1966 saw security at Rugby Radio Station greatly increased. A 12ft high fence (around 5 miles long) was erected around the whole of the ‘A’ and ‘C’ (Main Building) site. A further inner fence of the same construction was also added.
Motorised gates were fitted on the outer fence, with gatekeeping staff operating them during working hours. Security lighting was installed at all 820ft mast and stay bases. Parts of the ‘C’ Building which housed the transmitters were modified to make them a separate, more secure area. The transmitter staff were now isolated from the external staff and even had their own mess room within the Transmitter Hall.