Exploring an underwater tunnel at Akershus Fortress
Monday, November 7, 2016 / Akershus Fortress, Oslo, Norway
Words by Ronny Arnesen / Cave diver and explorer
For about 17 years ago the assignee heard rumors of a well at Akershus Fortress that was suppose to be an escape route out of the fortress. This of course excited my curiosity, but other the project drowned cause of too many other exciting projects.
Later in 2016, Arnar Snorrason came in contact with Tom Andersen after an excursion to the fortress by Oslo Fire Department. This lead to a project about exploring the rumors about the escape tunnel.
In the archives of Akershus Fortress, there is a report that is presenting an examination that was published in the local newspaper in August 1864. This report gave an impression about how big this tunnel system could be. But still, many questions remained to be answered. Was it possible for us to explore the tunnel again today with better technology? - We decided to give it a try.
This is a summary of the Norwegian report "Utforsking av brønnen ved Jomfrutårnet" by Ronny Andersen. Fin the Norwegian report here. This is an extract of the daily log from September 12th 2017, where Blueye was a used as a tool to explore the hidden tunnels in the well.
By the well house, we get ready to deploy the Blueye underwater drone (mini ROV), with support from Martin Ludvigsen from Norwegian University of Science and Technology (NTNU)
With calm movements, Martin drives the drone into the tunnel. It's pitch dark, but with the bright lights of the drone it is possible to get a good overview of the first room. The drone is approaching the narrow opening and the excitement is increasing as we start to enter the narrow passage into the next section.
Martin aims for the hole and flies through it. As the drone enters the new room, the visibility decreases, but it does not take long before we recognize that this room is much larger than the previous one. The floor and walls are gradually floating into each other, so it's hard to tell where the wall ends. But as the drone continues into the room, the walls come closer and form a narrow tunnel again.
After driving a couple for more meters, the tunnel is sealed with broken pieces of pipes and Tiling stones. The Blueye Pioneer has fully discovered new territory that had been inaccessible for many hundred years.
The drone turns around, and follows the yellow tether back to the entrance of the tunnel system.
The Blueye Pioneer has fully discovered new territory that had been inaccessible for many hundred years. This project could not have been more successful!
Report from exploration of the well at the Virgin Tower at Akershus Fortress (Norwegain)
Download the full report, "Utforsking av brønnen ved Jomfrutårnet" by Ronny Andersen in Norwegain here- Format
- application/pdf
- File size
- 7.01 MB
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Akershus Fortress
About halfway on the pathway is the end of the underground tunnel closed off. The well is on the other side of the wall in the left f the photo. Photo: Annika Persson -
Blueye Pioneer outside Akershus Fortress
Photo: Martin Ludvigsen -
Getting ready outside the well house
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Drone getting lowered into the well
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Blueye Pioneer lowered into the well
Photo: Martin Ludvigsen -
The well
Photo: Johnny Haglund -
Almost at the bottom of the well
Photo: Martin Ludvigsen -
Excited team having a first look of what's inside the tunnell
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Blueye app on phone resting on the edge of the well
Photo: Martin Ludvigsen -
Concentrated drone pilot navigating the tunnel
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Soldier from the Royal Guards guarding the entry to the fortress
Photo: Martin Ludvigsen -
Group photo after successfully exploring the full extend of the tunnell
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Another well to explore
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Having a look inside one of the other wells on the fortress
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Blueye Pioneer heading down the well
Photo: Martin Ludvigsen -
Drone in the water of the well
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Excited to see what's inside this well
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Akershus fortress
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Profile map of well and tunnell
The well at the Virgin Tower, scale 1:50. Drawing by: Arnar Snorrarson, Rolf Kolstad and Ronny Arnesen -
Top map of well and tunnell
The well at the Virgin Tower, scale 1:50. Drawing by: Arnar Snorrarson, Rolf Kolstad and Ronny Arnesen
