Grain Elevators of
Port Arthur & Fort William
Thunder Bay, ON

Appendix A: How Grain Elevators Work

Appendix A: How Grain Elevators Work

Anatomy of an Elevator

Elevators are designed to hold grain in an environment where it can be stored, sorted, and shipped. Because bulk grain behaves more like a liquid than a solid, it is elevated so that gravity can do most of the hard work. This is partly the reason why most elevators use silos made of concrete or brick; grain is heavy, and pushes out on the walls of an elevator like water pushes against the walls of a water tower or dam. Concrete especially does a good job to contain the mass of grain, support its own weight, and withstand the weight of the equipment on top of it.

Above the silos is a building called the headhouse or workhouse, which is where incoming grain is sorted into the silos below. It is full of movable tubes, scales, and conveyor belts that move and measure the incoming grain before it is sorted into the silos, or, depending on the design, one of the smaller spaces between the silos.

The cupola--the space above the silos--is surprisingly original. The building was too unstable for anyone to scrap it out. Seriously, the floor is a deathtrap.
The cupola–the space above the silos–is surprisingly original. The building was too unstable for anyone to scrap it out. Seriously, the floor is a deathtrap.

When grain enters the elevator, it does so from an area called the pit, so called because it is below the silos and often below the ground, making it easy for trains and trucks to unload. From there, a machine called a bucket elevator lifts the grain from the pit to the headhouse for weighing and silo assignment.

From the headhouse, grain would be transported to the silos themselves at the copula level, the floor directly above the silos. This floor would include a machine called a tripper which would move grain from a moving conveyor belt into floor ducts leading to the silos themselves.

Without a conveyor belt, this tripper seems lost. The job of this machine was simply to take grains from the moving conveyor belt and eject it into the silos via the chutes on the sides. Note all the dust collection venting added to the machine to suck up any explosive grain dust.
Without a conveyor belt, this tripper seems lost. The job of this machine was simply to take grains from the moving conveyor belt and eject it into the silos via the chutes on the sides. Note all the dust collection venting added to the machine to suck up any explosive grain dust.

A bucket elevatoris essentially a wide belt with horizontal buckets attached, which rotates, carrying grain upwards as fast as the belt can move. Bucket elevators are sheathed in metal so any lost grain from an upper bucket is caught by a lower bucket, keeping the whole operation cleaner.

All of the bucket conveyors crashed on this work floor when their casings were scrapped. Note all of the valves to open the grain flow.
All of the bucket conveyors crashed on this work floor when their casings were scrapped. Note all of the valves to open the grain flow.

Grain dust itself is flammable, and depending on the way it mixes with air, it has the ability to violently explode. This is another reason most elevators are primarily concrete: so that any explosion is bent upward, instead toward neighboring buildings and people.

In summary, grain enters the elevator by being dumped into the pit, where a bucket elevator brings it to the headhouse for weighing and sorting, then it is ducted to the copula and conveyed into a silo. To remove grain from a silo, valves at the bottom of the silos would open, allowing grain to flow back into the pit onto conveyor belts to a bucket elevator. From there, the grain will likely be weighed again in the headhouse before gravity takes it to trains or ships.

Belt Manlifts

Looking down a manlift on the ore dock side of the elevator. It's a belt-less belt-o-vator!
Looking down a manlift on the ore dock side of the elevator. It’s a belt-less belt-o-vator!

Quickly after its invention in 1886, vertically traveling belt elevators were common features in grain elevators.

Variably referred to as Humphrey Manlifts and Belt-o-Vators, these consist of a long rotating belt with hand holds and standing platforms, which were attached to the belt. When motors turned the belt, a worker could travel up or down by standing on the platform. Belt direction would be controlled by pulling a rope beside the cable up or down.

Belt-o-Vators have been scientifically proven to be the most badass alternative to staircases.