Preserving The Wrecks

In our last blog, we highlighted the damage commercial fishing is causing to marine life and cultural heritage.

The BBC is now reporting more damage to submerged history and this time it’s something close to AccuPixel director Simon‘s heart – the sole surviving Valentine tank in Studland Bay has seen its turret pulled off.

You can read the BBC report here.

There are seven tanks in the bay and all were lost during Exercise Smash conducted just six weeks before D-Day in 1944. Tanks were swamped in heavy seas and sadly six soldiers lost their lives. Today the tanks – and in particular the most intact – have become a permanent memorial to their loss.

Valentine tank in 2002
Taken sometime around 2003 and shot by Simon on slide film this image records the tank has an intact gun barrel.

Way back in 2015, when Simon was figuring out what underwater photogrammetry could do, the tanks were digitally preserved, including the most intact version. Damage recorded then included the loss of most of the gun barrel. A nylon rope used to buoy the wreck site had worn through the metal to the point of failure.

Valentine Tank in 2003
The schooling fish are attracted to the wreck site as it provides sanctuary in a dynamic and shifting seabed of gravel and slipper limpets.

Reprocessing the Images

Fast forward to today and the news has triggered a reprocessing of the 2015 data. A prerequisite of this is maintaining the RAW source images and for this, we use Lightroom and a NAS storage device.

Lightroom manages the catalogue of images. In practice, this means the Valentine tank originals can be retrieved in seconds and exported and the NAS holds the physical RAW files.

Once exported we ran a new project in 3DF Zephyr. Looking at the result we can see the flaws and issues the capture technique has recorded…to put it bluntly we wouldn’t do it like this today.

Valentine tank in 3DF Zephyr
2015 Valentine tank images reprocessed in 3DF Zephyr

Nevertheless, the 2015 source images represent a moment in time and record the tank in its condition at the time.

For comparative study this dataset becomes priceless. With the subsequent displacement of the turret, this view cannot be recreated.

This is where historical data and photogrammetry add immense value. We will be highlighting this in a forthcoming academic paper examining the changes recorded by comparative photogrammetry models of the SS Thistlegorm. On a 5-acre site we have been able to identify removal or relocation of some very discreet objects – more on this coming soon.

Preserving artefacts, from the smallest to entire shipwrecks, is something we do and provide consulting services and software to assist others.

Please get in touch if you would like to know more – we would be happy to discuss any project in more detail.

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