Smoke deflectors are vertical plates attached to the front of a steam locomotive

Steam locomotive

A steam locomotive is a railway locomotive that produces its power through a steam engine. These locomotives are fueled by burning some combustible material, usually coal, wood or oil, to produce steam in a boiler, which drives the steam engine...

 on each side of the smokebox

Smokebox

A smokebox is one of the major basic parts of a Steam locomotive exhaust system. Smoke and hot gases pass from the firebox through tubes where they pass heat to the surrounding water in the boiler. The smoke then enters the smokebox, and is exhausted to the atmosphere through the chimney .To assist...

. They are designed to lift smoke

Smoke

Smoke is a collection of airborne solid and liquid particulates and gases emitted when a material undergoes combustion or pyrolysis, together with the quantity of air that is entrained or otherwise mixed into the mass. It is commonly an unwanted by-product of fires , but may also be used for pest...

 away from the locomotive at speed so that the driver has better visibility unimpaired by drifting smoke.

Smoke deflectors became increasingly common on later steam locomotive designs as efficiency gains through improved smokebox

Smokebox

A smokebox is one of the major basic parts of a Steam locomotive exhaust system. Smoke and hot gases pass from the firebox through tubes where they pass heat to the surrounding water in the boiler. The smoke then enters the smokebox, and is exhausted to the atmosphere through the chimney .To assist...

 design and reduced back pressure on the cylinders in turn reduced the uplift of smoke exiting the chimney

Chimney (locomotive)

The chimney of a steam locomotive is a part of the exhaust system which helps in the creation of draught through the boiler and carries the exhaust steam and smoke clear of the driver's line of sight...

.

There have been various styles of smoke deflectors used by different railway operators worldwide. However, many are essentially a variation of one of two designs of Windleitbleche (smoke deflector) originating from the Deutsche Reichsbahn-Gesellschaft

Deutsche Reichsbahn-Gesellschaft

The Deutsche Reichsbahn – was the name of the German national railway created from the railways of the individual states of the German Empire following the end of World War I....

 (German national railways between the World Wars): the earlier, larger Wagner

Richard Paul Wagner

Richard Felix Paul Wagner was the Chief of Design in the design office of the Deutsche Reichsbahn in Germany from its inception in 1922 to 1942.. He held the rank of Reichsbahnoberrat....

type deflector, and the later, smaller Witte type deflector.