A Yemeni coast guard boat sails past the FSO Safer vessel at Ras Issa port in Hodeidah province, Yemen, on May 30.

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CNN  — 

Moored five miles off the coast of Yemen for more than 30 years, a decaying supertanker carrying a million barrels of oil is finally being offloaded by a United Nations-led mission, hoping to avert what threatened to be one of the world’s worst ecological disasters in decades.

Experts are now delicately handling the 47-year-old vessel – called the FSO Safer – working to remove the crude without the tanker falling apart, the oil exploding, or a massive spill taking place.

Sitting atop The Endeavor, the salvage UN ship supervising the offloading, UN Resident and Humanitarian Coordinator for Yemen David Gressly said that the operation is estimated to cost $141 million, and is using the expertise of SMIT, the dredging and offshore contractor that helped dislodge the Ever Given ship that blocked the Suez Canal for almost a week in 2021.

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How to remove one million barrels of oil from a tanker
06:49 - Source: CNN

Twenty-three UN member states are funding the mission, with another $16 million coming from the private sector contributors. Donors include Yemen’s largest private company, HSA Group, which pledged $1.2 million in August 2022. The UN also engaged in a unique crowdfunding effort, contributing to the pool which took a year to raise, according to Gressly.

The team is pumping between 4,000 and 5,000 barrels of oil every hour, and has so far transferred more than 120,000 barrels to the replacement vessel carrying the offloaded oil, Gressly said. The full transfer is expected to take 19 days.

The tanker was carrying a million barrels of oil. That would be enough to power up to 83,333 cars or 50,000 US homes for an entire year. The crude on board is worth around $80 million, and who gets that remains a controversial matter.

Here’s what we know so far:

Why the UN has been sounding alarms about this ‘ticking time bomb’

The ship has been abandoned in the Red Sea since 2015 and the UN has regularly warned that the “ticking time bomb” could break apart given its age and condition, or the oil it holds could explode due to the highly flammable compounds in it.

The FSO Safer held four times the amount of oil spilled by the Exxon Valdez off Alaska in 1989 which resulted in a slick that covered 1,300 miles of coastline. A potential spill from this vessel would be enough to make it the fifth largest oil spill from a tanker in history, a UN website said. The cost of cleanup of such an incident is estimated at $20 billion.

The Red Sea is a vital strategic waterway for global trade. At its southern end lies the Bab el-Mandeb strait, where nearly 9% of total seaborne-traded petroleum passes. And at its north is the Suez Canal that separates Africa from Asia. The majority of petroleum and natural gas exports from the Persian Gulf that transit the Suez Canal pass through the Bab el-Mandeb, according to the US Energy Information Administration.

The sea is also a popular diving hotspot that boasts an impressive underwater eco-system. In places its banks are dotted with tourist resorts, and its eastern shore is the site of ambitious Saudi development projects worth hundreds of billions of dollars.

A complex and risky operation

The first step of the mission was to stabilize and secure the vessel to avoid it collapsing, Gressly said. That has already been achieved in the past few weeks.

“There are a number of things that had to be done to secure the oil from exploding,” Gressly told CNN, including pumping out gases in each of the 13 compartments holding the oil. Systems for pumping were rebuilt, and some lighting was repaired.

Booms, which are temporary floating barriers used to contain marine spills, were dispersed around the vessel to capture any potential leaks.

The second step is to transfer the oil onto the replacement vessel, which is now underway.