S’pore oil spill: Poor weather delayed laying of booms around damaged ship, says contractor

SINGAPORE - Working in a thunderstorm at night, an oil spill recovery contractor required more than triple the time it would normally take to lay containment booms around a damaged vessel that was

leaking oil into the sea.

In all, it took nearly 15 hours from the time of the incident before the laying of that line of defence was completed.

Laying the booms alone took three or four hours, where it would have taken one hour under better conditions, said Captain Anuj Sahai, managing director of T&T Salvage Asia.

His company was engaged by the Maritime and Port Authority of Singapore (MPA) after the Netherlands-flagged Vox Maxima

reportedly lost engine and steering control

and hit Singapore-flagged bunker Marine Honour at 2.18pm on June 14. About 400 tonnes of oil from the vessel leaked into the sea.

Capt Sahai said he was alerted to the incident around 2.55pm that day.

Within half an hour, his team began mobilising three or four truckloads of gear from its warehouse in Tuas for the operation, he said.

“There was a lot of equipment and gear going out of the yard. It took about three hours to put all the gear onto the trucks and send it across to the Marina South Pier, which took another hour,” said Capt Sahai.

The pier had the crane required to load the booms onto vessels that took them to the affected site, he added.

After reaching the site, the crew took several hours to determine if it was safe to lay booms around the ship and the precautions needed. They started laying the booms at 1am or 2am.

“Once we were alongside the Marine Honour, it took about three or four hours to lay the booms because it was night-time and the weather was not so good,” he said.

The crew laid 200m of booms, with each 3m section weighing more than 100kg when inflated, around the vessel anchored at Pasir Panjang Western Anchorage.

The workers’ speed was impeded by strong winds and poor visibility in heavy rain, as they had to take precautions not to fall.

Under ideal weather conditions, deploying 200m of booms takes about an hour from the time the response vessel reaches the site until the booms are positioned and secured, Capt Sahai said. Stronger and sturdier booms take longer to deploy, and stronger currents can slow boats and delay the process.

The crew finished the task early in the morning at around 5.15am, said Capt Sahai.

T&T also laid booms at sites in Keppel Marina and Sentosa Cove on June 15, as well as an additional layer of fence booms around the Marine Honour and a third line of curtain booms over the next few days.

On June 20, the authorities said that 3.4km of booms had been deployed since June 14 across affected sites to contain the spill. Besides T&T, other contractors were also engaged to deploy the booms.

MPA took reporters to observe workers from T&T lay an additional 200m of black curtain booms at Siloso Beach in Sentosa on June 21, to supplement the red fence booms installed earlier.

Types of containment booms 

Containment booms are floating devices that create a barrier to limit the spread of oil on the water’s surface during a spillage so that it can be removed by skimmer machines. 

There are various kinds of booms. Fence booms are smaller, lighter and faster to deploy, but are less effective at containing oil. They are effective as a first response to swiftly and immediately contain spills, but less effective in high tides or strong currents that can carry oil over booms.

Curtain booms take longer to lay as they are bigger and heavier, but are more effective at containing spills as they are taller and have a 1m underwater curtain to block oil from moving across. Deploying them takes double the manpower and time as they must be inflated, unlike fence booms which have foam inside, Capt Sahai said. 

Absorbent booms, made from materials that absorb oil, are placed at the ends of lines of booms to plug gaps that oil can flow through. 

How booms are deployed

Before getting to the job, workers are given a safety briefing by the team supervisor on board the T&T Salvage response vessel, said Capt Sahai.

Workers on the deck check the line of booms for damage as it is unreeled.

The booms are then placed in the water, and a smaller boat with around four workers tows one end of the line to position it. Both ends of the line are anchored to the seabed or fastened to a secure structure like a rock.

The booms are monitored round the clock by a maintenance team that repairs them immediately if damage is detected, Capt Sahai added. 

Limitations of containment booms 

Despite

efforts to ringfence the Marine Honour and disperse the slick,

the oil spill had spread by the next day to the coastlines of East Coast Park, Labrador Nature Reserve, Keppel Bay, the Southern Islands and Sentosa, and the waters off Changi on June 17.

MPA set up containment booms in these areas and deployed equipment to skim oil off the water surface.

In a Facebook post on June 18, Transport Minister Chee Hong Tat said that booms may not completely prevent the oil spill from spreading as tidal currents and waves can carry the oil, which may go above or below the booms.

Another limitation of the booms is that once they are installed, their weight makes it difficult for the crew to relocate them to another site affected by the oil slick after the initial zone has been cleaned up, according to Capt Sahai.

Correction note: This story has been edited for accuracy.