We designed and procured the various component parts for this complex project including:

A bespoke TV transmission antenna system, some 16m in height; The antenna steel-work mounting and tower interface arrangements; 6” diameter coaxial feeder runs connecting the antenna to the equipment buildings on the ground below; and A fluid-filled structural damper system to sit atop the antenna and prevent potentially damaging oscillations of the tower.

In order to minimise service disruption and complete the project in a relatively short time-frame, we deployed a helicopter to lift the various sections onto the tower. Although helicopter lifts are a relatively common method for installing equipment onto buildings, masts and towers, this is the first time that the technique had been used on one of London’s major transmission structures.

The area around the site is a busy suburb of south London, so we faced the challenges of how to keep the flying time to a minimum and where to land the equipment and helicopter. We also had to address the PR issues in carrying out a high profile and highly visible activity among some crowded areas. This was all meticulously planned in advance and included negotiation with the CAA to gain the relevant approvals.

Once the new antenna system had been assembled and tested at our operations base, it was transported by road to site where the other elements were staged awaiting deployment of the helicopter. When the helicopter arrived we began by first removing the redundant Channel 5 antenna from the tower, then lifted the new structure in three sections weighing in total over 10 tonnes. This was carefully co-ordinated with our rigging teams working on top of the tower who secured the sections as they were flown in, thus building up the antenna.

Once complete we installed 3 tonnes of coaxial feeder, completed the technical testing and commissioning then handed Arqiva a fully working system ready for service as required.