Detailed Unexploded Ordnance (UXO) Threat & Risk Assessment
Total Page:16
File Type:pdf, Size:1020Kb
6 Alpha Associates Ltd Quatro House Frimley Road Camberley Surrey GU16 7ER United Kingdom T: +44 (0)2033 713 900 W: www.6alpha.com Detailed Unexploded Ordnance (UXO) Threat & Risk Assessment Meeting the requirements of CIRIA C681 ‘Unexploded Ordnance (UXO) – A guide for the Construction Industry’ Risk Management Framework 6 Alpha Project Number: P5126 Client: Elephant Construction Ltd Site: Tottenham House, Wiltshire Originator: Charlotte Cole Technical Review: Robin Rickard (15th April 2016) Released By: Lisa Askham (22nd April 2016) 1 Contents Contents 1 Acronyms and Abbreviations 2 Executive Summary 3 Assessment Methodology 5 Stage One – Site Location & Description 6 Stage Two – Review of Historical Datasets 7 Stage Three – Data Analysis 10 Stage Four – Risk Assessment 12 Stage Five – Risk Mitigation Measures 14 Figures Figure One – Site Location Figure Two – Site Boundary Figure Three – Aerial Photography (Current) Figure Four – WWII High Explosive Bomb Density 6 Alpha Project Number: P5216 1 www.6alpha.com - +44 (0)2033 713 900 Client: Elephant Construction Ltd [email protected] Site: Tottenham House, Wiltshire 2 Acronyms and Abbreviations AA Anti-Aircraft LAA Light Anti-Aircraft AAA Anti-Aircraft Ammunition lb Pounds AAC Army Air Corps LCC London County Council AFS Advanced Flying School LDV Local Defence Volunteers ALARP As Low As Reasonably Practicable LE Low Explosive AOD Above Ordnance Datum LSA Land Service Ammunition ARP Air Raid Precaution m Metres ATS Auxiliary Territorial Service MACP Military Aid to the Civil Power AXO Abandoned Explosive Ordnance MoD Ministry of Defence BD Bomb Disposal mm Millimetres BDO Bomb Disposal Officer NATO North Atlantic Treaty Organisation bgl Below Ground Level NEQ Net Explosive Quantity BGS British Geological Survey NFF National Filling Factory BH Borehole NGR National Grid Reference BPD Bomb Penetration Depth OD Ordnance Datum CDP Cast Driven Piles OS Ordnance Survey CFA Continuous Flight Auger OTU Operational Training Unit CIRIA Construction Industry Research and PBG Polar Blasting Gelignite Information Association PM Parachute Mine CPT Cone Penetration Testing PoW Prisoner of War CS County Series RADAR Radio Detection And Ranging EFTS Elementary Flying Training School RAF Royal Air Force ELG Emergency Landing Ground RBL Rifle Breach Loaded EO Explosive Ordnance RDX Research Department Explosives EOC Explosive Ordnance Clearance RFC Royal Flying Corps EOD Explosive Ordnance Disposal RML Rifle Muzzle Loaded ERW Explosive Remnants of War RN Royal Navy FAA Fleet Air Arm RNAS Royal Naval Air Service FPP Flight Pilot Pool ROF Royal Ordnance Factory FTS Flight Training School SAA Small Arms Ammunition GI Ground Investigation Sqn Squadron GIS Geographic Information Systems TA Territorial Army GL Ground Level TNT Trinitrotoluene GP General Purpose UK United Kingdom GPS Global Positioning Systems UN United Nations HAA Heavy Anti-Aircraft USAAF United States Army Air Force HE High Explosive UXB Unexploded Bomb HO Home Office UXO Unexploded Ordnance HSE Health and Safety Executive V Weapons Vergeltungswaffe – Vengeance IB Incendiary Bomb Weapons IED Improvised Explosive Device WAAF Women’s Auxiliary Air Force JSEODOC Joint Service Explosive Ordnance WD War Department Disposal Operations Centre WWI World War One kg Kilograms WWII World War Two km Kilometres 6 Alpha Project Number: P5216 2 www.6alpha.com - +44 (0)2033 713 900 Client: Elephant Construction Ltd [email protected] Site: Tottenham House, Wiltshire 3 EXECUTIVE SUMMARY Study Site The Client has described the Study Site as ‘Tottenham House, Wiltshire’. The Site is located at NGR 424906, 164104. Risk Level LOW/MEDIUM Potential Threat Sources The most probable UXO threat is posed by WWII German HE bombs, whilst IBs and British AAA projectiles (which were used to defend against German bombing raids) pose a residual threat. Furthermore additional threat items may include items associated with military activity and munitions storage, including LSA, SAA and AXO. Risk Pathway Given the types of UXO that might be present on Site, all types of aggressive intrusive engineering activities may generate a significant risk pathway. Key Findings During WWII, the Study Site was situated within Marlborough & Ramsbury Rural District and Pewsey Rural District, which recorded less than one and one HE bomb strike per 100 hectares respectively, both low levels of bombing. Luftwaffe aerial reconnaissance photography associated with the Site did not identify any primary bombing targets on-site or within 1,000m. Nevertheless, the Luftwaffe may have targeted Tottenham House and the surrounding area during WWII as it served as the ammunition depot headquarters and occupied several military camps. In addition, a railway station located nearby may have been considered a secondary bombing target. Furthermore, pillboxes located in the vicinity were likely to have been targeted in an attempt to reduce Luftwaffe aircraft losses. ARP records associated with the Site could not be located. Furthermore, additional research did not reveal any evidence of bomb strikes on-Site or in the vicinity. Moreover, whilst IBs may have fallen within the Study Site, they fell in such large numbers they were considered ubiquitous and accurate record keeping was either non- existent or perfunctory therefore, their prospective presence cannot be either corroborated or discounted. Official bomb damage mapping associated with the Site could not be located. Nonetheless, research revealed that the orangery and windows at Tottenham House were damage during WWII when stored munitions accidentally exploded. It is highly likely that bomb damage records associated with Tottenham House were recorded privately and not released into the public domain as military personnel used it as the ammunition depot headquarters. Research revealed that the Site was used as an ammunition depot during WWII and comprised of Tottenham House in the central sector and Lower Barn in the eastern sector, however the Site was largely undeveloped. Military camps were on-Site and Tottenham House was used as the ammunition depot headquarters. As a result, it is plausible that the Site was inspected for UXB entry holes following any air raids, however, prospective inspections were unlikely to have been comprehensive. The Site has not been subjected to any significant redevelopment post-war. Consequently, it is considered highly unlikely that any UXO would have been discovered and removed. As such, pro-active risk mitigation measures are recommended during any works on-Site. 6 Alpha Project Number: P5216 3 www.6alpha.com - +44 (0)2033 713 900 Client: Elephant Construction Ltd [email protected] Site: Tottenham House, Wiltshire 4 EXECUTIVE SUMMARY (…continued) Recommended Risk Mitigation All Groundworks in All Areas: 1. Operational UXO Risk Management Plan; appropriate Site Management documentation should be held on Site to guide and plan for the actions which should be undertaken in the event of a suspected or real UXO discovery (this plan can be supplied by 6 Alpha); 2. UXO Safety & Awareness Briefings; the briefings are essential when there is a possibility of explosive ordnance encounter and are a vital part of the general safety requirement. All personnel working on the Site should receive a briefing on the identification of a UXB, what actions they should take to keep people and equipment away from such a hazard and to alert Site management. Information concerning the nature of the UXB threat should be held in the Site office and displayed for general information on notice boards, both for reference and as a reminder for ground workers. The safety awareness briefing is an essential part of the Health & Safety Plan for the Site and helps to evidence conformity with the principles laid down in the CDM regulations 2015 (this briefing can be supplied by 6 Alpha). 3. On-Call Engineer; An on-call EOD Engineer will be able to identify and/or advise on the appropriate course of action in the event of any suspicious and/or real UXO finds. 6 Alpha offer three tiers of immediate telephone and/or email response. For further information, please contact 6 Alpha Associates: Website: http://www.6alpha.com Telephone: +44 (0)2033 713 900 Email: [email protected] 6 Alpha Project Number: P5216 4 www.6alpha.com - +44 (0)2033 713 900 Client: Elephant Construction Ltd [email protected] Site: Tottenham House, Wiltshire 5 ASSESSMENT METHODOLOGY Approach 6 Alpha Associates is an independent, specialist risk management consultancy practice, which has assessed the risk of encountering UXO (as well as buried bulk high explosives) at this Site, by employing a process advocated for this purpose by CIRIA. The CIRIA guide for managing UXO risks in the construction industry (C681) not only represents best practice but has also been endorsed by the HSE. Any risk mitigation solution is recommended only because it delivers the Client a risk reduced to ALARP at best value. UXO hazards can be identified through the investigation of local and national archives associated with the Site, MoD archives, local historical sources, historical mapping as well as contemporaneous aerial photography (if it is available). Hazards will have only been recorded if there is specific information that could reasonably place them within the boundaries of the Site. The amalgamation of information is then assessed to enable the researcher to provide relevant and accurate risk mitigation practices. The assessment of UXO risk is a measure of probability of encounter and