Today's Vocabulary and/or Trajectory Lesson

As I came in to work today, a memo was posted on the door. Apparently, we are getting the windows washed in our building, and the property manager felt the need to let us know what was happening. A particular sentence, however, caught my attention:

"Their employees will be propelling from the roof in order to reach every floor."

Really? The employees will be propelling from the roof?

For those of you new to the English language, to "propel" means "causing to move forward or outward with force." The action of going down a shear surface while attached to a rope, as someone may do while washing windows, is called "repelling."

For clarification, here's a visual demonstration:

REPELLING from the roof


PROPELLING from the roof
Of course, if they are propelling from the roof, I probably need to move my car.

Until next time,
The Jim