UXO Desk Study & Risk Assessment
Total Page：16
File Type：pdf, Size：1020Kb
Usworth, Tyne & Wear - UXO Desk Study & Risk Assessment Drafted by Stefan Lang Checked by Will Hazell Authorised by Mike Sainsbury Usworth, Tyne & Wear Document Title UXO Desk Study & Risk Assessment Document Ref. P5933-16-R1 Revision A Project Location Usworth, Tyne & Wear Client WSP Parsons Brinckerhoff Date 31st March 2016 This report has been prepared in relation to the specific requirement of the contract or commission. The report should not be used by third parties without prior consultation with Zetica Ltd. The copyright for this report remains with Zetica Ltd. No part of this report may be reproduced, published or amended without prior written consent from Zetica Ltd. The report refers to the conditions of the Site at the time of investigation/reporting. Zetica Ltd cannot accept liability for subsequent changes of Site conditions. Zetica Ltd may have relied on externally provided information. Zetica Ltd cannot be held responsible for the accuracy of such information or data supplied. The report has been written utilising relevant guidance and legislation in use at the time of report compilation. Subsequent improvement in techniques, changes in legislation or in site conditions may render parts of this report obsolete. If the report is utilised after such changes have occurred or at a time in excess of 1 year of the issue date, it would be prudent to contact Zetica Ltd to reassess the report under a new contract. P5933-16-R1-A 1 Usworth, Tyne & Wear UXO DESK STUDY & RISK ASSESSMENT Usworth, Tyne & Wear EXECUTIVE SUMMARY Zetica Ltd was commissioned by WSP Parsons Brinckerhoff to carry out an Unexploded Ordnance (UXO) Desk Study and Risk Assessment for an area of approximately 720 hectares (ha) to the south of the A184, between Gateshead and Sunderland, Tyne & Wear (‘the Site’). The aim of this report is to gain a fair and representative view of the UXO hazard for the Site and its immediate surrounding area in accordance with the Construction Industry Research and Information Association (CIRIA) ‘Unexploded Ordnance (UXO), a Guide for the Construction Industry’. Records indicate that less than 10No. High Explosive (HE) bombs fell on the Site during World War Two (WWII), reflecting a low local bombing density consistent with regional statistics. Most air raids in the vicinity of the Site were carried out by single aircraft dropping small numbers of bombs and therefore it is considered unlikely that any Unexploded Bombs (UXB) would have fallen unnoticed. No other significant sources of UXO hazard have been identified on the Site. Given this, it is considered that the Site has a low UXO hazard level, as shown in the following Figure, reproduced as Figure 7 in the main report. P5933-16-R1-A 2 Usworth, Tyne & Wear Figure UXO hazard zone plan of the Site Source: Client Not to Scale Very Low Low Moderate Legend High Very High Site boundary Given that several military aircraft are recorded crashing in the vicinity of the Site, the potential for scattered Small Arms Ammunition (SAA) to be present cannot be totally discounted. This is not considered to provide a significant UXO hazard. The main findings of the report are summarised below. No records of bombing or significant military activity on the Site during World War One (WWI) have been found. During WWII, the Site was located in a region which officially recorded a low bombing density. Records indicate that less than 10No. HE bombs fell on the Site during WWII. Incendiary Bombs (IBs) are recorded falling on the fields surrounding the Site. During WWII, the southern end of the Site encroached upon Royal Air Force (RAF) Usworth, an airfield initially used by Fighter Command and then for training activities. The part of the Site within the airfield boundary comprised residential facilities. Records indicate that at least 2No. aircraft crashed in the immediate vicinity of the Site during WWII. Numerous other aircraft crashed at RAF Usworth, within 1km of the Site. P5933-16-R1-A 3 Usworth, Tyne & Wear No significant post-WWII military activity has been identified on the Site. The Table below, reproduced as Table 5 in the main report, provides a UXO risk assessment for potential works on the Site. Further details on the methodology for the risk assessment are provided in Section 13.1 of the main report. Table UXO risk assessment for the Site Potential UXO Hazard Anticipated Works PE UXO Risk PD Severity Likelihood P = PE x PD P = PE x Rating Risk Shallow Excavations 1 1 1 1 5 5 Low UXB Deep Excavations 1 1 1 1 5 5 Low Piling/boreholes 1 1 1 1 4 4 Low Shallow Excavations 2 1 2 2 2 4 Low SAA Deep Excavations 2 1 2 2 2 4 Low Piling/boreholes 1 1 1 1 1 1 Low Shallow Excavations 1 1 1 1 4 4 Low Other UXO Deep Excavations 1 1 1 1 4 4 Low Piling/boreholes 1 1 1 1 3 3 Low PE (Probability of Encounter), PD (Probability of Detonation), P (Overall Probability) Shallow excavations defined as <1.0m below ground level (bgl). Risk Mitigation Recommendations To ensure that the UXO risk is reduced to As Low As Reasonably Practicable (ALARP) the following mitigation is advised: Where a low risk of UXO encounter is anticipated, industry good practice is simply to raise the awareness of those involved in excavations so that in the unlikely event that a suspect item is discovered, appropriate action is taken. This can be achieved through UXO awareness briefings to site staff. Clearance certification for borehole or pile locations is considered prudent only if a zero tolerance to risk is adopted. Zero tolerance is commonly adopted for sites that have safety critical infrastructure such as nuclear establishments and oil refineries. Table 6 in the main report gives recommended actions in relation to the potential UXO risk level and the anticipated Site activity. Further advice on the mitigation methods can be provided by Zetica on request. P5933-16-R1-A 4 Usworth, Tyne & Wear CONTENTS Page Executive Summary 1 INTRODUCTION 8 1.1 Project Outline 8 1.2 The Site 9 2 SOURCES OF INFORMATION 11 2.1 Historical Information 11 2.2 Zetica Ltd Defence Related Site Records 11 2.3 Zetica Ltd Bombing Density Records and Maps 11 2.4 Ministry of Defence and Government Records 11 2.5 Other Historical Records, Maps and Drawings 11 2.6 Local Authority Records 12 2.7 Local Record Offices and Libraries 12 2.8 Local Historical and Other Groups 12 2.9 Data Confidence Level 12 3 SITE HISTORY 13 3.1 General History 13 3.2 Pre-WWI Military Activity 18 3.3 WWI Military Activity 19 3.4 WWII Military Activity 19 3.5 Post-WWII Military Activity 19 4 WWII BOMBING 20 4.1 WWII Bombing in Tyneside, Wearside & Durham 20 4.2 WWII Strategic Targets 21 4.3 Bombing Density and Incidents 22 4.4 Geology and Bomb Penetration Depths 31 5 WWII DEFENCES 33 5.1 Bombing Decoys 33 5.2 Anti-Aircraft Defences 33 5.3 Barrage Balloons and Anti-Landing Obstacles 35 5.4 Anti-Invasion Defences 35 5.5 Pillboxes, Mortar and Gun Emplacements 35 5.6 Home Guard and Auxiliary Units 36 5.7 Minefields and Mined Locations 37 P5933-16-R1-A 5 Usworth, Tyne & Wear 6 MILITARY AIRFIELDS 38 6.1 RAF Usworth 38 6.2 Aircraft Crashes 40 7 EXPLOSIVES AND MUNITIONS ESTABLISHMENTS AND DEPOTS 41 7.1 Explosives and Ordnance Factories 41 7.2 Munitions Stores 41 7.3 Informal Munitions Depots 41 7.4 Munitions Disposal Areas and Bomb Cemeteries 41 8 FIRING RANGES AND MILITARY TRAINING AREAS 42 8.1 Small Arms Ranges 42 8.2 Artillery Ranges 42 8.3 Bombing Ranges 42 8.4 Training Areas 42 9 EXPLOSIVE ORDNANCE CLEARANCE ACTIVITIES 43 9.1 Abandoned Bombs 43 9.2 EOC Tasks 43 10 UXO HAZARD 44 10.1 Ordnance Types 44 10.2 Effects and Consequences 50 11 UXO HAZARD ASSESSMENT 54 11.1 UXO Hazard Level 54 12 UXO RISK ASSESSMENT 56 12.1 UXO Risk Level 56 12.2 Risk Management Recommendations 58 Appendices Appendix 1 WWII Bombing Incident List Appendix 2 Abbreviations Appendix 3 Glossary and Definitions Appendix 4 Bibliography Figures, Plates, Tables & Drawings Figure 1 Site location map Figure 2 Historical map, 1862 P5933-16-R1-A 6 Usworth, Tyne & Wear Figure 3 Historical map, 1913 Figure 4 Historical map, 1937 Figure 5 Compiled bomb impact map for the vicinity of the Site Figure 6 Plan of RAF Usworth, 1945 Figure 7 UXO hazard zone plan of the Site Plate 1 Recent aerial photograph of the Site Plate 2 Aerial photograph, 7th September 1971 Plate 3 Aerial photograph, 29th June 1993 (northern part of the Site) Plate 4 Aerial photograph, 29th June 1993 (southern part of the Site) Plate 5 Aerial photograph, 27th November 1945 Plate 6 Aerial photograph, 27th February 1946 (western part of the Site) Plate 7 Aerial photograph, 27th February 1946 (northern part of the Site) Plate 8 Aerial photograph, 4th October 1947 (north-eastern part of the Site) Plate 9 Aerial photograph, 4th October 1947 (south-eastern part of the Site) Plate 10 Aerial photograph, 4th October 1947 (southern part of the Site) Plate 11 Aerial photograph, 4th October 1947 (south-western part of the Site) Plate 12 Photograph of typical WWII small arms ammunition Plate 13 Photographs of a typical and an excavated WWII No. 36 hand grenades Plate 14 Photographs of WWII 2-inch and 3-inch mortars Plate 15 Photograph of a recently excavated 3.7” AA shell Plate 16 Photographs of typical fragmentary remains of IBs and a UXIB Plate 17 Photographs of typical AP (‘Butterfly’) bombs Plate 18 Photograph of a variety of UXB recovered by the Civil Defence during WWII Plate 19 Photographs of original and recently excavated WWII land mines Plate 20 Photograph of the 500kg WWII UXB at Bowers Marsh, 8th March 2010 Plate 21 Photograph of exposed UXO at Mappleton, 22nd July 2012 Plate 22 Photograph of WWI bomb, Isle of Sheppey, 2nd August 2012 Table 1 Bombing statistics Table 2 Estimated average maximum bomb penetration depths (no Alluvium) Table 3 Estimated average maximum bomb penetration depths (with Alluvium) Table 4 WWII HAA batteries within 10km of the Site Table 5 UXO risk assessment for the Site Table 6 Risk mitigation for assumed Site activities P5933-16-R1-A 7 Usworth, Tyne & Wear UXO DESK STUDY & RISK ASSESSMENT Usworth, Tyne & Wear Note: To aid the reader of this report, Zetica has colour coded each paragraph.