![](https://blog.uvm.edu/cwcallah/files/2019/08/IMG_0287-e1565793376358.jpg)
This tunnel has roll-up sides that are adjusted by turning a long pipe. The pipe provides leverage for easier rolling. With each turn, the pipe is slid back through the turnbuckle to make another turn possible.
This tunnel has roll-up sides that are adjusted by turning a long pipe. The pipe provides leverage for easier rolling. With each turn, the pipe is slid back through the turnbuckle to make another turn possible.