Watch Rob Murphy's report
A revolutionary air-conditioning kit which has stopped Brunel's famous SS Great Britain from rusting is being upgraded.
A fan which reduces the air humidity and stops the great ship from rusting was installed 15 years ago.
Now it is being replaced with a new system which will be 30% more cost-efficient.
The ship's conservation engineer Nicola Grahamslaw said: "The set-up we've got here at the SS Great Britain is totally unique.
"It was the first project in the world to set up a climate-controlled system like this for the purposes of conserving an object.
"The fan that's there has been in place for 15 years, it's still the original one that was installed at the time. It's not often one of these gets upgraded."
The SS Great Britain was launched in 1843 by Prince Albert. It was truly revolutionary - the world's first screw-propelled, iron-hulled ship.
She was built for speed and glamour - taking passengers to New York in the height of style. But the ship's career to the Americas was short-lived and soon she was taking Britons to Australia following the Gold Rush.
The SS Great Britain was fitted as a transporter in the 1880s and made her final voyage in 1886, damaged in a storm in the South Atlantic. She then struggled to the Falkland Islands where she was used as a storeship.
The SS Great Britain was salvaged and pulled across the ocean back to Bristol in 1970.
Years of restoration followed. In 1998, a survey suggested the ship had 25 years before she corroded away and so the new, arid air-conditioning system was installed.