While High Lead Logging technology played a major role in the development of the logging industry here in the northwest, Gin Poles were a simple adaptation used primarily for yarding and loading railcars. The following photo of McDougal & Biladeau Logging Company's Ravensdale operation shows a donkey engine providing the power required to load rail cars. The gin pole can be seen on your right.
The problem once again to be solved was finding a simple way to move these huge logs so that they could be transported. Rather than use a tall spar tree, smaller gin poles were used to attach guys that support a block and tackle for lifting loads. The gin pole in the above picture can be seen on the left. Steam powered donkey engines, fueled by wood, were once again the universal power source.
The above photo shows a railcar loading operation as does the photo that follows.
Interestingly, gin poles remain in use today though a bit more up to date as shown in the following photo from American Resource & Energy Company's Verticle Gin Pole Wind Tower Raising System. I don't think they use a donkey engine for power.