Am building a rope swing out at my farm over a deep hole in the...

Am building a rope swing out at my farm over a deep hole in the creek going through my farm. Building this in anticipation that we may have to spend
another lot of school holidays camping with the kids. Hopefully this will keep them occupied.
i have got a 12m tallowood log ready to be put up. I was thinking of cementing it in say 2 meters into the ground at about 3 meters from the creek on a bank which is 1 meter above the creek. I was putting a 2 meter gal pipe through the top of the tree 1m below the top of the log. To this pole I have a u bolt attached securely with a rope coming down about 8m long. We than safely swing into the creek.
any thoughts of idea?
thanks