IT was a tall order but an Oldham company with a head for heights wasn't fazed by the task of removing a world famous piece of London's skyline.

Delta International, based in Wrigley Street, have just finished dismantling the four 51 metre high chimneys at the capital's iconic Battersea Power Station as part of a multi-million pound re-development which will eventually comprise shops and office space.

The removal of the chimney pots - immortalised on the cover of Pink Floyd's album "Animals" which shows a pig flying over the power station - proved to be a skilled and time consuming task due to serious corrosion and decay since they were decommissioned in the early 1980s.

It took 250,000 hours over a three year period to complete the pain-staking work.

Known as "working at height specialists", Delta's experienced team used a self-climbing platform technique - designed in-house specifically for the demolition of tall structures such as chimneys, cooling towers and silos - to enable their workers to carefully dismantle each chimney piece by piece.

They are currently using a similar bespoke technique to dismantle a chimney at Sellafield nuclear plant and have recently removed and replaced an entire roof of a major industrial unit while work continued uninterrupted beneath them.

Delta's technical director, Nigel Matthews, played an instrumental part in designing the bespoke self-climbing platform allowing engineers to dismantle and remove each of the four concrete chimneys with no lost time accidents or delays.

The company's vast experience and knowledge was invaluable in putting forward engineering design solutions for a site that was not without significant challenges.

Built in the 1930s and 1950s, the chimneys were in a significant state of disrepair, all of which had to be taken account of when proposing a viable solution.

The self-climbing platform slowly rose up to the top of the chimney while simultaneously installing a safety ladder providing a primary access route to the platform. Once it reached the summit of the chimney, a series of temporary beams were fixed to the top of the stack allowing the platform to reach the summit.

At the top a scaffold was installed across the chimney opening allowing for a platform to be suspended on the inside. This allowed for essential stabilisation work to be carried out on the internal tiles of the chimney

Nigel explained: "As skilled and experienced engineers working at height on complex projects presents little difficulty for us but Battersea Power Station had on-site challenges that no-one could have predicted.

"One such challenge was discovering that. We had to come up with a solution quickly and one that would not cause any delays or increase costs on the project."

The chimneys - which have now been re-constructed as replicas - were removed using specialist equipment that could penetrate the concrete and dismantle it steadily and the debris was sent down rubber chutes.

There were also teams working beneath the Delta deconstructors so that had to be taken into account when disposing of the debris.

Delta operations director, Paul Bentley, said: "Health and safety is always paramount, particularly when working at such heights but knowing that we had people working below us for whole duration of the project meant extra vigilance. And we achieved it. Over the three years it took to complete using 250,000 man hours, we had no lost time accidents which was a major success for such a complex project."

Delta International - which was established in 1977 as a steeplejack company - has more than 40 years of experience of working at height on complex projects.

Nigel added: "This significant expertise proved invaluable on the Battersea Power Station project and we are proud to have been part of the restoration work for such an important London landmark.

"While the type of at height project has changed over the years, skills, expertise and experience remain a vital component."