Welcome to Viverone, where "hotline" means safety

These are Terna's stuntmen, yet despite initial appearances, they are not risking it all! In fact, just like stuntmen, they are trained to manage and control every risk. They do not work without a safety net. But their job is certainly a long way from a monotonous nine-to-five routine. So who are they? They are a squad of 140 operatives that perform "live-line" (also known as hotline maintenance) working, i.e. on the lines or large pylons that transport electricity at high- and extra-high-voltage on the national transmission grid managed by Terna. They work without interrupting electricity flow, without stopping the current, to prevent outages and guarantee the highest possible levels of service quality. This could not be done without rigorous and demanding training, which allows them to make agile, safe movements even at 60 metres up; the equivalent of a 20-storey skyscraper.

To find out how this is possible, we spoke to 35-year-old Andrea Zanotti, who qualified as an engineer at the Politecnico di Torino university and is now a live-line working supervisor, based at the training centre in Viverone, north-west Italy, where live-line operatives refine their skills. He tells us about fifty years of history, since live-line working was authorised in Italy in the '80s. And whilst France was the first country to launch these operations, Terna has developed amongst the most highly accredited expertise across Europe. There have been a total of 110,000 operations performed since the beginnings, an average of 1,500 per year, with peaks of up to 3,000 throughout the country.

To get an idea of the stakes in this type of highly specialised work, consider a lightbulb: LED or otherwise, any bulb draws current at 230 V (the transformer then reduces it to the few volts required for its operation) from the low-voltage distribution grid. In the case of Terna’s transport grid, the voltage ranges between 132 and 380 kV, thousands of times greater. We all know that if we stick our fingers in a 230-V socket, we risk very quickly dying from electrocution, but if we touched a high-voltage cable with our feet on the ground, a few thousandths of a second would be enough. If this is the problem, albeit in rather basic terms, how can we move around hanging from a cable transporting 380 kV, unscrew and replace a bolt and then return to the ground, all in complete safety?

«Our focus is on training as risk management», explains Andrea Zanotti. «You begin with an initial 14-week course, at the end of which you receive a special certification which is a bit like a driving licence. This indicates which activities you are authorised to perform. It is issued on the basis of specific requirements set out by ministerial decree. Nothing is left to chance, everything is strictly disciplined and we work in complete safety».

At the center in Viverone, training takes place on a structure that simulates the works that will then be performed on the real lines. This isn’t just any old site but was in fact a pumped-storage hydroelectric plant at the beginning of the last century. The center is nestled amongst the mountains and the training facility sits around the old upper reservoir, Lake Bertignano. Men resembling astronauts, cocooned in Faraday suits that protect them from the electric field train and climb around, relaxed at dizzying heights.

This is how they overcome fear and gain confidence in this job characterised by strict technical procedures and protocols. Subsequent training allows them to gain increasingly specialised expertise, such as how to work from a basket with insulating arm or become a "senior operative", a figure similar to the foreman on a construction site. Experience is key: it is no coincidence that the age of operators in the 140-strong live-line squad ranges from 25 to over 60 years. «This is a great strength in our line of work», adds Zanotti. «There is a combination of the physical strength of the youngest operatives and transfer of knowledge from more senior members of the team». Physical strength is important, for example, to move 4.5-metre-long insulating rods, while experience is essential for the senior operatives that monitor operations from the ground and verify the work of those working on pylons or on lines in aluminium baskets hanging at great heights.

Everyone is dressed in orange to make their movements clearer, while insulating components are red. «It is essential, for example, that the body does not come within two metres of a 380-kV line, and this is why fibreglass rods filled with polyurethane foam are used, each of which is subject to annual certification by accredited testing centres», stresses Zanotti. «Live-line working is not targeted at resolving faults but preventing them through maintenance aimed at ensuring the grid is in perfect working order, and avoiding outages for users».

Terna inspects up to 3,000 pylons per year, on foot or by helicopter, and then classifies the points subject to deterioration. This is the basis for works to be organised. Who are the users? Large-scale power-generation facilities that issue electricity to the grid, the entire distribution grid that transports it to homes and businesses, and certain large industrial enterprises that are connected directly to the high-voltage grid. Basically, every single one of us!