16/11/2022 Romania
“If you ever come across anything suspicious like this item, please do not pick it up, contact your local law e enforcement agency for assistance”.
By Laurentiu-Florin Constantinoiu, Eugen Rusu, Maria-Emanuela Mihailov
The mysterious Black Sea has many secrets yet to be discovered. This research presents the results of the biggest UXO survey project performed on the Romanian Black Sea coast after World War II, using towed sidescan sonar technology and oceanographic observations. The survey was carried out between 2015 and 2018 by the Romanian Navy’s hydrographic ship Commander Alexandru Cătuneanu and the Romanian Maritime Hydrographic Directorate. Most of the objects discovered were found to be sinkers, wreck debris or parts of chains, which do not represent a danger to navigation.
WWII and the Black Sea
The assessment was based on the archival research carried out by the Romanian Mine Warfare Data Centre (MWDC) at the Historical Service of the Army in Bucharest. As many as 112 files from the Romanian Royal Navy Command archive, the Sea Division and the Modern Romanian Navy Command were studied, related to mining/demining activities, naval combat actions and anti-submarine combat in the western Black Sea during World War II. Moreover, the Notices for Navigators from 1952 to 2011 were examined, extracting data referring to submarine obstacles, wrecks, pipelines and other contacts. More than 20 minefields were installed during World War II along the current Romanian coast, totalling approximately 3,000 sea mines of various types (UMA, UMB, VICKERS, EMC I, EMC II, FMB, UC, etc.), plus more than 3,000 protection mines and anti-sweep devices, generally known as unexploded ordnance (UXO). The Romanian and German forces launched these minefields using specialized ships. During the same period, an unknown number of magnetic minefields were launched along the Romanian coast by Soviet forces. Between 1946 and 1948, Soviet forces also carried out the first dredging operations, and a considerable number of mines were neutralized by dredging or shooting. Between 1946 and 1960, the documents studied so far show that approximately 600 mines and 300 protection buoys were destroyed by dredging, shooting or blasting. A significant number of contacts and debris from the historical minefields still lie on the Romanian Black Sea seafloor, posing a potential environmental threat and a danger to the fishery sector.
UXO Survey in the Black Sea
The sidescan sonar is known to be a valuable tool in Maritime Mine Counter Measures (MMCM) surveys, due to its ability to provide an accurate acoustic image of the seafloor and contacts above it. For this survey, an EdgeTech 4200 multi-pulse (MP) sidescan sonar was used. To achieve a higher swath width, the sonar’s lower frequency (300kHz), in MP configuration, was chosen for this UXO survey. The higher 900kHz frequency provides a higher pixel resolution, and therefore greater detail of the acoustic picture, and was used for wreck investigation. The positioning information (latitude, longitude, heading, speed) from the DGNSS sensor was combined with the attitude sensor of the tow fish (pitch, roll) for an accurate location of the sonar echoes on the seabed. The sonar’s acoustic signals were calibrated at least twice a day using a Valeport sound velocity profiler (SVP) that provided in situ sound velocity profile observations. In the northern part of the surveyed area, more oceanographic stations were needed due to the rapid change in the halocline, a result of the Danube River outflow. Additionally, the ship’s single-beam or multibeam hydrographic sonars were used to complement the survey and detect underwater obstacles that could damage the towed sonar. A comprehensive contact analysis was performed for every survey line to identify and classify the mine-like echoes from the sonar into a mine-like contact. Mine-like contacts are selected by assessing their sonar echo intensity, shape, size and shadow.
Results and Discussion
The survey results and analysis allowed the detection and classification of more than 2,000 contacts using the sidescan sonar processed images.
Imagini- Sursă: hydro-international.com
Inspectoratul pentru Situaţii de Urgenţă “Porolissum” Sălaj recomandă, pe această cale cetăţenilor, ca la găsirea unor elemente de muniţie neexplodată, să anunţe cel mai apropiat post de poliţie sau pompierii la numărul unic de urgenţă 112
Dear editors, Biography of a bomb is aimed at highlighting the danger caused by unexploded bombs. Moreover, the most important aspect is that we work completely non profit, raising awerness about this topic is what drives us. We apologize if we make use of pictures in yours articles, but we need them to put a context in how findings are done. We will (and we always do) cite source and author of the picture. We thank you for your comprehension
