Smokebox - Spark Arrester

Spark Arrester

A spark arrester is often installed within the smokebox. This may take the form of a cylindrical mesh running from the top of the blast pipe to the bottom of the chimney. The purpose of a spark arrester is to prevent excessively large fragments of hot ash from being exhausted into the environment where they may pose a fire risk. For this reason, spark arresters are generally installed on locomotives running through dry environments. The presence of a spark arrester may have a thermodynamic effect, distorting the draw of air over the fire and thereby reducing total power output. Thus their use can be contentious.