This week marks the 50th anniversary of the re-floating of the world’s first great ocean liner.

Designed by Isambard Kingdom Brunel, the SS Great Britain was the first iron-hulled, propeller-driven steamship when she was launched in Bristol on July 19 1843.

She was the largest and most efficient passenger ship in the world, widely referred to as “the greatest experiment since the Creation”.

Brunel was one of the most ingenious and prolific engineers in history, building 25 railway lines, more than 100 bridges and three ships.

The SS Great Britain was the most experimental steam ship of her time and revolutionised travel and set new standards in engineering, reliability and speed.

By 1970 she lay derelict in the Falkland Islands.

A record-breaking salvage operation saw her become the largest ship ever re-floated onto a pontoon and the 8,000-mile journey to the UK was the longest salvage tow ever attempted.

When the SS Great Britain returned to Bristol after 127 years away, thousands of spectators lined the River Avon to see the homecoming as she passed under the Clifton Suspension Bridge and into Bristol, resting back in her original dry dock on July 19 1970.

The ship’s return was just the beginning of a painstaking restoration project, which now sees the SS Great Britain transformed into a popular tourist attraction.

Diver Lyle Craigie-Halkett, who was a member of the salvage team, recalls: “We always said she wanted to come home.

“So many things went well where they could easily have gone the other way and been a total disaster.”

After moving the ship into deeper water, it was now down to the team to get the SS Great Britain onto the submersed pontoon.

“As the bow of the Great Britain started to rise above the surface and as she emerged more and more, we began to realise the enormity of our achievement,” Mr Craigie-Halkett said.

“The first thing that really impressed me was this lovely sort of ‘V’ shape. She just looked so lovely like a yacht, but much, much, much bigger.

“And although all the mussels were clinging on still and dripping water, and it started to get a bit smelly, she just looked so beautiful.

“I just stood there in amazement. I shouldn’t have been surprised, but I absolutely was gobsmacked.”

The ship was then towed on the pontoon back to Britain where she was carefully re-floated at Avonmouth Dock ahead of the final journey along the Avon.

Dave Sidwell, a captain of one of the tugboats which escorted on that final journey, said he did not realise the enormity of what he was involved in that day.

“Once we got into the river proper, the tide did most of the work,” he said.

“We got to what we call Black Rock and from Black Rock we can just see the Clifton Suspension Bridge, then we can see the people all lining up on the bridge.

“And then there were people on Portway and other people on the towpath and all of a sudden they’re shouting and cheering and there were more and more people.

“There was a flotilla of small boats coming out to meet us, so we were surrounded by a few small boats, they were blowing their little horns and clapping and cheering, so it was beginning to get exciting.

“When we got into the Cumberland basin, I don’t know how many people were there – thousands and thousands and thousands – so it was getting emotional by that point.”

Mr Sidwell, who is now a volunteer at SS Great Britain, said 50 years ago the ship had captured the imagination of the public and continues to do so today.

“I think it’s just being British and we we’ve got this thing about restoring old things, anything old we seem to like to grab hold of and try to look after it – it is a British thing I think,” he added.