Onlookers on the banks of the Forth Estuary were treated to a spectacular sight today as one of the most remarkable marine operations ever undertaken on the river unfolded.

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 the 200 metre long cargo barge, the Iron Lady, on Saturday.

The following morning the Pioneering Spirit, which was specifically 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 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 transit below the iconic 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 the Port of 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, Chief Operating Officer at Forth Ports, 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.”