Enemy Submarine in Tasmanian waters WW11
After mines were set in Bass Strait in 1944 routing of all shipping, except local traffic, south of Tasmania and ordering ships in southern Australian waters to zigzag and darken ship at night. This was introduced as a U Boat was reported in southern ocean waters.
U-Boat Commander Timm had meanwhile moved to a position south of Tasmania where U-862 encountered a tanker on a course for New Zealand. The target was moving quickly and the U-boat again surfaced to try to move into an attack position. With night and heavy rain making the approach more difficult, the attack was finally thwarted by the appearance of an aircraft that, apparently mistaking the U-boat for the tanker, attempted to exchange recognition signals. U-862 crash-dived and waited, but the expected counter-attack never came.
The U-boat continued moving up the coast and on Christmas Eve intercepted the American Liberty ship Robert J Walker off Moruya. The attack began at 02:55 on Christmas Day and continued for more than three hours. Liberty ships were well sub-divided with watertight bulkheads and five torpedoes were eventually needed to ensure the ship was finished.
Trials for using model boats to take the lines of a significant vessel using Photogrammetry to share with another museum. Mid 2020, Rhona Hollingsworth of the MMT asked Peter Higgs to consider doing Photogrammetry of a model “U” Boat they had as an exhibition at MMT but wanted to share with NZ. Both Tasmanian and NZ southern waters encountered German U Boats in 1944.
Link to 3D model
The Model U862 was researched, modified and then built by Phillip C Fowler for the Maritime Museum of Tasmania.
Photogrammetry was commenced but it was soon discovered that the photography process failed in Agisoft. After much research it was discovered that Photogrammetry fails on black surfaces due to the depth of field for the points, not resolving in the software.
We then masked the model with coloured masking tape and red dots so that the depths of field could resolve. The outcome was a very accurate set of lines drawings being made available to the Maritime Museum in NZ. This was a very valuable lesson learnt for the MMAPSS project and the handbook was edited accordingly.
This exercised proved that photogrammetry can be conducted on model boats held by Museums and local or community History houses.