Real Results in UXO Risk Environments

S.I UXO has successfully delivered risk mitigation solutions on projects of national significance. Our portfolio reflects our adaptability, technical expertise, and rigorous safety culture.

Case Study 1: Urban Residential Redevelopment (High UXO Sensitivity)

Client: Main Contractor (Tier 1)

Location: Greater London

Development: Demolition and construction of mixed-use residential blocks

Intrusive Works: Piling, bulk excavation, drainage, services

S.I UXO was appointed to manage UXO risk at a brownfield redevelopment site within a heavily bombed WWII urban area. A CIRIA C681-compliant Preliminary UXO Risk Assessment identified a moderate-to-high risk of unexploded aerial bombs, supported by historic bombing density data and wartime mapping.

To reduce programme risk, S.I UXO designed and executed a non-intrusive magnetometer survey, followed by targeted intrusive verification in pile locations. Advanced data processing enabled discrimination between shallow ferrous clutter and deeper bomb-sized anomalies.

Outcome:

  • No UXO encountered during piling or excavation

  • Planning conditions and Principal Designer requirements discharged

  • Client avoided blanket mitigation measures, saving time and cost

  • Works completed without delay or safety incidents

Case Study 2: Infrastructure Corridor (Linear Works)

Client: Civil Engineering Contractor

Location: Southern England

Development: Utility installation along a transport corridor

Intrusive Works: Trenching, thrust boring, trial pits

S.I UXO was engaged to support linear works crossing areas of historical military training and wartime infrastructure.

A Detailed UXO Risk Assessment identified variable risk levels along the route, requiring a segmented mitigation strategy rather than a one-size-fits-all approach.

S.I UXO implemented walked and towed magnetometer surveys to screen accessible areas and provided UXO engineer supervision during intrusive works in constrained sections where survey coverage was limited.

Outcome:

  • Proportionate UXO mitigation tailored to localised risk

  • No unplanned stoppages or emergency call-outs

  • Safe completion of works within a live operational environment

  • Full compliance with CDM and CIRIA C681 guidance

Case Study 3: Greenfield Development with Deep Foundations

Client: Property Developer

Location: Midlands

Development: Commercial units and access roads

Intrusive Works: Deep piles, attenuation tanks, services

Although the site appeared low-risk due to its rural setting, S.I UXO’s historical analysis identified previous military activity and undocumented bombing incidents within the wider area.

S.I UXO deployed its tracked CPT-based intrusive UXO detection system, integrating UXO verification with the geotechnical investigation. This approach provided high-confidence interrogation of deeper strata, addressing residual risk associated with large unexploded aerial ordnance.

Outcome:

  • UXO risk conclusively reduced to ALARP

  • No requirement for additional borehole magnetometry

  • Combined UXO and GI scope reduced duplication and cost

  • Robust technical justification accepted by client and designers

Case Study 4: Time-Critical Enabling Works

Client: Principal Contractor

Location: North West England

Development: Enabling works prior to redevelopment

Intrusive Works: Trial pits, shallow excavation, CBR testing

S.I UXO was appointed at short notice to support enabling works under a compressed programme. Following a rapid Preliminary UXO Risk Assessment, S.I UXO provided on-site UXO supervision and real-time risk management during intrusive activities.

Clear communication protocols and pre-start briefings ensured all site personnel understood UXO risks, reporting procedures, and emergency response measures.

Outcome:

  • Zero downtime despite high programme pressure

  • Safe completion of intrusive works

  • Client able to proceed to main works without additional mitigation

  • Strong contractor and H&S feedback

Case Study 5: UXO Identification and Controlled Excavation

Location: Bath Street

Scope: CIRIA C681 desk study; CPT investigation (174 pushes to 9.0 m); anomaly confirmation; planned controlled excavation

Outcome: Identification and safe management of a WWII SC50 aerial bomb

Delivery: Fully in-house by S.I UXO

A CIRIA C681-aligned UXO desk-based risk assessment was carried out for the Bath Street site, drawing on S.I UXO’s extensive in-house historical archives, primary source research, and analysis via our interactive UXO risk mapping platform. This work identified a clear and spatially defined risk linked to historic aerial bombardment.

S.I UXO managed the entire UXO mitigation process from initial assessment through to final confirmation, delivering every stage of the work using our own specialist team and equipment.

A targeted intrusive investigation was designed and undertaken using our CPT rig, “Percy”, with testing advanced to depths of up to 9.0 m. In total, 174 CPT pushes were completed across the site to provide comprehensive subsurface coverage. All CPT data was interpreted directly by S.I UXO specialists. This analysis led to the identification of a single discrete subsurface anomaly at approximately 4.3 m below ground level within cohesive clay strata.

The anomaly response was examined in detail and assessed against established UXB characteristics. A triangulation methodology was then applied to refine its position, depth, and dimensions, providing a high level of confidence that the object represented a UXB.

A carefully planned and controlled excavation followed at an agreed date, undertaken under strict safety procedures. This confirmed the presence of a World War II SC50 kg Luftwaffe aerial bomb, with heavily corroded suspension lugs and fuze. Following confirmation, appropriate safety measures were implemented, and close liaison was maintained with the relevant authorities pre to them ensuring the device was managed and made safe in a controlled and compliant manner.

The investigation reduced uncertainty for the project team, enabled informed risk management decisions, and avoided reactive delays during construction.

Bath Street highlights the value of combining detailed desk-based assessment with targeted intrusive investigation and specialist interpretation, ensuring potential UXO risks are identified early and managed safely through to resolution.

S.I UXO is a UK-based leader in unexploded ordnance risk management, delivering compliant services for land and marine developments with precision, safety, and integrity.

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