I used the worm gear drive (30 to 1 ratio) which turned the tines on a garden tiller. It was originally powered by a 5 HP horizontal engine. Gave a guy $5 for it. I cut off the unused side of the output shaft and attached a 14 tooth sprocket ( # 50 roller chain) through a simple clutch to the other side. A roller chain drives the winch drum (2.5" diameter x 5'' length) via a 36 tooth sprocket (from an old JD wheat drill) attached to a 1 1/8" drive shaft ( keyed). A 3/4 HP 1725 RPM electric motor with a 3" pulley drives the worm gear which has a 4" pulley mounted on the original drive shaft. The motor is actuated by a reversing switch for power in and out. Disengaging the clutch allows free spooling. A maximum tension of 1600 lbs stalls the motor and protects the system. It will turn a log in a few 10's of seconds...less than a minute. Constructing the winch took some minimal machining. I have a Bridgeport mill and a very old 20" Springfield lathe which helped.
Images are below.