Grain elevator
From Free net encyclopedia
- This article is about grain elevators. For other meanings of "elevator" see elevator (disambiguation).
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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. Originally constructed of wood, which was prone to fire, silos (or bins) are now made of steel or reinforced concrete. Bucket elevators lift grain to a distribution point, where it flows by gravity into one of a number of bins, which are then unloaded by gravity. The bins and their unloading chutes are designed so that trucks, rail cars or barges can be filled from them directly.
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.
Buffalo, New York, once the world's largest grain port, not surprisingly has the world's largest collection of concrete grain elevators, 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 its own small grain elevator that would serve the local growers. The classic grain elevator was made of wood and had 12 rectangular bins arranged in a 3 × 4 pattern. 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.
See also
- Peavey-Haglin Experimental Concrete Grain Elevator, in Minneapolis, Minnesota, the first reinforced concrete grain elevator in the United States