How can I communicate with deaf people effectively???

Question:

How can I communicate with deaf people effectively???

I work as a supervisor in a manufacturing factory. I always have to pass on information and give instructions to the workers as well as train them. On the other hand they have to report their job to me in paper form and in speech. Inside the factory, there are a lot of deaf workers. I find a difficulty to communicate with them effectively. Of course I don't know sign language. Some of them are very low educated or even never attend to any former school. They cannot understand any kind of language even their own mother tongue. Thus I can't even write those information on a piece of paper to let them know my notices. I never look down on them or refuse to communicate with them. May be some of them feel inferior about themselves, they refuse to communicate and cooperate with me. I want to treat them friendly instead of using my authority to force them to do the jobs. Can anybody tell me how to communicate with those deaf workers effectively?

Best Answer - Chosen by Asker:

find out how they communicate amongst each other or with their families. There has to be some way they understand.
When you find out - invite someone in who will assist with developing a strategic way of implementing their form of communication with you. Once you learn it, you should be able to accomplish what you want.
It will take time and resources, but obviously you are supportive of their right to work in your factory, so you need to get creative with your resources.