Spaces with low ceilings present a particularly challenging situation for those wishing to use backdrops. And olio drop is a form of a roll drop with a tube is at the bottom. Here are some terrific examples of their use and construction from around the Internet. Credits and copyright belong to those people and sites referred to within.
60 Minutes from CBS broadcast this terrific behind the scenes look at the creation and rehearsal process of Broadway's Spider-Man from Nov. 2010.
As you can see, an OOPS happened. While unloading several costumes from a pipe that was used for temporary storage, the supervisor wasn't paying attention and allowed too many costumes to be removed. 
| We're taking out some of the slack in our fly lines. The problem is that the pipes stop about 6 feet before the height of the ceiling. This cuts down significantly the height of our drops and scenery. |  |
This flying method is a very simple example. If you were to take it further, you could imagine how to fly a person. It works the same way, but uses much heavier equipment. The flying of people and of heavy objects is best left to the professionals who have the proper training and equipment.
| For our production of Dracula, we
needed a bat to fly around the stage. Not just up and down, but left to
right as well. You'll see that the bat is able to go up and down via
tie line through a pulley. This takes care of the up & down part |
 |
| Curtains are hung in either of a
few ways. Flat or full are the most popular. Flat is simply hanging the
cloth stretched across the pipe. Pulled tight it looks like a sheet on
a clothes line. |
 |