Extreme Dangerous Excavator Bulldozer Heavy Equipment Operator Skill, Amazing Modern Construction Machines: K-TEC, CAT D11T, CAT 627H, ... Just one thing I spotted, when they were building the columns the guy had his hands on the pins, only an idea but could you use two guys with a bar each  to line up with them instead, just had a bad mental image.  At the first video the excavator is not suitable it would take the spider, excellent excavators in the water to clean up the riverbed, minute 6: 54 that scale and silly, better a small periscopic platform on arms, rotating on a ring around to the cabin, allows repairs around the excavator as well as transporting personnel to the driver's seat.