US calls for study that could relax double-hulled oil tanker regulations, citing costs to build, energy consumption

The United States Department of Transportation Maritime Administration has issued a call for a study that is calling into question the future of double-hulled oil tankers.

On August 6, 2012 the Maritime Administration, also known as MARAD, issued a “solicitation” for a study on the Safety, Economic and, Environmental Issues of Double Hulls.

In the call for the study, MARAD says:

Following the Exxon Valdez disaster, the passing of the Oil Pollution Act of 1990 (OPA 90) led to the requirement to replace single hull petroleum tankers with double hull tank vessels sailing in U.S. waters. This requirement was soon adopted by the International Maritime Organization (IMO) and became a worldwide regulation. This means that, today, tank vessels worldwide are carrying thousands of extra tons of steel in order to meet the double hull requirements.

Though these double hulls reduce the threat of oil pollution as a result of grounding, they significantly increase the amount of energy needed to propel a vessel and increase the amount of air pollution into the atmosphere. As a result, the maritime industry’s carbon footprint and criteria pollutant emissions are increased.
In addition to the need to burn more fuel, it is acknowledged that double hulls can cause several other problems which will be detailed in this study.

Here in Canada, Enbridge Northern Gateway and its supporters, in briefings on maritime and tanker safety on the west coast of British Columbia, have always said that the changes following the Exxon Valdez disaster in Prince William Sound and the subsequent US Oil Pollution Act as almost guaranteeing that such a disaster could not happen again.

Now it appears that some people in the U.S. Department of Transportation may be worried that increased use of double-hulled tankers will cost too much. There’s also the apparent question of balancing the carbon footprint of increased emissions from tankers with the danger from a hydrocarbon spill.

The request for the study was covered by tanker industry sites such as Marine Link but only surfaced in major media on Sunday, when The National, an English-language newspaper in Abu Dhabi broke the story, “US maritime agency considers overhaul of oil-spill regulation”

Reporter David Black notes:

In July last year, the IMO adopted binding regulations to limit the expected gas emissions increase by reducing fuel consumption of ships by as much as 15 million tonnes in 2020, a 14 per cent reduction, and by 2050, by as much as 1,013 million tonnes. This will lead to savings in fuel costs for the shipping industry of up to US$200 billion a year, says the IMO.

Black says that the US agency seems “to suggest by abandoning the additional weight of double hulls the savings would increase and pollution be cut further, adding “On the other hand, since the introduction of double hulls, pollution from major oil spills has been reduced to practically zero.”

The National story says even the tanker industry itself is worried about the move, quoting the the international tanker owners’ organization.

“We have noted reports about Marad’s intended study on tanker double hulls but, except for what we gather from press articles, we have little knowledge on the reasoning behind this,” said Bill Box, Intertanko’s senior manager for external relations.
“From our members’ experience, double-hull designs have evolved into safe and reliable ships with an excellent safety and pollution prevention record. We might provide comments when such a study would be released by Marad.”


The requirements for the double-hull study, as posted by the US government are:

1. The Contractor shall conduct an assessment of the history in the evolvement of “The Double Hull Rules”.

2. The Contractor shall conduct the assessment of any rules that are being proposed in bodies such as the IMO, U.S. Congress and other such bodies’ worldwide as they relate to additional hulls for environmental reasons.

3. The Contractor shall assess all the relevant safety issues related to double hulls for each class of vessel. E.g. Double bottoms are difficult and expensive to maintain and can result in corrosion problems. Unchecked corrosion in older double hull vessels can lead to cargo leakage into a double bottom and the buildup of dangerous vapor which could cause an explosion under certain conditions. The Contractor will obtain data from appropriate organizations which details the issues in double bottoms on older vessels including cracking, leakage, and the potential for vapor buildup.

4. The contractor shall conduct a complete economic study of the consequences of Double Hulls. E.g. they significantly add to the construction cost of vessels. They result in the loss of cargo space which also adds to the carbon footprint since an additional vessel(s) is needed to carry the same cargo tonnage.

5. The contractor shall assess the complete consequences of the carbon footprint of designing, constructing, maintaining and operating vessels with double hulls. E.g. Apart from the extra propulsive forces and fuel needed, the carbon footprint of double hull maintenance is substantially increased.

6. The Contractor shall prepare a report on the results of the project. The report shall be grammatically correct and must be professionally written to a high level of competence in the English language. The report must clearly specify the safety, economic and environmental issues details above.