By Ronald Ahrens
On April 11, 1949, the Daily Times Herald, of Carroll, Iowa, reported a new elevator under construction in Glidden for the Farmers Co-operative Company.
“About 20 feet higher than the present buildings, the new elevator will be situated east of them,” the newspaper reported. “With the additional storage space the company, for several years the largest co-operative elevator owned and operated in Iowa, will be able to take care of a large amount of corn and beans grown extensively in the Glidden area.”
The bins had quickly risen to 100 feet in height.
Tillotson Construction Company, of Omaha, was using a crew of about 35 men, who worked 10 hours per day, the report continued, perhaps leaving out at this late stage that a continuous pour would have require successive shifts in order to reach 100 feet.
Completion of the 100,000-bushel elevator was expected by July or August, the report said.
Through the company’s construction record, we now know more about the elevator. It is the twin of another elevator built that year in Churdan, about 22 miles away on county and main highways.
Those elevators had an exact capacity of 102,000 bushels. They used 1083 cubic yards of reinforced concrete and 57.72 tons of steel, including jack rods. The 24-inch-thick main slabs were 48×48 feet in area. The overall weight of the reinforced concrete, rated at 4000 pounds per cubic yard plus the steel, was 2224 tons.
Each elevator could hold 3060 tons of grain, averaging 60 pounds per bushel. Including all machinery and the hoppers, the gross loaded weight was 5709 tons, for a bearing pressure of 2.52 tons per square foot.
The curved cupola, or headhouse, which was the important signature of a Tillotson elevator, stood 17 feet wide, 34 feet long, and 22 feet high.
These were single-leg elevators, each with a full basement and an electrical room. Pulley centers were at 125.67 feet.
Each boot pulley was 60 x 14 x 2 3/16 inches while each head pulley differed only by having an axle shaft 1 3/4 inches greater in diameter.
The six-ply Calumet belt supplied for each leg was, of course, 14 inches wide. Cups of 12 x 6 inches were to be set nine inches apart, although a note under “Remarks” somewhat ominously says, “Cups @ 12″ O.C. @ Glidden” and adds “Job Error.”
A 30-horsepower Howell electric motor drove the head pulley. The theoretical leg capacity according to manufacturer ratings was 6540 bushels per hour, but running at a conservative 80-percent of capacity meant a more realistic take-up of 5230 bushels per hour.
The remarks make one distinction between Churdan and Glidden, saying the former had a split bin for the drier while no bin was fitted at the latter.
The driveway was 13 feet wide. There were two dump grates of 9 x 5 1/2 feet and 9 x 15 feet.
Later entries show a 331,000-bushel storage with flat-bottom tanks was added at Glidden in 1954. The next year, Churdan was expanded with 198,960 bushels of new capacity. They used 2318 and 1351 cubic yards of reinforced concrete, respectively, and 116.5 and 79.5 tons of steel.
Other specs for Glidden’s storage:
Main slab: 33 1/2 to 49 x 127 feet for 5481 square feet in total
Weight of reinforced concrete: 4752.5 tons
Weight of grain: 9930 tons
Gross weight loaded: 15,007.5 tons
Bearing pressure: 2.97 tons per square foot
Main slab thickness: 24 inches
Height of drawform walls: 104 feet
Cupola (headhouse) dimensions (W x L x H): 14 x 98 1/4 x 8 1/3 feet
Top and bottom belts: 24 inches @ 600 feet per minute
Cross belts: 24 inches @ 600 feet per minute
Over 2,000 TONS??? Unbelievable! And what is “continuous pour”, may I ask?
Once the pouring of concrete began at ground level, it couldn’t stop until the walls were drawn up to specified height. Otherwise there would be horizontal seams where fresh concrete was poured atop the already hardened stuff. A seam compromises structural integrity. Here’s the link to a post we did a few weeks ago about the largest continuous pour ever attempted:
Here’s something else that addresses the question of a continuous pour: