Construction and Cranes

We have included several views of a construction site that is just across the street from where we were living in Bad Vilbel. It has been fun watching that project. When we moved in there was a parking lot on that corner. Then one day a caterpillar tractor was there digging up the asphalt. They moved in a huge machine that ground that up and loaded it on trucks and hauled it away. Then they started digging a hole for the basement. They had a precision operator with a big backhoe dig and shape the basement hole, and they then poured a thin layer of concrete to keep the shape of everything while they formed and placed reinforcement iron (re-bar). Soon they were pouring concrete for footers and a basement floor.
Then big trucks came in with pre-formed walls. Each wall was made of two slabs of concrete about 5 inches apart. These were carefully lowered so that reinforcing rods had were sticking up through the floor were now in the middle of the sandwich. When all the walls were in place and properly braced and sealed, they filled up the walls with concrete, with more rebar sticking out the top. Then more trucks carrying concrete slabs came and they carefully positioned the slabs on top of the walls and pillars to make a floor at ground level. Within hours, they had a crew in, positioning more rebar and a lot of flexible conduit of various types. Finally they poured concrete to complete the floor, and moved on to start walls for the next level.
They attached foam insulation material around the basement walls, and dump trucks came carrying the crushed blacktop that had previously been hauled away, which they used to back fill around the outside walls. German construction crews use several types of special compacting tools to tamp things down and in two days the backfill was complete on the two sides next to the streets. They got the major walls and pillars in place and filled with concrete just before Winter weather and the Christmas Holliday season stopped them, and since then there hasn’t been even a single workman appear on the project. We moved away mid January, and not a footprint could be seen in the snow anywhere on the project.

Some of the pictures show a type of crane that is very common in Germany. This one is one of the smaller ones. It was set up when they were still trucking away the dirt they dug out for the basement. The base of this one doesn’t move except to rotate, but some are mounted to a set of tracks like railway tracks that are temporarily installed. This allows the crane to move from side to side. All of them have a tall vertical tower that can be rotated, and there is a horizontal beam near the top. There is a trolley on the horizontal beam so loads can be shifted closer or farther away from the tower. The loads are carried by cables that come down from the trolley. These cranes are really quite functional.

You might remember that one like this was used in the construction of the conference center in Salt Lake. It was destroyed by the tornado that went through at the time. The operator of that one, like many in Germany, was in a little control room near the top, and when bad weather came he climbed down to safety. The one pictured here is controlled by an operator on the ground with a remote control.

This pictures shows our old apartment (on the left side in the roof structure) with the construction of the ground-level floor of the new hotel complete in the foreground.

The German people are very proud of these cranes. They were originally designed and made here. When I was a missionary 47 years ago, I showed some pictures of the Salt Lake Temple under construction, and in the picture you could see the “derrick” that they used to help with that project. The people were incredulous that someone else had worked out such a system before them.

One note: this one can’t handle very heavy loads, so when they installed concrete slabs for walls or floors they brought in another crane that is more like what we usually use in America. There are much better designs available here, however, and they are used at all construction sites. It is not unusual to see three or more of them on the skyline when traveling in areas that are growing.

We can see ten of them in this view of the skyline of East Frankfurt as we look out of our windows in our new apartment. I understand there are about 25 at the construction sites around the Frankfurt airport.

The one used in Salt Lake City was so big its horizontal arm could cover the whole building. Most of the loads were picked up from the other side of North Temple Avenue right by the North Gate into Temple Square. That crane had a cantilever system in which the top horizontal beam projected both front and back, and very heavy counterweights were shifted back and forth on the back side to balance with the loads that were being handled on the front. Germans are good at engineering, and their construction plans include a detailed schedule for the use of the construction crane so it can handle the thousands of lifting jobs in the right order for the job to move ahead smoothly.