The project is based on what is said to be one of the biggest photogrammetric surveys ever carried out on a shipwreck. An area of some three hectares was recorded through 24,307 high-resolution photos taken on 12 dives that took less than 14 hours under water.
As well as the outer shell, the internal decks, cabins and cargo were also recorded. Underwater photogrammetry allowed the 32m-deep wreck to be reconstructed in photo-realistic detail and 3D models to be created.
A merchant steamship sunk by a German bomber in 1941, the Thistlegorm has long been British divers’ favourite overseas wreck-site. The vessel was carrying supplies to support the Allied war effort in Egypt, including locomotives, aircraft components, trucks and motorcycles.
While the Thistlegorm Project may help divers to plan their dives and authorities to manage the wreck, it is intended primarily to open up the underwater experience to non-divers. It is part of the Presence in the Past maritime archaeology study, a Newton Fund project directed by Dr Jon Henderson of the University of Nottingham’s School of Archaeology in partnership with Al Shams (Cairo) and Alexandria Universities in Egypt.
The project was one of the first to use 360 video, says Dr Henderson.
“This was one of the most exciting things, because with 360-degree video we can now do guided tours around the wreck, so you can actually experience what it’s like to dive it.”
But Dr Henderson has also taken the opportunity to highlight the need to protect the Thistlegorm – from divers and dive-boats. “As it’s a really popular dive-site, there is a problem with the amount of divers on the site at the moment, because it’s not policed or managed.
“Aside from looting, the main issue we have is that a lot of the dive-boats that go out there are actually mooring onto the wreck itself because there is nowhere else to go.
“Dive-boats weighing 50 and 60 tonnes are tying ropes directly onto the vessel. This isn’t such a problem for the parts of the vessel that are quite strong, but equally we have seen some boats tying on to more fragile areas, including the guns, the bridge and the railings – which can cause damage. So we need to protect these sites.
“Carrying out a baseline survey such as this of exactly what’s there is the first step in doing that. We can then chart changes over time and look at what we need to protect. We can look at areas that would be better to moor on and come up with a management for the site.
“This is an important part of Britain’s and Egypt’s shared heritage and a monument to the herculean efforts of the Merchant Navy during the Second World War. Nine men died on the ss Thistlegorm, five Royal Navy gunners and four merchant sailors, just a small part of the 35,000 out of 135,000 Merchant Navy sailors that gave their lives during the war.
“In the Merchant Navy one in four men did not come back – that’s the highest proportion of all the fighting forces. We owe to the memory of these brave men to record and preserve their legacy.”
Take an underwater tour of the Thistlegorm here