Deutschland class ‘pocket battleship’

Lutzow (rear) and Admiral Scheer at Wilhelmshaven in 1939. Both ships survived until April 1945 when crippled (Lutzow) or destroyed (Scheer) by RAF bombing.

Whats the difference?? Deutschland class

With the construction of the first Deutschland class ‘pocket battleship’, the German Navy had broken new ground. In respect of the Versailles Treaty as amended by the 1922 Washington Agreement, German naval architects had apparently put a quart into a pint pot. It is the German contention that if there were a breach of the 10,000-ton displacement limit for cruisers, it was in the cause of more protection and not hitting power. Deutschland thrust the small Reichsmarine into the spotlight and aroused the political interest of the major naval powers.

On 8 January 1930 the Naval and Military Record remarked that, both strategically and tactically, the ship presented a factor impossible to ignore: Germany had proved to the world that major increases in battleship size were superfluous and bore no relationship to calculations of battle effectiveness, and on 22 January, in the same periodical, Sir Herbert Russell observed that the new type seemed to him to be the battleship of the future, combining the qualities of a battleship with those of a cruiser. By abandoning much conservative tradition out of sheer necessity, German warship designers had changed naval strategy: the Panzerschiffe soon underpinned oceanic commerce-raiding policy.

After Deutschland had berthed on 19 April 1935 following her long Atlantic voyage, Konteradmiral Carls reported to Fleet Command that ‘the ship has cruised 12,286 nautical miles in almost exactly 32 days. This corresponds to an average of 384 nautical miles per day at an average speed of 16 knots … since 20 hours for various stoppages has not been deducted, the averages are actually understated … as regards her sea-keeping qualities, propulsion machinery and suitability for tropical waters the ship proved excellent throughout the cruise … in my opinion the voyage has proved comprehensively the value and suitability of the ship and its class for extended cruiser operations.

Deutschland’s commander, Kapitan zur See Hermann von Fischel, reported on 18 June 1935: ‘During the five-week long Atlantic cruise of March/April 1935, as on earlier voyages, Panzerschiff Deutschland has proved an outstanding sea boat. Even in the three-day unbroken period of heavy weather with wind strengths from Force 8 to 10 and driving diagonally into a corresponding seaway and Atlantic swell, it was still possible to maintain a speed of 15 knots without danger … in heavy seas and swell from broadside, full speed could be maintained with rolls to a maximum of 24 degrees … stationary across the swell the ship rode with only light rolling movements … proceeding into heavy seas some damage was sustained by “A” turret, and as the foreship rose water was scooped as far aft as the upper deck amidships, such that the addition of a breakwater on the forecastle and deflectors forward of “A” turret is desirable … The ship spent twenty days in tropical waters. The motor drive was in no way affected adversely by the higher temperatures … one can summarise by saying that the engine plant has proved itself in all respects and seems especially well suited for the longer type of cruiser voyage …’
In general, however, all reports tended to play down deficiencies and weaknesses.

Hull and Armour Protection
The Deutschland class hybrid was an imaginative development in warship design resulting directly from the displacement restrictions imposed by the Treaty of Versailles. The ships were superior in fire power to any cruiser. At 10,000 tons’ displacement, Deutschland was a cruiser by definition but carried the armament of a capital ship, the armour being thin to keep her within the limit. Because the range of her guns, or the speed of the ship, could hold a faster or more powerful adversary, respectively, at a safe distance, a degree of armour thickness had been sacrificed in the interests of saving weight. Her deck armour was weak, but in this Deutschland did not differ from the ships of other navies: at the time designers had still not taken into account how dangerous would become the threat from the air. The air attack on Deutschland at Ibiza in 1937 may have driven this point home, but by then it was too late to strengthen the armour as the ship had been finely built to the weight margins. Initial moves towards more protection in this respect could be made with Admiral Scheer and Admiral Graf Spee, where the displacement was greater.

In 1930 the Heinrich Hertz Institute was given the task by the Reichsmarine of conducting extensive tests into the effects of vibration resulting from diesel propulsion aboard warships, and these were carried out between 1931 and 1934. The research activity investigated principally how the sensitive optics and trigonometrical computing equipment in the fire control centres, plus the welding in the ship’s hull, reacted to vibrational stresses.

Deutschland and the gunnery training ship Bremse were the first large warships to have exclusively diesel propulsion. The motors were double-acting two-stroke MAN marine diesels of uniquely light construction, a condition of manufacture having been a saving in weight even down to the foundations.

The tests showed that substantial vibration from the motors was felt throughout the ship and that this vibration was just as strong as that imparted by the propellers. The engine vibration had a frequency corresponding to the revolutions, while the exhaust discharge system had an audible frequency which was actually intolerable.

Worst affected were the rangefinders, which were unserviceable over a range of speeds, the operators experiencing fatigue at the optics after even short periods of observation; the gunnery, torpedo and searchlight optics reported similar but less extreme distress. At all these positions the vibration was occasionally so strong that it was impossible to obtain an image through the instrument. At certain speeds equipment installed in the battle-mast, and especially at the foretop, was unusable.

After the ships had been in commission for a short period, welded seams and the corners of the engine foundations burst and expanded so quickly that engine revolutions had to be strictly regulated to contain the damage. The overall picture, particularly with regard to the latter weakness, was at first so grave that diesel drive for warships began to be regarded as the wrong path in important policy circles. This was grist to the mill for conservatives advocating marine turbines, and the steam lobby experienced a major revival.

It is extremely difficult to eliminate vibration by modifications to a finished ship, even when the cause is clearly recognised, but, nevertheless, on existing diesel-driven units ways were generally found to reduce levels to tolerable limits. In Deutschland the motor chassis and foundations were strengthened; in the later ships of the class various compromise measures were introduced or levels accepted as an alternative to increasing engine weight and reducing propeller effectiveness or engine output. Aboard Admiral Scheer the foretop fire control centre was unserviceable because of longitudinal and transverse vibration at certain propeller revolutions. This problem was resolved by devising an independent suspension for the armoured foretop in parallel with a liquid absorbent for the horizontal vibration, which achieved a 90 per cent reduction in vibration levels.

Weapons and Fire Control Systems
For their size the Panzerschiffe were over-armed. This fault had its origins in the Versailles Treaty, which stipulated that a new battleship had to be a replacement for an existing obsolete unit, but it was impossible for Germany to construct a modern, combat-worthy battleship within the tonnage limitations. The Treaty provided for a cruiser tonnage limit of 10,000 tonnes without specifying a maximum armament, and the 1922 Washington Agreement stated that the maximum displacement for a cruiser was 10,000 long tons but with a maximum 8in calibre. The German ‘compromise’ was not a cruiser within either definition, and so a new type of warship altogether, a Panzerschiff, presented as the legitimate replacement for the pre-dreadnought battleship Braunschweig, came into existence.

From a general point of view, the 28cm calibre was too large for the cruiser hull. Even the 15cm (5.9in) secondary armament was more suitable aboard a battleship than a cruiser. In retrospect, a multi-purpose battery would have been preferable to the medium guns and at least the heavy Flak, and not only on account of the savings in weight. However, no satisfactory multi-purpose weapon was available at the time. German industry remained subject to Allied supervision and control until the mid-1930s, and the major companies were in the French-occupied Ruhr. By the time the situation had been remedied much valuable time had been lost. Initially Deutschland was fitted with the obsolete 88 mm (3.5in) anti-aircraft weapon which had been standard in the First World War; this was not replaced by the more modern 10.5 cm (4.1in) heavy A A gun until 1940. There were similar problems with the light Flak.

An acrimonious difference of opinion existed between the Engineering Branch of Naval High Command (OKM) and the Warship Gun Test Branch (AVKS) regarding the value of the Flak fire control system, and this had not been resolved even by the time the Bismarck class were in service.

Machinery
After initial defects in construction (not entirely the fault of the manufacturer) had been overcome in the first few years after commissioning, the engines proved themselves totally. Obviously the problems were worst in Deutschland and progressively less severe on board Admiral Scheer and Admiral Graf Spee. Sources opposed to the introduction of diesels in major fleet units made capital out of the defects and influenced the Reichsmarine to abandon the idea. The fourth and fifth Panzerschiffe, ‘D’ and ‘E’ (Scharnhorst and Gneisenau), were redesigned on the grounds of political necessity as battlecruisers and had steam turbine drive, as did the last German battleships Bismarck and Tirpitz.

Konteradmiral Fuchs wrote: ‘In October 19351 was made Departmental Head of A IV at the OKM. A IV dealt with matters of training and military questions in warship construction because all weapons specialists were attached to the department at the time. A I was responsible for warship construction, i.e. A I laid down the specific requirements for a ship type, from which, under the overall control of A IV, the so-called military requirements were worked out in collaboaration with K (Office of Naval Architecture). From these K and A IV drew up the design sketches. After these had been approved by the C-in-C of the Reichsmarine, K prepared the blueprints and supervised the building of the ship.

‘Hitler was very interested in the Navy, particularly the technical side. As Raeder was usually unable to answer specific technical questions and had to find out the answer for himself first, I was given the task of speaking to Hitler on the subject of developments in warship construction two or three times each year. It always amazed me how much technical information Hitler managed to absorb, even if some of the connections were missing. He set aside a surprising amount of time for my lectures, and if it was delivered in the morning, I would then be invited to lunch. One day I was seated next to a high Party functionary who told me, “Herr Kapitän, it is easy for you with the Führer because he is at heart a naval officer who missed his calling.” During these lectures Hitler would occasionally speak of his political intentions involving the Navy and as there was no propaganda point to be made I assume he was speaking of his real convictions. He said that the primary purpose of the Fleet must be to prevent a blockade of the German ports. Iron ore imports were of the greatest importance: when these were cut off in the Great War it had made a longer defence of Germany impossible. There could never be a question of the German [surface] Navy blockading enemy ports in the Atlantic theatre, and naval surface warfare would be limited to cruiser or merchant raider operations against the trade routes. For the latter reason, equipping the Panzerschiffe had been an important decision in the reconstruction of the Fleet. The suggestion had come from Vizeadmiral Bauer.

‘The tragedy in German warship construction was the return to high-pressure steam turbines for the large warships, although it was a satisfactory solution for smaller units in the coastal theatre. When I entered the OKM in October 1935 the decision had already been taken: high-pressure steam turbines for the battleships and heavy cruisers…

The Panzerschiffe could range into the Indian Ocean, whereas steam-turbine drive limited a battleship or cruiser to the North Atlantic. Actually, the term ‘range’ is misleading. Apart from the distance they could cover without refuelling, the Panzerschiffe could just drift, knowing that if necessary they could work up almost immediately to full speed at the push of a button. Steam must be kept up in a turbine ship even if stopped, for cold turbines need two hours to reach maximum output. The difference between the types of drive in distant oceans is therefore much greater than mere range.’

Former Marineoberbaurat Ehrenburg once explained in a lecture: ‘Diesel drive was common aboard small warships and universal on U-boats, and the merchant marine had adopted it long previously. When it was introduced aboard Bremse and Deutschland, ships of a size which had never previously been equipped with it, it aroused a determined resistance in naval engineering circles, who succeeded initially in having it rejected for future new construction … the development of new boilers types had led to the production of very high-pressure hot steam (60 to 70 atmospheres) with superheating to 470° in shipboard drive… in a number of respects the diesel had been equalled or overhauled for the time being … but in terms of thermal effectiveness the diesel has a lead of 37 per cent and with use of exhaust gases even 40 per cent.

The advantages of low fuel consumption, self-contained individual sets of motor, smaller openings in the armour deck as a result of faster exhaust expulsion, enclosed air intakes for combustion and so on were factors of too great importance in warship construction to be easily dismissed, even if the questions of vibration and noise remained problematical. The principal disadvantages of marine turbines were the uneconomic use of space, the over-complicated nature of the units, the difficulties of maintenance and repair, the time needed to build up steam and the high fuel consumption, especially when cruising – which was particularly disadvantageous since it limited range so severely as to make even North Atlantic operations questionable. On the other hand, many claimed advantages for diesel over steam had been refuted in practice. On balance there seemed nothing to choose between them, and, in the absence of a positive reason for adopting exclusively diesel drive, the decision to continue with the steam turbine for the large units on the stocks practically made itself.

Years of polemic for and against ensued, but not until 1938 did the question suddenly become topical again, and the majority were in favour of diesel. But the Germany Navy had missed the bus. Years which could have been devoted to the development of an improved diesel were lost. MAN-Diesel had continued the work privately, but they lacked the active support of the Kriegsmarine, which had given the nod to steam.

Discussions regarding the correct choice began before 1933. On 17 November of that year Admiral Raeder wrote to all four Departmental Heads requesting comprehensive reports on the pros and cons of a range of considerations. The Head of the General Naval Office summarised the various opinions: ‘The question of military use comes down firmly in favour of the turbine. If the construction of a high-pressure steam turbine suitable to the technical requirements is now feasible, I support the installation on the grounds of the military application

After the war, Grossadmiral Raeder explained: ‘My decision in favour of the high-pressure steam turbine was temporary until such time as a diesel type became available suitable to the greater demands and technical requirements made of it.’ However in a letter dated 4 July 1940 acknowleging his gratitude to the firm of MAN-Diesel, he stated that ‘… the engines of Admiral Graf Spee had been adequate to all tasks required of them throughout the entire period of the South Atlantic operation’. An officer of the cruiser stated to the author in a private letter that ‘the Spee was an absolutely first-class ship. MAN-Diesel can pride themselves on it. After four months at sea and despite heavy bottom fouling, the ship managed a half-knot more than the designed speed throughout the River Plate battle…’

Final Observations
On the whole the Panzerschiffe were political ships. They were to bring Germany political respectability within international naval treaties and win allies. In war, their task would be to safeguard the seaway to East Prussia and protect the Baltic entrances and the North Sea approaches. In 1929, when the great range of these ships was realised, grander prospects emerged for their deployment – attacks on French shipping off West African ports, in the Mediterranean and, if the political situation permitted, also off North Africa.

Germany had no overseas naval bases – perhaps her most significant disadvantage in comparison to the major sea powers – and when the idea of using the Panzerschiffe as commerce raiders on the world’s oceans was first conceived (probably in the summer of 1934 after Deutschland had completed her South Atlantic voyage) the need for purpose-built supply ships was realised. Sound refuelling methods had to be established, and extensive investigations were made using chartered tankers during the operations in Spanish waters. The experience gained was applied to the Altmark class naval oilers then under construction.

In the event, the Panzerschiffe were used as makeweights in the tonnage war, and only Admiral Scheer, with an adroit commander, skilful handling by the SKL (Naval Warfare Directorate) and a great deal of luck, paid a major dividend.

Warfare against merchant shipping is the business of light cruisers. The Royal and US Navies themselves had found the 20.3cm (8in) battery too ponderous for the task. Instead of the heavy cruiser types with which it equipped itself, the German Navy might have been better served by a class of well-armoured, fast, diesel-driven light cruisers of optimum armament for commerce-raiding purposes. This was not given consideration.

The German Fleet could never have been of a size to challenge Britain’s for control of the seas, and the question must be asked whether there was any logic in building ships of heavy cruiser size and above. They were too big for duties in the German Bight and adjacent areas, the era of the great sea battle being past, and they were only latterly of any use in the Baltic.

What the German Navy lacked was overseas bases and safe refuelling at sea far from home. The loss of seven out of eight supply ships stationed in mid-Atlantic for the Bismarck adventure in May 1941 after the enemy had seized the ‘Enigma’ coding machine and broken the ‘Ultra’ code drove this point home.

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