Salvaging the RFA Darkdale
This week’s post comes courtesy of Ceri Sansom…
The wreck of the Royal Fleet Auxiliary Darkdale, is all manner of things to all manner of people. It is a piece of sombre island history as a war grave; whilst it is also a very accessible dive site from James Bay and at 30-42m it has a wealth of pelagic and endemic fish.
The RFA Darkdale was one of the first casualties of a new German U-boat (U68) designed in 1941,that increased their penetration south of the equator for the first time, with technology still in use today. It is also part of the complicated Enigma machine story. Whitehall knew of the U-boat capability due to an intercept after the U-boat sunk the Silverdale, but due to the delicate source of the intelligence was not in a position to prepare the wider forces.
The RFA Darkdale was not designed for military service. After a short but lively history as the Empress Oil, it became the RFA Darkdale; a ‘fleet oiler’ or fuel storage vessel for ships in the South Atlantic, harboured in James Bay, St Helena. After just three months of service the Darkdale was struck on 22nd October shortly after midnight, under the necessary cover of darkness (the U-boat had to attack from the surface). It was hit by three of four torpedoes with the loss of 41 lives. In the conflagration the U-boat made its exit to meet its mission to ‘wreak havoc’ south of the equator.
On the sea floor the hull now lies in two parts. The deeper stern has been largely burnt out with panels sloughing off like fish scales, although there is still oil in one compartment. The bow is in exceptional condition and this is where the majority of the oil resides. Whilst in this condition the ship has not been a problem, but there are signs that age is beginning to make its mark and a significant oil leak in 2010 prompted a full investigation. This found that there was a problem requiring management and so it has been in the last three weeks that the MOD Marine Operations and Salvage team, Navy bomb disposal team and Swires Salvage have come to remove a substantial proportion of the oil in a controlled fashion.
The process has been to remove the unrelated ordnance found on the bow and immediate surroundings. It is unclear where these came from, as the bow is upturned, and the ordnance lay on top. Speculation suggests that they are possibly redundant shells from the land defences. The Naval bomb disposal team has removed all of the 38 shells, some of them fused, from the area and laid them to rest some two miles out to sea in a depth of 1km. The team has now departed on the RMS for Ascension.
The task of removing the oil is now with the MOD Operations and Salvage team, directed by Andy Liddell. The arrival of the Pacific Dolphin with its dive capability, including two decompression chambers, signalled the start of the hot-tapping procedure whereby valves are introduced to the remaining tanks to enable the oil to be withdrawn and seawater to replace it in a controlled fashion. The Pacific Supporter, a smaller vessel is in support to provide environmental contingency. It is uncertain exactly how much oil remains on the ship due to both the damage and the accuracy of the historical manifests, but the arrival of the Golden Oak tanker will take the remaining oil to South Africa for processing. Fascinatingly, after all these years, there is still a chance that some of the oil maybe suitable for sale and reused. It is anticipated that the works will be complete before 10th August, when the RMS returns from dry dock.
Based on the team’s previous experience salvaging the RFA Darkdale’s sister ship the Boardale, the salvage team is optimistic that the hull will be suitable to remain an attractive and safe dive site, as long as it is respected as a war grave and non-penetration laws are abided by. Having dived the RFA Darkdale I can testify to the richness of the marine life and the depth of the experience of coming into a significant piece of WWII history.
You can read more from Ceri on her blog, the5gigabytediet