Will Photograph At Night

I have decided to try and photograph after dark in the dump. I plan on using a flash with the Plaubel Makina 67. Not sure how well this will work. Focusing should be difficult. I also do not wnt to blind the workers or interfere with their ability to do their jobs. What they are doing for their families is more important than my chasing photographs. I have a head band flashlight and a small hand held unit hopefully they will help me from falling on my ass and allow me to work.