Construction at the controversial Radlett Strategic Rail Freight Interchange (SRFI) is entering a high-tech monitoring phase. Developer SEGRO has notified authorities that it will begin regular drone surveillance over the 1,000-acre site. SEGRO has assured local interests that the flights are a construction aid. However, the move comes against the backdrop of years of bitter local opposition. For the next two to three years, drones will become a regular presence in the Hertfordshire skies.
SEGRO has confirmed that flights will take place at least twice weekly to monitor construction progress, conduct site inspections and maintain detailed documentation of the extensive earthworks and infrastructure build. The developer emphasises that all operations are cleared by the Civil Aviation Authority and are being coordinated with emergency services to prevent unnecessary reports. The decision to formalise drone activity also carries a security dimension. The project has been the focus of one of the longest-running and most acrimonious planning disputes in UK rail freight, led by the campaign group which, at the height of its resistance, called itself “St Albans Fight the Freight”.
An end to the legal line
The Radlett SRFI will serve the Hertfordshire and London areas and, in fairness, can hardly be described as a wilderness development. It bounds onto the neighbouring M25 London orbital motorway and the Midland Main Line in an area of high population density. These factors may conversely make the case for such a facility more pressing, a view unlikely to be shared by campaigners.
The move to high-frequency surveillance follows a decisive legal turning point. In October 2024, the English High Court rejected an appeal regarding the sale of the former Radlett Aerodrome. Campaigners had argued that the land sale by Hertfordshire County Council was unlawful under the Metropolitan Green Belt Act 1938, asserting that the land should have remained open space in perpetuity. With the High Court’s dismissal, the legal campaign effectively ran out of options. Activists acknowledged that further challenges would require upwards of £100,000 (about €117,000) in funding, which the group did not possess. While the organisation continues to exist as a community “watchdog” monitoring planning conditions, the path for SEGRO to implement the SRFI is now legally clear.
The Christmas bridge
Physical progress is already visible. A major milestone was achieved during the Christmas 2024 blockade when Network Rail installed a new road-under-rail bridge. The operation required a full closure of the Midland Main Line to slide the structure into position. The bridge is a critical component of the scheme and will ultimately be adapted to provide the dedicated rail access lines branching from the MML into the terminal in a south-to-north-to-south horseshoe formation.
The development, once completed, will provide 335,000 square metres of sustainable logistics space. However, under the terms of the planning consent, none of these units can be occupied until the rail terminal is fully operational. This “rail-first” requirement is intended to ensure the project delivers on its promised modal shift.
Connectivity and gauge challenges
Radlett is positioned as a strategic hub for the London market, intended to facilitate the movement of goods from major ports including London Gateway, Southampton and Felixstowe. Current plans indicate that trains will enter and depart the terminal from the south, connecting with the wider London rail freight network.
However, the Midland Main Line presents an ongoing technical constraint. The route is not currently cleared to W10 or W12 gauge, meaning operators must use low-platform wagons or reduced-height loading. This does not preclude high-cube containers, but it does reduce the number that can be carried within standard train length limits. While SEGRO and Network Rail are examining potential gauge enhancements to the south of the site, the terminal is being marketed as an open-access facility from the outset, available to any regional business seeking to transfer freight from road to rail.
A landscaped compromise
In an effort to mitigate the impact on nearby communities, SEGRO’s master plan includes a substantial environmental component. Approximately 600 acres — 60% of the total site — will be dedicated to a country park featuring managed woodland and conservation grazing. The scheme also includes a new relief road for the village of Park Street to address projected increases in heavy goods vehicle traffic.
Freight services may still be several years away, but drone flights will now become a routine feature over the former wartime airfield. The site lies within an area under intense development pressure, and its complex gestation illustrates the challenges of delivering nationally significant infrastructure within the UK’s Green Belt. For SEGRO, the “eye in the sky” is a construction management tool; for elements of the local community, it signals that the dispute has moved from the courtroom to the construction phase.