The Wreck of DKM Bismarck − A Marine Forensics Analysis 1 The ...

The Wreck of DKM Bismarck − A Marine Forensics Analysis
second forward battery turret as it is third in line from west to east (assuming that it is directly
downhill from where it originally landed).
It is likely that the large pieces of debris that were lying on the decks fell directly from
the site of the sinking, having come off the ship when it capsized. The displacement of the
impact crater from the sinking site is probably the result of the wreck’s plunge and stall motion
as it plummeted through the 4,700-meter water column. It is likely that Bismarck planed forward,
bow first. The configuration of the impact crater and trough relative to the side scar and sinking
site supports the theory of a bow-first impact. It is consistent with a scenario in which the ship
planed north from its sinking position approximately 500 meters before striking the seamount.
Since the axis of displacement from surface to bottom aligns closely with the long axis of the
trough, it is fairly obvious that the wreck was planing lengthwise away from its sinking point. 39
What is clear from damage to the wreck and conspicuous lack of the lower hull in some
places is that the stern did not hit first, as Dr. Robert Ballard had postulated after he discovered
the wreck in June 1989. Large pieces of the lower hull residing within the slide scar also
disprove the conclusion of David Mearns from the 2001 ITN Expedition that torpedo hits tore
these away during the battles on the surface.
It is also obvious that the ship turned almost completely broadside to the slope for part of
the slide. It is likely that the hull slid a short distance stern first for the initial part of the slide,
then turned broadside before beginning a more bow-first plunge downhill. Once the bow dug
into the sediments then the stern swung around, again leading downhill. This scenario apparently
was repeated. The evidence for this conclusion will be discussed later.
Since Bismarck was observed to be oriented beam to the oncoming waves, during the
northwester storm with her starboard side to the lee side at the moment of sinking, it is likely that
the bow was facing to the northeast when the ship sank. This orientation is very consistent with
the distribution of turrets and mainmast along a similar longitudinal axis on the seamount.
Much evidence supports the conclusion that the ship plunged almost vertically for some
period of time in the water column. It may have undergone some complex gyrations as it righted
itself for the latter portion of its fall. Once the hull righted itself, the effects of the hull form were
probably responsible for the displacement of sediment we observed at the impact point with the
seamount.
At the moment of sinking, the stern end was still attached 40 . As the ship capsized and the
stern swung down relative to the more buoyant bow, hydrodynamic forces over the broad flat
surface of the stern may have detached it. Teak decking is snapped cleanly in a straight line
where the stern detached, suggesting a downward bending force (actually upward since the ship
was inverted). It is also possible that the stern was detached by other hydrodynamic forces as the
ship plunged. A piece of the stern was found by Dr. Ballard’s team, located with other light
debris in the debris field Northwest of the wreck. This is consistent with the stern separating
violently high in the water column.
As the ship sank through the water column, it is very probable that the bow was facing
north with a slight bow-down attitude, and was moving forward in stable “flight.” The starboard
rudder is severely damaged and bent. The clearances between the tips of the centerline propeller
39
This concept is frequently paraphrased as “All things being equal, the simplest solution tends to be the
best one.”
40
Seaman Statz, who was swimming 100 meters from the sinking ship before the final plunge, recalled
that the stern end was still attached. Mr. Statz’ memory proved to be remarkably accurate, based on
numerous details confirmed by imagery retrieved during the 1989 exploration of the Bismarck wreck.
47