With thousands of nearby trees to choose from, you’d think an electricity pole would be the least favoured option for a peckish woodpecker.
Yet when woodpecker holes were discovered drilled into a 22.5m tall wooden pole carrying electricity cables over a railway line, the bird’s bizarre behaviour took a far more serious turn.
But what started off as some pesky damage to two railway crossing spliced wooden poles, has led to an innovative solution.
Two specially designed Protean steel poles have now been erected at the side of the main Liverpool to Manchester railway line in an operation that required smart-thinking to ensure the structures remained cost effective and met the demands of the local landowner.
The project at Ewe Tree Farm, Hailewood, Liverpool, on the BXD line (Gateacre-Halewood) was overseen by Senior Project Engineer Eddie Rigby. He explained: “A contractor spotted a woodpecker hole three quarters of the way up the pole. There was no way of knowing how much rot is inside the pole, and there were obvious safety issues because of the location.
“The kind of pole – two wooden poles joined together – are old specification now. One option was a replacement steel lattice tower,” explained Eddie, “but while the landowner didn’t mind the pole he definitely didn’t want a tower.
“Another option was to cable underground, but that would have cost a couple of million pounds.
“We needed something that could do the same function as a pole, and the only option available had never been tried before in the UK.”
British Power International, which produces Protean steel poles, was called in to create a design. The height of the structures – necessary to clear the railway below - meant special attention had to be paid to ensuring the foundations and structure could cope with the wildest of weather conditions.
The work was carried out in early March, with the 132kV Ops team opting carrying out the construction task themselves, overseen by BPI. It involved closing the railway overnight, with crews joining sections of the poles together horizontally before they could be hydraulically raised to their final position and bolted in place. The screw type foundations alone stretched 12m underground.
The result is a galvanised steel pole which has just a small footprint on the landowner’s property – and the farmer can even choose what colour he’d like it painted.
Eddie, now a redesign engineer, added: “There are thousands of trees in that area. We’ve no idea why woodpeckers would pick an old electricity pole to feast on. But they did!”