The station's studio equipment was fairly standard for the time, consisting of a pair of turntables, a microphone, tape decks and a mixer. Whereas most radio stations played jingles and commercials from cartridges, City used reel-to-reel. In addition to the usual music programming, subsidised by Dutch and American evangelical shows, City also had the only comedy show on pirate radio - The Auntie Mabel Hour, a recorded programme in which the DJs acted out comic sketches and sang parodies of contemporary songs. Some of the show's material seems to have been stolen from The Goon Show and Round the Horne. Another novelty programme was The Anti-City Show, which invited listeners to send letters and reel-to-reel tapes of complaint about the station. It soon became a forum for listeners' complaints about anything that annoyed them.
The Port of London authority had placed wind and tide gauges on the isolated North tower, and often complained that Radio City's signal was interfering with the gauges' radio link to the mainland and potentially placing shipping at risk. Interference with official communications was a commonly-cited reason for the pirates to be banned, but Radio City was eventually to provide the Government with a much more compelling reason for their closure.
In September 1965, merger talks began between City and Radio Caroline South. A transmitter was delivered to the fort, intended to be used by Caroline when it jumped ship. The merger plans collapsed, and the transmitter was never paid for. Calvert then began discussions with Radio London regarding a merger, in a new venture called UKGM (United Kingdom Good Music).
In the early morning of June 20, 1966, a business associate of Calvert, Major Oliver Smedley (who claimed ownership of the transmitter), sent a group of men to take possession of Shivering Sands. That evening, Calvert visited Smedley's home and in the ensuing scuffle was shot by Smedley. The police were called and Smedley was charged with murder. Smedley was later acquitted on grounds of self-defence.
The killing spurred the Government into legislative action shutting down offshore pirate radio stations, passing the Marine Broadcasting Offences Act.
The 1975 rock music film Flame (AKA Slade in Flame), starring the band Slade, includes a scene in which the fictional rock band Flame visit Radio City for an interview, only to be airlifted to safety when the station comes under attack. It is later implied that the attack was staged by the band's unscrupulous manager in order to drum up publicity. The fictional attack was inspired by the actual 1966 boarding party; some of the actual news footage of the boarding is later seen on a fictional television news report.
Exterior shots of the visit were actually filmed on and around Shivering Sands, with the actor/musicians having to climb the actual ladders used by the Radio City DJs and suffering vertigo in the process. For the airlift scene a helicopter actually landed on the roof of one of the towers, but was not big enough to carry all of the actors, so they all had to enter on one side of the aircraft and then exit out of shot on the other.
The film crew hung a large Radio City banner on one of the towers, which was bigger and more professionally-made than the actual crudely-painted sign used by the station.
In one respect the film was not able to be authentic: the fort has no antenna. The original Radio City antenna mast had been dismantled in 1967. It was not possible to build a replica because of its huge size, and contemporary special effects techniques were not up to the task of replicating it.
Interior scenes were filmed on a soundstage. The interior dimensions of the tower are authentic, but the studio appears more professionally-equipped than the real one. In particular, the fictional studio contains cartridge machines which were never used by the real Radio City. The Radio City DJ was played by real-life DJ Tommy Vance, who was actually working on Radio Caroline in the 1960s.
In real life any interviews on the pirate stations would have been taped on land rather than exposing musicians to potentially hazardous (and expensive) sea crossings.