I'm in Chapter 6 fighting the underboss and can't get his health to drop below 10%.I thought maybe the crane has something to do with his death but I Can't get to it.The only ladder here won't give me a press F to climb option.Any help would be Appreciated.Spoiler O.K.
Nevermind I found the problem.After the underboss jumps off the collasping pallet of pipes I had to deactivate the unlimited health or his health won't drop any futher.I finished him off ok then.