After months of painstaking preparation, Mirabella V has her 300ft mast stepped in Southampton. Matthew Sheahan reports from the dockside.

Tuesday December 30, Southampton Docks, 0746 and the world’s biggest sloop rig starts to rise from the quay as sunrise paints the perfect backdrop.

At just under 300ft tall Mirabella’s mast is the world’s tallest sloop rig for a boat that has already broken a world record as the largest composite structure ever built.

After months of painstaking planning the most precarious part of the stepping went without a hitch as the two giant mobile cranes working in close harmony rotated the 42tonne mast from its horizontal position on the dock to the vertical.

Dressed with all her standing rigging the huge structure was an impressive sight as it dangled over the quay, suspended from a single point. The possibility of a failure now simply didn’t bear thinking about. Just one of the genoa furling units weighs 7 tonnes (and that doesn’t include the foil), keeping this strapped to the mast as it was raised through 90 degrees was a task in itself, let alone keeping control of all the other rigging and components. Little wonder that the maximum wind speed for the stepping operation was set at 15knots at masthead height.

By 10am the mast was ready to be craned out over the water before being suspended over Mirabella V’s deck. From there the next operation was to drag the two massive forestay units forward ready for connection to the deck, while at the same time balancing the rig in the fore and aft plane. Pulling around 15tonnes of equipment forward is a delicate operation that once again requires careful planning and execution.

Assuming the remainder of the exercise goes as smoothly as the first stages have, by the end of the day Mirabella V will be well on track for her official record as the world’s largest sailing sloop.

All this just yards from the world’s biggest cruise liner, the Queen Mary II that is undergoing her final preparations at Dock 4 for her official naming in the New Year.