Floating dock using 55 gal.drums for floats
I built a dock using plastic drums. I bought two steel truss's from a recycle outlet. These I welded together to form a frame.
Then, I made a swing-up landing gear from the rear wheel axle assembly of a car. The wheels raised and lowered using a winch and cable.
I was able to attach a tongue and hitch and could move it out of the water in the same manner as is done with a boat.
Just remember, the barrels must form two 'pontoons' to be stable.
One fellow that I know, placed the barrels cross-wise and it wouldn't float level.