A sandbox is a container on most locomotive

Locomotive

A locomotive is a railway vehicle that provides the motive power for a train. The word originates from the Latin loco – "from a place", ablative of locus, "place" + Medieval Latin motivus, "causing motion", and is a shortened form of the term locomotive engine, first used in the early 19th...

s and self propelled multiple unit

Multiple unit

The term multiple unit or MU is used to describe a self-propelled carriages capable of coupling with other units of the same or similar type and still being controlled from one driving cab. The term is commonly used to denote passenger trainsets consisting of more than one carriage...

s, or tram

Tram

A tram is a passenger rail vehicle which runs on tracks along public urban streets and also sometimes on separate rights of way. It may also run between cities and/or towns , and/or partially grade separated even in the cities...

s, (a type of train that runs on roads) that run on tramways and adhesion railways

Rail adhesion

The term adhesion railway or adhesion traction describes the most common type of railway, where power is applied by driving some or all of the wheels of the locomotive. Thus, it relies on the friction between a steel wheel and a steel rail. Note that steam locomotives of old were driven only by...

. The container holds sand

Sand

Sand is a naturally occurring granular material composed of finely divided rock and mineral particles.The composition of sand is highly variable, depending on the local rock sources and conditions, but the most common constituent of sand in inland continental settings and non-tropical coastal...

, which can be dropped on to the rail to improve rail adhesion

Rail adhesion

The term adhesion railway or adhesion traction describes the most common type of railway, where power is applied by driving some or all of the wheels of the locomotive. Thus, it relies on the friction between a steel wheel and a steel rail. Note that steam locomotives of old were driven only by...

 under very wet or steep conditions.

The sand may be delivered by gravity, by a steam-blast (steam locomotives) or by compressed air. Gravity sanding requires that the sand is dry so that it runs freely. Locomotives used multiple sandboxes, so that their delivery pipes could be short and near-vertical. Engine sheds in the UK were equipped with sand drying stoves, so that sandboxes could be refilled each morning with dry sand. Steam locomotives in the USA had a single sandbox, called a "sand dome" placed on top of the boiler where the rising heat helped to dry the sand. Even with this arrangement, sand pipes tended to clog, and by the 1880s, pneumatic sanding systems were being proposed.John B. Collin, Sanding Device for Locomotives, U.S. Patent 271,039, Jan 23, 1883.

The development of steam sanding was influential on locomotive design. As the sand could now be blown horizontally and directly under the wheels, it was no longer blown away by cross-winds before it could be effective. This prompted a resurgence of interest in some older single-driver

4-2-2

Under the Whyte notation for the classification of steam locomotives, 4-2-2 represents the wheel arrangement of four leading wheels on two axles, two powered driving wheels on one axle, and two trailing wheels on one axle....

 locomotive designs, that had previously been limited by their adhesion performance. The development of Holt's steam sanding gear on the Midland Railway

Midland Railway

The Midland Railway was a railway company in the United Kingdom from 1844 to 1922, when it became part of the London, Midland and Scottish Railway....

 in 1886 prompted Johnson

Samuel W. Johnson

Samuel Waite Johnson was Chief Mechanical Engineer of the Midland Railway from 1873 to 1903. He was born in Bramley, Yorkshire and educated at Leeds Grammar School.-Career:...

 to design his successful 'Spinner

Midland Railway 115 Class

The Midland Railway 115 Class is a class of 4-2-2 steam locomotive. They were known as "Spinners", possibly because of the wheelslip that the single large driving wheel caused. They were designed by Samuel W...

s' of 1887, twenty-one years after the last singles, and which would remain in production for a further sixteen years.

On diesel and electric locomotives and railcars, sandboxes were and are fitted close to the wheels so as to achieve the shortest possible length of delivery pipe.George T. Drew, Sand-Box for Cars, U.S. Patent 458,621, Feb. 20, 1891. Depots may have a sand drier installed to warm and to dry the sand before it is used.John G. McPherson, Sand-Drier, U.S. Patent 276,445, April 24, 1883.

See also

• Tram controls
• Sandite
  Sandite
  Sandite is a substance used on railways in the UK, Ireland and the Netherlands to combat leaves on the line, which can cause train wheels to slip and become damaged with flat spots...
  
  
• Slippery rail
  Slippery rail
  Slippery rail is a condition of railways caused by fallen moist leaves that lie on and cling to the top surface of the rails of railway tracks. The condition results in significant loss of friction between train wheels and rails, and in extreme cases can render the track temporarily unusable...