Whatever floats your boat! World’s biggest semi-submersible lifts an entire cruise ship out of the water so it can be taken for repairs in stunning 12-hour operation
- The £185 million BOKA Vanguard is the world’s largest semi-submersible dry dock and can carry large ships
- Crew on board the BOKA Vanguard can flood its ballast tanks sinking the deck 52 feet below the surface
- Sinking deck allowed crew on the 345-metre Carnival Vista cruise ship to drive into the BOKA Vanguard
- After emptying the ballast tanks, the BOKA Vanguard carried the Carnival Vista back to port for repairs
This amazing footage shows the world’s largest semi-submersible boat taking a 4,000 passenger cruise ship out of the water so engineers can perform repairs – without the vessel having to find a dry dock large enough to accommodate it.
The BOKA Vanguard was commissioned by the owners of the Carnival Vista cruise ship which had technical difficulties and needed urgent repairs. However, as the cruise ship was in the Bahamas, it was having difficulty finding somewhere it could be repaired and faced a long period out of service.
Instead, the massive semi-submersible flooded its ballast tanks to sink its deck allowing the 345-metre cruise ship to position itself inside the hull.
The BOKA Vanguard, pictured, is the world’s largest semi-submersible dry dock capable of carrying a cruise liner
A dug is used to pull the Carnival Vista, pictured into position inside the hull of the BOKA Vanguard, pictured
The BOKA Vanguard can flood its ballast tanks, sinking its deck more than 50 feet before the surface, allowing the 345-metre Carnival Vista to pull into position for lifting out of the ocean
The BOKA Vanguard then emptied its ballast tanks, lifting the cruise liner out of the water before taking her to port where repairs could be completed.
According to Maritime Executive, it took 12 hours for the BOKA Vanguard to recover the massive cruise ship.
With speeds of up to 14 knots (16 mph) while unloaded the ship can still reach up to 13 knots (15 mph) when carrying an oil rig or similar cargo.
When it reaches its destination, the Vanguard then submerges again before pulling away.
The vessel can also act as a floating dry dock which allows other ships and floating oil rigs to be raised from the water for maintenance or inspection without being towed and taken out of service for months.
In the summer of 2013 it was used as a dry dock for the Semi-submersible drilling platform Noble Paul Romano when there were no dry docks big enough for the rig in the Grand Harbour of Valletta off the coast of Malta.
The watertight deck allows water to flow over the deck safely and, when submerged, the deck lies up to 52 ft (16 metres) below the surface.
In a 12-hour process, the BOKA Vanguard pumps out its ballast tanks lifting the massive cruise liner from the water
The Vanguard is valued at $240million (£184.5million), and was built by Hyundai Heavy Industries in 2011 before being christened in November 2012.
Large steel sheets were made in a factory before being transported to different construction yards to be prepared for the ship.
They were then shipped to a building dock, where the Vanguard started to take form.
The ship is powered by four main engines driving two controllable pitch propellers (CPP) and, situated to the side of the deck, The Vanguard has a bridge, lifeboat area and living quarters capable of housing a crew of 40.
The vessel was designed by Dutch holding company Dockwise who were previously famed for being the brains behind the Blue Marlin, another semi-submersible heavy lift ship, which is now the third largest of its kind.
And it was almost used to bring the Costa Concordia to an Italian salvage yard in October 2013. The cruise ship ran aground and overturned off Isola del Giglio, Tuscany, in January 2012, killing 32 people.
But, even though a £23million ($30million) deal with Royal Boskalis Westminster was announced, the ship was refloated and towed to be scrapped in Genoa in July 2014 instead.
Once safely onboard, the BOKA Vanguard can take the Carnival Vista to port for repairs to be completed
The Carnival Vista developed technical problems while in the Bahamas and there was no suitable dry dock available for the vessel, which can carry 4,000 people on a cruise