February 2022, Graeme Cavers and his team of archaeologists set out in search of a mysterious underground passage called the Suterline. There are about 500 Iron Age structures in the Scottish Highlands, but no one knows what they were built for, and no one has ever found one intact.
“It could have been used to store grains in closed pots or dairy products like cheese,” said Matt Ritchie, an archaeologist at Forestry and Land Scotland. “Perhaps they were for safety, to keep valuables safe, or to keep slaves or hostages safe. It may have been.”
Fieldwork can help clarify the condition and structure of Suterrain, but it can take at least a week using traditional methods, Cavers says. That company, AOC Archeology, was enlisted by Ritchie to help map Crackney his Suterrain in Bogie Forest, Scotland.
Manual measurements using devices called theodolites (difficult to use in dark, narrow tunnels) have been replaced by laser scanners, which have improved significantly in the last few decades. “I used to connect to an external laptop,” says Cavers. “Data could only be recorded as fast as the connection. It ran over an Ethernet cable, so it was relatively fast. It had. It was the top of the range. Laptops at the time were very expensive.”
Technology has come a long way since then. Sneaking into her Cracknie Souterrain through her 50 cm opening in the ground, Cavers was handed a gray device the size of a shoebox: a Leica BLK360 laser scanner.
The spelunkers set up the device on a tripod in a 1-meter-high wet walkway, adjusted a few settings, and hit “scan.” It started moving and in one second he shot lasers at the tunnel wall 10,000 times. Cavers and his team have enabled him to take millions of readings within an hour without lifting a finger. “You’re going to be there longer to do what we did with Theodolite,” says Cavers.
Collecting large data sets is a challenge in itself. “Today we come back with his half a terabyte of data,” he says. “And we might do hundreds of projects a year. From an IT perspective it’s starting to get very difficult to manage. It is supposed to create a comprehensive archive.”
However, data pays. Spelunkers once would have had to draw and photograph underground channels from within dark passageways. Currently, he uses software (Trimble RealWorks, NUBIGON, and Blender) to create accessible 3D multicolor ‘point cloud’ models of him.
Team members can view the model from any angle, measure the distance between any two objects, and change color according to variables such as height and density. That means archaeologists like Richie can teach people about ruins without actually going there.
“[Cracknie] It’s very far away,” Richie says. “It is far from established walking routes and relatively difficult to access.” This means it is not well suited for guided tours or educational panels, but the 3D models can be viewed from anywhere. . Richie even managed to print a scale model and display it in a museum. The technology makes Britain’s cultural heritage more accessible and may one day help archaeologists like Ritchie unravel the mysteries of Scotland’s underground strata.
This article originally appeared in the January/February 2023 issue of WIRED UK Magazine.
