So How Good Are Those Double Hulls?

“Merits of Double Bottoms in Crude Oil Tankers as Applied to the ‘Exxon Valdez’ Spill of March 24, 1989”

Author:  Rik van Hemmen

Published:  June 1992

The Exxon Valdez spill was a true game changer in our industry.  Almost immediately it resulted in the development of regulations that would reduce oil outflow in the event of a grounding or collision, but it took a number of years for the U.S. Government to determine the optimal solution.

Today we know the ultimate solution resulted in a double hull requirement, but before all the research was performed and completed, we were asked to provide a technical opinion with regard to the effectiveness of double bottoms in the case of the Exxon Valdez spill.

We prepared this report and were very extensively deposed on the results during the Exxon Valdez litigation.  Despite strenuous efforts to discredit our results, we never received any level of comment that indicated our estimates were not reasonable.

A few years later, after the dust on the research started to settle, it turned out that our estimates had been dead-on.

Besides our outflow calculations, we also provided opinions in the report on operational considerations.  Those opinions, which we had based on actual operational data that came from double bottom and double hull ship operators, builders and salvors, were also widely challenged but never refuted.  These challenges were made by people who never bothered to look at the data and instead simply expressed their unsupported beliefs.

It is interesting to note that this study focused on grounding situations and at that time we were not convinced that double hulls were a significant improvement on double bottoms alone.  As time has passed, it appears that the decision to require double hulls was more effective than requiring double bottoms alone. Neither will prevent oil spills, but both reduce oil spills and the overall reduction by requiring double hulls probably has been better.

To download the full paper click this link:  Merits_of_Double_Bottoms_in_Crude_Oil_Tankers