U-8

Diary of the War: October 1916

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The wreck in two places at once

In this blog we’ve occasionally encountered wrecks that are in two places at once. The Mary Rose is a good example: after being raised in 1982, her principal structure lies in the Mary Rose Museum at Portsmouth, but she is still a designated wreck site offshore with some remains still in situ. We’ve also looked at the ship that was wrecked in two separate countries, leaving different bits behind each time.

HMS Nubian is another example of a similar phenomenon. One of the Tribal-class destroyers which patrolled the Dover Straits during the First World War (see the story of Viking, Ghurka, and Maori in action against U-8), she was sent out to intercept a surprise Channel raid by the enemy in the early hours of 27 October 1916. A visit by the Kaiser to Zeebrugge had led the Admiralty to expect a German landing west of Nieuwpoort (possibly a diversionary tactic which succeeded in drawing out some of the British naval forces towards Dunkirk?) (1)

There were six Tribal-class destroyers stationed at Dover, with HMS Zulu patrolling out at sea further west, and the net barrage guarded by 28 auxiliary trawlers and drifters, in company with the destroyer HMS Flirt. Against them 24 German destroyers were steaming up Channel: Flirt issued a challenge, which was returned, and they steamed past in the dark, assumed to be part of the British movements that night.

This was a fatal mistake since the first attack of the night resulted in the sinking of HMT Waveney II off the net barrage. Flirt went to her assistance: in the meantime those on board the auxiliary yacht Ombra had grasped the situation, reporting enemy activity to the authorities and ordering the remaining HMTs back to Dover. Flirt herself came under attack at ‘point blank range’ which blew up her boilers, causing her to sink within five minutes. The Queen troopship was then captured and despatched. remaining adrift for about six hours before foundering off the Goodwin Sands. Fortunately she was carrying mail on her run from Boulogne to Folkestone, rather than troops.

By this time the destroyers in Dover were steaming out to investigate. As Nubian approached the net barrage destined to snare submarines, she was on her own without support, though by now further assistance was coming from the Dunkirk and Harwich quarters, attempting to trap the German force in a pincer movement.

Six of the retreating patrol drifters, four of which were unarmed, were then sunk by the German raiders – Spotless Prince, Launch Out, Gleaner of the Sea, Datum, Ajax II and Roburn (which had also been involved in the engagement with U-8)

The Nubian reached 9A Buoy in the net barrage, from which the commotion had come, then turned about – straight into the German 17th Flotilla steaming towards her. The first two enemy torpedoes missed, but the third found its target and blew off her bows. The rest of the ship was taken in tow, but, as a gale sprang up, she drove ashore near the South Foreland.

You might think from the title of this article that that’s it: Nubian now rests in two places: in mid-Channel and near the South Foreland. In fact, her story is much more interesting than that. We return now to a bit-player in the events of 26-27 October 1916, HMS Zulu: a minefield in the Straits of Dover would ‘terminate her career’, in the words of the official history. (2) On the afternoon of 8 November 1916 she struck a mine which ‘shattered her after part’, with her bow section being towed to Calais.

Something of a pattern was emerging here . . .

In what was later described as a ‘grafting’ operation, (3) using the language of the pioneering plastic surgery techniques which emerged out of the injuries of the First World War, the two grounded sections – the  bow section of Zulu and the aft section of Nubian – were salvaged, joined together and given the portmanteau name HMS Zubian.

As Zubian, therefore, both wrecks rejoined the Dover Patrol. Who knows how many times she passed over the remains of her component ships below?.She would later be credited with ramming UC-50 (a misidentification: probably UC-79) (4) and would participate in the Zeebrugge raid of 23 April 1918. Several of the Tribal-class were disposed of in 1919 : unsurprisingly, Zubian was among them, after everything she had been through. (5)

Nubian was the ship that was salved because another ship was wrecked: fortuitous and resourceful recycling in a time of war.

Black and white photograph of warship at sea in the lower half of the photograph, seen in starboard view, bows towards the right of the image.
Aerial view of HMS Zubian, from starboard. To modern eyes this image looks commonplace, but we should remember that aerial views were literally a fresh perspective on ships at war. © IWM Q61101.

 

(1) Naval Staff Monographs, Vol. XVII. Home Waters, Part VII: June 1916 to November 1916  London: Admiralty, 1927, p185-189. The acccount here is principally derived from this source, supplemented by information from the wreck records in the National Record of the Historic Environment for each vessel lost (see links).

(2) ibid., p208

(3) The Times, 28 February 1935, No.47,000, p13

(4) uboat.net

(5) The Times, 22 November 1919, No.42,264, p9

 

U-8

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The oldest First World War German U-boat and the earliest German submarine to be sunk in English territorial waters – the U-8 – has been given protection by the Secretary of State for Culture as a Protected Historic Wreck site, on the advice of Historic England.

Pioneering underwater survey techniques were used in 2015 to survey the site and assist the case for its protection.

Exploring New Technologies for Underwater Research

Historic England recently commissioned an innovative survey of a First World War submarine wreck in order provide data to support its protection and to test the application of new equipment for archaeological research.

Autonomous Underwater Vehicles (AUVs) have been used offshore for some time and the development of smaller systems has opened up a range of inshore opportunities for archaeological investigation. With recent advances in technology, these small AUV systems boast a suite of remote sensors that can include impressive underwater survey tools: side-scan sonar, multibeam echosounder, sub-bottom profiler, magnetometer and an underwater camera.

In order to test such a system for use in underwater archaeology, we commissioned Wessex Archaeology to carry out an AUV survey of the German U-Boat U-8 located some 10 nautical miles off Dover. Our First World War wreck diary provides more details of the loss of the U-8.

For the investigation, we deployed an Ocean Server Iver3 AUV which carried Edgetech 2205 sonar transducers and towed a Marine Magnetics Explorer magnetometer (Fig. 1). The AUV was about 2m in length and weighed approximately 40kg; light enough to be deployed by two people. The stated endurance of 8 hours was enough to ensure sufficient coverage of the U-8 target area. However, it was not known how the system would cope with a moderate sea state and tidal streams of up to 2.6 knots, so it was therefore decided to deploy the system to coincide with slack water during neap tides to give the best operational window possible.

Man dressed in black to the right of the image looks over the railing of a boat at an underwater vehicle on the surface of the water to his left.
Fig. 1. The AUV used to survey the U-8. © Wessex Archaeology

Before the AUV could be used to acquire data over the U-8, its buoyancy needed to be adjusted for the salinity and density of the seawater and the underwater survey lines were planned on a laptop with software calculating where the AUV needed to dive down and where it was to come back up. Survey positioning was provided by a GPS receiver within the AUV when at the surface and below the surface positioning was provided by a RDI Doppler velocity log, depth sensor and corrected compass. The AUV can only be communicated with via Wi-Fi when it is at the surface.

Deployment of the AUV at the wreck site was relatively straightforward, even in the slight to moderate sea state encountered, and it was programmed to fly around 10m off the seabed. Unlike a conventional towed system though, the geophysicist was unable to see live images of data as the sensor passed over the seabed: there is no way of knowing that the data is of sufficient quality or that the survey lines have been positioned correctly to ensonify (image) the target site, until the AUV is recovered to the vessel. This can make for a nervous time whilst the geophysicist is waiting to see the data!

The sea state did have an effect on the performance of the AUV whilst in the water in two ways. Firstly, the waves tended to swamp the ‘conning tower’ containing the GPS tracking system, which meant that the AUV sometimes had difficulty acquiring a GPS signal, causing it to refuse to start surveying. Secondly, when slack water was lost, the AUV struggled to get into its start of line position as it laboured against the tide, unable to dive. However, its endurance seemed good despite this, with the AUV deployed for about 6 hours with no requirement for a battery change.

Following recovery of the AUV and data download we could see that the side-scan sonar imagery showed a clearly defined submarine with detail of the conning tower visible. Sharp detail was observed in the acoustic shadow that shows the presence of three distinct upstanding narrow features, two on the conning tower (possibly periscopes) and one just behind (interpreted as the radio mast) (Fig. 2).The magnetometer data was also of good quality with a large magnetic anomaly observed over the location of the wreck, as would be expected.

Side-scan sonar image showing vessel on its side, with its central structure clearly visible, picked out in white against an undulating textured yellowish brown background representing the seabed.
Fig. 2.  Image of the U-8 in side-scan sonar data. Crown copyright, image by Wessex Archaeology

Some challenges were identified with the bathymetry data, particularly where some of the smaller features observed in the side-scan sonar imagery were not visible owing to the relatively low resolution of the bathymetry (Fig. 3). In addition, the on-board camera did not pick up any footage of the U-8 despite the visibility being around 8m.

Multi-coloured textured image of seabed set against a plain black background. The seabed is primarily greens and blues, with a raised section in reddish hues representing the wreck above the seabed.
Fig. 3. Image of the U-8 in multibeam bathymetry data. Crown copyright, image by Wessex Archaeology

During this, our first, archaeological trial of an AUV, the system performed reasonably well, giving sharp imagery that has aided our interpretation of the U-8’s condition. We’ve learnt some important lessons for future operations, particularly in understanding the effects of tidal currents on the AUV during data collection. Use of the AUV proved a cost-effective method of survey in a busy shipping channel with the same methodology being applicable to other sites that are similarly difficult to reach, such as those in proximity to shore, those in deep water, or otherwise restricted in some way. The system is also particularly well suited to more benign waters such as ports, or natural and manmade harbours, and if the circumstances allow the system to be launched from shore, then the cost savings could be considerable when compared to established survey methods.

Toby Gane and Dr Stephanie Arnott, with Mark Dunkley

Toby Gane is a Senior Project Manager and Stephanie Arnott is a Senior Marine Geophysicist at Wessex Archaeology.

Mark Dunkley is Historic England’s marine designation adviser.

No.78 U-8, Straits of Dover

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Diary of the War No.8

On 4th March 1915 the first confirmed loss of a German U-boat in English waters during the war took place with the capture of U-8 off Dover, the culmination of a hunt that began when she was spotted in the Channel by HMS Viking. Viking opened fire, forcing U-8 to submerge but not without returning fire with a torpedo which missed its target, and U-8 was lost to sight.

Black and white illustration of U-8 submarine on the surface being approached by a destroyer, the crew assembled on the conning tower appealing for help.
Postcard of a contemporary illustration of U-8 being approached by a British destroyer. It is a work of subtle, as well as overt, propaganda, the text being complemented by the viewpoint from the side of a British destroyer, her lifeboat hanging from its davits, suggesting British humanity in coming to the rescue of an enemy crew appealing for help. By courtesy of Mark Dunkley

As the submerged U-8 continued on her way through the Straits of Dover, she became enmeshed in an anti-submarine net barrage. The requisitioned drifter Roburn spotted movement in the nets, and alerted the destroyers of the Dover patrol for assistance. The destroyer Ghurka* towed an anti-submarine sweep wire. These wires were fitted with explosive charges which detonated on contact with the target. Successful contact forced U-8 to the surface, whereupon Ghurka and Maori opened fire.

The crew were taken off and an attempt was made to tow the submarine back to Dover, but she foundered approximately one and three-quarters of a mile west of the southernmost tip of the Varne Bank, where she has now been positively identified by internal features.

The rescued crew, now firmly in British custody, were lined up at Dover on arrival. As the Daily Telegraph for 6 March 1915 (p9) had it: “The Germans were for the most part sturdily-built fellows – no doubt the pick of the German naval service mans the submarines”. The prisoners were marched through the town, escorted by the garrison of the Castle, and a crowd of local sightseers curious to see the enemy, to the Castle itself.

A view of Dover Castle on top of the hill, with the town below.
Dover Castle viewed from the High Street, Dover DP049659 © English Heritage Picture Library

The official Admiralty communiqué quoted in the paper gave away few details, stating only that U-8 had been sunk in the Channel off Dover, but the human interest aspect of the prisoners’ reception more than made up for it, as did the speculation over the intelligence value of the submarine (p8) and what it was thought to reveal about the U-boat war.

As for Roburn and Ghurka, they resumed their successful patrols off Dover, but they, too, were destined to fall victim to enemy action in the Straits of Dover. Roburn sank on 27 October 1916, after being shelled in a Channel raid by German torpedo boat destroyers. She was lost together with a Tribal class destroyer, which formed the nucleus of the Dover Patrol (Ghurka, Maori and Viking, as their names implied, were also Tribal class ships). Ghurka herself was mined on 8 February 1917 off Dungeness, and is one of those vessels whose remains are designated under the Protection of Military Remains Act.

The seabed of the Straits of Dover reveals a common heritage of sunken British and German vessels, a memorial to the warfare on the surface a century ago.

*not a misspelling: she was indeed Ghurka, rather than Gurkha.