Well the jib is finally finished, and pics are included below. Lots of fun to build. The overall height of the boom plus jib is about six feet five inches. In the pics below you will see it hoisting the last main tower to my Willis Tower. Willis Tower (steel structure, I have not completed the outside) is also in my MOC pages. Take a look for further details.
About this creation
Now, many have seen the youtube video of the 42009 attempting to lift the 8070 Supercar. Didn't work, epic failure (except when trying to lift with actuators, which I don't recommend. With this behemoth, I tried the same thing. However, my version is MOD'ed out (two additional motors, more bodywork) and therefore weights quite a bit more (1433 grams). Sad to say, mechanically, my 42009 couldn't lift the Supercar either. Motor too weak. However, structurally, pretty sound. With a little help, when it finally did lift the car, it held it without hardly any twisting or torquing of the chassis or lifting superstructure. Here is a pic of it lifting the 8070 and a video below.
I love the models with real force in functions, not only "movements for show" but serious power. And this crane is for me the first real Lego mobile crane, cause it can do the hard work! The structure is very well done to held such weight! Congrats!