Changing every single one of Sheffield’s 68,000 street lights is a complex business - it’s not just like changing a lightbulb.
The upgrading of the city’s 68,000 street lights to new LED models is the only one of its kind in the country - with San Franciso having a similar approach.
That’s according to the man in charge of Sheffield Council’s ambitious project to replace every single street light in the city with new LED bulbs.
The scheme is the only one of its kind in the country and similar to one in San Francisco, California, USA.
The project will be completed by 2017, and so far 24,000 lights have been replaced in about two years.
But it has not been without its problems.
Residents have complained about long delays, and open holes on their streets, while South East Sheffield MP Clive Betts publicly questioned the performance of council contractor Streets Ahead.
Now council bosses have shed more light on the complex work going on behind the scenes.
Each street has a bespoke lighting scheme designed to meet national standards, which means some street light columns may be removed and extras installed.
Ian Kirby, technical manager for Sheffield Council, said: “People view lighting columns like Marmite - they like having one near their house for security or they hate it blocking their view.
“We do try to locate them at boundaries of properties where possible.”
Lights have to be designed around standards and visible structures such as walls and houses.
And sometimes records about their location can be out of date.
This means teams are in the dark until digging begins, and if cables are found to be faulty, deeper or in a different location than expected district network operators must investigate.
Some cables have been encased in concrete since World War Two.
“This is sometimes why some holes are open for a little bit longer than we would like,” said Graeme Symonds, project director.
Safety barriers are put up around holes but can go missing.
The network operators have to approve the location of every street light and Amey has employed two of staff to speed up the process.
The LED lights come in 69 different designs and the production team must work six months in advance as they take three months to produce.
Moving a new lighting column is difficult without impacting on the entire street.
Graeme said the zonal approach - where one area of the city is given new lights and road surfaces at the same time - had made things more ‘challenging’ but most issues had been resolved.
He added: “I never thought it was this complex.
“Joe Public might equate it to changing a lightbulb at home, it’s not. We are restricted in so many ways above and below ground.”