It has been said that necessity is the mother of invention.
Worker safety during bin cleanout was the necessity at the ADM/Growmark terminal elevator at Morris, Illinois, U.S. This 1-million-bushel capacity facility situated along the Illinois River receives corn and soybeans by truck, then loads it onto barges for shipment to the Gulf.
Grain is stored in eight concrete silos and two large flat-bottom bins. When ready for barge load-out, the grain empties through a gravity-fed center onto a conveyor and then to the barge. When the bin is nearly empty, a sweep auger must be used for final cleanout. The sweep circles the bin floor, pushing any remaining grain to the center of the bin and onto the conveyor.
This type of cleanout is done two to three times a year in each bin.
A recent bin cleanout raised a safety red flag when it was noticed that workers who were required to be inside the bin during the operation had no control over the sweep auger, which could only be turned on and off from outside.
As entry into any confined space is always a key safety issue at grain elevators, this lack of control over the auger was a concern to Rich Hamilton, plant superintendent, and Dale Knapp, new project manager. That led to a discussion about possible alternatives, which led to the idea and subsequent invention of a bin sweep safety cable.
"We're always thinking of ways we can do things better," said Hamilton, who also has been an operations trainer and assistant superintendent during the seven and a half years he has worked for ADM. "When we put our employees in that tank, we want them to be as safe as possible.
"Our employees come to work each day with 10 fingers and 10 toes and they go home each day with 10 fingers and 10 toes."
Hamilton and Knapp sat down with the plant's maintenance supervisor, Tim Tesdal, and together the men came up with a design for a sweep safety cable.
Gathering some components from the plant's maintenance shop and ordering other parts from vendors, Tesdal wired a pull switch to the sweep auger motor. A cable was then run from the pull switch along the length of the sweep auger, held about 18 inches above the machine by four mounting points welded to the sweep frame.
As soon as a worker pushes or pulls the cable anywhere along its length, the pull switch shuts off the sweep auger motor. The sweep can be turned on again only from outside the bin.
Design and construction of the safety cable took about two weeks and installation took about eight hours.
The bin sweep safety cable has been used at the ADM/Growmark facility for nearly a year. Hamilton gave a presentation about the safety cable at this year's "Why Don't They? … I Did!" forum at the Grain Elevator and Processing Society (GEAPS) Exchange, held March 3-6 in Phoenix, Arizona, U.S. This forum highlights ideas and innovations that come directly from grain elevator workers.
Hamilton said the sweep safety cable has been well-received by his workers and his peers. The company also is considering filing for a patent on the device, he added.
But the real pay-off has been a safer cleanout operation, putting safety into the hands of the workers inside the bin.