Heating of cell towers and guy wires
This prevents hoar frost and icicles from forming on guy ropes
Radio masts for receiving and transmitting radio and television frequencies are often erected as slender tubular masts with a diameter of around 2 metres and a height of up to 250 metres. The antennas required for reception and transmission are housed in protective cylinders on the mast. To stabilise the entire radio mast against potential wind loads, it is secured by guy wires. In most cases, the guy wires are anchored in three directions, each offset by 120 degrees when viewed from a bird’s-eye perspective. Guy wires often need to be fixed at different heights to ensure the tower is sufficiently stable. For each level, three such guy wires are attached around the mast at angles of 120° each. They are usually anchored in the ground with solid concrete foundations.
Weather-related environmental conditions, such as high humidity and sub-zero temperatures, can lead to the formation of large areas of hoar frost and icicles. If these fall as a result of strong winds, they pose a significant danger to people and neighbouring buildings. The use of electric trace heating prevents the formation of hoar frost and thus ensures maximum safety.
Electrical heat tracing to prevent hoar frost and icicles
To prevent the formation of hoar frost or icicles in damp and cold weather conditions, thereby reducing the risk of accidents for pedestrians and motorists and protecting surrounding buildings, the guy wires on radio masts must be heated. A variant of the ‘EL-Rail’ fixed-resistance heating cable is used for this purpose. In this case, it consists of nine resistance heating cables connected in series, which are insulated against moisture with fluoropolymer. The heating cable is mounted directly onto the guy wire. Thanks to the measurement and control technology employed, the heating is controlled precisely and individually. The system offers high performance and has been operating trouble-free and with minimal maintenance for a decade.
Depending on the mast structure and climatic exposure, self-regulating heating cables may also be considered as an alternative or supplement to fixed-resistance solutions. The design and installation of a heating system for guyed radio masts presents a number of demanding technical challenges that require specialist expertise. A key concern is the prevention of high-frequency interference (HF interference): The heating cable must be designed and laid in such a way that it does not act as an unintended antenna or generate electromagnetic interference that could affect the radio or television signals transmitted by the tower. This requires careful cable selection, shielding measures where necessary, and close coordination with the tower operator and the regulatory authorities responsible for radio frequencies. Equally important is the assessment of structural integrity.
Key facts
- Moisture-resistant
- Structural robustness
- Durable and virtually fault-free
- Low maintenance
- High performance
The additional weight of the heating cable, its fixings and the associated junction boxes and cable ducts must be factored into the structural analysis of the tower – including the dynamic wind loads acting on the guy wires fitted with the cable. eltherm works closely with structural engineers and mast manufacturers to ensure that the installed system does not compromise the load-bearing capacity or fatigue life of the guy wire system. All these factors make mast de-icing one of the most technically demanding applications in the field of electric trace heating.
FAQ
If hoarfrost or icicles are dislodged by the wind at a certain height and fall, they can cause personal injury and damage to buildings. Vehicles in the vicinity may also be affected. To prevent this, electric trace heating systems are installed along the guy wires.
To prevent hoarfrost and icicles from forming on guy ropes in the first place, the guy ropes must be heated. Thanks to the resistance heating cables used, high humidity and sub-zero temperatures are no match for them. Our ‘EL-Rail’ resistance heating cable heats the guy ropes – the measurement and control technology used determines the right time to activate the heating.