<strong>The</strong> <strong>Wreck</strong> <strong>of</strong> <strong>DKM</strong> <strong>Bismarck</strong> <strong>−</strong> A <strong>Marine</strong> <strong>Forensics</strong> <strong>Analysis</strong> blades on first, with slotted bolt holes to allow the propeller to be adjusted slightly for maximum efficiency, then <strong>−</strong> once the best position was found from tests in the Baltic in the fall <strong>of</strong> 1940 <strong>−</strong> manufactured and installed solid, one-piece propellers to replace the experimental ones. In his recollection <strong>of</strong> leaving the center engine room after placing scuttling charges, LT Gerhard Junack advised author Bill Garzke, Jochen Brennecke 19 , and Dr. Oscar Parkes 20 that he left the engine room around 1010 with shining lights and a slowly turning shaft. For that shaft to keep turning, either the coupling in the shafting was parted by the jamming <strong>of</strong> the rudder into the center propeller, the keys holding the center propeller to the shaft failed in shear, or the propeller was able to keep turning once the intact portions <strong>of</strong> the three blades were free <strong>of</strong> the rudder structure. <strong>Bismarck</strong> underwent an extensive stay in the Blohm & Voss Shipyard from December 1940 until March 5, 1941. We have seen no photographs taken <strong>of</strong> the propellers during that stay <strong>−</strong> views taken in July 1940 cannot answer the question as to what was fitted when the battleship sortied for combat. It is very probable that single-piece propellers were fitted during that final availability. <strong>The</strong> dramatic discovery <strong>of</strong> the embedded blade in the rudder gives a new insight into the condition <strong>of</strong> the propellers and rudders at the time <strong>of</strong> the sinking <strong>of</strong> the battleship. Bolted blades are used today in controllable pitch propellers in FFG-7 and DDG-51 class ships, with hefty bolts. Until the James Cameron May 2002 Expedition, the seriousness <strong>of</strong> damage to the rudders was unknown. Photography <strong>of</strong> the underside <strong>of</strong> the hull revealed that the rudder stock for the port rudder had fractured. Did the force <strong>of</strong> the torpedo explosion bend this rudder, which was already canted outboard about 8 degrees, further to port causing it to contact the port propeller? <strong>The</strong> answer to that question is “no”, because the port propeller shows no sign <strong>of</strong> damage. Did the subsequent slamming <strong>of</strong> the hull in the heavy seas lead to the failure <strong>of</strong> the rudder stock through the forces <strong>of</strong> accelerated fatigue? <strong>The</strong> answer can never be known with certainty. In the meantime, the light cruiser Sheffield reported that <strong>Bismarck</strong> was heading to the northeast at a slow speed. Sea conditions hampered the Sheffield’s efforts to determine the nature <strong>of</strong> the damage caused by the torpedo attack. Due to her port turn, <strong>Bismarck</strong> closed range and then opened fire with her 380-mm guns in a brief engagement. Before the cruiser could open the range, <strong>Bismarck</strong>’s gunfire disabled Sheffield’s radar, caused minor fragment damage, and inflicted several casualties. This incident reminded the British that the <strong>Bismarck</strong> remained a formidable adversary, even if damaged and apparently unable to escape. Captain Lindemann ordered the ship to be slowed so that assessment <strong>of</strong> the damage in the stern could begin. He ordered two <strong>of</strong> his best damage control personnel, LT Gerhard Junack and LTJG Hermann Giese, to the area to determine the nature <strong>of</strong> the damage and to commence the needed temporary repairs. <strong>The</strong>ir efforts had to be halted at times, as Admiral Lütjens, Captain Lindemann, and CDR Oels wanted reports regarding the efforts to restore the steering function. Oels also sent two divers to the area to determine what damage occurred in the steering gear rooms. Lowering divers over the side was discussed, but sea conditions were causing the stern to rise and fall with such force that an accurate inspection was impossible and might have caused the death <strong>of</strong> the divers,as well. Attempts to steer the ship with the propellers were unsuccessful, due to the position <strong>of</strong> the starboard rudder in the race <strong>of</strong> the center propeller. <strong>Bismarck</strong> was doomed. 19 Schlachtschiffe <strong>Bismarck</strong>, Kohlers Verlag, 1960, page 361. 20 Dr. Oscar Parkes’ paper on <strong>Bismarck</strong> in the 1948 Transactions <strong>of</strong> the Royal Institution <strong>of</strong> Naval Architects. Dr. Parkes did not name the source except as a survivor. 16
<strong>The</strong> <strong>Wreck</strong> <strong>of</strong> <strong>DKM</strong> <strong>Bismarck</strong> <strong>−</strong> A <strong>Marine</strong> <strong>Forensics</strong> <strong>Analysis</strong> <strong>The</strong> edge <strong>of</strong> the damaged starboard rudder is shown below the hull opening for the fractured port rudder stock (arrow.) <strong>The</strong> damaged starboard rudder with the embedded centerline propeller blade. 17
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