Attempts to prevent drones from delivering drugs and weapons to inmates in UK prisons are being hampered by the crumbling walls of Victorian-era facilities. Prison governors have reported that plans to install tougher netting and window grilles have been set back because the old brickwork cannot support the extra weight.
Structural Challenges at HMP Pentonville
Recent efforts to fix anti-drone netting at HMP Pentonville in north London were stalled after engineers discovered that the bricks were too soft. The prison, built in 1842, uses London stock brick, which is known for its softness, and the mortar is aged, making it difficult to secure ropes and meshes. Sources said that steel brackets and supports must be designed to share the load, a complex task in confined spaces.
Surge in Drone Incidents
Charlie Taylor, the chief inspector of prisons for England and Wales, stated last month that the Prison Service has “ceded the airspace above many of our prisons to serious organised crime,” creating a “national security threat.” The number of drone-related incidents in prisons has risen by over 1,000% in four years. In the year to March 2025, 1,712 drone incursions were recorded, up from 138 in the year to March 2021. This figure excludes undetected drops.
Gang members now fly packages directly to cell windows, where inmates retrieve them with hooks. Inspectors have found packages weighing over 15kg, containing items such as weight-loss drugs, hair-loss treatments, anabolic steroids, and fast food.
Preferred Countermeasures
Nets fixed to walls can snag drone propellers, while window grilles prevent prisoners from pulling packages inside. However, Tom Wheatley, president of the Prison Governors Association, said such measures are not being introduced quickly enough due to structural concerns: “In some prisons, there are concerns that such measures put extra weight on the walls and the weight can be too much for the buildings.”
Government Response
Ministers are planning to roll out more anti-drone netting. David Lammy, the justice secretary, visited the Ukrainian military in January to learn about adapting battlefield tactics to combat drone use in jails. The government has promised £10 million for anti-drone measures, and a Prison Service spokesperson denied that walls are too weak, stating: “All improvements to prison security are tailored to individual jails, following detailed structural assessments to ensure they are safe and effective. We have invested over £40 million to fund a range of physical security enhancements.”
In March, a gang using drones to smuggle drugs into Pentonville and other London prisons was jailed. Inspectors had previously called for an overhaul of security in Victorian prisons after inmates at HMP Winchester dug through cell walls with plastic cutlery in 2024.
