Thinking about it.

   I am working on a draw bridge. (Today I was painting some of it).   The span is 36 inches x 18 inches.  It is a simple open girder bridge with two 30 inch high supports for each end that are painted grey.  They have metal plates that make contact with the bridge and control power to all 4 rails.  It is also nice and sturdy but the problem is that it is heavy.  I am afraid it will come crashing down and hurt someone.  So what I am thinking about is using a couple "Castle towers" like the ones shown sitting next to the bridge.  With a little modification I think I could turn it all into a working drawbridge that will use counter weights and pulleys to balance the weight of the bridge.  There would be a chain coming out the little windows to the bridge.  Obviously,  the wall would be gone and the catwalk could either stay or go.   I have looked at pictures of draw bridges and there are so many varieties that I am beginning to think why not a castle tower bridge?  I made a quick test with small pulleys that I have and I think it will work.  The main objective  is to make it safe and easy to operate.