Marine UXO Specialists

UKDC offers specialist UXO Survey and Clearance services for the marine industry.

When new Marine construction projects are planned, historical UXO must be taken into account. There are currently in excess of half a million (100,000 tonnes) of unexploded ordnance in the waters around the British Isles according to Government websites.

The initial phase of the UXO mitigation process is a desktop risk assessment. This will consist of studies of historical data to establish the likelihood of UXO being in the area of the construction project. This will result in a low, medium or high risk, however, a low risk result is not a guarantee that there are no UXO on the seabed in that area.

Following the desktop risk assessment, if the client deems it necessary (i.e a medium to high risk of UXO), a non-intrusive survey of the seabed is carried out using equipment such as: magnetometers, side scan sonars and 3D (seismic) chirp. The survey results will be examined by a suitably experienced geophysicist and UXO Expert, who will study all survey data anomalies to assess if they show any UXO type features including size, shape, and material. A target that show’s any similarity to a UXO is deemed a pUXO (potential unexploded ordnance). The client will be presented with a Master target List (MTL) to decide if works can continue around the pUXO or whether further investigation works are required to identify the pUXO. There are several options for intrusive investigation works, some use remote systems (ROV) and others involve the use of experienced divers. Completing the intrusive phase will conclusively identify the pUXO and deem if it a confirmed UXO (cUXO) requiring further remediation, or if it is “scrap” and can be discounted and or removed.

Experienced UXO qualified divers are generally the most efficient way to identify a pUXO particularly in shallow water and water with poor visibility. Using coordinates dictated from the non-intrusive survey the diver will conduct a search, circular or jackstay type searches depending on the seabed, visibility etc. Once the target is found a UXO qualified diver will identify the pUXO. There is a strict no touch policy when working around pUXO, however, in nil visibility the only way a diver can identify the pUXO is by feel. If the target is identified as a cUXO the UXO will be marked.

Actions on a cUXO: The initial action is to put a cordon in place and report the UXO to the relevant agency. This will be dictated prior to the project. If the target is in UK’s coastal water the police will be informed and the UXO will be dealt with by Royal Navy Clearance Divers. If the target is offshore, the target will need to be disposed of by the dive team and UXO company. Methods include low order deflagration where the ordnance is destroyed by burning out the explosive using a shaped charge. This is the preferred method as it has minimum environmental impact. If this is not possible due to the type of UXO or location, a high order detonation will be used. This involves blowing the ordnance up which could have serious consequences on the environment. There is also an option to mark and avoid or lift and shift, however, these will not destroy the UXO.

If the target is confirmed as non UXO the client will have decided prior to the project start whether to remove the target or leave in situ.

Read about a UKDiveworks Commercial UXO Survey case study?
Click here to view case study in Bristol Harbour
Click here to view case study in Silvertown