Concrete problems plagued consecutive elevator projects at Blencoe, Iowa

DSC_0578Story and photos by Kristen Cart

In the summer of 1954, Mayer-Osborn Construction built an elevator with a stepped headhouse in the northwestern Iowa town of Blencoe. As my dad, Jerry Osborn, explained, after the crew poured the first ten feet of concrete in the slip-form process, the concrete sides below the forms showed signs of crumbling. An investigation revealed that the concrete mixture had not been set correctly. It took as many hours to remove the concrete and start over as it did to pour it. Dad worked on the project and saw the fallout first hand.

The larger Tillotson elevator stands to the left. The Mayer-Osborn elevator obstructs the view of its large annex which extends behind it.

The larger Tillotson elevator stands to the left. The Mayer-Osborn elevator on the right serves a large annex which extends behind it. Photo by Kristen Cart

Builders were required to do a destructive test on the concrete mix at various stages of curing, to ensure the proper strength for each part of the elevator structure. Engineers tested various mix ratios to decide upon the best one. Naturally, this process was used at Blencoe, but when the mix was finally set and the pour began, it was done incorrectly. I can imagine the blue language wafting from the site as the concrete was taken down. Someone on the site had his ears pinned back pretty fiercely. But the construction continued, and a handsome elevator still stands there today, nearly 60 years later.

Not until this year, when Tim Tillotson located the Tillotson company records and photographs, did we discover that Tillotson Construction of Omaha faced a similar problem as they built their elevator nearby about a year later. This time, the error was not caught as early, and the consequences became immediately apparent.

Tim Tillotson said he thought the blowout happened in about 1955. Whether Tillotson Construction did the repairs and completed the project, or whether another contractor was brought in, is not known to me, but I hope to revisit the site later this year and learn more. The image below is a rare one. It is amazing that photographic evidence survived, serving as a cautionary note, lest any builder were to become overconfident.

Blencoe_blowout-1 copy

This company photo shows the blowout. On the right the completed Mayer-Osborn elevator may be seen.

Errors were a constant threat in this business. In the best cases, they manifested themselves in embarrassing delays, in the worst, they incurred expensive lawsuits or physical harm.

Tillotson Construction and Mayer-Osborn both recovered from their respective forays into bad concrete and lived to build again, leaving handsome and serviceable elevators at Blencoe and elsewhere. The lessons they learned were priceless.

How to build an elevator: Jerry Osborn’s firsthand account from Blencoe, Iowa

Story by Jerry Osborn and photos by Kristen Cart

The summer of 1954, before my senior year, I started working at the Hormel plant again, but after a few weeks my dad asked me to work on the elevator his company, Mayer-Osborn Company, was building at Blencoe, Iowa. This would be a different experience. Since I had no transportation of my own he took me to Blencoe and set me up in a motel near the site. He also took me to a shoe store to buy work shoes so I would be set to go to work. The wages weren’t great. They were $1 an hour just like all the other grunts on the job. No nepotism on this job. My job was to select the correct steel and see that it was laid properly as the slip forms were filled and jacked. Fortunately, I had enough engineering drawing work that I could read the blueprints. The slip operation had just begun when I arrived, so it was learn-on-the-run for me.

Things seemed to be progressing nicely until we were about twenty feet in the air. At that point it was noticed that some of the exposed concrete was crumbling and falling to the ground. This can’t be good. The operation was shut down immediately to determine what the problem was. It became obvious that the mix ratio of cement to sand and gravel was too low. The work to that point had to be torn down. The demolition was done over the weekend, and we were setting up to slip again on Monday. The concrete was mixed on the job and the appropriate mix weights were to be locked into the scales. Somehow the proper amount of cement was not designated. My brother, who had been on a lot of these jobs, was a supervisor on this job and should have checked the setting for the proper mix.

When operating properly, the concrete was mixed next to the elevator; each mix was dumped into a bucket hoist, which was lifted to the deck level. The mud was fed into two-wheel mud buggies. The buggies were then wheeled to and dumped at the place needing concrete. As this process took place another mix was in process, so when the hoist bucket was returned, it was once again filled and the whole process was repeated over and over until a height of more than 100 feet was reached. As the forms were filled, steel was laid and other features such as portholes were laid in place as the forms were jacked upward, exposing freshly set concrete at the bottom of the forms and providing more space at the top for more mud. A scaffold was built below but connected to the forms so men with trowels could smooth the fresh concrete as it was exposed below.

I had hoped to work until the slip was finished, but the restart didn’t leave enough time prior to football practice.

Gary Rich analyzes the leaning Maywood, Nebraska, elevator and storage annex

Ever since Kristen got me interested in the history of elevators, I am always looking for new avenues. One thing that I have noticed that Tillotson Construction Company, J. H. Tillotson, Contractor, and Mayer-Osborn Construction built grain elevators in eastern Colorado and western Kansas. However, I never knew them to build the storage annexes. There are cases in which one of these companies built the grain elevator; then another company called Chalmers & Borton would be in the same town within three to five years building a storage annex.

I was very excited when I walked up to the annex at Maywood, Nebraska. I saw the manhole covers had Mayer-Osborn on them. I knew that I found my first annex that was built by one of the three companies.

There is a major problem with this annex at Maywood. You can see the cracks in the annex and where they have tried patching them. I drove back to Maywood several days later. Part of the annex still has grain in it. I talked with a person at the office. They are planning on tearing down the annex sometime this year or 2013. They have not made up their mind if they will save the elevator or not. When you are standing looking at both the elevator and annex, it is hard to say which is leaning the most. It looks like the elevator is leaning towards the annex. But on the other hand, the annex is leaning towards the elevator. The image that shows the grain dryer, the bin nearest the elevator, has been emptied, as well as the center bin. The north side still has grain in the all the bins, as well as the bin on the southwest corner (the image that has the sunlight on it).

I finally found a grain annex that these companies built, but it will be history soon.

Tillotson Construction’s elevator at Dalton, Nebraska, shows unique features

Gary Rich contributed these photos from Dalton, Nebraska, along with the following analysis:

Tillotson Construction’s elevators were unique, with some features that I have not seen from other elevator builders. One major feature was the curved head house. I have only seen one other company that produced an elevator with the curved headhouse.¬†Another feature was that Tillotson put windows for light into the basement. Of course they had electric lights in the basement. I have not seen another builder put windows in the bottom part of the elevator. This must be a Tillotson trademark.¬†This elevator has the year of construction added to the manhole covers. It shows 1958. Tillotson did a great thing by adding this. All the elevators that I have been inside, I have not seen another company put the year on the manhole covers. The date was on each manhole cover inside the elevator.