UXO from Wartime Anti-Aircraft Artillery (AAA)

Crews rush to their Bofors guns at a South Coast anti-aircraft battery, 6 August 1944

Introduction  

World War II was a global conflict shaped by an unprecedented evolution in warfare - Air power - with the skies becoming a critical theatre of war.

As the Luftwaffe, Nazi Germany’s formidable air force, launched relentless bombing campaigns against the Allies, Anti-aircraft artillery (AAA) emerged as crucial. These ground-based weapon systems played a significant role in countering the aerial threat posed by the Luftwaffe bombers and fighters, contributing greatly to the overall Allied victory. This article explores the evolution, effectiveness, and impact during WWII of AAA, along with the enduring legacy of associated post war Unexploded Ordnance (UXO) contamination in the UK.

The Evolution of Anti-Aircraft Artillery

British 3.7-inch QF (Quick Firing) AAA – static Gun emplacement in WWII

The concept of anti-aircraft artillery was not new at the beginning of WWII, however, significant advancements emerged in its technology and deployment, with larger and more powerful weapons being used. As air power became increasingly decisive in military strategy, the need to counter enemy aircraft led to the development and widespread use of AAA. It is thought that approximately 1900 AAA sites were positioned across the South coast of the UK in 1940 alone. Initially, these guns were modified versions of standard field artillery, but they quickly evolved into specialised weapons designed specifically for targeting aircraft at various altitudes and speeds.

The most widely used and effective wartime British AAA guns were the 3.7-inch QF (Quick Firing) guns, developed in the late 1930s. Originally designed to counter high-altitude bombers, the 3.7-inch gun proved to be a crucial component of Britain’s air defence. With a maximum ceiling of over 40,000 feet and a firing rate of 10-20 rounds per minute, it became a symbol of the British resistance against the Luftwaffe. This gun played a vital role during key moments such as the Battle of Britain, where it helped protect the nation from the relentless German bombing raids.

 AAA - Strategic Deployment

The effectiveness of AAA was not solely dependent on the weapon itself but also on strategic deployment. During the Battle of Britain, the British Army's Anti-Aircraft Command played a vital role in defending the skies over the United Kingdom. Guns were placed in a wide array of locations, from coastal areas to urban centres, forming part of a comprehensive air defensive network which also incorporated early warning radar systems and ‘interceptor’ fighter squadrons. Key cities, such as London, were heavily fortified with AAA batteries to protect against the Luftwaffe’s Blitz—a sustained bombing campaign aimed at crippling British morale and industrial capability. Ports, factories, and military installations across the Southeast, often the first point of contact for enemy aircraft flying in from northern France, were surrounded by rings of AAA emplacements. These locations were chosen not only for their strategic importance but also because they were likely targets for the Luftwaffe’s bombing raids. Coastal defences, particularly along the South and East coasts of England, were also equipped with AAA to intercept incoming raids before they reached more populated or critical areas.

The Impact on the Luftwaffe

The introduction and effective use of AAA significantly impacted the Luftwaffe’s operations. The presence of AAA forced German pilots to fly higher, reducing the accuracy of their bombing runs and increasing the strain on their aircraft and pilots. At lower altitudes, aircraft were more vulnerable to small arms fire and other defences, creating a dilemma for Luftwaffe commanders who had to balance the need for accuracy with the risk of losing aircraft. During the Battle of Britain, AAA accounted for a significant number of Luftwaffe losses, complementing the efforts of the Royal Air Force (RAF). While exact figures are difficult to ascertain, estimates suggest that AAA fire was responsible for about one-third of the total aircraft shot down during the battle. In addition to direct kills, AAA fire caused considerable disruption to Luftwaffe bombing missions. Many German aircraft returned to base with damage from shrapnel, reducing their operational effectiveness and necessitating repairs.

AAA UXO Contamination

Wartime Anti-Aircraft Artillery Shell found on a beach in Dorset

While AAA was an effective deterrent against enemy aircraft, it also caused significant destruction, particularly in urban areas. The use of large-calibre shells, such as the 88mm or 3.7-inch rounds, resulted in considerable collateral damage when rounds missed their targets and fell back to the ground. This was especially problematic in cities like London, where the dense population and infrastructure were vulnerable to errant fire. Moreover, the legacy of AAA extends beyond the immediate destruction caused during the war. Unexploded ordnance (UXO) from anti-aircraft shells has remained a persistent hazard in many parts of Europe. Decades after the war, unexploded AAA rounds continue to be discovered, posing a threat to civilians and requiring ongoing efforts to locate and safely dispose of these remnants of war.

In the UK, encounters with AAA UXO routinely occur. For example, in 2021, a large unexploded anti-aircraft round was discovered in Portsmouth, prompting a major evacuation and bomb disposal operation. This underscores the enduring legacy of AAA, not just as a wartime defence measure but as a continuing safety concern in former battlegrounds.

How does Artios assess the threat?

When evaluating the wartime AAA UXO threat, Artios meticulously reviews detailed wartime records, taking into account the location of AAA positions, wartime bombing density around these locations to assess the engagement opportunities that AAA positions had, along with potential zones of fire. Additionally,  Artios analyses the post-war development and land use at the site through a detailed assessment of historic images and maps, identifying areas of low post-war development. These crucial factors directly influence the likelihood of encountering an unexploded AAA shell which may have fallen to the earth and remained undetected as UXO.

Artios is a leading supplier of impartial UXO desktop survey risk assessments and mitigation plans in the UK, covering Stages 1 to 3 of the CIRIA C681 process.

As Artios do not provide on-site mitigations at Stage 4, our clients can trust that our assessments are completely unbiased and enable them to make well-informed decisions on how best to control UXO risks to a level that is As Low as Reasonably Practicable (ALARP).