Grain Elevators
Small Elevator Image
Form and Function

How Do They Work?

A grain elevator is an awesome structure yet it seems simplistic. At first glance you are presented with a large concrete structure that resembles several farm silos strung together. Beyond the huge "towers" that are attached to one side of the elevator, and the fact that these "towers" ride on rails, there doesn't seem to be anything really complicated about the operation of an elevator. However, looks can be deceiving.

Close up of bins
An elevator is so big and strange looking that few people take the time to find out what goes on inside. Just keep in mind the word "elevate." In a grain elevator, the grain is carried up then dropped, elevated and dropped.

After a freighter is tied up alongside an elevator, the elevator's "marine leg", is lowered. The marine leg is a long, massive steel column which houses an endless chain with many buckets attached. The "leg" is dipped into a hold and the buckets bite into the grain and carry it to the top of the elevator (ranging in height from 70 to 140 feet).

Close up of bins
A view of one of the two marine towers on the Great Northern elevator.
Marine towers, in which the marine leg is housed, can either be in a fixed position or movable on car wheels. With a fixed tower the lake boat must be moved so the marine leg can get all the grain from the holds. The movable tower can reach a number of holds, but not all of them, so some ship movement may still be required. Power shovels can be used to drag the length of the boat's hold in order to reach the marine leg. The Scoopers may operate this power shovel but they may have to shovel and sweep by hand the last grain from the hold into the buckets that raise grain into the elevator.

When a ship's hold is full, a marine leg can carry grain to an elevator's top at the rate of 35,000 to 40,000 bushels an hour, but as the hold empties and the grain has to be fed to the leg by scoopers, this rapid rate is cut down to around 20,000 bushels an hour. Thus, a "fast house" with two marine legs can unload a 400,000 bushel freighter in ten hours.

When the grain reaches the top of the marine leg, it is dropped into a scale for its first weighing. These scales can weigh about 25 tons of grain at a time. After the weigh-in, the grain is boosted from the top of the marine leg to the top of the elevator proper, carried over the tops of the round bins which lie next to each other, and finally dropped into the assigned bins, according to the grade of the grain.

Unloading grain from a freighter.
Unloading grain from a canal boat. (LOC/DPC)
"The grain stays in the elevator's bins for varying lengths of time. During the summer and fall, it stays for only a short time, as it is usually transferred quickly to box cars for shipment to the coast. At the end of the shipping season, when storage bins in other cities have been filled with wheat passing through Buffalo, the elevators in Buffalo then fill up with the purpose of keeping the grain for a longer time. Extra storage space for the winter months is obtained by keeping the grain boats full and tying them up alongside the dock, withdrawing the load as it is needed." **

When grain is taken out of the mammoth bins, it is dropped from the bottom of the bin onto a huge scale and then elevated again to the top of the bins. From the top, it is dropped by gravity through long tubes into waiting barges and box cars. Large elevators can load more than one box car at a time. One elevator, for instance, has four spouts or outgoing legs which can load six 2,000 bushel box cars an hour.

As early as 1905 some marine legs in Buffalo elevators used the "pneumatic principle", a system of air flowing through a tube that sucked up grain like a giant vacuum sweeper. At first, bins were built of wood and usually lined with iron. After 1890 steel bins were built in a number of different arrangements. Since that time reinforced concrete has been used. Round bins were the most common shape though some were rectangular or shaped like a four-pointed star.

As mentioned earlier, some grain elevators in the Buffalo area were called "fast houses" by those who worked there, or stored grain there. Actually, the term "house" refers to the elevators workhouse situated at the top of the structure -- perhaps 250 feet or more above ground. The workhouse had room for lofter legs, shipping scales, cleaning and shipping equipment.

the Great Northern Elevator.
In a scene from the grain industry's glory days, an endless stream of freighters wait to unload grain at the Great Northern Elevator. (LOC/DPC)
Workers could have climbed ladders or ride personnel elevators to the top but either method would have been costly and time consuming. Consequently, grain elevators used an ingenious method called a "man lift." This was an endless moving belt stretching from basement to the the top with 12-inch square platform attached every 25 feet or so. To go up or down a worker had only to step on a wooden platform going in his direction and hold on.

How Were They Built?

Building a grain elevator either of wood or concrete required special skills in engineering and design. One bushel of wheat weighs roughly 60 pounds,so a 1,000,000 bushel capacity elevator contains about 30,000 tons of grain. This creates an average load on the foundation of about 10,000 pounds per square foot. Interesting of note is the fact that the land along the Buffalo River was marsh land with a low load-bearing capacity. So the elevators built before the 1920s had timber pilings driven down into the rock to help support the structure. Oftentimes, these pilings would have to be driven anywhere from 15 to 80 feet below ground level.

If an elevator was located further inland, soil conditions were much better for supporting a heavy structure. Also, steel and concrete came into their own as construction materials. For example, the Agway Elevator was built on a concrete mat 3 feet thick which in turn rests on a natural foundation of stiff clay.

But whatever the foundation for the elevator was, be it wood pilings or concrete slabs, construction of the elevator itself could begin once the base was completed. In 1907, the American Elevator was built of reinforced concrete, a method of taking steel rods and embedding them in the concrete to provide the reinforcement. This method was used to keep the bins from bursting open due to the outward pressure of the grain while at the same time directing the massive load of the grain down to the foundation. And obviously, concrete is fireproof.

Slipform construction.
This image show the construction of an elevator using the slipform method. (BECHS)
A method known as "slipform construction" was generally used to build reinforced bins. In the earliest stages of the elevators construction, a form usually four feet high was build on the foundation slab. Screw jacks placed at intervals of about seven feet were used to raise the form. Workers operated the jacks at a rate calculated to raise the form about 6 inches and hour giving the concrete time to set at the bottom before being exposed by the slowly rising form.

Using this method it took about 10 days for the Standard Elevator to reach the height of 125 feet, which was the average height of most bins. After the bins were complete, the workhouse was slipformed up until the elevator reached a height of 200 feet. Because of its complicated design, the workhouse was often built of steel rather than reinforced concrete.

The top deck of a grain elevator under construction was a very busy place. Placement of steel rods, pouring of concrete, and jacking of the form were continuous processes. Generally, each jack man had twelve jacks to tend to. A whistle sounded as the signal for each man to make one turn on each jack. Raising the form six inches required 288 turns -- almost five a minute -- on his jack. Understandably a jack man occasionally got tired enough to miss a few turns causing his section of the form to be lower than the rest, resulting in considerable stress on the form. For obvious reasons, this was not looked upon favorably by the job superintendent.

Superior Elevator construction.
The Cargil Superior elevator under construction in 1925. (BECHS/ARCADIA)
Supervising and inspecting the construction of a grain elevator by the slipform method was a formidable task. Concrete had to be poured properly and steel rods needed to be placed correctly so that they provided the required strength in the bin walls. Before construction began, workers would store enough reinforcing steel at the site to complete the job. After the job, having some of the steel left over caused some head scratching as the men wondered why they had any left at all. This led to the suspicion that some steel might have been left out, possibly at critical points. What followed next was pandemonium as the men wondered if the structure was up to design specifications.

According to legend, a great deal of steel ended up in the Buffalo River to cover up omissions or weaknesses in construction. Even if this were true, bin burstings were uncommon. Fires, explosions, and collapses for other reasons occasionally occurred, however, and these provided some of the most dramatic events in the history of the Buffalo grain industry.

When Things Went Wrong

Fire destroyed a number of the early wooden elevators in Buffalo. Newspapers related the story when the National and Globe Elevator on the Evans Ship Canal burned to the ground on October of 1963. The National and Globe had been built one hundred years earlier and was abandoned at the time it burned.

After the 1890s, construction with steel and reinforced concrete reduced the problem of fire, except in the grain itself. Spontaneous combustion of grain caused a slow, smoldering fire deep in the interior of a bin. Using water to douse the fire would spoil the unburned grain, so other methods were developed to deal with this problem. The bin may be "turned over;" that is, the grain run out to another bin to cool it off or dry ice can be placed on top. This generated heavy carbon dioxide gas that sank into the grain and smothered the fire below.

The Husted Elevator after the explosion.
The Husted Mill and Elevator after it exploded in 1913. (BECHS)
Grain dust is an extremely volatile substance that can explode without warning. One such explosion occurred in 1913 at the Husted Mill and Elevator. The explosion killed 33 people and injured 80 others. Exact causes of fires and explosions were very difficult to determine. Sparks from electrical equipment were blamed, so was static electricity built up on moving belts. Overheating or badly aligned machinery caused fires and there was always the problem of careless smoking.

Agway "B", one of the first elevators to be constructed of concrete in Buffalo, had topless bins like some of the older wooden elevators. However, topless bins proved to be unsuccessful at preventing fires and explosions. Fires would spread from one bin to another and if an explosion occurred it would cause a chain reaction with the dust from the other bins. There was also the ever-present danger of men falling into the bins.

Agway "A" and Eastern States were built later on using concrete covers for each of the bins. The theory was that if an explosion occurred, the cover would blow off without disturbing the other bins, much like a safety valve protects a steam boiler. The only problem was the fact that these concrete covers were twenty feet in diameter and weighed 4 tons. What would happen if one of the covers were blown into the air and landed in an area where men were working? Obviously not a pretty thought. Luckily, an accident such as that never happened.

Grain loading spout.
This is one of the spouts underneath a bin at Concrete Central. A worker only need to turn the wheel and the grain would fall by gravity into railroad cars.
As the years passed, special safety and health measures were added to the elevators to help prevent catastrophic accidents. Specially built enclosures prevented the escape of sparks or fire from electrical motors, switches, and lights. Smoking was prohibited in areas of possible exposure to grain dust, and workers began wearing face masks to guard against inhaling the dust. More modern elevators have temperature sensing cables inserted into each of the bins to detect when heat levels rise. A warning is then sent to a central point so action can be taken to prevent spontaneous combustion or other damage to the grain. Large bins may have ports near the bottom through which air can be blown to cool off the grain.

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Some of the photographs contained on this page were from
The Library of Congress, Detroit Publishing Company Collection,
The Library of Congress, Panaramic Photographs Collection,
The Buffalo and Erie County Historical Society,
The Western New York Heritage Institute and
Lower Lakes Marine Historical Society.

Additional photographs were from the book "Buffalo's Waterfront", another volume of Arcadia Publishing's "Images of America" series; written by Thomas E. Leary and Elizabeth Sholes. This book is available at most bookstores in the Western New York area, or through the Buffalo and Erie County Historical Society.

** Portions of this section were reproduced from the book "Grain Elevators" by Henry H. Baxter; Volume 26 in the "Adventures in Western New York History" series, published by the Buffalo and Erie County Historical Society.