Is Slower Better?

Posted by PortVision

Vessel speed reduction continues to create both opportunity and controversy, as the debate continues about the economic and environmental benefits and risks.  

A recent NOAA study reveals that the practice has been applied to protect endangered white whales that transit the waters of the East Coast where they seasonally migrate, feed and calve. The research, carried out from 2008 to 2013, began with a new regulation put in place by NOAA in December of 2008, requiring ships 65 feet in length or above to keep their traveling speed to 10 knots or less in the identified areas where the whales in order to prevent deadly collisions with ships.

NOAA informed the Ocean-Tanker-10798528,009 vessels that took part of the study via a number of outreach initiatives, both before and after the regulation was enforced. All were tracked remotely, and some 437 vessel/owners were found to exceed regulated speeds and were notified accordingly. Just 26 vessel/owners received actual infraction fines.

AIS data was used to observe vessel behavior, as well as dynamic GPS to determine position, speed and heading, etc. Over the course of the study, NOAA found that compliance began improving as more communication from particular notification programs between NOAA and vessels increased.

The Santa Barbara County Air Pollution Control District, in partnership with NOAA's ‘National Marine Sanctuaries, Channel Islands and the Environmental Defense Center, are carrying out similar vessel speed reduction initiatives with respect to reducing greenhouse gas emissions, air pollution, and protecting whales that travel along the California coast. The move will help bolster the Port of Los Angeles and Port of Long Beach’s vessel speed reduction programs which have already seen about 90% participation. Participation in the SB County's initiative includes taking part in the Ports’ program.

The goal is to reduce vessel speeds to 12 knots which would cut greenhouse gas emissions by 50% and NOx by 56%. In California, it’s estimated that equals nearly 2,580,000 tonnes per year and in the Santa Barbara Channel, approximately 369,762 tonnes annually.

In another study (masters thesis) on cutting fuel emissions through low speed steaming initiatives was carried out by the Department of Shipping and Marine Technology at Sweden’s Chalmers University of Technology. The Benchmarks and measures for better fuel efficiency 2012 paper, showed how critical the use of AIS data is for understanding and analysing vessel operational performance.

In addition to slow steaming, the paper also discussed other cost-savings measures, including weather routing, ballast and trim optimization and just-in-time port arrivals.

Two groups; one with 7,700 dwt and one with 12,700 dwt-type cargo ships were studied during 2010-2011; each group had 22 vessels. This was done to ensure there were as many similarities in the vessels with respect to design and operational scope as possible for the purposes of the research. Minimizing anchoring time in favor of speed reduction was the goal.

As evidenced here, slower speeds made a difference in reduced fuel consumption and reduced anchoring.  Proponents of slower steaming argue that it is good for the environment.  However industry has indicated that any environmental benefits could come with commensurate increased costs and lower supply chain efficiency.


Credit: WIGFORSS, J. (2012). Benchmarks and measure for better fuel efficiency: How AIS data can be used in operational performance analysis, Report no NM - 12/29, Department of Shipping and Marine Technology CHALMERS UNIVERSITY OF TECHNOLOGY Göteborg, Sweden. pp. 32.

Slow steaming increased during the economic downturn of 2008-2009 as a way to help cut costs but has remained one of the key ways to gain better fuel efficiency, among other measures.  

PortVision’s AIS vessel tracking service has been used in a number of vessel speed reduction initiatives, using AIS data for real-time ship tracking and historical review and reporting of global vessel movements.  You can learn more at, or by downloading the case study here.

PortVision 360 AIS Vessel Tracking

Posted on Feb 10, 2015 2:49:00 PM

Topics: Blog