Bournemouth University’s Maritime Archaeological department along with a group of students undertook a Fusion funded project to locate and investigate the state and preservation level of these seven tanks. Two weeks (07/07/2014 -18/07/2014) were spent diving in Poole Bay to achieve this goal.
About the Project
On the 4th of April 1944 in preparation for Operation Neptune, the Normandy landings of 6th June 1944, exercise “Smash I”, the biggest live-fire exercise of the war, was conducted in Studland Bay.
During this exercise, a special type of tank, the Valentine Duplex Drive (DD) amphibious tank was utilised in this major exercise; these tanks could be launched from a landing craft at sea and through the deployment of a canvas skirt and a propeller they could ‘swim’ ashore under their own power to provide armoured support for a landing force assaulting a fortified position, such as the Normandy beaches.
Although the majority of the tanks launched during this exercise got ashore, seven sank with the loss of six troopers.
The primary objective in this project was to find the tanks on the seabed, only two of the tanks had accurate known positions and are regularly dived. In total there were 40 “known” positions for the seven tanks. This task was made even more difficult as the remaining five tanks were “rendered safe” using controlled explosions by the Navy in the 1980s to avoid divers recovering live ammunition from the site.
Fortunately large areas of Poole Bay have been subject to a detailed bathymetric survey which provided an accurate map of the seabed revealing any anomalies in the vicinity of the unverified positions for the tanks. However, it is impossible to know if the anomalies identified on the bathymetry were tanks or any other raised feature on the seabed To overcome this, transects were run over the area with the boat’s depth sounder and once the anomaly appeared under the boat a shot was deployed from which a team of divers could be deployed to search the seabed visually and confirm whether or not it was one of tanks. This was not an easy task considering the size of the tanks (c.5m long) with a spread of coordinates over a kilometre squared area.
Once a tank was located a second dive team were sent in to photograph key features and search the debris field around it for any other diagnostic features. A third team used an ultrasonic thickness meter and a bathycorrometer to conduct scientific tests on the hull of the tank – this data was to be compared to surviving DD Valentines on the surface.
A full archaeological report on the project is forthcoming, which in addition to the condition of the tanks, mentioned above, will also explore the manner of the loss and the wider implications of Operation SMASH.