Grit bin
Encyclopedia
A grit bin or salt bin is an item of street furniture
, commonly found in countries where freezing temperatures and snowfall occur, which holds a mixture of salt
and grit which is spread over road
s if they have snow
or ice
on them. A grit bin improves winter road safety on roads which are not gritted by other means, such as from a winter service vehicle.
or shovel
is used to spread a thin layer of grit onto the road surface, covering any snow or ice. The salt lowers the melting point
of the snow causing it to melt (see sodium chloride
). The grit component improves the friction between a vehicle's tyre
s and the road.
Some grit bins have a small compartment, which could be used for storing a spade or shovel. The one featured in the photograph at the top of the page is filled through the top hatch.
, wood or even stone, though these are now increasingly being replaced by models constructed from plastic partly from safety concerns: vehicles/people hitting a plastic grit bin will suffer less damage. However, the lower weight of plastic makes grit bins easier to steal or tip over.
, such as arson
. The lid can also be left open, leaving rain
to wash away the salt in the mixture, rendering it useless. In the United Kingdom, the local county council
is usually responsible for maintaining and refilling grit bins.
Members of the public can inform their local council if a grit bin needs refilling, has been damaged or tipped over, or if there are no bins on a road that is not gritted by any other method.
In Norway, the problem with tipping grit bins over have been solved by making them large enough to hold about 500 kg of grit, and to continually keep it topped up.
Street furniture
Street furniture is a collective term for objects and pieces of equipment installed on streets and roads for various purposes, including traffic barriers,...
, commonly found in countries where freezing temperatures and snowfall occur, which holds a mixture of salt
Salt
In chemistry, salts are ionic compounds that result from the neutralization reaction of an acid and a base. They are composed of cations and anions so that the product is electrically neutral...
and grit which is spread over road
Road
A road is a thoroughfare, route, or way on land between two places, which typically has been paved or otherwise improved to allow travel by some conveyance, including a horse, cart, or motor vehicle. Roads consist of one, or sometimes two, roadways each with one or more lanes and also any...
s if they have snow
Snow
Snow is a form of precipitation within the Earth's atmosphere in the form of crystalline water ice, consisting of a multitude of snowflakes that fall from clouds. Since snow is composed of small ice particles, it is a granular material. It has an open and therefore soft structure, unless packed by...
or ice
Ice
Ice is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...
on them. A grit bin improves winter road safety on roads which are not gritted by other means, such as from a winter service vehicle.
How it works
Anyone may use a grit bin to clear a public path or road, though they are generally not intended for personal use. Typically, a spadeSpade
A spade is a tool designed primarily for the purpose of digging or removing earth. Early spades were made of riven wood. After the art of metalworking was discovered, spades were made with sharper tips of metal. Before the advent of metal spades manual labor was less efficient at moving earth,...
or shovel
Shovel
A shovel is a tool for digging, lifting, and moving bulk materials, such as soil, coal, gravel, snow, sand, or ore. Shovels are extremely common tools that are used extensively in agriculture, construction, and gardening....
is used to spread a thin layer of grit onto the road surface, covering any snow or ice. The salt lowers the melting point
Melting point
The melting point of a solid is the temperature at which it changes state from solid to liquid. At the melting point the solid and liquid phase exist in equilibrium. The melting point of a substance depends on pressure and is usually specified at standard atmospheric pressure...
of the snow causing it to melt (see sodium chloride
Sodium chloride
Sodium chloride, also known as salt, common salt, table salt or halite, is an inorganic compound with the formula NaCl. Sodium chloride is the salt most responsible for the salinity of the ocean and of the extracellular fluid of many multicellular organisms...
). The grit component improves the friction between a vehicle's tyre
Tire
A tire or tyre is a ring-shaped covering that fits around a wheel rim to protect it and enable better vehicle performance by providing a flexible cushion that absorbs shock while keeping the wheel in close contact with the ground...
s and the road.
Some grit bins have a small compartment, which could be used for storing a spade or shovel. The one featured in the photograph at the top of the page is filled through the top hatch.
Construction of grit bins
Grit bins were originally made of concreteConcrete
Concrete is a composite construction material, composed of cement and other cementitious materials such as fly ash and slag cement, aggregate , water and chemical admixtures.The word concrete comes from the Latin word...
, wood or even stone, though these are now increasingly being replaced by models constructed from plastic partly from safety concerns: vehicles/people hitting a plastic grit bin will suffer less damage. However, the lower weight of plastic makes grit bins easier to steal or tip over.
Problems
Grit bins can be subjected to vandalismVandalism
Vandalism is the behaviour attributed originally to the Vandals, by the Romans, in respect of culture: ruthless destruction or spoiling of anything beautiful or venerable...
, such as arson
Arson
Arson is the crime of intentionally or maliciously setting fire to structures or wildland areas. It may be distinguished from other causes such as spontaneous combustion and natural wildfires...
. The lid can also be left open, leaving rain
Rain
Rain is liquid precipitation, as opposed to non-liquid kinds of precipitation such as snow, hail and sleet. Rain requires the presence of a thick layer of the atmosphere to have temperatures above the melting point of water near and above the Earth's surface...
to wash away the salt in the mixture, rendering it useless. In the United Kingdom, the local county council
County council
A county council is the elected administrative body governing an area known as a county. This term has slightly different meanings in different countries.-United Kingdom:...
is usually responsible for maintaining and refilling grit bins.
Members of the public can inform their local council if a grit bin needs refilling, has been damaged or tipped over, or if there are no bins on a road that is not gritted by any other method.
In Norway, the problem with tipping grit bins over have been solved by making them large enough to hold about 500 kg of grit, and to continually keep it topped up.