A historic British engineering firm that supplied gearboxes for the Spitfire fighter during the Battle of Britain has been acquired by a German defence manufacturer. David Brown Defence (DBD), based in Huddersfield, Yorkshire, was taken over by Renk Group, a Frankfurt-listed company with €4.7 billion in revenue, in a deal reported to be valued at up to £190 million. The transaction marks a significant development in the defence manufacturing sector, as DBD continues to serve as a key supplier to the British armed forces.
Founded in 1860, David Brown Defence has a long-standing legacy in military engineering. Its products have equipped British naval and land forces for over a century, including providing transmission systems and gearboxes for the Royal Navy’s Astute-class submarines and the next-generation Dreadnought-class vessels that are central to the UK’s nuclear deterrent. The company also supplies equipment to Royal Navy warships and the British Army’s Challenger tanks and Boxer armored vehicles.
The buyer, Renk Group, with headquarters in Bavaria and operations across six countries including the UK, is known for manufacturing gearboxes for German and U.S. naval fleets. It already owns Horstman Defence Systems near Bath and employs approximately 4,400 people. Renk highlighted that the acquisition brings unique expertise in submarine gearboxes designed for low noise and vibration, technology deemed essential for future submarine platforms. The group also noted how DBD’s involvement in the Aukus submarine programme—an agreement between Australia, the United Kingdom, and the United States—fits within its expanding portfolio in naval and armored vehicle sectors. Renk sees the deal as strengthening its position within the Five Eyes defence partnership of the UK, US, Canada, New Zealand, and Australia.
The British government has endorsed the acquisition. Rupert Pearce, the UK’s national armaments director, described the deal as “a strong endorsement of the UK’s industrial base” and an important investment that underpins vital naval and land defence platforms. He added that it would enhance supply chain resilience, protect skilled jobs, and secure critical capabilities for UK forces.
David Brown Defence was sold by Stellex Private Equity, which had owned the company for three years. The firm employs around 530 people and has a notable history, having produced 10,000 gearboxes for British Army tanks during the Second World War and serving as the exclusive provider of gearboxes for RAF Spitfires. Renk’s CEO Alexander Sagel affirmed the company’s commitment to maintaining DBD’s operations in Huddersfield, stressing a long-term dedication to the UK defence industry.
The acquisition follows Renk’s historical roots as a supplier of gearboxes to tanks, warships, and aircraft during the Second World War, paralleling DBD’s own wartime legacy. The deal is expected to consolidate advanced engineering capabilities across both firms and reinforce their contributions to modern defence technologies.