Members of the University of Birmingham's Human Interface Technologies (HIT) Team recently discovered a torpedo net from World War Two at the bottom of Burrator Reservoir in Devon. The Team made the discovery whilst testing its two new mini-remotely operated vehicles (ROVs) – small unmanned submersibles, which will be used for BEng Engineering final year projects.
Rather than simply test the vehicles in clear open water, the researchers, led by Professor Bob Stone, decided to put the vehicles through their paces as part of a challenging underwater mission to establish once and for all whether or not the remains of a World War II torpedo net lay on the bottom of the huge reservoir at Burrator, north of Plymouth on the edge of Dartmoor.
The HIT Team decided to approach South West Water and South West lakes for permission to dive the two ROVs, a BlueROV2 and a Trident “underwater drone” (a smaller but highly agile submersible), into the Reservoir (taking advantage of it being at 50% capacity due to the 2018 summer drought), in order to discover if the remains of the nets still existed.
On both dives the Team’s goals were met and, despite the very murky conditions of the water, exacerbated by the ROV thrusters when approaching the bottom, some impressive images and video footage of the spheres and the grommets were acquired, indicating that, despite the decades of immersion, many of the structures were in remarkably good condition.
The search for the torpedo net came about following recent research conducted by the HIT Team’s Director, Professor Bob Stone. His research made use of a 3D model of the reservoir’s underwater topography, which in turn used sonar data originally collected by Professor Stone's team and a Cornish company, Swathe Services, in 2016. The detail in the model developed by the HIT Team was such that, when viewed side-by-side with an 1889 pre-flooding era map of the area, it was possible to identify roads, paths, walls, bridges and the foundations of Essworthy Farm.
More recently, Professor Stone discovered a number of smooth, regularly-spaced underwater objects in the vicinity of the surface remains of a suspension bridge, constructed in 1923 during work to raise the main dam to provide extra water for the growing city of Plymouth. Further investigation, using photographs taken by local villagers during the drought of 1959 indicated the presence of large spherical objects on the shoreline, resting on what appeared to be chain-like meshes, with one of the spheres still afloat.
Professor Stone explained: “The German Luftwaffe had conducted aerial photographic surveys of the Reservoir in 1941, presumably with the aim of torpedoing the dam at some future point, but the imagery was not of a resolution to see anything resting on the surface of the water.
"However, the images from the drought periods, plus one solitary picture taken just after the War showing the Reservoir at full capacity, confirmed that the spherical objects detected in our VR reconstruction were, in fact, the remains of the floats used to suspend an anti-torpedo net of interwoven metal rings, or 'grommets'".
The HIT Team, which is part of the University's School of Engineering, is no stranger to the Reservoir and its spectacular surrounding scenery. Its researchers are often seen in the area, undertaking aerial drone-based surveys to map out areas and sites of historical interest. During this summer's heatwave, the Team's previous work mapping a supposed "drowned village" at the bottom of the reservoir received significant national online and print coverage.
The Team will present their findings at two events in the near future, one at the Ironbridge International Institute for Cultural Heritage on 25October 2018, and a special Virtual Heritage afternoon for the Dartmoor Society at the Village Hall in Meavy, just a stone’s throw from Burrator Reservoir on 21 February 2019.
The HIT Team's discovery made the news. Please follow the link below to find out more: