Richard Sabin, who has curated the marine mammal collection at the Natural History Museum for 24 years was inspired to become a marine biologist after visiting the whale in the mammal hall when he was just 10 years old.“When I think about the ten year old me walking pars the dinosaurs and straight into the mammals hall to see the whales I am feeling as excited about this as I was then,” he said. “I honestly think we’ve created something unique.“I think when people see that enormous skeleton, in that wonderful space, any critics we have will be silenced and children over the next twenty to thirty years will come to see the whale as the new iconic specimen of the museum.” The blue whale is lifted into position at London’s Natural History MuseumCredit:BBC “And there is a big health and safety element. Getting it down safely and getting it up so it’s safe so that’s keeping me up at night.”Once all the bones were safely in the hall they were rearticulated and attached to the Victorian girders in the roof with steel wires to be pulled into place by a team of steeplejacks hanging from the rafters.But as the whale was lifted into a position, a sharp cracking noise echoed round the hall and the whole skeleton shuddered as a bolt attaching the vertebrae sheared off.Mrs Cornish added: “We were literally whale watching for hours, and there was a definite sense of nervousness when the bolt snapped. But their is a tremendous feeling of achievement now it is finally in place.“It’s taken the best part of three years. I feel emotional every time I walk under it and I can’t wait for the public to see it.”Horizon: Dippy and the Whale will be shown on July 13, BBC Two at 9pm. Hintze Hall reopens to the public on Friday 14th July. But unlike the dinosaur, which stood statically in the centre of the hall, the whale has been articulated to dive down from the rafters, tail flipping up and mouth agape as if plunging through a school of fish or scooping up visitors in its giant jaws as they enter the museum. The project, which has never been attempted before, was so challenging it required a huge team of conservationists, structural experts, riggers and even engineering experts RCI, who built the skeletons for the Tyrannosaurus rex in Jurassic Park. Blue whales are the biggest creature ever to have existed on Earth After decades in storage, she first went on display in 1934 in the new mammals gallery, where she has remained untouched ever since. Few visitors notice the whale is there because she is largely hidden by a huge replica of a blue whale which hangs beneath.Conservationists had to remove 81 years worth of dust before taking the 82ft skeleton apart piece-by-piece, carefully packing it, labelling it and repairing cracks with putty so it was strong enough to hang from the girders in Hintze Hall. The whale is replacing Dippy the Dinosaur which is going on tour Credit:Getty A nail-biting three-year project to hang the enormous skeleton of a blue whale in the place of ‘Dippy the Dinosaur’ at London’s Natural History Museum almost ended in disaster when a crucial bolt sheared off mid-hoist, a new BBC behind-the-scenes film has revealed.As the 4.5 tonne skeleton hung precariously in mid-air, emergency welders were called in to reattach the huge vertebrae to a massive steel frame to prevent the bones from slipping again.The heart-stopping moment is captured in special episode of BBC Two’s Horizon, narrated by Sir David Attenborough, which has followed the astonishing endeavour since 2014.Blue whales are the biggest animal that has ever lived on Earth and the huge skeleton was the overwhelming choice to replace Dippy, the massive diplodocus cast which has delighted visitors since 1979. The erection of the giant jigsaw took more than three weeks Credit:BBC The Horizon team travelled back to Wexford in Ireland, to find the original site where the whale washed up in 1891. The juvenile female, who was probably between 10 and 15 years old was still alive when she beached, but whale meat and oil were rich commodities at the time and locals wasted no time in harpooning the stricken creature to death.Her blubber was sold for oil and her meat sent to a dog food factory, but canny businessman William Armstrong contacted the Natural History Museum to see if they would take her skeleton, eventually selling her bones for £250. Riggers hoist the skeleton into place Credit:BBC Lorraine Cornish, the museum’s Head of Conservation, said: “When we put it back up and we have the public wandering underneath it we really don’t want bits of it to drop off onto them.“Some parts were missing completely. When the girls were cleaning the right flipper it was looking a bit suspicious as if the surface wasn’t quite the same as if it should be if it was natural bone, and after a few tests we found out that it was mainly plaster and so I think everyone was surprised about that.”The team was also dismayed to learn that the whale’s head was so big it could not fit through the Grade 1 listed doorways of Hintze Hall. They were forced to mount it on a giant steel frame and tip it onto its side to push it through the front doors where it was reunited with the rest of the 221 bones. Speaking during the tricky move, Jennifer Flippance, the Project Manager, said: “We’re doing a lot of things we’ve never done before, so it gives you a sense of nervousness. Want the best of The Telegraph direct to your email and WhatsApp? Sign up to our free twice-daily Front Page newsletter and new audio briefings.