Very cool. I love seeing these pictures.

what's piled on top of the driver side rear step?, is it used for counterweight? (to keep the back end down when the boom is stretched out over the front end) 

If that is what you think, you must not know about concrete pumping!!!!!

LOL Pump Pimp, I think those "counter weights" are throwing off the weight limits of your truck *grins* ..

But to answear 16"s question they look like bags of grout or cement ?

Hey Pimp, you may want to get the scraper out and remove the "worlds largest pump" sticker on your L.H. rear outrigger,I beleive the 70 meter has got yours beat ? *smiles*

Pump pimp advertises "truck mounted" so he does have the largest. The 70m is a tractor trailer.

believe it or not, there are machines out there that get very light when fully extended in within a certain working range... We have a brand X 40 meter that from the factory, has several large steel plates welded between the rear tow hooks for "counterweight"... not intended as disrespect towards your machine, just a simple question... And yes, sacks of cement would make sense, as I am guessing it would take an entire skid full of it to prime that beast! LOL

We usually use slick pack to prime the pump but with 2 in slump and 2 in stone... we use 2 bags of cement instead.   And we've had brand "S" with 1000K counterweight between the tow hooks.

hahaha that was funny Pump Pimp.