UXO is a phrased use to describe Unexploded Ordinance items, such as grenades, bullets and artillery. An UXB is an Unexploded Bomb, and many UXOs and UXBs remain today on ex military training areas or areas targeted by air raids in World War II.
UXOs and UXBs are obviously a threat to health and safety; and they can also create unnecessary environmental damage and cost implications. An UXO survey will assess whether there are any UXO causes for concern, which may be more common than you first think. Between 2006 and 2009, 15,000 UXOs were discovered on construction sites in the UK. A 1,000kg bomb was found in East London in 2008 which had the potential to cause considerable damage, thus highlighting the importance of an UXB or UXO survey.
Often bombs and UXOs will have travelled laterally, meaning many are hidden underground. A Geophysical UXO survey will typically detect large UXBs up to 5 metres, and smaller items which are buried up to 2 metres deep. Because of their targeting in World War II, London and Portsmouth are where most UXBs have been discovered.
The identification and location of harmful artillery is often essential at the design stage of construction projects, and an UXO survey may be of particular relevance to the redevelopment of brownfield sites. The type of UXO survey will depend upon a number of factors, including the likely type of UXO and its depth (often determined by the area’s location), the ground conditions and the proposed use for the land. The survey may be used to ensure health and safety, or for use in archaeological exploration. UXO surveys can be categorised into three groups. Non-intrusive surveys involve the sensing of items from the surface, intrusive surveys involve data collection from sensors inside the ground, and marine surveys detect UXOs and other metallic objects under the sea.
Magnetometry is one of the more common techniques used in non-intrusive surveys, which uses Electro Magnetic Systems. Intelligent software manages the findings of UXO surveys into a comprehensive set of data, filtering out any ambient magnetics. This data is then assessed and demonstrated in a way which the client will understand.
Buried fuel tanks and air raid shelters are another reason why a geophysical survey may need to be carried out, as they can create construction problems. The prominence of badger sets also show up in these surveys, and as they are a protected species, they must be considered during construction works. Geophysical surveys can also be used to show the characterisation of land forms, which can be done on a big scale. Other uses for these surveys are reinforced concrete mapping, used for locating foundations and such, when more foundations or a borehole are required; and high frequency structural radar, used for showing features within a building, such as hidden flues and chimneys, historic features and voiding.
If an UXO is discovered in a geophysical UXO site survey, the surveyors will stop all works, evacuate the area and contact specialist disposal experts. Once the area is declared safe it will be possible to continue development.
SUMO Services Ltd carry out all areas of geological surveying nationwide. Their services cover UXO surveying, utility mapping and detection, topographic surveying, archeological surveying and geophysical surveying.
