Grain elevator

From Wikipedia, the free encyclopedia

1928 Burrus Elevator (slipformed concrete silo construction in Lubbock, Texas. A steel reinforced concrete elevator with 123 silos shown just prior to demolition in 2004

Historic Cooperative Elevator, a row of corrugagated steel hopper bottom bins on the left and cribbed annex bins on the right, Crowell, Texas

View of corrugated steel grain bins and cable guyed grain elevator at a grain elevator in Hemingway, South Carolina

Old wooded cribbed grain elevator and livestock feedmill in Estherville, Iowa.

View of jumpformed concrete annex silos on the left and slipformed concrete mainhouse at an elevator facility in Edon, Ohio.

This article is about grain elevators. For other meanings of "elevator" see elevator (disambiguation).

Grain elevators are buildings or complexes of buildings for storage and shipment of grain. They were invented in 1842 in Buffalo, New York by Joseph Dart, who first developed a steam-powered mechanism, called a marine leg, for scooping grain out of the hulls of ships directly into storage silos. Older grain elevators and bins often were constructed of framed or cribbed wood and were prone to fire. Grain elevator bins, tanks and silos are now usually constructed of steel or reinforced concrete. Bucket elevator are used to lift grain to a distributor or consignor where it flows by gravity through spouts or conveyors and into one of a number of bins, silos or tanks in a facility. When desired, the elevator's silos, bins and tanks are then emptied by gravity flow, sweep augers and conveyors. As grain is emptied from the elevator's bins, tanks and silos it is conveyed, blended and weighted into trucks, rail cars, or barges and shipped to end users of grains (mills, ethanol plants, etc.)

Prior to the advent of the grain elevator, grain was handled in bags rather than in bulk.

Grain elevators are a constant sight in the grain-growing areas of the world, such as the North American prairies. Larger terminal elevators are found at distribution centers, such as Chicago and Thunder Bay, Ontario, where grain is sent for processing, or loaded aboard trains or ships to go further afield.

Grain elevators can make unpleasant neighbours, but usually neighbors are very aware of what a grain elevator is. However, in the right neighbourhood, they can be ignored. These houses in Halifax, Nova Scotia , were constructed in the 1990s long after the elevator had been constructed and are valuable dwellings due to their location within a desirable part of the city. In the summer of 2003, there was an explosion a this particular elevator, sparking a fire that took seven hours to extinguish after holes were blown out of the large concrete structure. [1]

Buffalo, New York, once the world's largest grain port, not surprisingly has the world's largest collection of concrete grain elevators^{[citation needed]}, most of which are presently idle but are still a dramatic presence on the city's waterfront. In the early 20th century, Buffalo's grain elevators inspired modernist architects such as Le Corbusier, who exclaimed, "The first fruits of the new age!" when he first saw them. Buffalo's grain elevators have been documented for the Historic American Engineering Record and added to the National Register of Historic Places.

In farming communities, each town had one or more small grain elevator that would serve the local growers. The classic grain elevator was constructed with wooden cribbing and had 9 or more larger square or rectangular bins arranged in 3x3 or 3x4 or 4x4 or more patterns. Wooden cribben elevators usually had a driveway with truck scale and office on one side, a rail line on the other side and additional grain storage annex bins on either side.

In more recent times with improved transportation, centralized and much larger elevators serve many farms. Some of them are quite large. Two elevators in Kansas (one in Hutchinson and one in Wichita) are half a mile long. The loss of the grain elevators from small towns is often considered a great change in their identity and there are efforts to preserve them as heritage structures. At the same time, many larger grain farms have their own grain handling facilities for storage and loading onto trucks.

Grain elevator operators buy grain from farmers, either for cash or at a contracted price, and then sell futures contracts for the same quantity of grain, usually each day. They profit through the narrowing basis, that is, the difference between the local cash price, and the futures price, that occurs at certain times of the year.

Before economical truck transportation was available, grain elevator operators would sometimes use their purchasing power to control prices. This was especially easy since farmers often had only one elevator that was within a reasonable distance of their farm. This led some governments to take over the administration of grain elevators. An example of this is the Saskatchewan Wheat Pool. For the same reason, many elevators were purchased by cooperatives.

A recent problem with grain elevators is the need to provide separate storage for ordinary and genetically modified grain to reduce the risk of accidental mixing of the two.

An interesting problem the old elevators had was that of silo explosions. Fine powder from the millions of grains passing through the facility would accumulate and mix with the oxygen in the air. A spark could spread from one floating grain to the other creating a chain reaction that would destroy the entire structure. (This dispersed-fuel explosion is the mechanism behind fuel-air bombs.) To prevent this, elevators have very rigorous rules against smoking or any other open flame. Many elevators also have various devices installed to maximize ventilation, safeguards against overheating in belt conveyors, legs, bearing, and explosion-proof electrical devices such as electric motors, switches and lighting.