Offshore Services

Offshore UXO Solutions

UXO presents a potential risk to the development and continued operation of offshore projects, principally due to contamination from minefields, naval conflicts, aerial bombing, military shipwrecks, military training, and the dumping of munitions/explosives.

Given the highly complex and challenging offshore marine environment, Ordtek has developed a range of skills and services to meet this demand. The key to the approach is transparent decision-making. Ordtek has developed the following workflow to guide clients through the risk management process.

Phase 1 and 2 - Desk-based UXO Risk Assessment

Within the desk-based UXO risk assessment, the risk is identified and assessed against the probability of encounter and consequence of detonation, taking into account the expected activities on site. Using pertinent records from a number of sources Ordtek can accurately build up a history of hazards and their proximity to a project.

UXO Risk Assessment

The entire scope and life-cycle of the proposed project will be considered;
All available geophysical and geotechnical data will be considered;
Relevant military personnel will be interviewed;
The history of the region will be considered;
Relevant historic and modern military records will be researched and presented;
Wartime activities will be researched and presented;
The holistic UXO threat will be considered, including the types that could be encountered, the probabilities of encountering them as well as exposing their potential mechanisms and risks of detonation;
An outline assessment of how UXO interacts with the natural environment and conditions will be made;
UXO hazard database will be created of the threat items;
The risks regarding UXO will be assessed and benchmarked against the relevant standards;
The consequences of an inadvertent High Explosive (HE) and Chemical event will be considered.

Phase 3 - Risk Mitigation Strategy

Reducing the UXO Risk to ALARP

Based upon the findings of the risk assessment, we will provide strategic options for reducing the UXO risk to ALARP. Properly applied, the ALARP principle not only ensures that client funds are targeted appropriately (thus delivering best value for money), they also ensure that any safety and risk mitigation systems are brought to bear in accordance with the principles understood and endorsed by the law in general and the Health and Safety Executive (HSE) in particular.

The risk mitigation will advise a scope that is both relevant to the magnitude of work planned on site and proportionate to the cost to lower the risk.

Phase 4 - Pre-Installation Geophysical UXO Survey

Services Ordtek provide prior to acquisition include:

Geophysical Survey Tendering and Market Screening

Ordtek will approach companies who can provide UXO geophysical survey, inspection and/or clearance support and assess their capability and methodology in order to identify the best contractor to undertake the operation.

Tender Support and Contractor Selection

Ordtek can supply a suitable consultant to work alongside the Client to evaluate the tender documents and advise the Client on the suitability of methodologies. Work to achieve the objective can be undertaken either at Ordtek’s offices or at the Client’s premises.

Geophysical Survey Technical Specification

Ensuring any geophysical surveys can detect the minimum UXO threat item identified in the mitigation strategy.

Geophysical Survey QA/QC Plans

Ordtek can specify the deliverables required from geophysical surveys in order to ensure the survey can detect the items specified and provide an auditable quality assurance trail.

Geophysical Survey Gap Analysis and Existing Data Processing – Data processing of geophysical datasets, including magnetometry, side scan sonar and multi-beam echo sounder.

Verification Documentation and Test Pieces

Ordtek can specify the documentation and test pieces required for verification tests, during the mobilisation phase. The verification test will aim to achieve the following:

Document the capabilities and limitations of each geophysical detection instrument selected for UXO risk mitigation.
Confirm the achievable probability of detection and confidence levels for a known item.
Observe each geophysical detection instrument operating in the contractor’s configuration, using the survey contractor’s personnel and methodologies.
Evaluate the survey contractor’s data collection, data transfer quality, and data QC method(s).
Evaluate the survey contractor’s method(s) of data analysis and evaluation.
Document system reliability.
Illustrate how predictive models compare to a known item.

Phase 5 – Target Discrimination and Data Handling

Developing offshore projects, such as wind farms, require where possible minimal operational constraints. The reasons behind this desired precision is both for technical and commercial/insurance purposes. However, the presence of geophysical contacts, some of which are potentially UXO, may hamper engineering design.

Depending on the stage of the project the effect will not only delay offshore operations but may have a much larger impact on the overall site design and effort to investigate these problematic geophysical contacts. This situation has been driven by a difficulty to discriminate between potential UXO and, for example, natural geological features. This is especially the case in areas of boulder fields and high magnetic background geology (e.g. outcropping igneous bedrock). However the problems can be even more significant around ports and other harbour facilities where man-made features hamper geophysical interpretation.

Robust discrimination of non-UXO from UXO is a very important step in marine UXO risk management. In many instances the desired performance level is not currently being reached by the wider industry. In Ordtek’s experience many geophysical datasets fall below the accuracy criteria required to identify UXO, with some solutions being hardly any better than random estimation, often with an overreliance on fabricated “surrogate items”.

Ordtek set out to remove the inefficiencies in UXO detection and interpretation through processes that provably locate and identify UXO with high accuracy. The proposed solution is a marine based geophysical contact location and identification method using a technique for modelling and identifying objects using the basis of complex datasets. The solution fuses geophysics, geotechnical data and ordnance characteristics, and determines best algorithms/fit for each dataset. The techniques used include information theory, geophysics based modelling, signal processing modelling, and proprietary data from real bombs and mines. The challenge is to integrate these techniques and to determine the key information content, in order to extend the accuracy of predictive modelling.

The process has proved successful on some of the most challenging renewable developments across Europe. Ordtek have identified numerous items of UXO from geophysical datasets including German bombs and American mines.

On other projects where initial geophysical target grading had resulted in 1,000’s of magnetic and side scan sonar anomalies across the site, being recommended for either investigation or avoidance, were reduced to a figure of less than 10% using Ordtek’s interrogation of geophysical contacts.

Phase 6 – Mitigative Actions

Cable and Pipeline Route Engineering

Generally, ALARP sign-off is given after hazard avoidance buffers have been established on the condition that no works take place inside the buffer.

However, if the works cannot practically proceed without violating the buffer, the area to sign-off will be reviewed against the proposed route and consultation between UXO consultant and design team will take place to highlight the best potential areas for re-routing.

Target Investigation

Ordtek can provide Client and EOD representatives to oversee geophysical survey and Explosive Ordnance Disposal activities during ROV or diver-based inspection and disposal campaigns. Ordtek’s Client/EOD representatives provide overarching UXO safety via briefings to the crew and ensuring sufficient survey data deliverable requirements are met. We have a host of representatives including former Royal Navy EOD Clearance Divers and geophysical survey technicians.

Phase 7 – ALARP Sign-off Certification

To provide evidence of the risk management process we can provide documentation to evidence to the project stakeholders and contractors that the UXO risk has been mitigated to a legally acceptable level (ALARP).

The Vessel Assurance and ALARP Sign-off Certificate is a comprehensive document that is unique to any particular location. The certificates are registered internally at Ordtek’s offices, and are available for auditing by relevant external bodies including the Health & Safety Executive (HSE), the developer and Marine Warranty Surveyors. The certificate is underwritten by Ordtek’s external Professional Indemnity Insurance.

These can be provided either ahead of the geotechnical campaign, certifying intrusive engineering activities, or ahead of construction, certifying assets.

Phase 8 – Mitigation of Residual Risk

Explosive Ordnance Disposal (EOD) Engineer Site Supervision

Ordtek can supply an EOD engineer to oversee site activities and ensure, should UXO be found, it is dealt with as quickly and efficiently as possible.

UXO Safety and Awareness Briefings

To make all site staff aware of the risk of encountering UXO, Ordtek can provide UXO safety and awareness briefings.

UXO Recognition and Management Training

This package is in addition to the safety and awareness briefing and includes the training of a “UXO Coordinator” to supply further training to site workers (such as agency workers) who have missed the initial briefing.

24/7 On-call Service

Should the risk on site be deemed low/medium, enough to not warrant an EOD representative on board but enough of a risk of encountering UXO, Ordtek can provide an on-call service during working hours for the duration of the intrusive works.