 15 and John and Catherine Walker and their 3 children at no. 17 were given a weeks notice to quit their houses, a decision that was later reversed. The householders suffered sticking doors and windows followed by cracks appearing in walls and ceilings, loose plaster, gas pipes being cut off and “intermittent shocks from underground blasting.” Residents of Prospect Bank Terrace claimed that the tunnel was being dug only 10 feet below the surface when it should have been 30 feet deep. Depute City Engineer Mr A. S. Crockett replied that there was no commitment to it being that deep and it was about 15 feet below to allow for a sufficient gradient for downhill flow. Again, the houses are there to this day so this was obviously not terminal damage.
Bungalows at Prospect Bank Crescent shored up. Scotsman, August 30th 1973The success of the scheme can be measured in whether or not it cleaned up the inshore waters of the Forth off of Edinburgh and Leith. Limits on the “amenity” beaches were set at 2,400 E. coli per 100ml water. The raw sewage entering the works at Seafield was 20,000,000/100ml. The scheme reduced the levels in the beach waters to 1,000/100ml in the worst flow conditions; 60% below the limit.
From 1978 to 1998, in more than 2,600 voyages, the MV Gardyloo dumped 8.5 million tonnes of the concentrated sewage sludge of the citizens of Edinburgh and Leith into the North Sea. It was as a direct result of the EC (as it was) Urban Waste Water Treatment Directive that this practice ended and secondary treatment of the sludge was finally commenced. The Gardyloo had been passed to the East of Scotland Water Authority in 1996 during another local government reform, and was sold out of service in 1999. After 5 years service as a general purpose tanker she was bought by a company in Azerbaijan and transferred to the Caspian Sea where, in a strange but somehow apt about turn, she is now the drinking water tanker Shollar!
Note to readers: unfortunately in April 2026, a third-party plug-in more than exceeded its authority and broke many of the image links on this site. No images were lost but I will have to restore them page-by-page, which may take some time. In the meantime please bear with me while I go about rectifying this issue.
If you have found this site useful, informative or amusing then you can help contribute towards its running costs by supporting me on ko-fi. This includes my commitment to keeping it 100% advert and AI free for all time coming, and in helping to find further unusual stories to bring you by acquiring books and paying for research.
Or please do just share this post on social media or amongst friends and like-minded people, sites like this thrive on being shared.Explore Threadinburgh by map:
Travelers' Map is loading...
If you see this after your page is loaded completely, leafletJS files are missing.These threads © 2017-2026, Andy Arthur.
NO AI TRAINING: Any use of the contents of this website to “train” generative artificial intelligence (AI) technologies to generate text is expressly prohibited. The author reserves all rights to license uses of this work for generative AI training and development of machine learning language models.
#Lochend #Logan #Restalrig #StMargaret
