What are UXO and UXB surveys?

UXOs are Unexploded Ordinance; a phrase used to describe buried bombs, grenades or artillery shells. A UXO survey will scan terrain or marine environments for such safety risks, ensuring construction works can be carried out without unnecessary health or financial risks.

Unexploded Ordinance items, such as grenades, bullets and artillery, are often abbreviated to UXOs. A 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.

These prove an obvious health, safety and environmental risk, with significant cost implications if they cause damage. A UXO survey will assess whether there are any UXO causes for concern, which may be more common than you first think. It has been reported that over 15,000 UXOs were found between 2006 and 2009, in the UK alone. A 1,000kg bomb was found in East London in 2008 which had the potential to cause considerable damage, thus highlighting the importance of a 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.

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. To choose a type of UXO survey, a number of factors will need to be assessed. The ground type, proposed use, likely UXO in that area, and its likely depth will all need to be considered. The survey may be used to ensure health and safety, or for use in archaeological exploration. There are three types of UXO survey. 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 UXO surveying. Intelligent software manages the findings of UXO surveys into a comprehensive set of data, filtering out any ambient magnetics. The data will then be considered and presented in a way which is clear to the client.

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. Geophysical surveys also show buried mineshafts, air voids and cavities such as vaults, crypts, sewers and heating ducts, and subsidence is a good indicator of such air voids. 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. Geological surveys also show the characterisation of land forms, and can be carried out on a large 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.

When an UXO is discovered, specialist disposal experts may need to be contacted. Once the area is declared safe it will be possible to continue development.