Derfflinger: an Inverted Life

WARSHIP NOTES This section comprises a number of short articles and notes, generally highlighting little known aspects of warship history. DERFFLINGER: AN INVERTED LIFE long with the other battlecruisers of the German High Seas Fleet, SMS Derfflinger (launched at Hamburg on 17 July 1913) was scuttled at Scapa Flow on 21 June 1919, capsizing and sinking at 1445 hours. During the 1920s and 1930s, most of the fleet was refloated, the capital ships (and some destroyers) being towed to Rosyth Dockyard, where they were demolished.1 All but one of the big ships had been raised upside down and had thus to be scrapped in dry dock, of which Rosyth had three. Derfflinger was the last ship to be raised, rising to the surface in late August 1939,2 having had all openings sealed and been pumped full of compressed air (see drawing). Under normal circumstances, she would then have been prepared for the tow to Rosyth and for her docking there.3 However, before she could leave Scapa, the Second World War had broken out, meaning that the Rosyth dry docks were all now earmarked to support the Royal Navy. Thus, they were no longer available to Metal Industries, since 1933 responsible for salvage operations at Scapa, once they had completed cutting up the wreck of the battleship Grosser Kurfürst (work commenced on 24 August 1938) in No.2 Dock. Derfflinger was therefore towed behind the island of Rysa Little, opposite Hoy, within Scapa Flow, and moored there with ten 7.5-ton anchors, awaiting events.4 The war effort’s demand for scrap metal meant that the question of her future was reopened a few months later, in February 1940. It was argued that the 25,000 tons of scrap built into the hulk, which included armour plate and non-ferrous metals, justified the risk of tying up a dock for the four months that was cited as necessary for scrapping the battlecruiser.5 The Director of Dockyards pointed out, however, that the Rosyth docks were the only docks on the East coast capable of taking capital ships, that they had been almost continuously occupied since the previous October, and that blocking one for even four months was therefore too much of a risk, particularly in light of the expected German offensive in the Spring. In addition, Commander-in-Chief Rosyth also noted the potential value of Derfflinger as a blockship for sealing the secondary entrances of Scapa Flow, although she proved to have too great a draught to be considered. On the other hand, it soon became clear that two other big ships which might have yielded significant quantities of scrap, the ex-battleships Iron Duke (gunnery training ship) and Centurion (radio-controlled target), had ongoing war roles.6 In addition, since the ability to salvage the hull of the sunken training ship (ex-56,551grt liner) Caledonia (ex-Majestic, ex-Bismarck), was unproven – although 7,000 tons was soon removed from her upperworks, the hull was not finally raised until July 1943 – the issue of Derfflinger was revisited in March. A tentative proposal was then made that she might be docked after the cruiser Belfast was removed from No.1 dock in June, following emergency repairs resulting from her mining on 21 November 1939, prior to proceeding to Devonport for reconstruction (she left dock on the 27th). Metal Industries stated that it was possible to break up the ship in 16-20 working weeks, and that it might be done in such a way that the hulk could be removed from the dock during the first 6-8 weeks, should an extreme emergency arise. However, nothing was done to act on this, presumably due to the fall-out from the German attack on the Low Countries and France in May 1940. The idea remained alive, however, until the Admiral Superintendent at Derfflinger at sea, following her 1917 refit, during which she received a tripod foremast. (Author’s collection) Derfflinger slips under the waters of Scapa Flow at 1445 on 21 June 1919. (C.W. Burrows, Scapa and a Camera [London, 1921], p.34) Aidan Dodson looks at the twilight career of the German large cruiser (battlecruiser) Derfflinger during the Second World War, during which she spent longer afloat upside-down than she had done the right way up, despite a number of attempts at arranging for her scrapping. A 175 WARSHIP 2016 When raised, Derfflinger still retained all four turrets and the remains of her funnels and superstructure. To allow her to be docked for scrapping, her draught needed to be significantly reduced; thus ‘B’ and ‘C’ turrets were removed at her wartime berth behind the island of Rysa Little, together with all remaining top-hamper. (Adapted from McKenzie, Trans. Inst. Eng. & Sbdrs. Scot. 93, fig. 4) Sketches showing key stages in the raising of Derfflinger during 1938/39. The first stage involved the fitting of airlocks of between 28 and 40 metres in height on the bottom of the capsized hulk, allowing water to be displaced by compressed air and workmen to enter the ship to gradually seal openings and restore its watertight integrity. This was done in such a way that the hull was divided into seven airtight transverse compartments, while the longitudinal torpedo-bulkheads were also sealed to create similar longitudinal compartments along the flanks. These allowed the actual raising to be fine-tuned, in particular in removing the ship’s 20.5° list to starboard – a technique that had been honed by more than a decade’s experience of raising such inverted wrecks. The bow was raised first, to allow divers to inspect the underside (ie superstructure!) of the ship and check for any issues prior to bringing the stern of the ship to the surface. (Adapted from McKenzie, Trans. Inst. Eng. & Sbdrs. Scot. 93, figs. 2 & 3) Rosyth produced a minute in August that undermined the case. He pointed out that the break-up period cited was shorter than the time previously taken to scrap such vessels, and that cranage and storage space previously available would not now be. In addition, the time to remove and reinstate the support blocks in the dock would add six or seven weeks to the timeline. He thus considered that if Derfflinger were to be broken up at Rosyth, the dock would probably be unavailable for naval purposes for 6-7 months at the very least. He also doubted that the hulk would indeed remain floatable during the first weeks of scrapping. There were also manpower issues and questions as to where the hulk could be moored prior to docking. This killed the Rosyth option, while a proposal to use a dry dock at Southampton was also dropped for operational reasons – although the idea would be revived later. Nevertheless, the scrap shortage continued, and in March 1942 the British Iron and Steel Corporation (Salvage), which had now requisitioned the hulk from Metal Industries, proposed that a new effort be made to break-up Derfflinger, and that Peterhead harbour, half way between Scapa and Rosyth, could be used. Approval was given on 5 April, the original conception being that she would be moored inside the breakwater and scrapped there. In the subsequent discussions, Metal Industries pointed out that the non-use of a dry dock would present challenges, as the moment that any cut was made into the hull, compressed air would be released and the hulk 176 would sink: it would not be possible to conduct the usual afloat scrapping process, whereby the removal of material gradually lightened the hull, allowing it to float ever higher in the water, until it could be beached for final dissolution. Accordingly, the concept was changed to beaching the hulk in the shallows on the opposite side of harbour, where the highest section would be broken up, the remainder of the hulk then having appropriate decks and bulkheads resealed to allow refloating and rebeaching. The move of the hulk from Scapa to Peterhead was planned for the end of May, which then slipped to 7 June. Four days prior to departure, however, Metal Industries reported that having gone into the matter further, they had concluded that the break-up plan was not after all practicable. The tow was thus cancelled. Derfflinger’s steel continued to exert a draw (as did that of Caledonia, significant effort being expended on the difficult work of her salvage). Accordingly, the idea of breaking up the ship at Southampton was revived in January 1943, and approved in February. But in March the need for a strong escort between the Orkneys and the south coast, the lack of depth in the Southampton approach channel, and the availability of labour were raised as concerns by C-in-C Portsmouth. There were also worries as regards tying up the only two dry docks big enough to take her at Southampton, the King George V and Trafalgar, which were particularly used for merchant ships and armed merchant cruisers. Crucially, Chief Salvage Officer, Scapa, was of the view that, given experience with the much shorter tows of other High Seas Fleet inverted hulks to Rosyth, Derfflinger was insufficiently seaworthy to survive a tow all the way to Southampton. This and other objections led the project to being cancelled on 22 March 1943. In June 1943, the Director of Sea Transport suggested that the hulk could be moved to the Firth of Forth against the possibility of dock availability, or that it might be possible to break her up on a beach or in a tidal basin in the Bristol Channel. In favour of the latter location was that the exceptionally large rise and fall of tide there would make the process easier than at Peterhead; it was also closer to the South Wales steel works. The Bristol Channel option was considered further, but dropped in August, although some ideas put forward for camouflaging the hulk as a group of barges were kept in case any move were to take place in the future. WARSHIP NOTES The hulk of Derfflinger in the process of being docked in AFD.4 in November 1946. (CPL) AFD.4, with the hulk of Derfflinger, arrives at Faslane in tow from the mouth of the Clyde, where the docking process had been carried out. The structures on the underside of the battlecruiser housed the passage crew and also the compressors necessary for periodically topping-up the air inside the hull that kept it afloat. The chimney-like pipes seen protruding at a slight angle from the hull are the airlocks giving access to the interior of the hull, with the extensions used during the raising removed. (Author’s collection) 177 WARSHIP 2016 AFD.4 and Derfflinger coming alongside at Faslane, where the battlecruiser would be finally broken up. Behind them is Iron Duke, her after part already partially dismantled (the mainmast is in the process of being removed), following her own arrival from Scapa on 19 August 1946. (Author’s collection) This was seemingly the last wartime attempt to scrap Derfflinger, which continued to lie at her berth in Scapa Flow. With the end of the war, her final disposal could go ahead, and two turrets and the aft conning tower were removed (the turrets being released from inside the ship) to reduce the minimum draught of the hulk from 12.3 metres to the maximum allowable figure of 12 metres in the Rosyth dry docks. However, in March 1946, the Admiralty informed Metal Industries that Rosyth docks remained unavailable, meaning that an alternative dock had to be found, the wartime studies of the Peterhead option having made clear that a dry berth was needed to properly dismantle such an upturned vessel. A solution was found when Metal Industries obtained in July 1946 the lease of the former Military Port No.1 at Faslane, on the Gare Loch in the Clyde estuary, as its new principal shipbreaking yard, replacing Rosyth. Nearby, at Rosneath at the mouth of the Gare Loch, was the 32,000-ton-capacity Admiralty Floating Dock (AFD) 4, which had been built by Swan Hunter in 1912, and served in the Medway until 1915. It had subsequently been operated in the Tyne, at Portland and at Devonport before being moved to Scotland in September 1941. Now surplus to requirements, a careful study indicated that it could accommodate Derfflinger; it was therefore acquired at the same time as the Faslane lease. Derfflinger was then towed to the Clyde, where she was docked with some difficulty, the dock having to be sunk 2.5 metres below its normal maximum depth to accommodate its unusual contents, leaving it with a freeboard of only 2 metres. The dock and battlecruiser were then towed to Faslane, arriving towards the end of the year, where they were berthed against the wharf. They lay just aft of Iron Duke, which had also spent the war at Scapa, grounded after bomb damage, and had been sold to Metal Industries in March 1946, refloated in April and 178 arrived at Faslane in August. It took some 15 months for Derfflinger to be entirely dismantled. It was briefly considered whether AFD.4 might be used to break up the remains of the liner Berengaria (ex-Imperator), which had been partly dismantled at Jarrow between 1938 and 1940 and had since languished in the Tyne in two pieces, but instead the dock was sold in June 1948 for further service abroad: it still survives in use at Bergen-Laksevåg, after over a century of service.7 Footnotes: 1. 2. 3. 4. 5. 6. 7. The key sources for the salvage and scrapping of the High Seas Fleet are S.C. George, Jutland to Junkyard (Cambridge: Patrick Stevens Ltd., 1973; reprinted Edinburgh: Birlinn, 1999) and I. Buxton, Metal Industries: Shipbreaking at Rosyth and Charlestown (Kendal: World Ship Society, 1992). See also G. Bowman, The Man Who Bought a Navy: The Story of the World’s Greatest Salvage Achievement at Scapa Flow (London: Harrap, 1964; republished by Peter Rowlands & Stephen Birchall, 1998) and T. Booth, Cox’s Navy: salvaging the German High Seas Fleet at Scapa Flow, 1924-1931 (Barnsley: Pen & Sword, 2005) for the first period of work. Curiously, many standard reference works state in error that she was raised in 1934 and broken up at Rosyth during 1935–36. The salvage and scrapping of Derfflinger are described in detail in T. McKenzie, ‘Marine Salvage in Peace and War’, Transactions of the Institution of Engineers and Shipbuilders of Scotland 93 (1949–50), pp.124–39, with a summary in the works cited in Note 1. See also Warship 2008, p.149. For this and other aspects of the history of the hulk between 1939 and 1943, documentation is contained in National Archives file ADM1/13330. As base/accommodation/harbour defence and base ship/ training vessels, respectively. For a history of Admiralty floating docks, see Ian Buxton, Warship 2010, pp.27–42.