Here is a good view of the gin pole in operation during the raising of the driveshed, hope you enjoy because I well remember each year the culmination of our full year's work right through some of the hottest days. This was labour day, and everything went as scheduled.
One thing that I din't mention was the 2 front centre posts were not on plates but rather just on large flat stones set as closely to the right elevation as possible. That made them longer than the 2 outside posts, and when framing them one had to remember the difference in length.