Work project, float plane dock pilings had been jacking for ages these were 2.7/8" steel posts (14foot long)driven into the pond floor they were not long enough to stay put and kept working out, as the pond is connected to a tideal lagoon the dock had to rise and fall with the tides with a smaller 2" pipe telescoping inside to ride up and down with the dock.
I chose to keep the same design but go from 14 foot pilings to 21 footers, used a telehandler and a chain to pull the old ones, After all them years of trouble when it was time to pull em out some hung up and were hanging on like grim death to a sick chicken! the ole telehandler was bounceing round on front tires next to the pond(did I mention the brakes were bad?) and the operator had both feet on the brake peddal the whole time (I chocked the front wheels)
We straped a fish tote to the forks as a man basket to work the pneumatic post pounder.
The ground in this area is glacial deposit with beach ridges, beach ridges form over time they are not allways gravel, some the layers are peat and some flat beach rock to battle the whole way down, some layers you can drive half way and hit perafrost then you get nowhere allot the time we end up peening the top the post so much that have to pull off the post guide and gring the mushroomed end to release the post guide thats bolted to the 75# driver.