Why did steam-powered ships make fuel conservation a navigation concern?

The advent of steam-powered ships in the 19th century introduced fuel conservation as a critical duty for navigators because steam propulsion required carrying large quantities of fuel, which directly competed with a vessel's ability to transport cargo.12

Early steamships faced significant constraints, as the weight and volume of fuel needed for long-distance voyages often left little room for paying loads. Because fuel was costly and occupied space that could otherwise be used for cargo, minimizing consumption became essential for economic viability. Beyond a necessary safety factor, carrying excess fuel was inefficient, as it needlessly reduced the ship's cargo capacity. Consequently, managing fuel efficiency became a fundamental objective of modern navigation, alongside traditional duties like staying on course, avoiding collisions, and adhering to strict schedules.321