RPS Energy Ltd Explosives Engineering Services UXO Below: Mitigating Marine UXO Risk Presented by Victoria Phillips 1
Aim To deliver an overview of Unexploded Ordnance (UXO) in the marine environment, the Risks posed during Engineering works, and to consider appropriate strategies for mitigations 2
What is Unexploded Ordnance? United Nations Definition Unexploded Ordnance (UXO) are explosive munitions, which have not yet been set off. UXO may already have been fired, dropped, or launched, but it has failed to detonate as intended. 3
Other Definitions AXO: Abandoned Explosive Ordnance. Explosive ordnance that has not been used during an armed conflict, that has been left behind or dumped by a party to an armed conflict, and which is no longer under control of the party that left it behind or dumped it. Abandoned explosive ordnance may or may not have been primed, fuzed armed or otherwise prepared for use. ERW: Explosive Remnants of War. Unexploded Ordnance (UXO) and Abandoned Explosive Ordnance (AXO). MEC: Munitions & Explosives of Concern From: IMAS 04.10 Glossary of mine action terms, definitions and abbreviations.
Contamination Sources Numerous historical activities across the world have left a legacy of UXO contamination: - Conflict / Battle Areas - Weapons Testing /Training - Bombing & Firing Ranges - Aircraft Wrecks - Ship Wrecks - Coastal Batteries - Sea Dumped Munitions & Scuttled Vessels 5
Conflict WWII North Sea 6
Conflict WWII North Sea 7
Artillery & Bombing Ranges - UK 8
Aircraft Wrecks South Pacific 9
Ship Wrecks -Thames Estuary The Richard Montgomery - Loaded with 7000 tons of explosives - If the munitions detonated the consequences could be catastrophic 10
Dumped Munitions - Army secret ocean-dumping program - from 1944 to 1970 - Nerve and mustard gas agent, Chemical filled bombs, landmines, rockets, Radioactive waste - Operation CHASE (Cut Holes & Sink Em) - Army cannot say exactly where all weapons were dumped from WWII to 1970 - During WWI munitions were not to be brought into the harbour and were dumped prior to entry 11
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Ordnance Variants - Air Delivered Bombs - Land Service Ammunition - Projectiles - Small Arms Ammunition - Land Mines - Rockets / Missiles -Sea Mines -Torpedoes -Depth Charges -Chemical Warfare Material - 13
Air Delivered Bombs Left: High Explosive Bombs Below Left: 1000lb HE Bomb Below Right: 8.5lb Practice Bomb 14
Land Service Ammunition Above: Hand Grenades Top Left: Bazooka Bottom Left: 3 Mortar 15
155mm French Projectiles - Used in the Persian Gulf 155mm USSR WWI White Phos 16
Landmines Above: British Mk2 AT Mine Right: VS 69 Bounding Mine 17
Naval Weapons Torpedoes Naval Artillery Ammo Depth Charges Limpet Mines German Ground Mine WWII Buoyant Mine
Chemical Warfare Material (CWM) Above: US Munitions dumping program Top Middle: UK chemical weapons dumping Bottom Right: US disposal ship Top Right : Liven Projector WWI 19
UXO Risks - Initiation HE ordnance does not generally spontaneously explode. Unfuzed HE requires significant energy to induce initiation. Potential initiation depends on ordnance fuzing and investigation activity. Examples are: Drill / piling impact on bomb fuze pocket, which has build up of picric acid crystals Cutter dredger strikes percussion fuze on a mortar Seabed Plough strikes a sensitive munition 20
Water can have a suppressive effect on explosive events Therefore the safety/danger distances will be significantly reduced in the event of an underwater detonation, dependant on the depth of water. This affords some protection to personnel and equipment. This protection is lost once items of ordnance are brought to the surface. Underwater Explosions
Explosion Underwater Effects Differ to explosions in air because: Water is a different consistency and produces extremely effective tamping or cushioning effect To achieve Target Damage at a distance larger charge weights are used in most underwater weapons. BUBBLE PULSE EFFECT is often used in mines to advantage.
Torpedo Testing Torpedo wearhead - 1200 LB TNT. The warhead detonates below the keel, as opposed to striking it directly. The resulting pressure wave of the explosion "lifts" the ship and can break its keel in the process. As the ship "settles" it is then hit again as the explosion itself rips through the area of the blast. 23
UXO Assessment & Mitigation Desk Based Risk Assessment Risk Mitigation Strategy Sign off 24
Desk Based Assessment - If possible should be undertaken at the planning Stage - Site scope - Intertidal &/or Offshore - Water Depths & Seabed Type/ Mobility - Site History - Understanding of Site works - Methods of installation - Identify Hazard Levels - Identify Appropriate Mitigation - Ordnance Records - Detailed Historical Search - Hydrographical Mapping - Accessing Archived Data - Identify Dumping locations - Weapon Characteristics (NEQ, Fuzing ) 25
Mitigation Strategy Proactive Measures: - Avoidance - Detection (survey) - Investigation - Disposal Reactive Measures: - Safety Briefings - UXO Supervision & Management Plans - Screening 26
Detection - Geophysical Survey Sub Bottom Profile Magnetometry / EM Side Scan Sonar www.rpsuxo.com 27
Ordnance variations: - ferrous / non-ferrous - size / weight / shape Geophysical Techniques - Survey Considerations Burial/Penetration depths: - is the ordnance on the sea bed or buried Sea bed composition Sediment mobility Water depths Detection capability: - Fish/Array Height - Line spacing Positional accuracy - GPS / USBL 28
Anomaly Investigation Divers Hand Held Detectors,Air Lifts & Tactile Search ROV s TSS / SmartSearch, Dredge Pumps / Sonar www.rpsuxo.com 29
Disposal Towing the mine/uxo Diver attaching lifting bag Towing the mine/uxo 30
Thank you for attending Any Questions? 31