Two oil tankers collided about 1 nautical mile south of Tuas Extension off the coast of Singapore yesterday (Tuesday), causing a liquefied butane gas leak, the Maritime and Port Authority of Singapore (MPA) announced.
The Singapore-flagged LPG (liquid petroleum gas) tanker, Crystal Sunrise, was reportedly picking up a pilot when it collided with the westbound Greece-registered tanker Astro Saturn, chartered by European trading house Trafigura.
The Crystal Sunrise’s ballast tank was damaged, causing butane to leak from one of the cargo tanks, while the Astro Saturn suffered damage to its port anchor and bow, the MPA reported.
An estimated 1,800 metric tonnes of butane gas had leaked, the MPA said, but its high evaporation rate meant it would have been carried south away from the city-state and most would have rapidly dissipated to below flammable levels within an hour and posed no risk to shipping.
The MPA said it was investigating the incident.
The Singapore and Malacca straits are one of the world’s busiest sea lanes, where the US Navy’s John S McCain last August collided with an oil tanker, resulting in the deaths of 10 US sailors.
In September 2017, five sailors died after a dredger and tanker collided in Singaporean waters.
This week, the Agency for Science, Technology and Research’s Institute of High Performance Computing at Singapore Management University and Fujitsu said it was developing predictive technology to prevent ship collisions.
“We can confirm that the Astro Saturn is on TC [time charter] to Trafigura and is carrying fuel oil,” a Trafigura spokeswoman told Reuters.
The Crystal Sunrise, built in 2013 and owned by Japan’s Kumiai Navigation, is listed a very large gas carrier with a deadweight tonnage of 54,070 tonnes carrying LPG from West Asia.
Astro Saturn is an Aframax with a deadweight tonnage of 105,167 tonnes and is anchored at Tanjung Pelepas in Johor, Malaysia, close to Singapore.
Trade sources said the Crystal Sunrise, which was carrying Qatari butane, had been chartered by Japanese LPG trading company Gyxis.
East Asia is facing a relative shortfall of butane versus propane, while North Asian butane demand for the petrochemical sector has been healthy. This has switched the normal Asian propane/butane spread to a premium for butane.
Prior to this, butane had been at a discount as deep as US$30 per million tonnes versus propane between the end of November 2017 and earlier this month, amid ample West Asian butane supplies and via the arrival of mixed US LPG cargoes.
Busy shipping lanes near Singapore. Picture credit: Flickr