Detailed Unexploded Ordnance (UXO) Threat Assessment Project Name Horsey Way Cycle Route Section 3, Eastbourne Client East Sussex County Council Site Address Eastbourne, East Sussex, BN23 Report Reference 2166RV00 Revision 00 rd Date 23 January 2015 Originator RV Find us on Twitter and Facebook st 1 Line Defence Limited Company No: 7717863 VAT No: 128 8833 79 Unit 3, Maple Park, Essex Road, Hoddesdon, Herts. EN11 0EX www.1stlinedefence.co.uk Tel: +44 (0)1992 446 974 [email protected] Detailed Unexploded Ordnance Threat Assessment Horsey Way Cycle Route Section 3, Eastbourne East Sussex County Council Executive Summary Site Location The site is situated in the town of Eastbourne – East Sussex on the South Coast of England. The proposed sites covers largely undeveloped land to north of the residential area of Langney – Eastbourne, and east of the Birch Industrial Estate. The site is divided into the three individual sections according to site plans that have been made available by the client and consist of a proposed cycle route (see Annex C). Section 1 extends from Lottbridge Drove and runs parallel with the Horsey Sewer towards residential property on Rotunda Road. Section 2 follows on from Section to the north of residential property on Rotunda Road, across undeveloped greenfield land towards Langney Roundabout where the proposed cycle route comes to an end. Section 3 joins at the intersection of Section 1 to the east of residential property on Rotunda Road and extends down towards Worth Way along the route of Crumbles Sewer. This section of the cycle route will include access along Worth Way and Winston Crescent. The site covers an expanse of ground that is largely greenfield / undeveloped in nature along the route of a proposed cycle route. Section 1 and Section 3 of the proposed site plan runs parallel of Horsey Sewer and Crumbles Sewer respectively. Section 2 of the site boundary is planned to occupy greenfield land from the end of Section 1 towards Langney Roundabout. The site is planned to include a number of bridge points at 4m wide. The main shared footway / cycle way will range from 2 to 2.5m in width. The site is centred on the approximate OS grid reference: TQ 6272401645 Proposed Works The planned works will include a cycle route along the proposed site footprint. The exact type / extent of groundwork will vary within the site boundary however it is planned to include a sub base (comprising of granular Type 1 sub-base material on separator membrane) ranging from 150mm to 270m, a binder base (comprising of DBM binder course) of either 50m or 90m and a surface course (comprising of a dense graded surface course) of 25mm throughout the cycle route. 50 x 50 x 500mm tanalised softwood pegs will be set at 1.5m centres and at all joins in the edge boards. Bridges will be constructed at individual points where bridging is required. The intrusive works are shallow in nature. Geology and Bomb Penetration Depth Geological data / borehole information provided by the client has been assessed as part of this Detailed UXO Threat Assessment. Taking into account the geological strata of the site area it has been assessed that a 500kg bomb could have had a maximum bomb penetration depth of at least 12m below WWII ground level. Penetration depth could potentially have been greater if the UXB was larger (though only 4% of German bombs used in WWII over Britain were of that size). Note that UXBs may be found at any depth between just below the WWII ground level and the maximum penetration depth. UXO Risk Assessment 1st Line Defence believes that there is a Medium Risk from UXO across the site. This assessment is based on the following factors: The Threat from German Air-Delivered Ordnance: During WWII the County Borough of Eastbourne was subject to a Low / Moderate density of bombing, according to Home Office bomb data figures, with 62 bombs recorded per 1000 acres. However it should be noted that the former County Borough boundary covered a large area of land that extended out from the main town of Eastbourne. This included areas of a rural nature which were not heavily bombed and therefore lowers the recorded bombing density. The main town of Eastbourne sustained a relatively High Density of bombing throughout WWII with two individual sources quoting the total number at either 674 incidents or 792 incidents. This was compounded by incendiary bombing that totalled an approximate number of 4000 1kg / 2kg Incendiaries. The main town of Eastbourne was a target for Luftwaffe raids throughout WWII due its location on the South Coast of England which made it a potential landing location for German forces in the event of an invasion. Individual targets of strategic interest were located throughout the area and included a power station a short distance to the south-west of the site location; see Annex M. Eastbourne bomb location mapping and written bomb incident records, obtained from local archives, record HE Report Reference: 2166RV00 II © 1st Line Defence Limited www.1stlinedefence.co.uk Detailed Unexploded Ordnance Threat Assessment Horsey Way Cycle Route Section 3, Eastbourne East Sussex County Council UXO Risk Assessment bomb incidents within the vicinity of the proposed site. A consolidated account of bombing activity in the area has been compiled for reference and has been overlaid onto WWII-era reconnaissance imagery and contemporary satellite imagery; see Annex P and Annex Q. Historical mapping indicates that the site was not subject to structures / development during the WWII period. However the site location resided close to residential property (along Rotunda Road). There are no structures within the site boundary to which bomb damage can be attributed. WWII-era aerial reconnaissance imagery indicates the presence of bomb cratering a short distance to the east of the planned cycle route at the location of a confirmed bombing incident; see Annex S2. The imagery does point to bomb damage to the south-east of the site in the vicinity of Queen’s Crescent and Queen’s Road. Examples of bomb damage on the town of Eastbourne can be seen in Annex U. Bomb damage is a key factor in an investigation of this nature. If a large amount of debris was present it would increase the likelihood of evidence of UXBs going unnoticed and unrecorded (the entry hole of a 50kg UXB can be as little as 20cm in diameter). Open / undeveloped ground cover and areas of dense vegetation can also be a consideration when assessing the likelihood of UXO / UXBs being present at a location. Two individual UXBs are known to have fallen in the general vicinity of the proposed site. See Annex P & Q for the approximate locations of these incidents. Section 3 of the proposed cycle route intersected an area of allotment gardens. Records state that the UXB from a salvo of HE bombs on the area failed to be recognised and was only discovered when intrusive redevelopment of the area began a number of years after the war. This example is indicative of areas that may be accessed yet the ground cover can conceal the signs / indicators of UXO. A number of incidents concerning the discovery of UXBs in the Eastbourne area, in the post WWII-era, are included in press articles; see Annex V. It is inevitable that there remain undiscovered UXBs throughout the wider area that would not have been identified in post-raid inspections for signs of UXO. Records state that approximately 4000 1kg / 2kg Incendiaries were dropped over the entirety of Eastbourne. 1kg Incendiary Bombs in particular are occasionally encountered on construction sites today and are typically discovered at shallow depths due to limited ground penetration capabilities. The Threat from Allied Military Ordnance: No recorded history of direct military occupation (from WWI-era to the contemporary period) within the proposed site boundary could be found. A 19th Century Martello Tower was located a short distance to the south of the proposed cycle route. A Martello Tower was a small defensive fort used for the mounting of an artillery gun. It is not unknown for artillery / cannon shells to be discovered in the vicinity of 19th Century military garrisons. Static anti-tank / vehicle defences were situated within the vicinity of the easternmost section of the site boundary during WWII. There is no evidence to suggest that items of explosive ordnance would be associated with this feature, but other additional unrecorded defensive positions may have been present in the area. WWII- era aerial reconnaissance imagery also highlights a defensive-firing position to the south of the anti-tank defences. It is apparent that scrubland has been cleared at this location in order to provide optimum arcs of fire towards the coastline. A Rifle Range was located approximately 600m to 1km to the east of the site location according to historical mapping from 1930. The design of this firing range indicates that firing took place in an easterly direction towards the coastline and would not have impacted the site of proposed works. A defensive minefield was located to the south and east of the site boundary at an approx. distance of 600-700m during WWII. There is no evidence to suggest that this would have impacted the site of proposed works due to the presence of civilian housing / occupation throughout the site area. Langney Bridge to the north-east of the site location also held explosive charges during WWII. This was in place in order to destroy the bridge in the event of an invasion. There is no evidence to suggest that these features would have had a direct impact on the site of proposed works.