Sample No. 1 was handed over to the MPA on 01.09.2000 and tested from 08.-28.09.00. The results were outlined in their first Report No. 1.3./00/3664 – see Enclosure 3 - of which the following shall be quoted:
»The strained micro-section specimens from the fracture area of the starboard front bulkhead show an extensive destruction of the initial structure components. These plastic deformations within the micro range indicate exposure to extremely heavy shock forces, such as happens from the effect of a substance detonating.
The resulting heat, which is created during such a shock by the internal friction whilst overcoming the sliding resistance, is responsible for the changes within the structure. Since the sliding does not occur in phases but undulatively (as a consequence of the movements of displacements) this is also recognisable as undulative formation of the structural parts. Already at a distance of ca. 9 cm from the specimen strained strongest only little change to the structural characteristics were established.
Based on these results it is probable that the main strained area is to be found at another part of created hole.
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There are significant differences of the structure conditions in the micro sections of the specimens recognisable which depend on the place from where the specimens were taken.
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The structure of specimen 13/00/3664 G022 shows significant changes in way of the fracture edge area (pictures 26-33). These plastic deformations in the micro range do indicate exposure to extremely heavy shock forces such as happens from the effects of a substance detonating. The resulting heat, which is created during such a shock by the internal friction whilst overcoming the sliding resistance, is responsible for the changes within the structure. Since the sliding does not occur in phases but undulatively (as a consequence of the movements of displacements), this is also recognisable as undulative formation of the structural parts (pictures 26-33). The shearing bands created are in particular clearly visible on the pictures 27 and 28. The initial structural parts are extensively destroyed. On the overview of the micro section of specimen 13/00/3664 G022, pictures 24 and 25, the undulative condition of the structural parts is recognisable also in the macro range. The undulative condition of the fracture edge is located at the inside of the bulkhead.
Whether the jagged lines on the right hand side of picture 32 indicate internal cracks has to be established by further examinations.The in volume panel-shaped iron carbide parts of the perlite are unable to resist the strong micro processes. The destruction of this perlite, marked on the micro section as lamellar structure, becomes particularly clear on pictures 29, 31 and 33. A destruction of the lamellae has occurred which cannot occur by any comparable mechanical technological influence. The processes of explosive treatments of metallic materials as for example explosive hardening and explosive cladding have to be excluded. These processes show in surface-near areas comparable effects.
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It has to be concluded that the pressure waves also in areas, where by means of light microscopes, only little deformation is recognisable, did result in hardening due to structure deformation in the micro range; (deformation of the perlite grain, change of the solidification density).«
The MPA carried out further examinations on the same sample from 10.-26.10.00 which are outlined in Report No. 1.3/00/3669 – see Enclosure 4. The results and conclusions are summarised as follows:
»On consideration of all the examinations carried out the highest strains recognisable by the change of the structural parts in the above explained way, has been determined at specimen 1.3/00/3664 GO22.
All the other micro-sections do support these results.
They do not, however, show the strong changes as e.g. the wavy change of the structure in the areas near the fracture and the destruction of the initial structure arrangement. The plastic changes in the micro area, indicating an extremely strong shock effect, such as occurs during detonations, are recognisable in all specimens.
A general characteristic for a detonation is the destruction of the shell type build-up of the perlite. In the pictures made by SEM it is apparent that the cementite of the perlite did not coagulate, which would have indicated the influence of heat alone, but the lamellar structure was changed beyond recognition by mechanical strain. Internal cracks which are also characteristic of shocks from strain by detonations could not be proved by the topographic examinations performed.
Also the increase of hardness indicates a hardening of the material which also appears during detonations.
The results obtained do allow the conclusion that the positions most affected by the detonation was in another area of the damaged material. In the following all the examination results are outlined again, which, according to our experience, do occur when there has been a detonation:
- the appearance of parallel shear bands (Neumann bands)
- changes respectively destruction of the cementite lamellas in the perlite
- hardness increase
- plastic deformation in the micro area (wavy arrangement of the structure parts)
The characteristics, determined during the examinations, which are consistent with the effects of a detonation, allow the conclusion, that the deformation velocity in the material must also have been in the detonation range. It is not possible to state the actual speed because it depends on a number of unknown influence factors, as e.g. the extent of transmission losses. Its lower limit in the case of a detonation should be about 1000 m/sec.«
The conclusions drawn by Brian Braidwood from the examination results of the MPA-Brandenburg read as follows:
- The structural deformation of Sample 1 could only have been causes by an explosion.
- The increase in hardness measured in Sample 1 could only have been caused by an explosion.
- Overall, the findings of this technical report are further evidence that there was an explosion in the ESTONIA, in the vicinity of the starboard forward bulkhead from which Sample 1 was taken.
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