to offer the greatest heating surface where the fire is hottest. The most notable user of the Belpaire firebox in the United States was the Pennsylvania Railroad. Other railroads, such as the Great Northern and Illinois Central, had locomotives with Belpaire fireboxes. Illinois Central 4-6-0 #382, Casey Jones' engine, had a Belpaire firebox. Steam is usually collected at the front corners of a Belpaire firebox, allowing for a domeless boiler. The top of the firebox, rather than being horizontal, is visibly higher at the front than at the rear to reduce the risk of water being carried over with the steam. Wootten firebox The Wootten firebox was very tall and wide to allow combustion of anthracite coal waste. Its size necessitated unusual placement of the crew, examples being camelback locomotives. Combustion chamber Some fireboxes were equipped with a so-called combustion chamber, this is a distinct component from the firebox and tubes - a large single extension of the firebox space, into the boiler barrel, and above the brick arch and separated from the grate and the fire bed, this placed additional space between the fire and the rear fire tube/flue sheet. This allowed more complete combustion (reducing fuel wastage) and increased firebox surface area for greater heat-transfer, these factors Improved both boiler efficiency and fuel economy. The improved combustion (which reduces carbon-soot ejection) reduced the carry over of ash and soot into the fire-tubes and smoke box, reducing the frequency of cleaning required. Soot buildup and scale buildup (on the water side) severely reduce heat transfer through the fire tubes/flues, reducing steam generation and boiler efficiency. Buildup of soot and scale can also lead to overheating and subsequent tube failure if not cleaned properly to remove soot (with water, compressed air and cleaning rods) and scale with boiler washouts and water treatment e.g. Porta Treatment (minimizes and virtually prevents scale buildup) is named after the Argentine locomotive engineer Livio Dante Porta, who invented it. Fireman's duties The fireman's role on a steam locomotive is to ensure the driver has an adequate supply of steam at his disposal at all times. This is achieved by maintaining a supply of fuel to the fire, monitoring the smoke from the fire and controlling it by the use of primary air through the fire bed/grate and secondary air through the firebox door and maintaining the boiler water level by use of steam injectors so