Tuesday, May 12, 2015

Scott And Carol Present - An On Site Construction Tour of Switchback at ZDT'S Amusement Park

One of the more interesting projects for this season is moving along in Seguin, Texas.

Danny and Sarah Donhauser welcomed us for visit to personally see how Switchback is progressing. Danny has left the operation of ZDT in Sarah's hands and is working pretty much on construction only, until the coaster is finished.


Here the excavation has been done for this section and you can see how the foundation has been tied together. Danny stated that the poor soil conditions require a more extensive support structure, but it should last much longer since they are doing it right from the beginning. The foundation extends 27 to 30 feet below ground level and there are 128 pilings.

Here you can see some of the first ledgers that have been installed. All of the pressure treated yellow pine is onsite and ready to be installed once the tracking can get started.

The extreme angle of the  track show here led to an interesting phone call back to the guys at The Gravity Group. Danny thought there was an issue with the short length of the foundation so he checked it because he thought a mistake had been made, but all was well, because now you can see that the shorter width is correct due to the high banking.

Switchback uses a steel support structure, and here you can see the "assembly line" for the bents. This is a larger version of the erector set you may have played with as a child.

They are quite large and it is a good thing the Donhauser's own the whole block, because they need the space. Some of these tall bents should be put in position in about 2 weeks if the weather cooperates during the rainy season. That will result in a major change to the skyline of ZDT's Amusement Park. Due to the nature of Switchback, it will have two toppings instead of just one, just another unique feature of the ride.

The coaster is so tightly fit squeezed in between the buildings that on this section the lifts must be assembled vertically in place because the crane cannot get to a reasonable position. Of course larger cranes are available, but for just such a small portion of the ride it would not be economically feasible, so they work the structure up, one piece at a time.

The process for Switchback has to ebb and flow due to not being able to continuously do each of the processes. First they dig, then that equipment gets moved out and then they pour concrete, and then they erect the lifts. Usually  projects just start at one end and move across the site but here discrete operations are required. Yes the coaster will go through this corner of the building.

More than one building had to be modified to fit in the roller coaster. Here is another one, which should result in a great sideways head chopper during the ride. Hopefully later this summer we can all ride a coaster like our great grandparents did during the first golden age of rollercoasters. We can hardly wait. Our thanks to Danny and Sarah for their great hospitality and continued wishes for good weather this summer.