What is a friction crane?

A friction crane is an older model of crane like an American Crawler 9210 or 4100 who's boom arm is controlled manually by a gear driven system where the operator must engage the clutch and throw gear sticks to operate the boom, cab and tracks.... These cranes are typically much stronger and have much stiffer booms than say a modern hydro crane.

They are good in heavy civil operations where they will take a lot of abuse because of their stout construction.