Vessel Fuel Monitoring System (FMS): Fuel per Engine, Measured

MANTRAZ is a vessel fuel monitoring system for owners and operators who want to know what each engine burns, not just what the vessel used in total. RPM, speed and fuel consumption are shown per engine, side by side, and main engine fuel is measured by a marine fuel flow meter on both the supply and the return line.

Why one fuel number is not enough

A daily total for the whole vessel tells you that fuel was used, not where or why. If one engine burns more than the others, or consumption climbs while speed stays the same, a single figure hides it. When that figure comes from manual logs, it is also hard to separate a real change in consumption from a recording mistake.

How the vessel fuel monitoring system works

Main engine fuel is measured by flowmeters on the supply and return lines. Measuring both matters, because fuel that flows back to the tank was never burned. Auxiliary engines are usually estimated from running hours, and MANTRAZ reports keep measured and estimated fuel apart, so a measured figure never quietly mixes with an estimate.

Alongside fuel, each engine shows:

• RPM and vessel speed
• fuel density and temperature
• engine running hours
• exhaust temperature
• power meter readings, where a power meter is installed

Everything sits on one timeline, so you can move through the day and watch how consumption followed RPM and speed.

What pushing the engine harder costs

The most direct use is putting a price on speed. Move the timeline to a stretch where the engine was pushed harder and the fuel line shows what that cost. A general sense that running hard burns more fuel becomes a figure for a specific engine on a specific day.

Measured consumption also carries through the rest of MANTRAZ. Voyage reports turn it into litres per nautical mile and fuel per running hour, and the Remain On Board balance subtracts what the engines burn from the fuel on board.

Measured and estimated, kept apart

Knowing which numbers were measured and which were estimated is what makes the data hold up in a discussion. When a report shows main engine fuel from the flow meters and auxiliary engine fuel from running hours as separate figures, nobody has to wonder where a total came from.

Who uses it

Fleet and technical teams in the office use per-engine data to follow how engines behave across the fleet and to spot an engine that does not match the rest. Crews benefit as well: a clear figure for what extra RPM costs makes conversations about how the vessel is run concrete instead of a matter of opinion.

See it on the map

On the MANTRAZ homepage, open the engine and fuel chapter and move the timeline to see consumption follow the engine. To see the same view with your own fleet's data, contact the team for a demo.