New tidal optimisation reveals significant bunker savings

Applied oceanography specialist Tidetech has introduced tidal optimisation as a critical tool for improving efficiency on coastal shipping routes.

In simulations developed for transits through the English Channel, a time difference of 12.8 per cent was shown between ‘best case’ and ‘worst case’ passage times when using optimal tide and current (based on an 8000 TEU container ship steaming at 21kt). This is the approximate equivalent of $9,400 of bunker costs saved on one journey.

Tidetech managing director Penny Haire said tidal optimisation was a major development for efficiency and sustainability in shipping.

“It’s clear that no stone is being left unturned in the drive to improve efficiency of shipping… the influence of tide and current is an obvious challenge to address,” Ms Haire said.

“The reason it’s not been addressed before is that the information just hasn’t been available… now it is and can make a significant difference if applied correctly.

“Our accurate, high-resolution global tidal data can be integrated into bridge systems allowing ships to make use of advantageous current, steam at more efficient speeds and minimise fuel used and time spent in transit.”

Speed optimisation using accurate tidal stream data differs from weather and route optimisation in that it is about choosing the best time to transit a passage where a choice of route is limited or restricted (channel transits, controlled shipping lanes, ferry routes, etc).

With route restrictions and the presence of tides, efficiency is found in timing the journey relative to current/tide – leaving/arriving at the right time to take advantage of best current and optimising speed to maximise the positive effects of the current.

Using the English Channel as an example, timing a vessel’s arrival at the entrance to the channel correctly means the ship can make the most efficient passage through the Channel by going with the optimal flow of water.

Tidetech’s English Channel simulation shows the best case transit at slow steaming speeds of 19kt is 32 minutes faster than the worst case transit at 21kt. Based on an 8000 TEU container vessel, this is a difference of approximately 35.8 tons of bunkerage (or approximately $25,000). 

Another example of how tidal optimisation can be effective is in ferry timetable scheduling. 

Ferry companies will be able to schedule their departures more effectively to achieve the desired arrival time with minimal fuel use. In areas of strong tide it’s been operationally difficult for ferries to judge the correct amount of power/speed required to minimise fuel use while maintaining schedules.

Tidetech currently offers tidal optimisation for over 25 locations around the world through its GlobalTide catalogue.

The analysis of tidal optimisation for the English Channel can be watched here – 

Tidetech is a technical supplier to the 34th America’s Cup and the 2011-12 Volvo Ocean Race.