The Submarine Under the Park, Part 2 – Digging Deeper

The Submarine Under the Park, Part 2 – Digging Deeper

28 Jul 23
Posted by: LT TOM KEMP RN
Message from the Editor

The author continues his investigation into the Dartmouth Coronation Park submarine mystery, having gained some key allies and a Ground Penetrating Radar kit. A 10 minute read.

Having finally put pen to paper and fulfilled a long-held ambition of writing for the Naval Review, I was absolutely thrilled to see my article concerning the ‘Submarine Under the Park’ make it to print in NR 111/1. I duly proceeded to pat myself on the back and heartily congratulate myself on a leave period well-spent, assuring my wife that I was, at long last, done banging on about “that bloody submarine.”

Then an email dropped into my Inbox. It was from Dr Simon Roffey, of the University of Winchester, Hampshire. A former submariner himself (he served on HMS Onslaught in the 1980s), he had read about my efforts in the Navy News and was willing (and, perhaps more importantly, able) to help progress the search a step further. He, along with his colleague and fellow enthusiast, Dr David Ashby, also of the University of Winchester, were willing to travel to Dartmouth and spend almost three days conducting a Ground Penetrating Radar (GPR) survey of Coronation Park, in the hope that we might be able to identify some trace of the hull of HMS E52 below the surface. With some reluctance, I informed my wife that she might have to tolerate this obsession for just a little while longer.

With permission to conduct our survey granted by a supportive and proactive Dartmouth Town Council (encouraged, perhaps, by the timely appearance of a sink hole near the centre of the park?), we identified a date and set our plan in motion.

The weather could scarcely have been worse and, armed with the University of Winchester’s GPR kit and a near-limitless supply of can-do spirit, Simon and David set to work in the pouring rain.

After the first day the results did not look promising. Far from finding the glaring red, reflective echo of a 181ft-long hull, the search area, selected after careful analysis of contemporary images, yielded nothing. I had been harbouring concerns that, prior to reclaiming the park from the river, the engineers may have moved the hull to mark the new limit of the land and serve as a breakwater whilst the Mud was filled in. If this were the case, then the hull would lie under the road along the Embankment and would be significantly harder to identify. Our intrepid archaeologists were not perturbed, however, and cheerfully set to work the following day, shifting their search area to the east.

Our first set of results. The red box indicates our initial Search Area, based on contemporary images.

This move was to exploit the possibility that the boat could have been dragged off the foreshore and onto a lower portion of the Mud prior to being interred. This led us to consider the width and height of the boat, once again. The Group III E-class submarines had a beam of 12.5ft and a height (including the conning tower and 12-pdr deck gun, both of which were likely removed) of 22.5ft[1] (or 23.5ft according to M P Cocker).[2]

Chart OCB 2253 B1, dated 1903, showing Coombe Mud some 18 years prior to HMS E52 being dragged onto the drying height. The original drying height now sits between 2 and 3.3m below the present-day level of Coronation Park, meaning that whatever is left of HMS E52 ought to sit between that depth and the surface. Chart sourced and reproduced by the kind permission of the UK Hydrographic Office.

The 1903 chart of the Dart records the portion of the Mud where the boat was expected to lay as having a charted depth of between -6ft and -9ft (that is to say that the mud flat sat between 6 and 9ft above Chart Datum and would, therefore, only be covered at High Water). It stood to reason, then, that even if the hull had sunk some way into the drying height, it would still have jutted several feet above the desired ground-level (not conducive to a flat and aesthetically appealing recreational park!). We mused over whether the hull could have been compressed or ‘flattened’ (almost a certainty) but agreed that it was worth searching in a ‘deeper’ portion of the park.

Historic England Aerial Photo EPW024213 – The River Dart, looking Northwards, and Coombe Mud, the year before the Mud was sold to Dartmouth Town Council. The potential hulls are circled in the righthand image, for clarity. Imagery reproduced by the kind permission of Historic England.

Simon and David concluded their survey and returned to Winchester to crunch through the data they had collected. Whilst doing so, David came across some aerial photography of Dartmouth, dated 1928, that showed Coombe Mud, partially flooded, with what could be the hulls of ex-German Torpedo Boat Destroyer S24 and HMS E52, lying end-to-end. This imagery gave me hope for several reasons. Firstly, it supported the account given by Derek Blackhurst, writing in 2001, that two hulks (S24 and a nameless submarine) had been towed to Dartmouth together in 1921 from Brixham (where HMS E52 had been sold that same year)[3] and used as a breakwater.[4] Secondly, it suggested that the park had been reclaimed from west to east, and not the other way around, thus making it unlikely that the hull was entombed within concrete under the Embankment road, as I had earlier feared. This latter revelation, made by David, suggested that our assumptions were sound and that we were getting closer to finding our query.

A ‘slice’ of the park, 90-100cm below the surface. The blue/aqua returns indicate an absence of metal or stone. The red ‘reflections’ indicate the presence of metal and are observable right down to the original drying height. The approximated positions of the hulls, as per the 1928 aerial photography, are indicated by the red ovals.

The imagery resulting from the survey reveals consistent returns or ‘reflections’ that, to the optimist/believer, conform to the expected positions of HMS E52 (lying north to south) and S24 (lying east to west), as per the 1928 aerial photography. The results were not uniform and suggest that the hulls (or whatever is left of them) are very far from being intact (further reinforcing the notion that they must have been compressed or ‘flattened’). Cautious not to let my enthusiasm get the better of me, it is important to consider the ‘known unknowns’ still at-large (all the while remaining watchful for ‘unknown unknowns’!).

The first: Using only GPR, we have no way of positively differentiating between the ‘reflections’ of S24 and HMS E52 other than by their length (HMS E52 was originally 181ft long while S24 was approximately 233ft long – if either hull proves to be in excess of 181ft, therefore, we can discount that this wreck could be HMS E52). Secondly, local legend (further reinforced by local historians) has it that the US Army, having been encamped on Coronation Park during the Second World War, left an unquantified amount of kit and equipment behind when they left, burying much of it to save having to take it with them. The possibility therefore remains, however unlikely, that they buried said kit in a 181ft long line, intent upon confusing and frustrating the efforts of 21st century archaeologists, historians, and submariners. We also know that a series of sewage/water pipes run under portions of the park. Whilst none of our findings, thus far, resemble such pipes, we must continually apply caution to make sure we aren’t mistaking this pipework for torpedo tubes or fragments of pressure hull!

So, what comes next? And does it matter?

Simon and David have offered to return to Dartmouth, potentially as early as the first quarter of 2024. It is hoped that a second GPR survey, supplemented by magnetometry, now that we have had a chance to pause and consider the results from the first (and cross-reference these results against more aerial photography), will help us to ‘fill in the blanks’ and further reinforce our conclusions. Whether hunting submarines at sea or under parks, it is all too easy to see what you want to see and watch as a mass of relatively benign red dots take on the shape of a buried vessel, all by themselves. More evidence is still required.

Ever the optimist, the prospect exists to take things one step further and consider whether a borehole or small trench might be employed to recover one of these ‘dots’. Recovering a scrap of hull-plating, handful of nuts and bolts or the remnant of any piece of equipment that could positively identify the vessel as an E-class submarine would constitute irrefutable proof of the boat’s identity (HMS A8 remains a possible, however unlikely, candidate) but such a project would depend entirely on the Town Council’s appetite to take a shovel to one of their most popular and picturesque recreational spaces. But that isn’t to say I haven’t asked…

Aside from being my personal hobbyhorse for the better part of the last year, and having intrigued the local community for decades, answering this question will not only confirm, once and for all, the final resting place of one of HM Submarines (and a pretty successful one, at that!) but would also serve to reiterate the fact that our naval heritage is all around us and can often (and must) be clawed back from obscurity. Our time and energy could scarcely be better spent.


[1] Akermann, Paul, Encyclopaedia of British Submarines, 1901-1955, (Paul Akermann, 1989), p. 146.

[2] Cocker, M. P., Observer’s Directory of Royal Naval Submarines 1901-1982, (Frederick Warne: London, 1982), p. 25.

[3] Lyon, D.J., The Denny List Part III: Volume 3, (National Maritime Museum, 1975)

[4] Blackhurst, Derek, Philip & Son Ltd, Shipbuilders & Engineers, (Ships in Focus Publications: Preston, 2001), p. 24.