Pioneering Spirit: Spectacular sight of largest construction vessel in Forth
Onlookers were treated to a spectacular sight at the weekend as the world’s largest construction vessel took part in a major marine operation in the Forth.
In an operation spanning two days, Allseas’ Pioneering Spirit – at 382 metres long and 124 metres wide the largest construction vessel in the world – transferred its huge cargo of a topside drilling platform onto a 200-metre-long cargo barge, the Iron Lady, on Saturday.
And yesterday the Pioneering Spirit, which was designed for the single-lift installation and removal of large offshore platforms, separated from the Iron Lady and the cargo barge was towed clear.
The Pioneering Spirit then set off once more for the North Sea.
With its cargo safely secured to its deck, the Iron Lady was then towed westwards yesterday afternoon along the River Forth by Forth Ports’ tugs the Craigleith, Inchkeith and Fidra in a carefully planned operation to ensure the structure had sufficient clearance to pass below the Forth Bridge, then the Forth Road Bridge and finally under the Queensferry Crossing, before berthing alongside at the Port of Rosyth.
It is scheduled to remain moored at Rosyth for around six weeks before being towed back east along the river to the Energy Park Fife in Methil, where its cargo will be unloaded for decommissioning.
Stuart Wallace, the chief operating officer at Forth Ports, said that watching the Pioneering Spirit travelling along the Forth would have been something memorable for onlookers.
He said: “It was a truly spectacular sight to see this huge vessel offloading its cargo within our deep water on the River Forth.
"Watching the Iron Lady towed safely into the Port of Rosyth by our tugs against the backdrop of all three Forth crossings was a bit special too.
"However, we can expect to see sights like these more and more frequently as oil and gas decommissioning projects from the North Sea and elsewhere gather momentum.
"The Forth estuary’s deep and sheltered water, alongside the decommissioning facilities on both the River Forth and River Tay, make this an ideal location for operations like this weekend’s.”
The idea of creating a vessel that could lift entire platforms was first discussed by Allseas technical director WP Kaldenbach around 1987, but it would be 23 years before construction began at the South Korean shipyard Daewoo Shipbuilding & Marine Engineering Co in June 2010.
Pioneering Spirit sailed from Daewoo in November 2014 and arrived at the Maasvlakte 2, in Rotterdam, for completion and commissioning on January 8, 2015.
After the topside lifting system was installed she left Rotterdam on August 6, 2016.
The boat is the world's largest vessel in terms of her gross tonnage (403,342gt), breadth (123.75m) and displacement (1,000,000 tonnes).
In July 2019, Allseas announced it planned to upgrade the lift capacity from 48,000 tonnes to 60,000 tonnes to enable the removal of the Statfjord A platform in the North Sea.