In spring 2022, staff at Cemex’s quary on the Dungeness headland in Kent, came across a wooden shipwreck while excavating in the quarry lake for aggregate. In the year since its initial discovery, working for Kent County Council and funded by Historic England, the wreck has been investigated and recorded by archaeologists and discovered to be a rare example of a late 16th-century vessel. To celebrate the discovery of the Dungeness wreck a year on, we are releasing a series of blogs going behind the scenes. In this blog we look at the unique challenges presented by waterlogged material, and how they were overcome.

Marine archaeology has a unique set of challenges associated with the discipline, but one of the trickiest to overcome is waterlogged material. In the right conditions, materials can be preserved underwater for hundreds or even thousands of years and look almost the same as when they were last used. However, looks can be extremely deceiving, and waterlogged artefacts may be more fragile than they first appear. They are unlikely to be able to bear their own weight once removed from the ground, and loss of water from the outer surface begins as soon as the wood is exposed during excavation. These outer surfaces are often where the most useful information (such as tool marks, decoration, or potential sapwood) is preserved, and it is important not to let the surface become damaged by rapid drying out or rough handling. Waterlogged finds must, therefore, be kept wet and recording carried out quickly before they deteriorate.

This can be a difficult task to complete, especially for large sections of shipwreck. For example, the Mary Rose was sprayed with chilled water and a mixture of chemicals for over 19 years after it was raised from the seabed to prevent it drying out before it was fully conserved, while the Newport Ship timbers were kept submerged in numerous water tanks. The Dungeness shipwreck material encountered the same challenge, with some considerable extra pressure due to the weather conditions at the time - 2022 was the UK's warmest year since records began. Thankfully, before our team arrived on site to record the ship’s timbers, Cemex fashioned a bespoke tank to submerge the remains to prevent deterioration.

As we began to record the wreck, keeping it wet was almost a full-time job, with buckets of water and hoses being deployed by our archaeologists on site before a watering system was set up.

Keeping timbers wet on site Keeping timbers wet on site

Keeping timbers wet on site.

In order to determine the preservation condition of the wreck, a selection of samples taken from timbers were analysed. The analysis focused on the loss of wood substance to determine the condition of the wood, as a greater loss of substance indicates higher degradation levels of the wreck. For each sample, measurements were taken to determine the maximum water content, the shrinkage, and the basic density of the timbers. A pin test was also done on each sample to cross-reference against the other results and provide an additional metric to measure the preservation condition.

A total of 13 samples were taken from various locations on the ship. Ten of these samples were from larger timbers, the remaining 3 were taken from planks. Due to the size of the samples, a smaller piece was cut off from each one. These smaller pieces were cut to ensure they included material from the outside to the centre of each timber to account for the expected differences in preservation levels between the outer and inner material. The results of the tests showed that the wood from the wreck was in a good state of preservation.

Despite being in a busy quarry site, the staff at Cemex voluntarily put an exclusion zone where the wreck was found in the lake so that any potential further material would not be disturbed. Once the phase of recording was complete in the summer, and following discussions with Kent County Council and Historic England regarding future storage of the timbers, they were returned to a secure location within the quarry lake. Doing so has the advantage of ensuring that the ship assemblage remains together and available for study in the future. The material was covered by sand that had been excavated from the quarry, thus returning the timbers to their original environment, ensuring that the timbers remain in a suitable, permanently waterlogged environment, for continued preservation. Check out the final blog in this series to find out what we have learnt about the ship so far!