The Admiralty had no salvage organisation at the outbreak of war and, apart from a few pumps and other obsolescent equipment in various dockyards, had no salvage resources of any kind. The heads of existing salvage organisations were therefore allocated areas in which they agreed to be responsible for salvage and for full co-operation with the Admiralty. Metal Industries, for example, was allocated the northern area, covering the waters from Cape Wrath to the Moray Firth and the Orkney, Shetland and Faroe Islands. As soon as possible the Admiralty then formed its own salvage department under the direction of Commodore, later Rear-Admiral, A.R. Dewar. When planning for the invasion of Europe began, McKenzie’s ability was rated so highly that in January 1944 he was appointed Principal Salvage Officer, North-West Europe, on the staff of Admiral Sir Bertram Ramsay, Allied Naval Commander-in-Chief, Expeditionary Force. McKenzie was commissioned in the rank of Commodore RNVR and was subsequently decorated with the orders of the CB and CBE. For his work in clearing Dutch canals of obstructions, the Dutch government also appointed him an officer of the Order of William.
For seven long years throughout the war and well into peacetime, Derfflinger lay bottom up, kept afloat by a small maintenance party who lived for the whole time in a hut built on the ship’s bottom. No other ship has ever remained so long afloat upside-down.
In 1946, after raising Derfflinger about 70 feet because of her funnels and superstructure, she was prepared for the tow to Rosyth. The hull was reasonably watertight, and to replace lost air it was merely necessary to operate compressors two or three times a week for two or three hours at a time. The compressing plant was in the company’s vessels Bertha, Metinda and Imperious. But the Admiralty now needed their dry dock at Rosyth, and Metal Industries had to find another place to dispose of her. About this time the Admiralty had for disposal a surplus, 40-year-old, 30,000-ton floating dock. Metal Industries bought it to tow Derfflinger in it to the Clyde, where she was eventually docked at Faslane Port.
But floating docks are not designed to carry ships upside-down. McKenzie, writing of Derfflinger’s unequal distribution of weight, said:
There can be no question of carrying the Derfflinger mainly along the centre line as the two turrets and the two turret rings were the lowest points capable of carrying a heavy load, and had the load been concentrated on these points it would certainly have wrecked the dock. After careful study and calculations it was decided to rest the ship lightly on the forward turret, on B turret barbette ring, the port and starboard plating of a heavy tank-like structure near midships, parts of the midship deck structure, the after super turret barbette ring, the after turret, and on 50 or more nests of blocks and/or shores under the casemates and other strong points along the ship’s side.
The various heights necessary were calculated from drawings and the divers had to fit only the capping blocks. Chain cable was used as ballast for each nest of blocks in such a way that buoyancy was just negative. This enabled blocks to be left in position yet easily movable by divers.
Perhaps the most intricate work connected with this part of the salvage operations was getting Derfflinger into dry dock, for the dock had to be sunk eight feet below its normal maximum working depth, and even so Derfflinger would have only six feet freeboard to the top of the dock walls or side tanks, and there was still only six inches clearance over the blocks at the lowest points. Moreover, the margin of stability was low, so that air pressures in the various sections had to be delicately balanced lest the ship should settle and foul the dock bottom while being manoeuvred into the required position. This work was successfully accomplished and, as the pressure was reduced, the ship settled firmly on the pre-selected points.
The work of blocking up went hand-in-hand with the difficult and delicate task of exactly maintaining the ship’s level. Six divers completed the blocking up in just over four weeks. McKenzie declared that only a team of first-class divers could have carried out this work successfully. Then, in just over 24 hours, the dock was slowly raised by pumping until its deck was above water level. The repair department of the firm of Alexander Stephen & Sons Ltd assisted Metal Industries with this operation. W.B. Johnstone, a director of this firm, considered that the greatest difficulty experienced in the control of the dock during the docking and lifting was in judging the exact amount of water in the tanks. The Navy had apparently decided that piping between the tanks and radiators were of no importance as they had corroded away. The only method of checking the amount of water in the double-bottom tanks after the dock was submerged was to wait until the dock floor emerged from the water, then remove a manhole door and check the height of water in the tank. When lifting a vessel on to a floating dock the main principle is to watch the breakage, or bending, that takes place during the whole lifting procedure. The dock must be kept as straight as possible, and for a dock of the length of the one used, no more than three inches of breakage is acceptable. Surprisingly the gauge fitted by the Admiralty for checking the breakage was on the floor of the dock and could therefore only be watched and recorded after the vessel had been lifted. Special water gauge pipes were therefore run along the dock walls, and a theodolite was placed at one end of the dock to keep a check on the breakage during the lifting operation but, as darkness fell, chances had to be taken during the final lift. Another disturbing feature was the bad riveting in several tanks midships and, before the operation could begin, some 4,000 bolts had to be fished through the bottom of the dock so that the leaky tanks could be made watertight in order to give the maximum lifting capacity. J. Robertson and McGillvray, whose responsibility it was to mark off the dock bottom, fix blocks etc, had only a small scale drawing, all in German, to work from, for the Admiralty seemed to have very few drawings available and these were far from accurate.
The most difficult part of the work now lay behind them, but what remained was still far from easy. As the six-ton quayside cranes were inadequate for the task, a 60-ton floating crane was bought from the Ministry of Transport to operate on the seaward side of the dock. The projecting ends of the ship were removed, and on each end of the dock, derrick-cranes of 12-ton capacity which could be moved on rails were erected. On the dock walls were three-ton and five-ton cranes which were used to move material within their capacity. After the ship had been cut down to the armour deck level, sheer legs were erected on the deck and the great main armour plates, each weighing from 20 to 30 tons, were lowered on to a steel truck specially built for the task on the dock’s deck. The truck then moved along a railway track which had been laid to the end of the dock where the armour plates were lifted off by the floating crane.
In just over 15 months Derfflinger was completely reduced to 20,000 tons of scrap, and soon afterwards Metal Industries sold the dock to foreign buyers, having no further use for it themselves.
Derfflinger was the last ship of the German fleet to be raised. The battleships Kronprinz Wilhelm, Markgraf and König lay in the deep channel between Cava and Barrel of Butter in 22 to 25 fathoms with lists of 30 to 40 degrees, though the lists were slowly decreasing as their upperworks subsided into the mud, and the light cruisers Cöln, Karlsruhe and Brummer lay too deep to be dealt with economically. So Metal Industries accepted the conclusion reached by their experts that any ship in 30 or more fathoms of water could be written off as an economic salvage operation except for the recovery of a valuable cargo, and abandoned them.
The Admiralty then decided to use Scapa Flow once more as a base for the Home Fleet, and these last few enemy ships were left to rust away. But at the end of World War II events occurred which completely altered the scrap value of steel in the remaining wrecks. These were the atomic explosions in Japan, which resulted in contamination of the atmosphere by fall-out. This has meant that all steels made after 1945 are to a very slight extent radioactive. However, the level of radioactivity is one of the very lowest, and substantially below any form of health hazard. Nevertheless it is still high enough to disturb the most delicate of radioactive detectors
. Now steel is required for shielding radioactive detectors from background radiation. Other materials, such as lead, are not suitable, for they frequently have naturally occurring activity. Moreover, furnace lining thicknesses are sometimes tested by the use of radioisotopes which add still further to the activity level in steel. Large quantities of air, either as air or as oxygen, are required in the making of every ton of steel, and it therefore follows that for the most sensitive shielding experiments, pre-1945 steel is essential, and the scarcity value of such steel of a thickness of two and a half inches or more became double the value of steel manufactured after 1945.
Shipbreaking Industries Ltd profited by this when breaking up the armoured decks of HMS Vanguard and several other ships whose steel fulfilled the requisite specifications. It is believed that the only remaining main sources of thick, pre-1946 steel are the first HMS Vanguard, HMS Royal Oak in Scapa Flow, probably a few obsolete South American fighting ships and the battlecruiser Goeben which was obtained by Turkey on 16 August 1914, renamed Jawuz Sultan Selim and in 1936 again renamed Yavuz. Turkey is still trying to sell this vessel, which will in all probability eventually be reduced to scrap by foreign shipbreakers.
But the last few survivors of the scuttled fleet were not to be left undisturbed, for Mr Arthur Nundy, owner of a marine salvage company known as Nundy (Marine Metals) Ltd, acquired the hulks. He made no attempt to raise any of the vessels. In any case they lay at too great a depth for sustained effort by divers. Markgraf lay in 45 metres of water, König in 40 metres and Kronprinz Wilhelm in 35–40 metres, and the cruisers Cöln, Karlsruhe and Brummer at varying depths. Nundy therefore concentrated upon blasting open their bottoms and taking out piecemeal any side armour, armoured decks and non-ferrous metals he could recover by a combination of skin-diving and helmet-diving, the former bearing a higher proportion to the latter than is usual. He was particularly interested in thick steel free from radioactivity, which is essential for certain types of surgical apparatus, for example, for screens and machines used in the treatment of cancer.
A skin diver cannot safely descend to a depth of more than 120 feet without needing a stop for decompression on the way up again. At this depth, as had been stated before, the blood soon becomes saturated with dissolved gases, including nitrogen, and carries them to various parts of the body where they are absorbed at different rates depending upon the organ. For example, cartilages and tendons have a poor blood supply, and it therefore takes a long time for them to absorb the gases. But it also takes a very long time for these parts of the body to release their dissolved gases back into the bloodstream when the diver begins his ascent. The inert gases, such as nitrogen, cause decompression sickness. If the diver surfaces too quickly, then the gases come out of solution, due to the decreasing pressure. while still trapped in particular parts of the body such as knee-joints and elbows – hence the ‘bends’. Ruptured lung tissue can also be caused by air embolism if a diver surfaces too quickly.
It is to be regretted that Mr Nundy has been reluctant to disclose the nature of his work, but it is said that his divers descended to about 70 feet quickly, placed explosive charges and quickly surfaced again. Then another quick dive to attach slings and grabs, followed by another quick surfacing. Nundy ceased operations as soon as the work became unprofitable and, as there is no longer any possibility of the hulks being lifted, it would seem that the last chapter has been written on the greatest salvage operation of all time.
The main credit for the salvage of the German fleet belongs to Cox and McCrone who provided the capital and initiative for embarking upon the work and accepted responsibility for its success or failure, and to McKenzie, upon whose skill and ability both relied. Professor A.M. Robb, DSc, when vice-president of the Institution of Engineers and Shipbuilders in Scotland, in paying tribute to McKenzie’s work, said:
In addition to the supervision of an immense amount of detail, there are the larger problems which demand that the salvage officer must be a bit of a naval architect and a bit of an engineer: there are some tricky problems in naval architecture involved in the use of compressed air. To have the qualities of a naval architect and an engineer is very desirable, but there is something even more important – the possession of that invaluable but indefinable quality recognised as ‘savvy’.
APPENDIX 1
Vice-Admiral von Reuter’s Account of the Scuttling
Extract from Vice-Admiral Ludwig von Reuter’s book, Scapa Flow – Das Grab der deutscher Flotte, published in Leipzig, 1921.
As usual, two English communications ships (Signalverbindung) lay alongside (the Emden), also another vessel which had begun to pump a supply of water into the Emden’s tanks. Had I made known the order (to sink), the natural excitement of the Emden’s crew could not have been concealed from the crews of these vessels. They would have raised the alarm, recalled the English Admiral, and obstructed the sinking of the other ships.
Shortly after 12 o’clock, Friedrich der Grosse began to list more and more as she sank deeper; her boats had already been lowered and lay by the stern. Now, loud and clear, from her bell came single notes – the signal ‘abandon ship’. We watched the crew climb into boats, and the boats being lowered. Friedrich der Grosse heeled over still further. Water streamed through her open ports. After a few minutes she turned over and sank to the depths. The air forced through her funnels created two great eddies of water. Then all was silent. The time was 16 minutes past 12.
The bell seemed to have vitalised all the other ships as though this was the signal for which they had been waiting. Everywhere the activity increased. Here boats were being lowered to the water, there crews were dragging their heavy kitbags to the bulwarks. Elsewhere boats were being manned and were putting off to loud cheers from the crews. An English guard-ship, which had for some time lain near Friedrich der Grosse, and may have noticed her exceptional list with concern and excitement, was puzzled by the bell signal and the resultant manning of the boats. When the giant ship suddenly overturned and sank before their eyes, they were so shocked that they lost their heads and opened a wild fire on the unarmed and defenceless occupants of the boats, although the latter were waving the white flag. At the same time they also sounded their siren. Its urgent wail startled the crews of the other English guard-ships out of their lethargy – understandable enough on a warm summer morning when their admiral was away. As is customary when a coarse people experience a rapid change from idyllic peace to extreme excitement, they lost their heads and blindly vented their rage upon everything which seemed to them contrary to the normal state of affairs.
Their panic spread to the English destroyers which had remained behind in harbour. Under its effect such cruelties were perpetrated on the defenceless German crews that England is robbed of any right to express indignation against German war criminals. It was fortunate that the sinking of Friedrich der Grosse was quickly followed by that of König Albert, Moltke and Brummer; others were approaching their end. The number of boats drifting with shipwrecked sailors grew so fast that the English vessels in their confusion did not seem to know upon which boat they should fire first. So they turned quickly from one to another, and it is due to this constant change that greater mischief was not wrought.
The end of Friedrich der Grosse and also of Brummer which lay astern of Emden, had also excited the English vessels lying alongside the latter. As the crew of Emden were dining below deck, they had noticed nothing of events in the harbour, but now it was time to order the sinking of Emden also. Under the direction of the commanding officer, the valves and underwater broadside tubes were opened and the water poured in. One of the English communications vessels, probably from fear of being sucked down into the depths by Emden, tried to disengage. I gave orders, however, that it was to be kept attached to Emden until the latter’s crew were safely aboard it.
As the English fire upon the German boats continued without slackening despite the hoisting of white flags, I decided to visit the English admiral asho
re to induce him to order a cease-fire. As I was unaware of the position of his official HQ and of the boat landing point I boarded with my staff the other English communications ship, one which was held ready for my visits. It landed us in a rock-strewn bay. We had seen from a distance that a car was racing up at top speed. In it sat a young man wearing tennis gear. The captain of the drifter referred to him as the Shore CO. He seemed to me to be very young. I begged him to order cease-fire. He was dreadfully excited, and scarcely listened and certainly did not understand a single word of mine. He ran off, to return shortly afterwards with a camera. Then he jumped into a waiting speedboat and roared out of the bay. I assumed that he would order a cease-fire, but I was disappointed in this. The English drifter was to take us back to Emden. It was an ebb tide, and as we steered out of the bay we got stuck on a sandbank. Even with my personal assistance all efforts failed to get the heavy, clumsy boat afloat. The hills along the bay blocked our view of the ships. Only my admiral’s flag on Emden was visible – it just refused to disappear! For probably an hour we were stuck on the sandbank cut off from world events; at last, with the turn of the tide, we drifted free and could sail out of the bay.
And what a scene it was! Before us, Grosser Kurfürst rose sharply into the air. With a racket both anchor chains parted, and the ship listed to port and capsized, the red paint on her bottom glaring across the blue sea. Many anchorages were by this time forsaken for the journey to the sea-bed.
English destroyers tore into the bay with foam at their bows. One of them drew alongside Emden and tried to blow up the anchor-chain in order to tow her into shallow water. As Emden sank deeper, I ordered the drifter to change course from Emden and steer for Bayern whose crew, lying and sitting on rescue buoys, were drifting near their ship. We took them on board and immediately Bayern turned over with water streaming through her open ports. In a few minutes the bulkheads were flooded, and the giant ship capsized and sank, the German flag still flying and the crew honouring her last voyage with three cheers. Now there was borne to us on the light wind the sound of salvoes from English destroyers which sought to halt the work of destruction on our cruisers. A tough battle was being fought out there. Once again the spirit of war arose in those magnificent officers and men who had no weapons to help them – only their sense of duty. And so, despite heavy fire from the enemy destroyers and guard-vessels, they carried on with their work of destruction. Six Flotilla which suffered especially had received the signal at an unfavourable moment when the English had recovered their nerve. Of 50 ships, 46 were sunk, a great performance! As I tried to reach them, English ships of the line rushed into the bay at top speed, ready for battle, their 38 centimetre guns aimed at the remnant of my unit. It was time for me to visit the English admiral and effect the cessation of hostile action. The fire weakened and was gradually stilled. In the background, the great cruisers were in their death-throes: Seydlitz capsized; the bulkheads and forecastles of Derfflinger and von der Tann were already flooded. They would soon be finished. Only Hindenburg lay flat upon the water, but she was settling. I recalled that her commanding officer wanted to sink her on an even keel. Of the ships of the line, only Baden, with a list, and Markgraf, apparently intact, were above water. Emden was afloat, also Nürnberg. Frankfurt seemed on the point of sinking. Then Bremse, under tow by English destroyers, foundered. Her brave captain, First Lieutenant Schacke, managed to sink her, even though his ship was now manned by a British crew. During my journey to the English flagship, more boats containing rescued men were taken in tow.
From Jutland to Junkyard: The raising of the scuttled German High Seas Fleet from Scapa Flow - the greatest salvage operation of all time Page 15
