Memories of cranes and pushing the Georgia buggy in Alta, Iowa

The formwork is clearly seen at the Alta elevator rises. The catwalk around the bottom was for the concrete finisher, who smoothed and patched the freshly formed surface. Photo from the Neil A. Lieb Archive.

Commentary by Neil A. Lieb, photo from his archive.

From a telephone interview on July 22, 2014

On the upper left-hand corner, there’s a crane. That crane we used to haul the steel up to the top, the rebar, the jackrods. That’s all we used it for. You didn’t tie up the other hoist, you used that one. I think it’s called a jack crane. It was an electrically operated crane. The railroad tracks are on the bottom, that’s the end of a box car in the lower right. That doorway—that’s used when you’re loading grain after the thing was all over with.

When I first started, I pushed the Georgia buggy.  It’s probably the worst job in the world because it’s very physical. They weighed 1000 pounds. At Alta, I progressed to laying steel. All the new hires always got to push the concrete because that was the hardest work. There was a big turnover when you started out because pushing Georgia buggies wasn’t very much fun.

Night and day in 1950, Tillotson’s grain elevator rose in Alta, Iowa

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Commentary by Neil A. Lieb, photos from his archive

From a telephone interview on July 22, 2014:

It was commercial power for the lamps. The only thing that was noisy was the mixer and the hoist. Once you got about 40 feet off the ground, all that anybody heard was people talking to each other. That’s the top of the driveway (seen in the photo), about 16 feet, so they’re about 25 or 30 feet off the ground. On a construction site, there’s lumber all over everywhere. Today they keep track of it very carefully because people steal it. But when we were building these, nobody stole lumber. People in Iowa and the Midwest, they didn’t steal lumber from a construction site like they do out here (California.) See the scaffolding below the forms? A cement finisher finished the concrete as it came out of the forms. That’s all he did, all night long.

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Those cars…I didn’t have a car at Alta. Those shacks were probably, lower right, the office, and the other was where we kept the tools. We built a lot of those things and then we tore them down. Slip-form construction was a major engineering feat. They built concrete grain elevators before slip-forms. They had steel forms they’d fill with concrete.

 

 

 

The gun fired, and continuous action of many processes began in Alta, Iowa

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In this post, Charles J. Tillotson elaborates on Neil A. Lieb’s previous comments, describing the above photo from his archive. The jack rods referred to in the text are the tall, slender steel poles seen throughout the photo.  

They often say, a picture is worth a thousand words and this one fits the bill perfectly. The photo is truly an aid to describing the method of slipform construction that was used in grain elevator construction. Neil mentions the one-handed placement of the jack rod, so I’ll start with that.
 
Slipform construction is made up of many complex disciplines which have to all work together in order to provide the final poured-in-place concrete product.

As mentioned prior to this, the slipping of the formwork used in this type of construction was provided by a series of screw jacks placed apart by an engineered calculation sufficient to lift each jack’s portion of the formwork assembly.

Each screw jack was supported by a wooden, U-shaped yoke, the legs of which were attached to the vertical concrete formwork. Inserted in the top (or horizontal) portion of each yoke was a screw jack (similar to that used in jacking building foundations). A smooth one-inch jack rod was then inserted into the top head of the jack and threaded down through it until stopping at the foundation slab. 

The formwork is clearly seen at the Alta elevator rises. The catwalk around the bottom was for the concrete finisher, who smoothed and patched the freshly formed surface. Photo from the Neil A. Lieb Archive.

The wooden formwork is clearly seen at the Alta elevator rises. The scaffolding around the bottom was for the cement finishers, who smoothed and patched the freshly formed surface. Photo from the Neil A. Lieb Archive. 

A series of horizontal wooden rails at about waist height (looks like a railroad track) were then built directly above the open formwork, the “ties” of which were placed at prescribed intervals and used as a template spacer for inserting the actual vertical reinforcing steel. (See the small, half-inch rebar rods extending vertically out of the open bin forms at each cross tie). The vertical rebar was staggered slightly in an alternating fashion so as to allow the half-inch horizontal rebar to be threaded through the vertical rebar. On the vertical 2x4s that are attached to the exterior side of the formwork and rise above the entire deck assembly, so-called targets placed on their tops were used in leveling the deck in order to provide a final elevator that rose plumb and straight above the foundation.

As the screw jacks were turned (each jack was turned the same amount), the foreman on deck used a leveling instrument and sighted on each target to insure that the formwork was rising true plumb and level. If any of the targets did not align with true level, the portion of the deck out of plumb was corrected by extra turns of the screw jack or jacks as necessary to bring that portion of the deck up level with the rest of the formwork. 

Not shown in the photo is the horizontal rebar that was required to form a steel reinforced grid integrally cast in the concrete to form a reinforced concrete structure. Initially, the horizontal steel was wire-tied in place to the vertical rebar prior to one side of the forms being installed.  This placement occurred only to the height of the wood bin forms. Once the form-lifting began, the horizontal steel was placed by hand by pushing and threading the rebar horizontally through the vertical rebar. Because of the vertical movement of the formwork, close attention was required as to the spacing between horizontal rebar. 

Now, try to imagine: the start gun is fired and the continuous action of the many processes begins, never to stop until the wooden forms and finished structure reaches the prescribed vertical height (some 120 feet) eight days later. Manual labor is involved in each discipline. Personnel changes occur, but each position is filled by a replacement. The gun is fired, cement is mixed and lifted to the deck of the formwork via a Georgia buggy, and the content is dumped into the open form. The pouring of the cement into the formwork is continued in a circular fashion around the entire deck until it reaches a prescribed height in the form. 

The finished elevator. Photo from the Neil A. Lieb Archive.

The finished elevator. Photo from the Neil A. Lieb Archive.

Once the cement is allowed to solidify in the forms on the foundation slab, the jacking operation begins and the formwork starts its vertical lifting and slipping process. The jacks are turned, the cement is poured, the vertical rebar and jackrods are placed and spliced, and all the while the horizontal rebar is positioned at the proper height and spacing. Pour cement, turn jacks, place rebar, check deck level, and on and on through night and day until the construction reaches final height. The most problematic aspect of this system is the placing of the horizontal steel at the correct spacing, the placement of formed openings in the bins, keeping the hoist in operation, mixing the cement, and obtaining enough set time of the cement mixture so that as the finished concrete walls do not fall apart or slough off.     

Also, hanging beneath the formwork structure is the scaffolding for the cement finishers who dutifully serve to patch and smoothly finish the concrete surfaces appearing at the bottom of the vertically slipping formwork. 

 

 

Building a grain elevator required a whole boxcar of lumber

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Commentary by Neil A. Lieb, photos from his archive

From a telephone interview on July 22, 2014:

Decks for the formwork are stacked at upper-right corner of the foundation. Piles of sand and gravel are for concrete. It took one complete boxcar-load of lumber to build most elevators. Everything came by rail in those days.

One thing you did, you re-used all that lumber many, many times. The inside walls of forms were all taken down, taken apart, and the lumber was all reused. We always had a crew of two or three guys cleaning lumber, taking the nails out and cleaning the concrete off of it. Slip-form lumber was seldom reused. By the time you stripped the forms out at the top, that lumber fell 120 feet to a concrete slab and by the time it got there, it was moving. So when it hit, it pretty well disintegrated.

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This is probably the third or fourth day. They went about six inches an hour. The boxes were put in the forms to leave holes where they wanted a hole. On the inside, they’d want a hole to put a spout or something. They’re all pre-made and numbered. The shift foreman’s responsibility is to make sure they’re put in where they’re supposed to be. They have a given height and given location.

You always knew how high you were because in the elevator’s water shaft there was a continuous measuring stick so you knew exactly how high off the ground you were. It was important that these boxes be put in at a certain height.

You also had a continuous ladder. We used to race up and down.

You see the jacks are on the outside. The guys looking over the rails, this is the back side. Way on the other side is where the cement is coming up. You can’t see a hoist.

 

 

 

 

 

 

 

Stabbing jack rods one-handed and borrowing smokes in Alta, Iowa

scan0007Commentary by Neil A. Lieb, photo from his archive

In a telephone interview July 22, 2014, Neil describes this dramatic scene:

Everything is in place, I can tell you that. This is all ready to go. The big long ones are jack rods. if you follow them down you can see the jack. One-third into the picture from right, you can see the jack heads. You turn those a quarter turn at a time.

An interesting thing about jack rods, to impress the new hires, the old timers… They were eight-foot-long, one-inch cold-rolled steel weighing about 65 pounds. The trick was that you pick up the rod and put it in the jack with one hand. it was something you just did. Just to demonstrate ability, I guess. Everybody on the crew could stab a jack rod one-handed.

Around the outside wall, the thin rods are vertical rebar. If you look in the middle, you can see the hold that the concrete goes in.

Bracing for the hoist is what cuts across the roofline of the house.

Wayne Baker, foreman, is probably the one striding through the middle. Baker never bought cigarettes. When I worked in construction, everybody smoked. I don’t ever remember seeing him pull out a pack of cigarettes.

The Alta, Iowa, grain elevator’s unique layout was ‘a different kind of job’

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Commentary by Neil A. Lieb and photos from the Neil A. Lieb Archive

This post’s two photos show early stages of work on Tillotson Construction Company’s grain elevator at Alta, Iowa, in the spring of 1950. In a July 22 phone conversation, Neil Lieb, who worked on this elevator as a Tillotson employee (1949 to 1951) described details:

Three tanks on right, two on left, a square tank on left … The little tanks were a lot more trouble to make. Alta was not designed by Tillotson. It was designed by some outfit out of Kansas City. So it was a different kind of a job, and it was specifically designed—they had some kind of a grain-drying system that was relatively new. When these [elevators] were built, they didn’t dry the grain. It had to be dry before you put it in. Alta had some kind of a drying system. These bins were all designed—the whole idea was you could have smaller quantities of grain stored that was wet, and you’d run it out of these bins and through the dryer into the bins below. Half full of wet grain, the other half full of dry. The dry was taken back and dumped in the major silos.

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The co-ops in Iowa were very large in those days, with hundreds of members signed up. They would take a sample out of the load and do a moisture content test. So they would test each load and put it in one of these tanks based on how much moisture it had. When they went to dry it, it would take out the required amount of moisture. I know we had a lot of extra electrical work.

The plans for the elevator are inscribed on the elevator [slab], so you could set the forms where they belonged. The scribing was done a couple of days after the slab was poured. So when you build forms and moved them in, you knew exactly where to put them. It looked like it was all hit and miss, but it wasn’t.

Sixteenpenny nails were used in nailing together the forms. When you’re doing this, the foreman will count heads. You make all these interior pieces before you do anything else. When you make these, the foreman counts out heads, and he opens that many kegs of sixteenpenny nails, and they’re all supposed to be empty when you go home at night. Fifty-pound kegs and twenty-ounce hammer, and you start the nail and drive it with three strokes. The nail is a little over seven inches long. When you do that all day long for several days, you develop a real good right arm.

Analysis of photos from Tillotson Construction’s job in Alta, Iowa

 

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By Charles J. Tillotson with photos from the Neil A. Lieb archive

The images from the Neil A. Lieb Archive are the best historical, phase-by-phase photos that I’ve seen yet. They give the layman a good concept of what actually takes place, from start to finish, in building a grain elevator.

A few comments I might add:

The excavation for the foundation began with dynamite.

Excavating the foundation began with a bang.

Neil writes about the use of dynamite during the excavation process. Dynamite was used for foundation excavation on many a job because of the deep frost. We even used it for cutting the foundation of the reinforced concrete garage we built on the old place in Omaha. We were young ’ns then, but still got to set (light) the fuses to a few charges.

I remember getting the neighbors excited about what the hell we were doin’ now.

By the way, the garage utilized slip-form construction with steel stays instead of wood for the formwork—another of Dad’s experiments. He was interested in finding materials that could be reused over and over, rather than having to buy lumber formwork for every new job. I guess this method didn’t make a lot of sense, as he never tried it out on an elevator.

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This photo is an historical testimony as to how the so-called unskilled, common man could be taught layout along with measuring, wood cutting, and other carpentry skills. The labor used to build these forms and construct the entire grain elevator structure was obtained, for the most part, from the inhabitants of the local vicinity where the elevator was to be built. Most of the workmen had no experience whatsoever in the construction industry.

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People used to marvel at how the cement went into the top of the formwork and came out the bottom of the forms, in a set-up, semi-solid state, all occurring whilst the deck and forms continued to extend upwards, being jacked up on screw jacks. Once the slipping of the forms began, it never stopped, unless by a power outage, a severe storm, or some other interference.

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Beneath the deck and main formwork, a sub-scaffolding was constructed to provide access to the exterior face of the concrete structure, which required patching and touch-up for a final smooth finish. A rich mixture of cement, sand, and lime was used which was applied to the concrete face by hand, usually covering the entire exterior surface, removing all blemishes. The finish material was hoisted in five-gallon buckets to the finishers. These workmen traversed the scaffold of wood planking—usually two, 2 x 12s laid flat between the wooden hanger frames that attached to the formwork above. Very dangerous work without a safety net!

At the ground level, a workman on a tractor would load a Georgia buggy with cement, to be hoisted to the top and placed in the formwork. Small skip loaders, tractors with scoop-type buckets mounted on the front, were an essential tool used during construction. This included scooping up the sand, gravel, and cement to make concrete and placing them in a mixer.

Neil A. Lieb collection Once the concrete was ready for placement, the tractor scoop was filled with the cementitous mixture and transported to the side of the elevator whereby the tractor would dump its load into a Georgia buggy to be hoisted up to the deck for placement.

Because of the extensive use of the tractor, more than one would be worn out. During the extremely active 1950s, Tillotson Construction Company would purchase Ford Ferguson tractors a dozen at a time, just to keep up with the need for replacement

The logistics of material supply was always challenging for the grain elevator builder. Usually, the projects were located in very rural farmland areas, where the supply of lumber, steel, sand, gravel, cement, gasoline, and oil was miles from the site. Because the construction utilized the slip-form method, the operation never stopped once it began, making it paramount that the supply of materials be established beforehand along with a comfort level that there would be no interruption once the job started.

Neil has noted (in an as yet unpublished commentary) the mixture of the gleaming, white, finished “paint,” which wasn’t really paint at all but instead a cementitious mixture that lasted for a very long time. Some of the elevators existing today still boast the original finish. Tillotson was among the few contractors that finished out their jobs this way.

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Training the local unskilled labor in the processes of placing and wire-tying the reinforcing steel –and of pouring concrete, turning screw jacks, keeping the slip-form deck level, et cetera– were just a few of the many headaches the job superintendent had to bear during the initial start-up phases.