drawings of steam engine

Hi, I am researching steam cranes used in Boston for construction around 1895-1910. I am trying to create some drawings that show how the steam cranes worked. I am more of an artist than an engineer - so I'm looking for a little help in understanding the nuts and bolts. I have a couple drawings that attempt to give a visual explanation of the engine. Is there someone who would be willing to look at them and give some feedback? Thanks, Joe McKendry ps.- I would also be interested in finding out more info. on the particular type of engine used at the time. It stood upright, was mobile, and was about 12 feet tall.