T&A Survey | UXO projects

Identification of German aerial bombs in Rijsenhout

On June 18 and 19, the EODD detonated several bombs, two of which very large, on the beach at Bloemendaal. That resulted in an amazing spectacle with flying sand and lots of fire. The two largest were German aircraft bombs of 1,000 and 1,200 kilos, originating from a field near Rijsenhout. T&A Survey and van Heteren approached and identified the bombs on behalf of SGN and the municipality of Haarlemmermeer.

Diving in a cofferdam

It was quite a job to successfully identify the igniters without moving the bombs, which were located at approximately 8 meters minus ground level. For this purpose, T&A/van Heteren have placed a circular cofferdam around the objects. The cofferdam was mechanically excavated. The pit was then pumped full of water and a specialized UXO diving team sucked the soil away above the bomb.

Identification

The identification of the bombs and their igniters was done based on accurate dimensions and high-resolution video images. The divers were followed in real time above the water. In addition, T&A made use of techniques that had not been used for these purposes before, such as an underwater 3D laser scanner and X-ray equipment. The last two German bombs have been identified with an identifier specially developed for this project by T&A Survey and Baars-CIPRO.

The igniters of the bombs appeared to be equipped with a Zünderzwischenstück, an adapter that was placed on the igniter of large aircraft bombs to make it fit better under the aircraft. This means that the identification numbers on the igniter were not visible. T&A survey and Baars-CIPRO together with the EODD have developed a device to remove this adapeter from the igniter under water, in order to enable identification. The identification showed that the igniter was no longer working. The explosives therefore did not constitute a safety risk.

Preparing for detonation

Since January the bombs were temporarily secured in Rijsenhout. They could not be detonated there because the size of the bombs was so large that the bottom of the Haarlemmermeer would not have been able to handle it. That is why the beach in Bloemendaal was chosen. Before the detonation could take place, UXO survey of the surroundings was necessary. This dune area was part of the Atlantic Wall. During the investigation some anti-invasion objects such as Rommel asparagus and tetrahedras were found that were placed on the beach during WWII. After the clearing of the location, two dates for detonation were set together with the Explosives Clearance Service (EODD) and the municipality of Bloemendaal.

Meticulous

The operation required a lot of preparation and everything had to be meticulously coordinated. Early in the morning the bombs were transported to Bloemendaal in EODD trucks and with police escort. After the EODD applied the explosive charges, the bombs were covered with 10 meters of sand. Air traffic above the coast was stopped and the surrounding water, beach and dunes were cleared. For example, boats, swimmers, hikers and other interested people were kept at a distance by the police, forestry, Rijkswaterstaat and the rescue brigade. Just before the explosion, a police helicopter scanned the area with infrared equipment to ensure that the area was cleared.

Extraordinary

The bomb that was detonated on 19 June was a 1,200 kg German aircraft bomb of the SC1200 type, which contained 631 kilos of explosives. As far as is known, a bomb of this size has never before been found in the Netherlands.

Municipality wide preliminary UXO survey for Deventer

Gemeentebreed vooronderzoek explosieven Deventer

During the Second World War, the municipality of Deventer experienced several acts of war, including bombings and battles on the ground. Defense structures such as trenches and gun emplacements were also constructed at that time. As a result UXO were left behind in the ground around the bridges and the railway track, but possibly also in other places in the municipality. T&A Survey carried out a municipality-wide historical preliminary study on behalf of the municipality of Deventer.

The municipality of Deventer wanted to gain insight, in connection with planned and future earthworks, into which areas are suspected of the presence of UXO. Conducting one preliminary survey for the entire municipality is financially more favorable than having individual surveys carried out for areas where there are currently building plans. After completion of a municipal preliminary investigation, individual preliminary investigations are no longer required. A detailed historical preliminary investigation prevents unnecessary costs for explosives detection or approximation work by accurately delimiting the suspect areas in three dimensions.

T&A has an archive with a large amount of historical data on virtually all Dutch municipalities. We would also like to use our knowledge for the benefit of your municipality!

Reference list preliminary UXO research

Client	Project goal
Gemeente Deventer	Update municipality-wide investigation and formulation of UXO policy
Witteveen + Bos	Preliminary investigation conflict period an post-conflict period, Volkel
Omgevingsdienst Regio Utrecht (ODRU)	Preliminary investigation conflict period, Driebergen-Rijsenberg
Consortium Grensmaas	Preliminary investigation conflict period, Maas Stein - Belgium
Vermillion	Quick scan UXO and preliminary investigation municipality Súdwest Fryslân and Fryske Marren
Gemeente Súdwest Fryslân	Combined UXO and archaeological preliminary investigaion en formulation of UXO policy.
Arcadis	Preliminary UXO investigation for noise reduction project (MJPG), district RWS West-Nederland Zuid.
Movares Nederland	Preliminary UXO investigation along state an provincial roads in East and North-West NL.
Witteveen + Bos, DE-Consult	Prelimainary UXO investigation of 14 municipalities in Zeeland, Brabant and Limburg
Gemeente Zwijdrecht	Municipality-wide preliminary investigation

Gemeente Sliedrecht	Municipality-wide preliminary investigation
ProRail	All ProRail properties and areas
Gemeente Haarlemmermeer	Municipality-wide preliminary investigation Haarlemmermeer
Hoogheemraadschap Schieland en Krimpenerwaard	Area-covering preliminary investigation
Gemeente Voorst	Municipality-wide preliminary investigation Voorst
Antea Group	Quick scan UXO
Gemeente Tiel	Municipality-wide preliminary investigation Tiel
Movares Nederland	Preliminary investigation various railway locations
Arcadis	Preliminary investigation various railway locations
Gemeente Deventer	Municipality-wide preliminary investigation Deventer
Rijkswaterstaat Zee en Delta	Risl Analyses various sand mining locations
Sweco Nederland	Maintenance of waterways (GOVa)
Gemeente Roerdalen	Municipality-wide preliminary investigation Roerdalen
Witteveen + Bos	Transmission system Dutch coast

Reference list UXO research and detection

Client	Project goal
Municipality of Haarlemmermeer, SGN	Approach and identification German bombs Rijsenhout
Rijkswaterstaat	Combined waterbottom survey North Sea
OpenIJ	Waterbottom detection for constuction of new seaport IJmuiden
Province of Noord-Holland	Detection and approach trajectory A9
GMB - Van Oord	Detection and approach Mijnerswijk, Arnhem
Klerk Waterbouw	Detection and approach locks IJmuiden and Schellingwoude
Rijkswaterstaat	Detection and approach project Ruimte voor de Lek
Water Authority Hollands Noorderkwartier	Detection North Sea
Bouwcombinatie Stadsbrug Nijmegen	Detection and approach new bridge over Waal river
Municipality of Rozendaal	Detection and approach De Del, Rozendaal
OceAnco - Alblasserdam Yachtbuilding B.V.	Detection and approach
Vilente	Detection and approcah Gemeente Renkum
Prologis	Detecion survey Fokkerpark, Schiphol
Province of Noord-Holland	Detection and approach Ringvaart and Haarlemmermeerpolder
Dosco Dredging	Detection and approach Aarkanaal, Gouwe and Oude Rijn (ZH)
Ballast Nedam - De Klerk	Detection and approach sheetpiles Amsterdam-Rijnkanaal
Bedrijvenschap Regio Gouda	Detection survey municipality of Zuidplas
Municipality of Bronckhorst	Detection survey and slavaging operation WWII aircraft
Municipality of Deventer	Approach of suspect locations
BAM Roads	Detection and approach A12
Rijnland Water Authority	Detection IJsseldijk Gouda
Hattum and Blankevoort Regio Noord	Detection and approach for construction of an underpass
ProRail	Approach railway track Utrecht CS-Leidse Rijn
Municipality of 's-Hertogenbosch	Detection and approach Orthen fortress and Hervensedijk
Boskalis Nederland	Detection and approach A20, municipality Zuidplas
Van Heteren Weg- en Waterbouw	Detection and approach airport Leeuwarden
Municipality of Rheden - GWW Ingenieurs	Detection and approach Geerfdenwei, Rheden