What is an auxiliary boiler primarily used for?

An auxiliary boiler is primarily used to supply steam for heating, sanitation, and various other auxiliary systems onboard a vessel. This is important because the steam produced by these boilers serves multiple purposes, including heating living quarters, providing hot water for sanitation, and supplying steam for machinery that requires steam for operation, such as certain pumps and evaporators. Unlike the main propulsion systems of a vessel, which are responsible for driving the ship through the water, auxiliary boilers support the functional and comfort systems that keep the crew and equipment operational. Thus, their role is vital for the overall efficiency of the ship's daily activities.