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B. Comments on the Different Examination Reports Available in the Light of Possible Explosions by Brian Braidwood, MBIM, MIExpE

7. The DN Institute Clausthal-Zellerfeld

Initially only Sample 2 was handed over to the scientist in charge, Prof. Dr. Neubert, which however could not be examined fully as is explained by Prof. Neubert below:

»Since non-destructive testing was to be carried out the fracture edges and the uninfluenced basic material of both samples were examined by means of roentgenization. Due to the size of sample No. 2 testing by means of synchrotonradiance was considered to be appropriate because by this method the sample could be examined in its original condition. The testing condition and the results are laid down in the Preliminary Report DN 20130-01 “Examinations of a Shipbuilding Steel”. In summary it can be concluded that directly at the fracture edge of sample No. 2 areas with extremely massive deformation were found. The deformation area still to be proved has a thickness of about 100 µm. By means of the Scherrer formula the crystal size at the measuring point was calculated from the half height breadth of the results of the roentgenization. The calculations revealed that crystal size in way of the fracture-near area is smaller by factor x compared to the areas of uninfluenced material, a clear indication for a very high degree of deformability respectively a very high deformation velocity. More detailed statements cannot be made because for this roentgenization photographs made by roentgen rays with a longer wave length, e.g. copper Kα, would be required.«

The Institute received, subsequently, the relevant specimen of Sample 1 for further testing from the MPA Brandenburg which proved comparable results as obtained by the MPA and the conclusions by Prof. Neubert read as follows:

»The roentgenographical verification of martensite in way of the actual fracture edge leads to the conclusion that the areas of this microstructure became austenised during the deformation process several years ago, i.e. have been heated to a temperature of more than 700°C.
By combining the results of the roentgenographical measurements with the research results published with regard to the influence of deformation velocities on the change of structure of non-alloyed carbon-steels, a deformation velocity between 1,000 to 10,000. m/s has to be considered for the present case. According to the relevant literature such a range of velocities can only be achieved by detonations and/or shootings.«

Brian Braidwood arrived at the following conclusions:

»Any explosion will produce very high temperatures in the immediate vicinity of the explosion. In the case of high explosives, the temperatures would be consistent with the figure of 700 degrees C quoted in this report.
The velocity of detonation or VOD of a normal high explosive is about 6,500 m/s. This is consistent with the range of velocities quoted in the Clausthal-Zellerfeld report.
The findings of this technical report are further evidence that the damage to the starboard forward bulkhead in the “Estonia” was caused by the detonation of a high explosive charge.
From the second (Clausthal-Zellerfeld) technical report, I conclude that:

    1. The massive structural deformation visible in the specimen from Sample 1 (running number 1.3/00/3664 GO2 2) was indisputably caused by an explosion.

    2. The clear indication of a very high degree of structural deformation found in Sample 2 was indisputably caused by an explosion.

    3. Overall, the findings of this technical report are further evidence that there was an explosion on the “Estonia”, in the vicinity of the starboard forward bulkhead from which Sample 1 and Sample 2 were taken.«
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