How Do Major Spills Still Happen With Double Hull Tankers?

by Ship & Bunker News Team
Wednesday August 15, 2018

A June 23 oil spill in Rotterdam waters has raised a number of questions, not least of which is, how do spills still happen when today's tankers are double hulled?

The incident happened after the 1996-built, double-hulled tanker Bow Jubail made contact with the Botlek terminal jetty and ruptured its hull, resulting in a spill of 217 metric tonnes (mt) of HFO.

The intention of a double-hull design is to prevent a spill in the event of such a collision.

Legislation introduced following the 1989 grounding of the Exxon Valdez kicked off a phase-out of single-hulled tankers that saw their elimination by 2015, and edge cases for partially protected tankers by 2017.

The problem is that there is no requirement for the same level of protection for bunker tanks.

"Bow Jubail has a double hull for the cargo tank area, but not for the bunkers tanks," a spokesperson for its owner, Odfjell, confirmed to Ship & Bunker.

This apparent legislative oversight was not lost of SafeWaters Underwriting Managers, who in a 2016 insight piece discussing the history of the single-hulled tanker phase-out, asked whether the industry had done enough.

"Today we have ships navigating the waters that carry as much or more bunkers (FO and DO) than a midsize tanker and they carry it in their double bottoms (single shell)," SafeWaters writes.

"Have we actually ruled out single hull 'exposure'?

Those interested in the history of the single-hull phase-out can find SafeWaters' full article here: https://safewatersmarine.com/insight5/