Removing the 7,000-tonne Troll Solution platform from the seabed would be challenging for any salvage firm, let alone one that’s recently gone through a merger. We reveal how the maritime services company, Ardent, succeeded where others had failed.
Ardent (previously Titan Salvage and Svitzer Salvage) had salvaged many large vessels in its time, including the Costa Concordia, which made the headlines when it capsized off the coast of Italy in 2012. It was also the company that managed to finally remove the wreck of the New Carissa in 2008, nine years after it ran aground on the Oregon coast.
But as any of Ardent’s operations team would tell you, every salvage project is different. And the Troll Solution platform in the Bay of Campeche was no exception. Henry Chan, Communications Manager for Ardent, explains.
“We’d decommissioned jack-ups [mobile platforms that can raise their hull over the surface of the sea] before, including the West Atlas – but it was intact, so it was still on the surface of the sea,” he says. “The Troll Solution jack-up was completely underwater and partly submerged in mud. This meant we had to design new equipment, as well as use existing equipment in unconventional ways.”
The result was the biggest wreck removal in the industry in 2016 – and one that showed Ardent as a force to be reckoned with.
How ardent got involved with salvaging the Troll Solution platform
The Troll Solution is a self-propelled, self-elevating unit that’s a jack-up, oceangoing vessel, heavy lift crane and offshore accommodation platform all in one. In May 2015, the platform had been carrying out maintenance work on the wellhead platform CAAN-A, in Mexico’s Bay of Campeche, when one of its legs failed. Two workers died and dozens were injured in the accident.
Various attempts to r e-float and salvage the platform failed and it finally sank to the seabed at a depth of around 30 metres. It came to rest just two metres from the live CAAN-A wellhead platform.
It was then that Ardent was invited to tender for the task of removing the wreck. But once it had been selected as the sole contractor, the company couldn’t begin the salvage operation straight away. First, it had to marshal its key subcontractors, mobilise equipment and even develop some specialist equipment of its own.
One of Ardent’s subcontractors, a Dutch firm called Conquest Offshore, provided an MB-1 crane barge – one of the vessels used on the Costa Concordia. The barge measures 446 foot by 118 foot and can lift up to 1,400 tonnes. Another company, TGS, supplied the 1,000-tonne hydraulic wreck grab on board. There were also two smaller material barges, several tug boats and a DPII DSV vessel.
Workers lived on board the Conquest MB-1, which could accommodate up to 60 people offshore, and an on-shore team meant Ardent could operate a shift system.
The challenges of salvaging from the seabed
If, like the West Atlas project, the platform had still been on the surface, the salvage team could have lowered its legs and towed it away for dismantling. But the fact that the wreck was on the seabed presented some unique challenges – and one Ardent had to be inventive to overcome.
A key challenge was lack of space. “Ordinarily, we’d use chains or diamond cables to push- or pull-cut the deck house into pieces we could lift,” explains Shelby Harris, Ardent Americas Operations Director. “But a push-cut involves building a large framework around the platform, which we couldn’t do because it was so close to the live wellhead. Obstructions also meant that we couldn’t bore the tunnels into the seabed that we’d need for a pull-cut.
“We also needed guillotine cuts to section the hull, but industry-standard guided guillotines only work on the surface. So we took a different approach: one that was completely tailored to the job in hand.”
Ardent’s naval architects and salvage masters put their minds to the second problem and designed a guided guillotine that could work with precision underwater. It was this proprietary tool that cut the hull into 31 pieces. To cut the deck house into six sections, the salvage team used existing equipment – the Ardent chain pullers – in an unconventional way. The Conquest MB-1 barge was then able to lift all the pieces from the seabed to the surface for removal from the site.
It’s a reminder of just how big this project was that each of these pieces weighed between 250 and 800 tonnes. Throw in the fact that the weather in that part of the world can be inclement, to say the least, and completing this wreck removal was a very impressive achievement.
A merger that plays to the strength of both companies
Ardent’s aim is to bring the salvage mind set to the oil and gas industry. So, removing the Troll Solution platform was a great project for the company to do.
“Starting only one year-plus after Crowley Maritime Corporation and Svitzer merged their salvage companies to create Ardent, it gave us a great opportunity to show how strong we are together, and how well we can bridge the maritime and oil and gas industries,” says Chan. “And having completed this wreck removal successfully, we’re confident of two things: that we absolutely have what it takes to take on equally big and challenging projects; and that we’re right in our strategy to move into the field of decommissioning.“
As our CEO, Peter Pietka, has said: ‘We look forward to more challenges and collaboration with our partners in the offshore industry in the near future.’
David Smith has been working with Ardent (then Titan Salvage) for over 20 years advising the company on the liabilities associated with carrying out salvage operations like this one and where to place those liabilities in the insurance market.
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For more information contact David Smith, Deputy CEO of Marine on + 44 (0) 207 466 6663 or email email@example.com