The pocket battleship design was approved by Admiral Zenker then C-in-C of the navy. They used diesel engines because of the great difficulties in WWI of refueling raiders. Germany did not have any overseas bases. The new ships were designed to get maximum efficiency in 10,000 tons. Firepower, speed and range was best satisfied with diesel engines. The pocket battleship design was the very best of German technology. The MAN 9-cylinder engine was an excellent machine and it was used in the latest auxiliary vessels like Altmark. The problem turned up when the MAN engines were used in sequence in a warship that needed sustained speeds over 20knots. At this high speed the vibrations of the main engines caused splitting of the support brackets of the auxiliary engines. This caused distortions in the auxiliaries and in the main engines. MAN manuals suggested the auxiliary engines should be thoroughly inspected in dry dock every 1000 hrs of operation. The realistic, safe operational speed of the eight 9-cylinder engines in the pocket battleships proved to be about 17-knots. If this is added to their poor armor protection the design was not a battleship nor a heavy cruiser but closer to a gunboat.
The propulsion system consisted of four motor rooms containing two MAN 9-cylinder double acting two stroke diesels, combined with an auxiliary engine for each two main engines. Excessive vibrations damaged the auxiliary engines when speeds above 20-knots were maintained for long periods.
In 1939 Admiral Scheer lay in Wihelmshaven awaitng major refit. When war was declared Deutschland and Admiral Graf Spee were assigned raiding missions in the North and South Atlantic. Deutschland soon ran into difficulties and was recalled. She had serious structural and engine problems. A good opportunity to derive important information to aid the Scheer refit.
Meanwhile, Graf Spee accomplished excellent results in the early days of her mission. A close examination of Langsdorff's log provides many criticisms of the ship and the Arado airplane. Langsdorfff went to great lengths to document problems, particularly with the engines. Also, we see that he received up to date information regarding the political and military actions of the day. In this edition of the Kriegstagebuch you can see that pages for September 9 and September 10 are missing. Also, a blank page is shown on October 7/8 and Langsdorff's personal entries end on 10 December, when the information comes from the naval attachee. One wonders what the missing pages contained. Perhaps OKM (Admiral Raeder) was in direct touch with Langsdorff.
In any case, we know that Hitler signed off the costs and authority to build the Z-plan in January 1939. Raeder immediately ordered six H-class super battleships. Keels for H-39 and J-39 were laid down and Admiral Fuchs given a 15 man team at Bloehm and Voss to expedite these giants. At the same time Raeder was demanding additional funds and assets at the Fuehrer naval conferences to build submarines. Efforts were made to divert materials from Bismarck, Tirpitz and Graf Zeppelin that were in advanced stages. It was decided that minimum advantage could be gained. A halt was placed on the H-class battleships but orders for materials already placed were fullfilled and research and developement continued. The propulsion system for the two H-class battleships in the stocks was 12 MAN 9-cylinder double acting two stroke diesels with an auxiliary engine for each pair of main engines. The same set up that had failed in the pocket batttleships.
Future research and developement was considering a combination of diesel and steam propulsion but in 1939 Raeder was building the world's greatest battleships without a proven engine. Imagine what Goering would have done with such information.
Langsdorff knew the importance of the diesel spin off. He totally destroyed all evidence when he blew up the ship. Raeder quietly changed tactics and moved to build submarines. Admiral Scheer was refitted and sent out on a well managed and documented cruise - highlighting the wonderful performance of the engines. It is sobering to find in todays news that the heaviest ships afloat using full time diesel engines cannot expect a top speed above 20-knots. The Deutschland class were rated for top speeds of 26-knots and the H-class were rated for top speeds of 30 knots.
Engine problems plagued Deutschland and Scheer. Langsdorff described in detail his engine problems. Indeed the problems with the Diesel engines are quite often mentioned in the German literature. For instance, as soon as 1956, Friedrich Ruge, a naval officer and naval historian, who later became the first chief of staff of the West German navy, mentioned in his account of naval warfare in WWII (Friedrich Ruge: Der Seekrieg 1939-1945, 2nd ed., K. F. Koehler Verlag, Stuttgart 1956) problems with the Diesel engines of the DEUTSCHLAND-class pocket battleships. Besides noise and vibrations they experienced some difficulties with the engine’s basements, which made a long mainentance works in the shipyard necessary, as Siegfried Breyer and Gerhard Koop mention in their book („Von der EMDEN zur TIRPITZ", Bernhard & Graefe, Bonn 1997). Also Rasenack in his book on the ADMIRAL GRAF SPEE gives some hints on problems with the engines, which were, however, mainly caused by the long time at sea and the necessity of a general overhaul. The problem is, that you can find hints on engine problems, but no throughout examination of the DEUTSCHLAND-class vessels propulsion system. As far as I can tell from my sources, the main problem was, that Diesel engines were, at least for vessels of that size, a rather new, unproven technology. This was also one of the reasons why the Kriegsmarine relied on steam turbines for their battleships and heavy cruisers instead of the diesel engine. The diesel engines in testing grounds were fine, no trouble, but once they are inside a ship, that´s another story.
Regarding the H-class super battleships, in 1939 they were still in design stages beginning with about 60,000 tons and finally reaching 120,000tons. Hitler gave Raeder the authority to build them in January, 1939 while assuring Raeder that he would avoid any immediate war with Britain. Raeder ordered six super battleships and began to build two of them, H-39 and J-39 were designed to use twelve 9-cylinder MAN diesels They were cancelled in October 1939, but 1200 tons of steel were laid in the keel for H-39, 3500tons were machined and 12,000 tons more ordered. J-39 proceeded a little more slowly but the intent to build these ships is clear.
I have researched minutely and never found any coordinated criticsm of the pocket battleships especially the engines. On the other hand, history in the form of military experts, academic professors etc. unanimously applauds the 1940/41 cruise of Admiral Scheer. Admiral Raeder shouted the good news that the engines had performed "very well".
The captain of Scheer on the cruise (Theodor Krancke) wrote a book about his ship and the cruise. I have heard that he claims the ship outpaced a destoyer at 27.5 knots on the final run into home port. In Scheer's operational record we see that she was in Wilhelmshaven from 3rd May 1939 until October 1940 undergoing major refit. She emergerd as a new ship. She had received the knowledge of all the Deutschland and Graf Spee problems. On the cruise she had an oiler, and a supply ship in attendance and meetings with other auxiliary cruisers. She had the latest radar and B-Dienst and SKL closely monitored her progress. It is my opinion that this cruise was "stage managed" to dispel any doubts about the quality of the design and the engines.
1939. Raeder is in total control of the naval service. He has a few trusted high level naval officers on his side. He thought that he could manipulate Hitler into accepting the importance of the navy, especially after the war. He had convinced Hitler of the prestige and power represented with great battlerships. Raeder was not in agreement with the nazi party "hard line" policies but believed Hitler could unit a devided Germany. His political enemies were:- Goering, C-in-C airforce, Heydrich, C-in-C SD and many others that distrusted the navy. I find the Graf Spee saga entwined in German politics at the highes level when wartime conditions encouraged secrecy - in the national interest. I agree with you that it would help sustain confidence in history to support the future actions of nations if the truth emerged postwar, after a reasonable amount of time. Raeder could have written a more honest memoir, Krancke also knew the political implications the diesel engines, Admiral Boehm would also know the same. They did not break the code of secrecy and we may never know why. Whether for personal considerations like pensions or in the overall national interest.
9-cylinder two stroke diesels installed in the pocket battleships. They were great engines on shore but gave all kinds of problems when installed inside a ship's hull. Then we move to Raeder's decision to build two H-class 56,00 ton battleships using the same model of engine.
It is easy to see that Krancke's cruise with Admiral Scheer was programmed very carefullly for full success, including validating the diesel engines. When we go a bit further into Scheer and Lutzows' record after the cruise and after Lutzow's refit These warships did very little duty that the design called for ie. commerce raiding alone in the wide oceans.
The MAN diesels in the pocket battleships did not deliver as expected. The same type of engines were selected for the H-class super battleships. Admiral Raeder ordered six of these and began building two hulls in 1939. It is very strange that MAN's museum propaganda on line shows the company developement and the major inovative products they produced over many years. However, the diesel engines supplied and installed in the three pocket battleships are not shown.
The problem with the two engine systems we are looking for ( 9MZu42/58 for P/B and 9MZu65/95 for H-class) is high vibration at high speed. Both systems needed auxiliary engines to operate. These auxiliaries could not tolerate sustained vibrations. I'm guessing that the Kriegsmarine tried to correct this problem with Deutschland and Admiral Scheer and Graf Spee over the years. It is also possible that the ship builder Bloehm and Voss built the engines under a MAN licence. We know that MAN had covered their butt by issuing a maintenance requirement to examine the auxiliaries thoroughly every 1000-hours. We also know that MAN has proud records of diesel operation in many ships in the 1933 era but no further use of the two engines we are looking for is evident.
Until I know differently I will assume that the missing pages from our copy of the diary has communications directly between OKM (Raeder) and Langsdorff. On the British side, I am assuming there is information involving national security in 1947 when the materials were examiined. Maybe and probably involving British worldwide wireless interception and de-coding (Ultra in Bletchley Park)
The first copy of the Kriegstagebuch was published in 1992 (I can´t remember the exact date) in Germany. I think it was published based on the copy the British had. The original I think was captured by the British. So far, the British had denied they had anything. I asked if they had german captured documents under a Secret Policy Act or something but they keep saying no. Also cheked with the Imperial War Museum, Kew Gardens and Library of Congress. Nothing. The British published a mini Kriegstagebuch in 1947, but they took away every reference to the engines (why?) Then there was a copy edited by the German Foreign Office (Joachim "demi-sec"). This one I believed is based in the original one brought by Ascher. Be there as it may, no one seems to have the original one. Recently, 200 copies were published here in Uruguay, based in the one from 1992.
But two days are missing (why?). It says that they´re missing in the original as well. Bullshit. In the real logbook I bet the missing pages are not "missing". That´s one of the questions I want to answer. I can´t understand why so many years after the war, the British go nuts when asked about this.
I´ve asked Blohm and Voss if they ever manufactured diesel engines under MAN´s licence between the years 1920-1940. No answer. I´ve also asked MAN if the have any reports of engines tests, failures, design, anything about the engines Graf Spee had. Nothing, the sent me brochures about how good they were. I insisted and they sent me some pictures. They didn´t answer my questions and said that´s all they had. I doubt it.
It is widely accepted that Admiral Harwood discovered the GS. That his expertise as a sailor was they key for that. In the margins of an English report, I´ll try to look for it, some admiral wrote "Harwood will never know how much help he received locating the GS". I think this is in connection with Ultra.
I do know that when Hitler visited Italy in May 1938 he was particularly interested by the superior Italian naval architecture and engines, and he commented that the Italian battleship they were cruising on had no vibrations even at high speed. My source for that is Puttkamer.
I have read the book by Kranke three times and I am completely convinced that my assumption that this was a carefuly planned strategy to divert questions away from the engines was correct. Kranke was an insider from OKM and became Captain of Scheer while it was in Wilhelmshaven gettinig the major refit. Almost one year before the mission began. The supply ship Nordmark boarded special equipment and personnel to enable engine repairs at sea. The engines were repaired several times and before the ship returned home the hull was scraped and painted. Then on the final miles of the homeward trip she ran at top speed and claimed loudly that the engines worked very well. Also, on board Scheer was a film crew making propaganda. They used a secret hiding place in mid-Atlantic in co-operation with other auxiliary raiders. When home bound, Gneisenau and Scharnhorst drew attention away from Scheer and Hipper led the way through the Denmark strait.