Lean Marine – automated tools to manage fuel consumption

Sep 03 2020

Lean Marine of Gothenburg, Sweden, makes an automated digital device which runs on the ship’s bridge, to ensure that the vessel never uses more fuel than planned , and to automatically adjust the propeller pitch.

Lean Marine of Gothenburg, Sweden, makes a hardware device “FuelOpt” which runs on a ship’s bridge, ensuring that vessel consumption is never higher than planned on a tonnes per day basis.


Also, if the vessel has a controllable pitch propeller, it can automatically adjust propeller pitch for optimum operations.


The device is also able to transmit information about vessel operations, which can be analysed in cloud software and made available to fleet superintendents, in a tool called “Fleet Analytics”.



FuelOpt is a hardware device which runs on the ship’s bridge, adjusting the speed of the vessel to ensure that it does not go higher than a planned maximum fuel consumption per day.


In bad weather the engine will have to work harder to keep the set RPM, which leads to higher fuel consumption. With FuelOpt set to a maximum consumption this will not happen, but RPM will instead be reduced, and fuel consumption be limited.


It does not override any of the crew’s ability to control the vessel, but is designed to make crew’s life easier, replacing the need for a person to constantly monitor and make manual adjustments nonstop. This is an arduous task, prone to be affected by human error, says Sarah Zitouni, business development manager, Lean Marine, and a mechanical engineer.


“FuelOpt is an extension of the hand of the bridge crew,” she says. “To have maximum efficiency of the vessel, in theory, you should be regulating all the time. For a human, this is close to impossible. We put a machine on the bridge to do that.”


As an “on top” propulsion control system FuelOpt sends orders to the propulsion system, similar to how a crewmember would. It does not bypass any safety system onboard. The system receives information from the vessel Integrated Automation System (IAS), which most tankers have, Lean Marine says, similarly to how a dynamic positioning system works.


Some vessels have an “eco speed” or “slow steaming” option – but in this case, there is no way for seafarers to check what the system is actually doing, Ms Zitouni says. “What if that speed doesn't get checked, you think it is in eco speed mode, but it is actually half a knot higher than you planned? With FuelOpt you can be sure whatever you set onboard is followed across the whole journey.”


The company claims that up to15 per cent fuel savings are possible from this system. As an example it could save 225 tonnes of fuel a year for a 200,000 dwt bulk carrier, with 11MW propulsion power and a fixed pitch propeller, with 25 per cent of its sailing time in harsh weather conditions.


The system is designed to be simple to use, on the basis that it is unlikely to be used if it is too complicated.


Installation can be done during a port stay, no dry docking is required, just some cable pulling.


As a minimum, the system needs to connect to a fuel flowmeter, so it can see the amount of fuel actually flowing to the engine. It also needs to connect to a shaft torque meter, which measures the amount of torque (force causing rotation around an axis) which the engine is creating. You can use flowmeters and torque meters from any supplier.


It cannot be operated from outside the vessel, so does not provide any hole for a hacker to exploit.


The system has been sold on 175 vessels including tankers. Tanker clients include Stenersen, Team Tankers (which acquired Laurin Maritime in 2018), Utkilen, Ektank, Älvtank, Veritas Tankers, and Wisby Tankers.


The system has been installed on vessels with power of 3MW to 42MW, from small cruise vessels of 650 DWT to bulk carriers up to 200,000 DWT.


Controlling propeller pitch

If a vessel has a controllable pitch propeller, the device can automatically adjust the propeller pitch, to achieve the desired speed while allowing the vessel to rotate at its optimum RPM (revolutions per minute).  Each engine is designed to operate at a certain RPM and is most efficient at that speed.


By adjusting the propeller pitch, you can adjust the thrust up or down, and the fuel consumption accordingly, while having the same RPM.


The system algorithms decide what adjustment is needed based on the input trends and automatically executes the optimal settings.


Many ships with controllable pitch propellers have a “combinatory curve” onboard with a pre-set safety margin to the engine load limit, which show what power output you are getting from the engine at a certain RPM rotation and a certain propeller pitch. 


If you have a “combinator” device, you can apply the values on this static curve. But FuelOpt acts as a dynamic combinator, adapting in real-time to the sea and vessel conditions to get the maximum efficiency possible taking into account instantly engine load limit.


On a chemical / product carrier carrying 50,000 dwt, 11MW engine, with a controllable pitch propeller, sailing from the Pacific to Atlantic, spending 25 per cent of time in unfavourable conditions, Lean Marine estimates the system can achieve 3 tonnes per day fuel savings, which makes 600 tonnes per year.


Fleet Analytics

Lean Marine also offers a performance management software called Fleet Analytics, for analysing performance data.


The software is cloud hosted, and receives data from FuelOpt. This enables fleet operations staff to see performance data for the whole fleet or individual vessels.


A 12-month subscription to Fleet Analytics is included with every new purchase of FuelOpt.


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