What is the optimum vessel speed?

[Kristinn A. Aspelund]

I've been following the dialogue on optimum speed of ships for some time now. We have been looking at what is the optimal vessel speed with many of our customers at Marorka for years now. It is quite interesting now when fuel prices are higher that the optimal vessel speed should be changing. For me it is interesting to read these points on that average speed of 21 knots for container vessels is still far from optimum.

I believe that selecting the "correct" speed for vessel is one of the essentials for marine energy management so I'm very interested to see this dialogue forming publicly. I feel also that within the shipping companies this dialogue has been going on for a long time and there you will have it in more details.

What I've learned that from energy efficiency point of view the optimum speed differs between ship types. And when you consider what is the optimum speed of a vessel there are some other issues to consider. For example how do you make up your average speed? How pressed are your schedules etc. We have been using our Maren Energy Management System to figure out the optimal average speed and speed profile for ships.

To really benefit form speed profile studies you will need to equip the navigators on board with the right tools to analyze their own performance. I think you will also need some real benchmarks from your operation to work with.